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1.
Am J Epidemiol ; 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38992341

RESUMO

Background and Objective Postmenopausal women tend to experience significant changes in body composition, particularly abdominal adipose tissue (AAT) deposition patterns, which are hypothesized to be critical factors influencing future cardiometabolic disease risk. Physical activity has a demonstrable effect on body composition and overall health. However, there is little evidence for how different intensities and durations of physical activity over a sustained period of time influence AAT patterns and other measures of body composition in postmenopausal women. We emulated a target trial of physical activity interventions, including the 2018 Physical Activity Guidelines for Americans recommendations, on 3-year changes in AAT and body composition. Methods We analyzed observational data from 4,451 postmenopausal women aged 50-79 years in the Women's Health Initiative (WHI) to emulate a three-year target trial of adhering to increasing minutes of moderate (at least 15, 30, 75, 150, 300 minutes/week) and vigorous (at least 15, 30, 75, 150 minutes/week) physical activity aligned with the physical activity guidelines. All participants had repeated whole body Dual X-Ray Absorptiometry (DXA) scans with derived abdominal visceral (VAT) and subcutaneous adipose tissue (SAT). The measured differences in average levels of VAT, SAT, and other body composition measures determined at end of follow-up were estimated with the parametric-g formula. Results Over 3 years, interventions of increasing minutes of moderate activity would result in dose-dependent reductions in abdominal VAT, SAT, and overall body fat, and increases in lean soft tissue, with the greatest estimated benefit at the 2018 physical activity guideline recommendation of 150 mins/wk or more. Compared to no intervention, if all participants had adhered to at least 150 mins/wk of moderate physical activity, they would have 16.8 cm2 lower VAT (95% CI -23.1, -10.4), 26.8 cm2 lower SAT (95% CI -36.3, -17.3), 1.3% lower total body fat% (95% CI -1.8, -0.7), 1.2 % higher total lean soft tissue% (95% CI 0.7, 1.8), and 2.6 kg lower total bodyweight (95% CI -3.6, -1.5). We saw similar patterns in our vigorous-intensity activity interventions - if all participants adhered to at least 150 mins/wk, they would have experienced 6.7 cm2 lower VAT (95% CI -17.7, 4.3), 13.3 cm2 lower SAT (95% CI -28.8, 2.1), 1.0 % lower total body fat percent (95% CI -2.0, 0.0 ), % higher total lean soft tissue percent (95% CI) and a 0.9 kg lower total bodyweight (95% CI -2.7, 0.8). Conclusion This hypothetical emulated intervention indicated that postmenopausal women who adhere to physical activity guideline recommendations would experience beneficial changes in abdominal VAT, SAT, and overall body composition over 3 years. The study results underscore the imperative to explore further how physical activity may serve as a potential determinant of body composition.

2.
Hum Reprod ; 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890130

RESUMO

STUDY QUESTION: What is the association between reproductive health history (e.g. age at menarche, menopause, reproductive lifespan) with abdominal adiposity in postmenopausal women? SUMMARY ANSWER: Higher visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) tissue levels were observed among women with earlier menarche, earlier menopause, and greater parity. WHAT IS KNOWN ALREADY: Postmenopausal women are predisposed to accumulation of VAT and SAT. Reproductive health variables are known predictors of overall obesity status in women, defined by BMI. STUDY DESIGN, SIZE, DURATION: This study is a secondary analysis of data collected from the baseline visit of the Women's Health Initiative (WHI). The WHI is a large prospective study of postmenopausal women, including both a randomized trial and observational study. There were 10 184 women included in this analysis. PARTICIPANTS/MATERIALS, SETTING, METHODS: Data were collected from a reproductive health history questionnaire, dual-energy x-ray absorptiometry scans, and anthropometric measures at WHI baseline. Reproductive history was measured via self-report, and included age at menarche, variables related to pregnancy, and age at menopause. Reproductive lifespan was calculated as age at menopause minus age at menarche. Statistical analyses included descriptive analyses and multivariable linear regression models to examine the association between reproductive history with VAT, SAT, total body fat, and BMI. MAIN RESULTS AND THE ROLE OF CHANCE: Women who reported early menarche (<10 years) or early menopause (<40 years) had the highest levels of VAT. Adjusted multivariable linear regression results demonstrate women who experienced menarche >15 years had 23 cm2 less VAT (95% CI: -31.4, -14.4) and 47 cm2 less SAT (95% CI: -61.8, -33.4) than women who experienced menarche at age 10 years or earlier. A similar pattern was observed for age at menopause: compared to women who experienced menopause <40 years, menopause at 50-55 years was associated with 19.3 cm2 (95% CI: -25.4, -13.3) less VAT and 27.4 cm2 (-29.6, 10.3) less SAT. High parity (>3 pregnancies) was also associated with VAT and SAT. For example, adjusted beta coefficients for VAT were 8.36 (4.33, 12.4) and 17.9 (12.6, 23.2) comparing three to four pregnancies with the referent, one to two pregnancies. LIMITATIONS, REASONS FOR CAUTION: The WHI reproductive health history questionnaire may be subject to poor recall owing to a long look-back window. Residual confounding may be present given lack of data on early life characteristics, such as maternal and pre-menarche characteristics. WIDER IMPLICATIONS OF THE FINDINGS: This study contributes to our understanding of reproductive lifespan, including menarche and menopause, as an important predictor of late-life adiposity in women. Reproductive health has also been recognized as a sentinel marker for chronic disease in late life. Given established links between adiposity and cardiometabolic outcomes, this research has implications for future research, clinical practice, and public health policy that makes use of reproductive health history as an opportunity for chronic disease prevention. STUDY FUNDING/COMPETING INTEREST(S): HRB and AOO are supported by the National Institute of Health National Institute of Aging (R01AG055018-04). JWB reports royalties from 'ACSM'S Body Composition Assessment Book' and consulting fees from the WHI. The remaining authors have no competing interests to declare. TRIAL REGISTRATION NUMBER: N/A.

3.
Int J Obes (Lond) ; 47(4): 288-296, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36739471

RESUMO

BACKGROUND: Abdominal adiposity, including visceral and subcutaneous abdominal adipose tissue (VAT and SAT), is recognized as a strong risk factor for cardiometabolic disease, cancer, and mortality. OBJECTIVE: The primary aim of this analysis is to describe longitudinal patterns of change in abdominal adipose tissue in postmenopausal women, overall and stratified by age, race/ethnicity, and years since menopause. METHODS: The data are from six years of follow up on 10,184 postmenopausal women (7828 non-Hispanic White women, 1423 non-Hispanic Black women, and 703 Hispanic women) who participated in the Women's Health Initiative (WHI). The WHI is a large prospective cohort study of postmenopausal women across the United States. All participants in this analysis had DXA scans in the 1990s as part of the WHI protocol. Hologic APEX software was used to re-analyze archived DXA scans and obtain measures of abdominal adipose tissue. Analyses examined differences in abdominal adipose tissue, overall adiposity, and anthropometric variables. RESULTS: There were important differences in VAT and SAT by age and race/ethnicity. In women <60 years, VAT increased over the follow-up period, while in women ≥70 years, VAT decreased. Non-Hispanic Black women had the highest levels of SAT. Hispanic women had the highest VAT levels. Women more than ten years since menopause had less SAT and more VAT than women less than ten years since menopause, resulting in a higher VAT/SAT ratio. There was a moderate to strong correlation between measures of abdominal adipose tissue and anthropometric measurements of body size. Still, there were substantial differences in the quantity of VAT and SAT within BMI and waist circumference categories. CONCLUSIONS: These results demonstrate differences in VAT and SAT according to age, race/ethnicity, time since menopause, and compared to standard measures of body composition in a large and diverse cohort of postmenopausal women.


Assuntos
Pós-Menopausa , Gordura Subcutânea , Humanos , Feminino , Estudos Prospectivos , Composição Corporal , Gordura Intra-Abdominal/metabolismo , Saúde da Mulher , Índice de Massa Corporal
4.
Cancer Causes Control ; 34(Suppl 1): 159-169, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36840904

RESUMO

PURPOSE: The Centers for Disease Control and Prevention's National Comprehensive Cancer Control Program (NCCCP) requires that states develop comprehensive cancer control (CCC) plans and recommends that disparities related to rural residence are addressed in these plans. The objective of this study was to explore rural partner engagement and describe effective strategies for incorporating a rural focus in CCC plans. METHODS: States were selected for inclusion using stratified sampling based on state rurality and region. State cancer control leaders were interviewed about facilitators and barriers to engaging rural partners and strategies for prioritizing rural populations. Content analysis was conducted to identify themes across states. RESULTS: Interviews (n = 30) revealed themes in three domains related to rural inclusion in CCC plans. The first domain (barriers) included (1) designing CCC plans to be broad, (2) defining "rural populations," and (3) geographic distance. The second domain (successful strategies) included (1) collaborating with rural healthcare systems, (2) recruiting rural constituents, (3) leveraging rural community-academic partnerships, and (4) working jointly with Native nations. The third domain (strategies for future plan development) included (1) building relationships with rural communities, (2) engaging rural constituents in planning, (3) developing a better understanding of rural needs, and (4) considering resources for addressing rural disparities. CONCLUSION: Significant relationship building with rural communities, resource provision, and successful strategies used by others may improve inclusion of rural needs in state comprehensive cancer control plans and ultimately help plan developers directly address rural cancer health disparities.


Assuntos
Neoplasias , População Rural , Humanos , Atenção à Saúde , Neoplasias/epidemiologia , Neoplasias/prevenção & controle
5.
Osteoporos Int ; 34(4): 693-701, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36692543

RESUMO

We evaluated the influence of two endogenous hormones on bone health in older women. Higher FSH was associated with bone disease, especially in lower estradiol environments. FSH attenuated the relationship between estradiol and bone. This may provide a mechanism through which future clinical research intervenes on bone loss. INTRODUCTION/PURPOSE: Despite preclinical evidence for an inverse association of follicle-stimulating hormone (FSH) and bone mineral density (BMD), no large epidemiologic studies have evaluated the separate and joint influences of FSH and estradiol on bone in postmenopausal women. METHODS: In a cross-sectional study of 675 postmenopausal women, we evaluated associations of serum FSH and dual X-ray absorptiometry (DXA)-classified areal BMD as well as low bone mass or osteoporosis (T-score < - 1.0) of the femoral neck and total hip. We stratified this analysis by serum estradiol (cut at the median). We tested whether FSH mediates the association of estradiol and BMD using the Sobel test. RESULTS: In linear regression models, there was a significant inverse association of serum FSH with both femoral neck and total hip BMD (both p < 0.01) when adjusted for age, hormone therapy (HT) use, and diabetes. In fully adjusted logistic regression models, women in the highest FSH tertile had higher odds of low bone mass/osteoporosis at the femoral neck (OR = 2.98; 95% CI = 1.86-4.77) and at the total hip (OR = 1.74; 95% CI = 1.06-2.84) compared to those in the lowest FSH tertile. We report evidence of effect modification by estradiol in stratified models and an interaction term. FSH met all criteria of a mediator, including an estimated 70% attenuation of the estradiol-BMD relationship (Sobel p value < 0.001). CONCLUSIONS: FSH is associated with higher odds of having low bone mass/osteoporosis even after accounting for HT use. FSH is a mediator of the relationship between estradiol and BMD in healthy postmenopausal women. Larger, prospective studies of FSH concentrations and bone health are needed.


Assuntos
Osteoporose Pós-Menopausa , Osteoporose , Feminino , Humanos , Idoso , Hormônio Foliculoestimulante , Pós-Menopausa , Estudos Transversais , Estudos Prospectivos , Estradiol , Densidade Óssea , Absorciometria de Fóton
6.
J Nutr ; 153(1): 301-311, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36913466

RESUMO

BACKGROUND: Vitamins, minerals, and natural product (NP)-derived dietary supplements are commonly used among women with breast cancer, where interactions with treatments and the disease are possible, emphasizing the importance for health care providers to be aware of supplement use. OBJECTIVES: The study aimed to investigate current vitamin/mineral (VM) and NP supplement use among those diagnosed with breast cancer, including usage based on tumor type or concurrent breast cancer treatments and primary information sources for specific supplements. METHODS: Social media recruiting to complete an online questionnaire self-reporting current VM and NP use and breast cancer diagnosis and treatment information primarily attracted US participants. Analyses, including multivariate logistic regression, were performed on 1271 women who self-reported breast cancer diagnosis and completed the survey. RESULTS: Most participants reported current VM (89.5%) and NP (67.7%) use, with 46.5% (VM) and 26.7% (NP) using at least 3 products concurrently. Top-reported (>15% prevalence) products were vitamin D, calcium, multivitamin, and vitamin C for VM and probiotics, turmeric, fish oil/omega-3 fatty acids, melatonin, and cannabis for NP. Overall, VM or NP use was higher among those with hormone receptor-positive tumors. Although overall NP use did not differ according to current breast cancer treatments, VM use was significantly less common among those currently undergoing chemotherapy or radiation, but higher with current endocrine therapy. Among current chemotherapy users, specific VM and NP supplements with possible adverse effects were still used by 23% of respondents. Medical providers were the primary information source for VM, whereas NP information sources were more varied. CONCLUSIONS: Because women diagnosed with breast cancer commonly reported concurrent use of multiple VM and NP supplements, including those with known or underexplored risks (or benefits) in breast cancer, it is important for health care providers to inquire about and facilitate discussions regarding supplement use in this population.


Assuntos
Suplementos Nutricionais , Neoplasias , Suplementos Nutricionais/efeitos adversos , Vitaminas/uso terapêutico , Minerais , Inquéritos e Questionários , Modelos Logísticos
7.
Cancer ; 128(20): 3630-3640, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35996861

RESUMO

BACKGROUND: Although adherence to the American Cancer Society (ACS) Guidelines on Nutrition and Physical Activity for Cancer Prevention associates with lower risk of obesity-related cancer (ORC) incidence and mortality, evidence in Black and Latina women is limited. This association was examined in Black and Latina participants in the Women's Health Initiative (WHI). METHODS: Semi-Markov multistate model examined the association between ACS guideline adherence and ORC incidence and mortality in the presence of competing events, combined and separately, for 9301 Black and 4221 Latina postmenopausal women. Additionally, ACS guideline adherence was examined in a subset of less common ORCs and potential effect modification by neighborhood socioeconomic status and smoking. RESULTS: Over a median of 11.1, 12.5, and 3.7 years of follow-up for incidence, nonconditional mortality, and conditional mortality, respectively, 1191 ORCs (Black/Latina women: 841/269), 1970 all-cause deaths (Black/Latina women: 1576/394), and 341 ORC-related deaths (Black/Latina women: 259/82) were observed. Higher ACS guideline adherence was associated with lower ORC incidence for both Black (cause-specific hazard ratio [CSHR]highvs.low : 0.72; 95% CI, 0.55-0.94) and Latina (CSHRhighvs.low : 0.58, 95% CI, 0.36-0.93) women; but not conditional all-cause mortality (Black hazard ratio [HR]highvs.low : 0.86; 95% CI, 0.53-1.39; Latina HRhighvs.low : 0.81; 95% CI, 0.32-2.06). Higher adherence was associated with lower incidence of less common ORC (Ptrend  = .025), but conditional mortality events were limited. Adherence and ORC-specific deaths were not associated and there was no evidence of effect modification. CONCLUSIONS: Adherence to the ACS guidelines was associated with lower risk of ORCs and less common ORCs but was not for conditional ORC-related mortality. LAY SUMMARY: Evidence on the association between the American Cancer Society Guidelines on Nutrition and Physical Activity for Cancer Prevention and cancer remains scarce for women of color. Adherence to the guidelines and risk of developing one of 13 obesity-related cancers among Black and Latina women in the Women's Health Initiative was examined. Women who followed the lifestyle guidelines had 28% to 42% lower risk of obesity-related cancer. These findings support public health interventions to reduce growing racial/ethnic disparities in obesity-related cancers.


Assuntos
Exercício Físico , Neoplasias , American Cancer Society , Feminino , Hispânico ou Latino , Humanos , Neoplasias/epidemiologia , Neoplasias/prevenção & controle , Obesidade/complicações , Obesidade/epidemiologia , Fatores de Risco , Estados Unidos/epidemiologia , Saúde da Mulher
8.
J Clin Densitom ; 25(2): 189-197, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34404568

RESUMO

INTRODUCTION: Visceral adipose tissue (VAT) is a hypothesized driver of chronic disease. Dual-energy X-ray absorptiometry (DXA) potentially offers a lower cost and more available alternative compared to gold-standard magnetic resonance imaging (MRI) for quantification of abdominal fat sub-compartments, VAT and subcutaneous adipose tissue (SAT). We sought to validate VAT and SAT area (cm2) from historical DXA scans against MRI. METHODOLOGY: Participants (n = 69) from the Women's Health Initiative (WHI) completed a 3 T MRI scan and a whole body DXA scan (Hologic QDR2000 or QDR4500; 2004-2005). A subset of 43 participants were scanned on both DXA devices. DXA-derived VAT and SAT at the 4th lumbar vertebrae (5 cm wide) were analyzed using APEX software (v4.0, Hologic, Inc., Marlborough, MA). MRI VAT and SAT areas for the corresponding DXA region of interest were quantified using sliceOmatic software (v5.0, Tomovision, Magog, Canada). Pearson correlations between MRI and DXA-derived VAT and SAT were computed, and a Bland-Altman analysis was performed. RESULTS: Participants were primarily non-Hispanic white (86%) with a mean age of 70.51 ± 5.79 years and a mean BMI of 27.33 ± 5.40 kg/m2. Correlations between MRI and DXA measured VAT and SAT were 0.90 and 0.92, respectively (p ≤ 0.001). Bland-Altman plots showed that DXA-VAT slightly overestimated VAT on the QDR4500 (-3.31 cm2); this bias was greater in the smaller subset measured on the older DXA model (QDR2000; -30.71 cm2). The overestimation of DXA-SAT was large (-85.16 to -118.66 cm2), but differences were relatively uniform for the QDR4500. CONCLUSIONS: New software applied to historic Hologic DXA scans provide estimates of VAT and SAT that are well-correlated with criterion MRI among postmenopausal women.


Assuntos
Gordura Intra-Abdominal , Pós-Menopausa , Absorciometria de Fóton/métodos , Tecido Adiposo , Idoso , Feminino , Humanos , Gordura Intra-Abdominal/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Pessoa de Meia-Idade , Gordura Subcutânea
9.
Health Promot Pract ; : 15248399221131318, 2022 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-36433816

RESUMO

BACKGROUND: Although exercise has been shown to improve cancer survivorship in other communities, cancer exercise studies among Native American communities are rare. We sought to adapt a Navajo-tailored cancer exercise pilot program to serve a broader Native American cancer community. METHODS: Tribal experts representing 10 different Tribal Nations were engaged in small focus groups (n=2-4) to assess program materials for cultural appropriateness and adaptation to expand tribal inclusiveness. Facilitated by a trained Native American interviewer, focus groups were provided a primer survey and then reviewed intervention materials (protocols, incentives, logo, flyers, etc.). Consensus was reached by the research team on all program adaptations. RESULTS: The program name, Restoring Balance, layout, graphics, and symbols were considered culturally appropriate overall. Program exercises and biomarker measurements were viewed as valuable to health improvements in the community. Important color, linguistic, and logistic program modifications were recommended to improve cultural alignment. The order of incentive items was revised to highlight restoration and the logo rotated to align with the four corners of the earth, an important cultural element. Linguistic modifications primarily related to prior traumatic research experiences in Native American communities where data had been taken without adequate community benefit or permission. Program emphasis should be on nurturing, added value and giving. CONCLUSION AND RELEVANCE: The methodology used for cultural expert review was successful in eliciting adaptations to expand the tribal inclusiveness of Restoring Balance. Culture, as well as historically traumatic research experiences, among Native American populations must be considered when adapting health promotion programming.

10.
Br J Cancer ; 123(2): 316-324, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32376888

RESUMO

BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) arises from cholangiocytes in the intrahepatic bile duct and is the second most common type of liver cancer. Cholangiocytes express both oestrogen receptor-α and -ß, and oestrogens positively modulate cholangiocyte proliferation. Studies in women and men have reported higher circulating oestradiol is associated with increased ICC risk, further supporting a hormonal aetiology. However, no observational studies have examined the associations between exogenous hormone use and reproductive factors, as proxies of endogenous hormone levels, and risk of ICC. METHODS: We harmonised data from 1,107,498 women who enroled in 12 North American-based cohort studies (in the Liver Cancer Pooling Project, LCPP) and the UK Biobank between 1980-1998 and 2006-2010, respectively. Cox proportional hazards regression models were used to generate hazard ratios (HR) and 95% confidence internals (CI). Then, meta-analytic techniques were used to combine the estimates from the LCPP (n = 180 cases) and the UK Biobank (n = 57 cases). RESULTS: Hysterectomy was associated with a doubling of ICC risk (HR = 1.98, 95% CI: 1.27-3.09), compared to women aged 50-54 at natural menopause. Long-term oral contraceptive use (9+ years) was associated with a 62% increased ICC risk (HR = 1.62, 95% CI: 1.03-2.55). There was no association between ICC risk and other exogenous hormone use or reproductive factors. CONCLUSIONS: This study suggests that hysterectomy and long-term oral contraceptive use may be associated with an increased ICC risk.


Assuntos
Colangiocarcinoma/epidemiologia , Anticoncepcionais Orais Hormonais/efeitos adversos , Hormônios/efeitos adversos , Neoplasias Hepáticas/epidemiologia , Idoso , Ductos Biliares , Ductos Biliares Intra-Hepáticos , Bancos de Espécimes Biológicos , Colangiocarcinoma/induzido quimicamente , Colangiocarcinoma/metabolismo , Colangiocarcinoma/patologia , Estudos de Coortes , Receptor alfa de Estrogênio/genética , Receptor beta de Estrogênio/genética , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Hormônios/uso terapêutico , Humanos , Histerectomia/efeitos adversos , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Menopausa/efeitos dos fármacos , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Fatores de Risco , Reino Unido/epidemiologia
11.
J Cancer Educ ; 35(3): 493-500, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-30756323

RESUMO

Native Americans experience cancer-related health disparities. Yet, little is known about the current cancer experience in one of the largest Native American tribe, Navajo. A qualitative study of among Navajo cancer survivors, in which focus groups and individual interviews included questions related to perceptions of cancer causes, prevention, and treatment, allowed us to evaluate several aspects of the cancer experience from the Navajo perspective. An experienced, bilingual facilitator led the discussions using a standardized guide. Discussions were audio-recorded, documented by field notes, translated, as needed, and transcribed. NVivo software was used to summarize major themes according to the PEN-3 and health belief models. Navajo cancer survivors (N = 32) were both males (n = 13) and females (n = 19) that had been previously diagnosed with a variety of cancers: colorectal, breast, ovarian, cervical, esophageal, gall bladder, stomach, prostate, kidney, and hematologic. Many survivors had accurate knowledge of risk factors for cancer. Barriers to screening and clinical care included language, expense, geography, fear, lack of information, skepticism related to Western medicine, and treatment side effects. While some survivors experienced familial support, others were isolated from the family and community due to the perspective of cancer as a contagion. However, resilience, hope, trust in select community organizations, a desire to restore balance, and to support younger generations were positive attributes expressed regarding the treatment and recovery process. These evaluations need to be replicated across a larger cross-section of the Native cancer survivor community.


Assuntos
Sobreviventes de Câncer/psicologia , Indígenas Norte-Americanos/psicologia , Neoplasias/psicologia , Feminino , Humanos , Indígenas Norte-Americanos/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Neoplasias/etiologia , Neoplasias/prevenção & controle , Percepção , Pesquisa Qualitativa , Fatores de Risco
12.
Am J Epidemiol ; 188(10): 1838-1848, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31274146

RESUMO

Concerns about reverse causality and selection bias complicate the interpretation of studies of body mass index (BMI, calculated as weight (kg)/height (m)2) and mortality in older adults. The objective of this study was to investigate methodological explanations for the apparent attenuation of obesity-related risks in older adults. We used data from 68,132 participants in the Women's Health Initiative (WHI) clinical trial for this analysis. All of the participants were postmenopausal women aged 50-79 years at baseline (1993-1998). To examine reverse causality and selective attrition, we compared rate ratios from inverse probability of treatment- and censoring-weighted Poisson marginal structural models with results from an unweighted adjusted Poisson regression model. The estimated mortality rate ratios and 95% confidence intervals for BMIs of 30.0-34.9, 35.0-39.9 and ≥40.0 were 0.86 (95% confidence interval (CI): 0.77, 0.96), 0.85 (95% CI: 0.72, 0.99), and 0.88 (95% CI: 0.72, 1.07), respectively, in the unweighted model. The corresponding mortality rate ratios were 0.96 (95% CI: 0.86, 1.07), 1.12 (95% CI: 0.97, 1.29), and 1.31 95% CI: (1.08, 1.57), respectively, in the marginal structural model. Results from the inverse probability of treatment- and censoring-weighted marginal structural model were attenuated in low BMI categories and increased in high BMI categories. The results demonstrate the importance of accounting for reverse causality and selective attrition in studies of older adults.


Assuntos
Índice de Massa Corporal , Mortalidade , Pós-Menopausa , Idoso , Causalidade , Estudos de Coortes , Feminino , Humanos , Pessoa de Meia-Idade , Modelos Teóricos , Obesidade/epidemiologia , Obesidade/mortalidade , Distribuição de Poisson , Fatores de Risco , Viés de Seleção , Estados Unidos/epidemiologia
13.
Int J Cancer ; 143(3): 543-551, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29488210

RESUMO

Obesity has been postulated to increase the risk of colorectal cancer by mechanisms involving insulin resistance and the metabolic syndrome. We examined the associations of body mass index (BMI), waist circumference, the metabolic syndrome, metabolic obesity phenotypes and homeostasis model-insulin resistance (HOMA-IR-a marker of insulin resistance) with risk of colorectal cancer in over 21,000 women in the Women's Health Initiative CVD Biomarkers subcohort. Women were cross-classified by BMI (18.5-<25.0, 25.0-<30.0 and ≥30.0 kg/m2 ) and presence of the metabolic syndrome into 6 phenotypes: metabolically healthy normal weight (MHNW), metabolically unhealthy normal weight (MUNW), metabolically healthy overweight (MHOW), metabolically unhealthy overweight (MUOW), metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO). Neither BMI nor presence of the metabolic syndrome was associated with risk of colorectal cancer, whereas waist circumference showed a robust positive association. Relative to the MHNW phenotype, the MUNW phenotype was associated with increased risk, whereas no other phenotype showed an association. Furthermore, HOMA-IR was not associated with increased risk. Overall, our results do not support a direct role of metabolic dysregulation in the development of colorectal cancer; however, they do suggest that higher waist circumference is a risk factor, possibly reflecting the effects of increased levels of cytokines and hormones in visceral abdominal fat on colorectal carcinogenesis.


Assuntos
Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/etiologia , Síndrome Metabólica/complicações , Obesidade/complicações , Fenótipo , Idoso , Biomarcadores , Índice de Massa Corporal , Feminino , Seguimentos , Humanos , Resistência à Insulina , Síndrome Metabólica/metabolismo , Pessoa de Meia-Idade , Obesidade/metabolismo , Razão de Chances , Vigilância da População , Pós-Menopausa , Medição de Risco , Fatores de Risco
14.
Int J Obes (Lond) ; 42(6): 1185-1194, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29892038

RESUMO

BACKGROUND/OBJECTIVE: Childhood obesity has been separately associated with cardiometabolic risk factors (CMRs) and increased risk of fracture. However, both augmented and compromised bone mass have been reported among overweight/obese children. Metabolic dysfunction, often co-existing with obesity, may explain the discrepancy in previous studies. The aim of this study was to examine whether the relationship between adiposity and dual-energy X-ray absorptiometry (DXA) derived bone mass differed in young girls with and without CMR(s). SUBJECTS/METHODS: Whole-body bone and body composition measures by DXA and measures of CMR (fasting glucose, high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), systolic and diastolic blood pressure, waist circumference (WC)) were obtained from 307, 9- to 12-year-old girls. Girls with 1 or ≥ 2 CMR(s) were considered to be at risk (vs. no CMR). Multiple linear regression was used to test the relationship of total fat mass with total body bone mineral content (BMC) after controlling for height, lean mass, CMR risk, and other potential confounders. RESULTS: There was a significant interaction between CMR risk and total body fat mass. When girls were stratified by CMR group, all groups had a significant positive relationship between fat mass and BMC (p < 0.05), however, girls with ≥ 2 CMRs had a lower BMC for a given level of body fat. Total body fat was not significantly related to bone mineral density (p > 0.05). CONCLUSION: Fat mass has a positive relationship with BMC even after controlling for lean mass. However, the positive relationship of fat mass with BMC may be attenuated if multiple CMRs are present.


Assuntos
Adiposidade/fisiologia , Densidade Óssea/fisiologia , Doenças Cardiovasculares/etiologia , Síndrome Metabólica/etiologia , Obesidade Infantil/complicações , Absorciometria de Fóton , Pressão Sanguínea , Composição Corporal , Índice de Massa Corporal , Doenças Cardiovasculares/fisiopatologia , Criança , HDL-Colesterol , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Síndrome Metabólica/fisiopatologia , Obesidade Infantil/metabolismo , Obesidade Infantil/fisiopatologia , Estudos Prospectivos , Fatores de Risco , Triglicerídeos , Circunferência da Cintura
16.
J Clin Densitom ; 21(4): 583-594, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29705002

RESUMO

The ability to assess skeletal muscle adipose tissue is important given the negative clinical implications associated with greater fat infiltration of the muscle. Computed tomography and magnetic resonance imaging (MRI) are highly accurate for measuring appendicular soft tissue and muscle composition, but have limitations. Peripheral quantitative computed tomography (pQCT) is an alternative that investigators find valuable because of its low radiation, fast scan time, and comparatively lower costs. The present investigation sought to assess the accuracy of pQCT-derived estimates of total, subcutaneous, skeletal muscle, intermuscular, and calculated intramuscular adipose tissue areas, and muscle density in the midthigh of young girls using the gold standard, 3 T MRI, as the criterion. Cross-sectional data were analyzed for 26 healthy girls aged 9-12 years. Midthigh soft tissue composition was assessed by both pQCT and 3 T MRI. Mean tissue area for corresponding adipose compartments by pQCT and MRI was compared using t tests, regression analysis, and Bland-Altman plots. Muscle density was regressed on MRI skeletal muscle adipose tissue, intermuscular adipose tissue, and intramuscular adipose tissue, each expressed as a percentage of total muscle area. Correlations were high between MRI and pQCT for total adipose tissue (r2 = 0.98), subcutaneous adipose tissue (r2 = 0.95), skeletal muscle adipose tissue (r2 = 0.83), and intermuscular adipose tissue (r2 = 0.82), and pQCT muscle density correlated well with both MRI skeletal muscle adipose tissue (r2 = 0.70) and MRI intermuscular adipose tissue (r2 = 0.70). There was a slight, but statistically significant underestimation by pQCT for total and subcutaneous adipose tissue, whereas no significant difference was observed for skeletal muscle adipose tissue. Both pQCT-estimated intramuscular adipose tissue and muscle density were weakly correlated with MRI-intramuscular adipose tissue. We conclude that pQCT is a valid measurement technique for estimating all adipose subcompartments, except for intramuscular adipose tissue, for the midthigh region in young/adolescent girls.


Assuntos
Tecido Adiposo/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Músculo Esquelético/diagnóstico por imagem , Coxa da Perna/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Criança , Feminino , Humanos , Sobrepeso/diagnóstico por imagem , Obesidade Infantil/diagnóstico por imagem , Gordura Subcutânea/diagnóstico por imagem
17.
Am J Hum Biol ; 30(5): e23149, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30129276

RESUMO

OBJECTIVE: In adults, certain body fat depots have greater impact on cardiometabolic risk than total adiposity. Whether similar relationships exist in children is uncertain. The aim of this study was to examine the relationships among dual x-ray absorptiometry (DXA) measures of body fat distribution and total body adiposity with cardiometabolic risk factors in Hispanic girls. METHODS: Measures of total percent body fat, percent of total fat within the android, gynoid, leg, and trunk regions, and cardiometabolic biomarkers (insulin, glucose, homeostatic model assessment of insulin resistance (HOMA-IR), triglycerides (TG), low and high lipoprotein cholesterol (LDL-C, HDL-C)) were obtained from 232 Hispanic girls (age 10.7 ±1.1 years). Regression models for each metabolic parameter were run against adiposity measures. Partial correlations of the adiposity measures were used to compare associations between adiposity measures and the cardiometabolic risk factors, controlling for somatic maturation. RESULTS: Total and regional adiposity were significantly related with cardiometabolic risk factors (P < 0.05) except fasting glucose. The partial correlations of total and regional adiposity measures with each cardiometabolic biomarker were similar. More variance was explained for insulin and the HOMA-IR (33%-43%) than other risk factors. Partial correlations for the percentage of total fat in the gynoid and leg regions with insulin, HOMA-IR, TG, and LDL-C were negative, and positive with HDL-C. CONCLUSION: Measures of total and regional fat perform similarly in predicting cardiometabolic risk in Hispanic girls. A higher proportion of fat distributed in the gynoid or leg region is associated with lower cardiometabolic risk.


Assuntos
Adiposidade/fisiologia , Distribuição da Gordura Corporal/efeitos adversos , Doenças Cardiovasculares/epidemiologia , Hispânico ou Latino/estatística & dados numéricos , Absorciometria de Fóton , Adolescente , Arizona/epidemiologia , Doenças Cardiovasculares/etiologia , Criança , Estudos Transversais , Feminino , Humanos , Fatores de Risco
18.
Prev Med ; 95: 103-109, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27932054

RESUMO

Falling significantly affects quality of life, morbidity, and mortality among older adults. We sought to evaluate the prospective association between sedentary time, physical activity, and falling among post-menopausal women aged 50-79years recruited to the Women's Health Initiative Observational Study between 1993 and 1998 from 40 clinical centers across the United States. Baseline (B) and change in each of the following were evaluated at year 3 (Y3) and year 6 (Y6; baseline n=93,676; Y3 n=76,598; Y6 n=75,428): recreational physical activity (MET-h/wk), sitting, sleeping (min/day), and lean body mass by dual energy X-ray absorptiometry (subset N=6475). Falls per year (0, 1, 2, ≥3) were assessed annually by self-report questionnaire and then dichotomized as ≤1 and ≥2falls/year. Logistic regression models were adjusted for demographics, body mass index, fall history, tobacco and alcohol use, medical conditions, and medications. Higher baseline activity was associated with greater risk of falling at Y6 (18%; p for trend <0.0001). Increasing sedentary time minimally decreased falling (1% Y3; 2% Y6; p<0.05). Increasing activity up to ≥9MET-h/wk. (OR: 1.12, 95% CI: 1.03-1.22) or maintaining ≥9MET-h/wk. (OR: 1.20, 95% CI: 1.13-1.29) increased falling at Y3 and Y6 (p for trend <0.001). Adding lean body mass to the models attenuated these relationships. Physically active lifestyles increased falling among post-menopausal women. Additional fall prevention strategies, such as balance and resistance training, should be evaluated to assist post-menopausal women in reaching or maintaining levels of aerobic activity known to prevent and manage several chronic diseases.


Assuntos
Acidentes por Quedas/estatística & dados numéricos , Exercício Físico/fisiologia , Comportamento Sedentário , Saúde da Mulher/estatística & dados numéricos , Acidentes por Quedas/prevenção & controle , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Recreação , Fatores de Risco , Estados Unidos
19.
Oncology (Williston Park) ; 31(10): 711-7, 2017 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-29083464

RESUMO

Exercise is associated with significant reductions in the recurrence and mortality rates of several common cancers. Cancer survivors who exercise can potentially benefit from reduced levels of fatigue, and improved quality of life, physical function, and body composition (ie, healthier ratios of lean body mass to fat mass). The amount of activity required to achieve protective effects is moderate (eg, walking 30 minutes per day at 2.5 miles per hour). However, many healthcare providers report a lack of awareness of the appropriate exercise recommendations across the phases of cancer survivorship, considerations regarding the timing of exercise interventions, and the ability to refer patients to exercise programs specifically aimed at cancer survivors. The American College of Sports Medicine notes that exercise is generally safe for most cancer survivors, and inactivity should be avoided. Their guidelines for exercise call for 150 minutes of moderate or 75 minutes of vigorous aerobic activity per week, and 2 days per week of resistance training (eg, with exercise bands or light weights). Survivors with lymphedema, peripheral neuropathy, breast reconstruction, central lines, and ostomies should follow specific precautions. Providing health professionals with the training and tools needed to provide adequate recommendations to their patients is essential to improving patient outcomes. To facilitate adherence among communities with the greatest need and poor access to services, cultural and environmental adaptations are critical.


Assuntos
Sobreviventes de Câncer/psicologia , Terapia por Exercício/normas , Exercício Físico/fisiologia , Exercício Físico/psicologia , Promoção da Saúde/métodos , Pacientes/psicologia , Qualidade de Vida/psicologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Atitude Frente a Saúde , Feminino , Guias como Assunto , Humanos , Masculino , Pessoa de Meia-Idade
20.
Nutr J ; 16(1): 15, 2017 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-28231807

RESUMO

BACKGROUND: Childhood overweight and obesity remains high, contributing to cardiometabolic risk factors at younger ages. It is unclear which measures of adiposity serve as the best proxies for identifying children at metabolic risk. This study assessed whether DXA-derived direct measures of adiposity are more strongly related to cardiometabolic risk factors in children than indirect measures. METHODS: Anthropometric and DXA measures of adiposity and a comprehensive assessment of cardiometabolic risk factors were obtained in 288, 9-12 year old girls, most being of Hispanic ethnicity. Multiple regression models for each metabolic parameter were run against each adiposity measure while controlling for maturation and ethnicity. In addition, regression models including both indirect and direct measures were developed to assess whether using direct measures of adiposity could provide a better prediction of the cardiometabolic risk factors beyond that of using indirect measures alone. RESULTS: Measures of adiposity were significantly correlated with cardiometabolic risk factors (p < 0.05) except fasting glucose. After adjusting for maturation and ethnicity, indirect measures of adiposity accounted for 29-34% in HOMA-IR, 10-13% in TG, 14-17% in HDL-C, and 5-8% in LDL-C while direct measures accounted for 29-34% in HOMA-IR, 10-12% in TG, 13-16% in HDL-C, and 5-6% in LDL-C. The addition of direct measures of adiposity to indirect measures added significantly to the variance explained for HOMA-IR (p = 0.04). CONCLUSION: Anthropometric measures may perform as well as the more precise direct DXA-derived measures of adiposity for assessing most CVD risk factors in preadolescent girls. The use of DXA-derived adiposity measures together with indirect measures may be advantageous for predicting insulin resistance risk. TRIAL REGISTRATION: NCT02654262 . Retrospectively registered 11 January 2016.


Assuntos
Adiposidade , Doenças Cardiovasculares/epidemiologia , Síndrome Metabólica/epidemiologia , Obesidade/epidemiologia , Absorciometria de Fóton , Glicemia/metabolismo , Composição Corporal , Índice de Massa Corporal , Proteína C-Reativa/metabolismo , Doenças Cardiovasculares/sangue , Criança , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Estudos Transversais , Feminino , Humanos , Modelos Lineares , Síndrome Metabólica/sangue , Obesidade/sangue , Estudos Retrospectivos , Fatores de Risco , Triglicerídeos/sangue , Circunferência da Cintura
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