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1.
Breast Cancer Res ; 26(1): 45, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38475816

RESUMO

BACKGROUND: Breast density (BD) is a strong risk factor for breast cancer. Little is known about how BD develops during puberty. Understanding BD trajectories during puberty and its determinants could be crucial for promoting preventive actions against breast cancer (BC) at early ages. The objective of this research is to characterize % fibroglandular volume (%FGV), absolute fibroglandular volume (AFGV), and breast volume (BV) at different breast Tanner stages until 4-year post menarche in a Latino cohort and to assess determinants of high %FGV and AFGV during puberty and in a fully mature breast. METHODS: This is a longitudinal follow-up of 509 girls from low-middle socioeconomic status of the Southeast area of Santiago, recruited at a mean age of 3.5 years. The inclusion criteria were singleton birth born, birthweight between 2500 and 4500 g with no medical or mental disorder. A trained dietitian measured weight and height since 3.5 years old and sexual maturation from 8 years old (breast Tanner stages and age at menarche onset). Using standardized methods, BD was measured using dual-energy X-ray absorptiometry (DXA) in various developmental periods (breast Tanner stage B1 until 4 years after menarche onset). RESULTS: In the 509 girls, we collected 1,442 breast DXA scans; the mean age at Tanner B4 was 11.3 years. %FGV increased across breast Tanner stages and peaked 250 days after menarche. AFGV and BV peaked 2 years after menarche onset. Girls in the highest quartiles of %FGV, AFGV, and BV at Tanner B4 and B5 before menarche onset had the highest values thereafter until 4 years after menarche onset. The most important determinants of %FGV and AFGV variability were BMI z-score (R2 = 44%) and time since menarche (R2 = 42%), respectively. CONCLUSION: We characterize the breast development during puberty, a critical window of susceptibility. Although the onset of menarche is a key milestone for breast development, we observed that girls in the highest quartiles of %FGV and AFGV tracked in that group afterwards. Following these participants in adulthood would be of interest to understand the changes in breast composition during this period and its potential link with BC risk.


Assuntos
Neoplasias da Mama , Feminino , Humanos , Pré-Escolar , Criança , Estudos de Coortes , Chile , Puberdade , Menarca , Obesidade
2.
Int J Cancer ; 155(4): 627-636, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38567797

RESUMO

Whether trace metals modify breast density, the strongest predictor for breast cancer, during critical developmental stages such as puberty remains understudied. Our study prospectively evaluated the association between trace metals at Tanner breast stage B1 (n = 291) and at stages both B1 and B4 (n = 253) and breast density at 2 years post-menarche among Chilean girls from the Growth and Obesity Cohort Study. Dual-energy x-ray absorptiometry assessed the volume of dense breast tissue (absolute fibroglandular volume [FGV]) and percent breast density (%FGV). Urine trace metals included arsenic, barium, cadmium, cobalt, cesium, copper, magnesium, manganese, molybdenum, nickel, lead, antimony, selenium, tin, thallium, vanadium, and zinc. At B1, a doubling of thallium concentration resulted in 13.69 cm3 increase in absolute FGV (ß: 13.69, 95% confidence interval [CI]: 2.81, 24.52), while a doubling of lead concentration resulted in a 7.76 cm3 decrease in absolute FGV (ß: -7.76, 95%CI: -14.71, -0.73). At B4, a doubling of barium concentration was associated with a 10.06 cm3 increase (ß: 10.06, 95% CI: 1.44, 18.60), copper concentration with a 12.29 cm3 increase (ß: 12.29, 95% CI: 2.78, 21.56), lead concentration with a 9.86 cm3 increase (ß: 9.86, 95% CI: 0.73, 18.98), antimony concentration with a 12.97 cm3 increase (ß: 12.97, 95% CI: 1.98, 23.79) and vanadium concentration with a 13.14 cm3 increase in absolute FGV (ß: 13.14, 95% CI: 2.73, 23.58). Trace metals may affect pubertal breast density at varying developmental stages with implications for increased susceptibility for breast cancer.


Assuntos
Absorciometria de Fóton , Densidade da Mama , Oligoelementos , Humanos , Feminino , Chile/epidemiologia , Adolescente , Densidade da Mama/efeitos dos fármacos , Oligoelementos/análise , Oligoelementos/urina , Estudos Prospectivos , Criança , Mama/efeitos dos fármacos , Mama/crescimento & desenvolvimento , Neoplasias da Mama/epidemiologia
3.
FASEB J ; 37(1): e22698, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36520012

RESUMO

Folate plays an important role in the modulation of one-carbon metabolism and DNA methylation through a complex biosynthesis pathway. Folate deficiency during pregnancy has been associated with an increased risk for birth defects. This study investigates the extent to which the availability of folate and S-Adenosylmethionine (SAM) affects placental DNA methylation. We hypothesized that maintaining sufficient levels of folate and SAM is particularly important in individuals carrying the MTHFR C677T polymorphism. Maternal- and cord blood was analyzed to genotype the MTHFR rs1801133 SNP. Red blood cell (RBC) folate, vitamin B12, SAM, and S-Adenosylhomocysteine (SAH) were analyzed in cord blood. Epigenome-wide methylation analyses were performed on 90 placenta tissue samples isolated from the fetal side of the placenta; 45 originating from mother-infant dyads homozygous for the MTHFR C677T variant and 45 originating from mother-infant dyads with the homozygous wild type MTHFR677 genotype. Verification of the results was performed using pyrosequencing assays. Genome-wide placental DNA methylation patterns were relatively stable and not significantly affected by levels of one-carbon metabolites. MTHFR genotype was associated with DNA methylation of several loci, including a locus in the MTHFR region. RBC folate and particularly the SAM:SAH ratio did affect overall CpG DNA methylation in some CpG regions when the loci were split according to their CpG island relation. This was most evident in participants carrying the MTHFR C677T variant suggesting a stronger influence of the biosynthesis pathway on the overall placental DNA methylation in MTHFR TT individuals than in MTHFR CC individuals.


Assuntos
Metilação de DNA , Ácido Fólico , Metilenotetra-Hidrofolato Redutase (NADPH2) , Placenta , Feminino , Humanos , Lactente , Gravidez , Carbono/metabolismo , Metilação de DNA/efeitos dos fármacos , Metilação de DNA/genética , Ácido Fólico/metabolismo , Ácido Fólico/farmacologia , Ácido Fólico/uso terapêutico , Genótipo , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Placenta/efeitos dos fármacos , Placenta/metabolismo , S-Adenosilmetionina/metabolismo , Vitamina B 12/metabolismo
4.
BMC Neurol ; 24(1): 123, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38614986

RESUMO

BACKGROUND: Multiple Sclerosis (MS) represents the most common inflammatory neurological disease causing disability in early adulthood. Childhood and adolescence factors might be of relevance in the development of MS. We aimed to investigate the association between various factors (e.g., prematurity, breastfeeding, daycare attendance, weight history) and MS risk. METHODS: Data from the baseline assessment of the German National Cohort (NAKO) were used to calculate adjusted hazard ratios (HR) and 95% confidence intervals (CI) for the association between childhood and adolescence factors and risk of MS. Analyses stratified by sex were conducted. RESULTS: Among a total of 204,273 participants, 858 reported an MS diagnosis. Male sex was associated with a decreased MS risk (HR 0.48; 95% CI 0.41-0.56), while overweight (HR 2.03; 95% CI 1.41-2.94) and obesity (HR 1.89; 95% CI 1.02-3.48) at 18 years of age compared to normal weight were associated with increased MS risk. Having been breastfed for ≤ 4 months was associated with a decreased MS risk in men (HR 0.59; 95% CI 0.40-0.86) compared to no breastfeeding. No association with MS risk was observed for the remaining factors. CONCLUSIONS: Apart from overweight and obesity at the age of 18 years, we did not observe considerable associations with MS risk. The proportion of cases that can be explained by childhood and adolescence factors examined in this study was low. Further investigations of the association between the onset of overweight and obesity in childhood and adolescence and its interaction with physical activity and MS risk seem worthwhile.


Assuntos
Esclerose Múltipla , Obesidade Infantil , Humanos , Adolescente , Masculino , Adulto , Sobrepeso/epidemiologia , Esclerose Múltipla/epidemiologia , Exercício Físico
5.
BMC Public Health ; 24(1): 433, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38347566

RESUMO

BACKGROUND: The COVID-19 pandemic restrictions posed challenges to maintaining healthy lifestyles and physical well-being. During the first mobility restrictions from March to mid-July 2020, the German population was advised to stay home, except for work, exercise, and essential shopping. Our objective was to comprehensively assess the impact of these restrictions on changes in physical activity and sedentary behavior to identify the most affected groups. METHODS: Between April 30, 2020, and May 12, 2020, we distributed a COVID-19-specific questionnaire to participants of the German National Cohort (NAKO). This questionnaire gathered information about participants' physical activity and sedentary behavior currently compared to the time before the restrictions. We integrated this new data with existing information on anxiety, depressive symptoms, and physical activity. The analyses focused on sociodemographic factors, social relationships, physical health, and working conditions. RESULTS: Out of 152,421 respondents, a significant proportion reported altered physical activity and sedentary behavioral patterns due to COVID-19 restrictions. Over a third of the participants initially meeting the WHO's physical activity recommendation could no longer meet the guidelines during the restrictions. Participants reported substantial declines in sports activities (mean change (M) = -0.38; 95% CI: -.390; -.378; range from -2 to + 2) and reduced active transportation (M = -0.12; 95% CI: -.126; -.117). However, they also increased recreational physical activities (M = 0.12; 95% CI: .117; .126) while engaging in more sedentary behavior (M = 0.24; 95% CI: .240; .247) compared to pre-restriction levels. Multivariable linear and log-binomial regression models indicated that younger adults were more affected by the restrictions than older adults. The shift to remote work, self-rated health, and depressive symptoms were the factors most strongly associated with changes in all physical activity domains, including sedentary behavior, and the likelihood to continue following the physical activity guidelines. CONCLUSIONS: Mobility patterns shifted towards inactivity or low-intensity activities during the nationwide restrictions in the spring of 2020, potentially leading to considerable and lasting health risks.


Assuntos
COVID-19 , Corrida , Humanos , Idoso , Comportamento Sedentário , Pandemias , COVID-19/epidemiologia , Exercício Físico , Alemanha/epidemiologia
6.
J Nutr ; 153(1): 253-259, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36913459

RESUMO

BACKGROUND: Early onset of menarche is considered an important risk factor for a number of diseases in adulthood. Iron intake may be related to pubertal timing because of its role in childhood growth and reproductive function. OBJECTIVE: We investigated the relation between dietary iron intake and age at menarche in a prospective cohort of Chilean girls. METHODS: Overall, 602 Chilean girls were included in the Growth and Obesity Cohort Study, a longitudinal study that began in 2006 when the girls were 3-4 y old. Starting in 2013, diet was assessed every 6 mo through 24-h recall. The date of menarche was reported every 6 mo. Our analysis included 435 girls with prospective data on diet and age at menarche. We used a multivariable Cox proportional hazards regression model with restricted cubic splines to estimate HRs and 95% CIs for the association between cumulative mean iron intake and age at menarche. RESULTS: Most girls (99.5%) attained menarche with a mean (standard deviation) age at menarche of 12.2 (0.9) y. The mean dietary iron intake was 13.5 (range: 4.0-30.6) mg/d. Only 3.7% of girls consumed below 8 mg/d, the RDA. After multivariable adjustment, cumulative mean iron intake had a nonlinear association with menarche (P-for-nonlinearity: 0.02). Iron intakes above the RDA, between 8 and 15 mg/d, were associated with progressively lower probability of earlier menarche. Above 15 mg/d, the HRs were imprecise but tended to approach the null as iron intake increased. This association was attenuated after adjusting for girls' BMI and height before menarche (P-for-nonlinearity: 0.11). CONCLUSION: In Chilean girls, iron intake during late childhood, independent of body weight, was not an important determinant of menarche timing.


Assuntos
Ferro da Dieta , Menarca , Feminino , Criança , Humanos , Estudos de Coortes , Estudos Prospectivos , Estudos Longitudinais , Ferro , Chile , Dieta , Puberdade
7.
Age Ageing ; 52(1)2023 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-36702514

RESUMO

BACKGROUND: The European Working Group on Sarcopenia in Older People (EWGSOP) updated in 2018 the cut-off points for low grip strength to assess sarcopenia based on pooled data from 12 British studies. OBJECTIVE: Comparison of the EWGSOP2 cut-off points for low grip strength to those derived from a large German sample. METHODS: We assessed the grip strength distribution across age and derived low grip strength cut-off points for men and women (peak mean -2.5 × SD) based on 200,389 German National Cohort (NAKO) participants aged 19-75 years. In 1,012 Cooperative Health Research in the Region of Augsburg (KORA)-Age participants aged 65-93 years, we calculated the age-standardised prevalence of low grip strength and time-dependent sensitivity and specificity for all-cause mortality. RESULTS: Grip strength increased in the third and fourth decade of life and declined afterwards. Calculated cut-off points for low grip strength were 29 kg for men and 18 kg for women. In KORA-Age, the age-standardised prevalence of low grip strength was 1.5× higher for NAKO-derived (17.7%) compared to EWGSOP2 (11.7%) cut-off points. NAKO-derived cut-off points yielded a higher sensitivity and lower specificity for all-cause mortality. CONCLUSIONS: Cut-off points for low grip strength from German population-based data were 2 kg higher than the EWGSOP2 cut-off points. Higher cut-off points increase the sensitivity, thereby suggesting an intervention for more patients at risk, while other individuals might receive additional diagnostics/treatment without the urgent need. Research on the effectiveness of intervention in patients with low grip strength defined by different cut-off points is needed.


Assuntos
Sarcopenia , Idoso , Masculino , Humanos , Feminino , Sarcopenia/diagnóstico , Sarcopenia/epidemiologia , Avaliação Geriátrica , Força da Mão , Prevalência
8.
Int J Mol Sci ; 24(16)2023 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-37628977

RESUMO

Prebiotics are believed to exhibit high specificity in stimulating the growth or activity of a limited number of commensal microorganisms, thereby conferring health benefits to the host. However, the mechanism of action of prebiotics depends on multiple factors, including the composition of an individual's gut microbiota, and is therefore difficult to predict. It is known that different bacteria can utilize inulin and xylooligosaccharides (XOS), but an overview of which bacteria in the human gut may be affected is lacking. Detailed knowledge of how bacterial growth is affected by prebiotics is furthermore useful for the development of new synbiotics, which combine a living microorganism with a selective substrate to confer a health benefit to the host. Hence, we developed a statistical model to compare growth in vitro among typical human gut bacteria from different phylogenetic lineages. Based on continuous observation of the optical density (OD600), we compare maximal growth rates (rmax), maximal attained OD600 (ODmax), and area under the growth curve (AUC) of bacteria grown on inulin or XOS. The consideration of these three parameters suggests strain-specific preferences for inulin or XOS and reveals previously unknown preferences such as Streptococcus salivarius growth on XOS.


Assuntos
Inulina , Prebióticos , Humanos , Inulina/farmacologia , Filogenia , Oligossacarídeos/farmacologia
9.
Breast Cancer Res ; 24(1): 3, 2022 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-34998441

RESUMO

BACKGROUND: Frequent sugar-sweetened beverage (SSB) intake has been associated with indirect markers of breast cancer risk, such as weight gain in adolescents and early menarche. How SSB intake relates to breast composition in adolescent girls has not been explored. METHODS: We evaluated the association between prospective intake of SSB and breast density in a cohort of 374 adolescent girls participating in the Growth and Obesity Cohort Study in Santiago, Chile. Multivariable linear regression models were used to analyze the association between average daily SSB intake quartiles and breast composition (absolute fibroglandular volume [aFGV], percent fibroglandular volume [%FGV], total breast volume [tBV]). Models were adjusted for potential confounding by BMI Z-score, age, daily energy intake (g/day), maternal education, hours of daily television watching after school, dairy intake (g/day), meat intake (g/day), waist circumference, and menarche. To examine the sensitivity of the association to the number of dietary recalls for each girl, analyses were further stratified by girls with one dietary recall and girls with > one dietary recall. RESULTS: A total of 881 dietary recalls were available for 374 girls prior to the breast density assessment. More than 60% of the cohort had > one dietary recall available. In multivariable analyses, we found no association between SSB intake quartile and aFGV (Q2 vs Q1 ß: - 5.4, 95% CI - 15.1, 4.4; Q3 vs Q1 ß: 1.3, 95% CI - 8.6, 11.3; Q4 vs Q1 ß: 3.0, 95% CI - 7.1, 13). No associations were noted for %FGV and tBV. Among girls with at least one dietary recall, we found no significant associations between SSB intake quartiles and %FGV, aFGV, or tBV. CONCLUSION: Overall, we observed no evidence that SSB intake was associated with breast density in adolescent Chilean girls.


Assuntos
Neoplasias da Mama , Bebidas Adoçadas com Açúcar , Adolescente , Densidade da Mama , Chile/epidemiologia , Estudos de Coortes , Feminino , Humanos , Estudos Longitudinais , Estudos Prospectivos , Bebidas Adoçadas com Açúcar/efeitos adversos
10.
Hum Mol Genet ; 29(2): 335-350, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31868881

RESUMO

Despite the many advances made in the diagnosis and management of preeclampsia, this syndrome remains a leading cause of maternal mortality and life-long morbidity, as well as adverse fetal outcomes. Successful prediction and therapeutic intervention require an improved understanding of the molecular mechanisms, which underlie preeclampsia pathophysiology. We have used an integrated approach to discover placental genetic and epigenetic markers of preeclampsia and validated our findings in an independent cohort of women. We observed the microRNA, MIR138, to be upregulated in singleton preeclamptic placentas; however, this appears to be a female infant sex-specific effect. We did not identify any significant differentially methylated positions (DMPs) in singleton pregnancies, indicating that DNA methylation changes in mild forms of the disease are likely limited. However, we identified infant sex-specific preeclampsia-associated differentially methylated regions among singletons. Disease-associated DMPs were more obvious in a limited sampling of twin pregnancies. Interestingly, 2 out of the 10 most significant changes in methylation over larger regions overlap between singletons and twins and correspond to NAPRT1 and ZNF417.


Assuntos
Epigênese Genética , Feto/metabolismo , MicroRNAs/metabolismo , Placenta/metabolismo , Pré-Eclâmpsia/genética , Adulto , Estudos de Coortes , Metilação de DNA , Feminino , Regulação da Expressão Gênica/genética , Estudo de Associação Genômica Ampla , Humanos , Masculino , MicroRNAs/genética , Pentosiltransferases/genética , Pentosiltransferases/metabolismo , Placenta/patologia , Pré-Eclâmpsia/metabolismo , Gravidez , Gravidez de Gêmeos/metabolismo , Sexo , Transcriptoma/genética , Gêmeos/genética , Dedos de Zinco/genética
11.
Eur J Epidemiol ; 37(4): 429-436, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35653006

RESUMO

The German National Cohort (NAKO) is an ongoing, prospective multicenter cohort study, which started recruitment in 2014 and includes more than 205,000 women and men aged 19-74 years. The study data will be available to the global research community for analyses. Although the ultimate decision about the analytic methods will be made by the respective investigator, in this paper we provide the basis for a harmonized approach to the statistical analyses in the NAKO. We discuss specific aspects of the study (e.g., data collection, weighting to account for the sampling design), but also give general recommendations which may apply to other large cohort studies as well.


Assuntos
Projetos de Pesquisa , Estudos de Coortes , Feminino , Humanos , Estudos Longitudinais , Masculino , Estudos Prospectivos
12.
Breast Cancer Res ; 23(1): 49, 2021 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-33902651

RESUMO

BACKGROUND: Mammographic breast density (MBD) and benign breast disease (BBD) are two of the strongest risk factors for breast cancer. Understanding trends in MBD by age and parity in women with BBD is essential to the clinical management and prevention of breast cancer. METHODS: Using data from the Early Determinants of Mammographic Density (EDMD) study, a prospective follow-up study of women born in 1959-1967, we evaluated MBD in 676 women. We used linear regression with generalized estimating equations to examine associations between self-reported BBD and MBD (percent density, dense area, and non-dense area), assessed through a computer-assisted method. RESULTS: A prior BBD diagnosis (median age at diagnosis 32 years) was reported by 18% of our cohort. The median time from BBD diagnosis to first available study mammogram was 9.4 years (range 1.1-27.6 years). Women with BBD had a 3.44% higher percent MBD (standard error (SE) = 1.56, p-value = 0.03) on their first available mammogram than women without BBD. Compared with parous women without BBD, nulliparous women with BBD and women with a BBD diagnosis prior to first birth had 7-8% higher percent MBD (ß = 7.25, SE = 2.43, p-value< 0.01 and ß = 7.84, SE = 2.98, p-value = 0.01, respectively), while there was no difference in MBD in women with a BBD diagnosis after the first birth (ß = -0.22, SE = 2.40, p-value = 0.93). CONCLUSION: Women with self-reported BBD had higher mammographic breast density than women without BBD; the association was limited to women with BBD diagnosed before their first birth.


Assuntos
Densidade da Mama/fisiologia , Doenças Mamárias/patologia , Adolescente , Adulto , Doenças Mamárias/diagnóstico , Doenças Mamárias/epidemiologia , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/patologia , Criança , Feminino , Seguimentos , Humanos , Mamografia/estatística & dados numéricos , Paridade , Gravidez , Estudos Prospectivos , Fatores de Risco , Adulto Jovem
13.
J Infect Chemother ; 27(11): 1621-1625, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34376349

RESUMO

BACKGROUND: In 2016, the Japanese government set the National Action Plan on antimicrobial resistance to reduce antibiotic prescriptions. However, the trends and variations of antibiotic prescription patterns in a routine healthcare setting during the fiscal year 2013-2018 across different clinics at a national level are unclear. METHODS: This retrospective cohort study included all clinics with >100 pediatric outpatients with infectious diseases per month during the fiscal year 2013-2018 using a national database in Japan. We investigated the trends in antibiotic prescription rates and their patterns and variations across different clinics over the six years following the 2019 World Health Organization Access, Watch, Reserve antibiotic groups, and Amoxicillin Index. RESULTS: A total of 2278 clinics with 94,414,170 infectious disease-related visits were eligible for the study. Most clinics showed higher Watch percentages (median 85.4%; IQR, 68.5-95.1) than Access percentages (median, 13.8%; IQR, 4.2-30.7) and Amoxicillin Index (median, 13.3%; IQR, 3.9-30.4). The introduction of the Action Plan changed annual absolute reductions in the antibiotic prescription rates from -16.0 DOTs/1000 visitors (95%CI, -16.4-15.6) to -239.3 per 1000 visitors (95%CI, -240.0-238.6). However, these impacts were heterogeneous across clinics. From 2013 to 2018, 41.4% reduced the antibiotic prescription rates by >33.3% (median, -1035.5 DOTs/1000 visitors; IQR, -1519.4-680.2), 18.7% did not change the rates (median, -40.3 DOTs/1000 visitors; IQR, -168.4-68.6), and 7.3% increased the rates by >10% (499.5 DOTs per 1000 visitors; IQR, 232.6-837.5). CONCLUSIONS: We observed the National Action Plan's impacts and extensive prescription variations across different pediatric clinics. However, one-fourth of clinics did not improve antibiotic prescription patterns even after introducing the Action Plan.


Assuntos
Antibacterianos , Prescrições de Medicamentos , Amoxicilina , Antibacterianos/uso terapêutico , Criança , Humanos , Japão , Padrões de Prática Médica , Estudos Retrospectivos
14.
Biom J ; 63(7): 1366-1374, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33960007

RESUMO

Habitual diet can influence health-related outcomes directly, but such effects may also be modulated indirectly by gut microbiota. We consider randomized trials and the question to what extent the effect of diet on an outcome of interest is mediated through the gut microbiome or whether there is a diet-microbiome interaction identifying subgroups of individuals who are more susceptible to specific dietary effects. The baseline microbiome by itself may be a modifier of the effects of diet on health. Yet, the high dimensionality of microbiome data requires innovative statistical approaches to identify potential mediating or moderating effects. To motivate our proposal for an appropriate analysis workflow, we consider a randomized trial that investigates the effect of a 4-week vegan diet on the diversity of gut microbiota and branched-chain amino acid metabolism in healthy omnivorous volunteers. To address the challenge of compositional microbiome data, we consider an adaptation of the lasso for penalized estimation of multivariable regression models with a large number of microbiotic taxa. This is plugged into a classical regression mediation effect analysis strategy. The interaction effects are obtained via an approach that can directly estimate them without having to deal with main effects. As a result we obtain signatures comprised of microbiotic taxa with potential mediating and moderating effects. Some taxa no longer show up as mediating, when taking moderating effects into account. Thus, the proposed analysis strategy allows to identify specific mediating effects, while avoiding potential erroneous conclusions, where moderating effects might have believed to be mediating effects.


Assuntos
Microbioma Gastrointestinal , Microbiota , Dieta , Fezes , Humanos
15.
Breast Cancer Res ; 22(1): 104, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33004039

RESUMO

BACKGROUND: Systemic inflammation may play a role in shaping breast composition, one of the strongest risk factors for breast cancer. Pubertal development presents a critical window of breast tissue susceptibility to exogenous and endogenous factors, including pro-inflammatory markers. However, little is known about the role of systemic inflammation on adolescent breast composition and pubertal development among girls. METHODS: We investigated associations between circulating levels of inflammatory markers (e.g., interleukin-6 (IL-6), tumor necrosis factor receptor 2 (TNFR2), and C-reactive protein (CRP)) at Tanner stages 2 and 4 and breast composition at Tanner stage 4 in a cohort of 397 adolescent girls in Santiago, Chile (Growth and Obesity Cohort Study, 2006-2018). Multivariable linear models were used to examine the association between breast composition and each inflammatory marker, stratifying by Tanner stage at inflammatory marker measurement. Accelerated failure time models were used to evaluate the association between inflammatory markers concentrations at each Tanner stage and time to menarche. RESULTS: In age-adjusted linear regression models, a doubling of TNFR2 at Tanner 2 was associated with a 26% (95% CI 7-48%) increase in total breast volume at Tanner 4 and a 22% (95% CI 10-32%) decrease of fibroglandular volume at Tanner 4. In multivariable models further adjusted for body fatness and other covariates, these associations were attenuated to the null. The time to menarche was 3% (95% CI 1-5%) shorter among those in the highest quartile of IL-6 at Tanner 2 relative to those in the lowest quartile in fully adjusted models. Compared to those in the lowest quartile of CRP at Tanner 4, those in the highest quartile experienced 2% (95% CI 0-3%) longer time to menarche in multivariable models. CONCLUSIONS: Systemic inflammation during puberty was not associated with breast volume or breast density at the conclusion of breast development among pubertal girls after adjusting for body fatness; however, these circulating inflammation biomarkers, specifically CRP and IL-6, may affect the timing of menarche onset.


Assuntos
Biomarcadores/sangue , Densidade da Mama , Mama/imunologia , Inflamação/imunologia , Menarca , Puberdade , Mama/crescimento & desenvolvimento , Mama/metabolismo , Proteína C-Reativa/metabolismo , Criança , Estudos de Coortes , Feminino , Humanos , Inflamação/metabolismo , Interleucina-6/metabolismo , Receptores Tipo II do Fator de Necrose Tumoral/metabolismo , Fatores de Risco , Maturidade Sexual
16.
J Nutr ; 150(7): 1680-1692, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32232406

RESUMO

The human microbiota is a key contributor to many aspects of human health and its composition is largely influenced by diet. There is a growing body of scientific evidence to suggest that gut dysbiosis (microbial imbalance of the intestine) is associated with inflammatory and immune-mediated diseases (e.g., inflammatory bowel disease and asthma). Regular consumption of fermented foods (e.g., kimchi, kefir, etc.) may represent a potential avenue to counter the proinflammatory effects of gut dysbiosis. However, an assessment of the available literature in this research area is lacking. Here we provide a critical review of current human intervention studies that analyzed the effect of fermented foods on the composition and/or function of the human gut microbiota. A total of 19 human intervention studies were identified that met this search criteria. In this review, we discuss evidence that consumption of fermented foods may modify the gut microbiota in humans. Further, there is cursory evidence to suggest that gut microbiota compositional changes mediate associations between fermented food consumption and human health outcomes. Although promising, there remains considerable heterogeneity in the human populations targeted in the intervention studies we identified. Larger longitudinal feeding studies with longer follow-up are necessary to confirm and enhance the current data. Further, future studies should consider analyzing microbiota function as a means to elucidate the mechanism linking fermented food consumption with human health. This review highlights methodologic considerations for intervention trials, emphasizing an expanse of research opportunities related to fermented food consumption in humans.


Assuntos
Alimentos Fermentados , Microbioma Gastrointestinal , Bactérias/classificação , Humanos
17.
Environ Res ; 182: 109053, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31923847

RESUMO

Telomere length correlates with morbidity and mortality. While telomere length appears to be influenced by hormone levels, the potential impact of exposure to endocrine-disrupting chemicals (EDCs) has not been studied. We examined the association between maternal gestational concentrations of biomarkers of EDC exposure and telomere length at birth in the Harvard Epigenetic Birth Cohort. EDC (phenols and phthalates) biomarker concentrations were measured in maternal spot urine samples during the first trimester and telomere length in maternal and cord blood collected at delivery among 181 mother-newborn singleton dyads. Maternal and newborn telomere length exhibited a positive correlation (Spearman ρ = 0.20 (p-value< 0.01). Infant telomere length was associated with maternal biomarker concentrations of specific EDCs, and most of these associations were observed to be infant sex-specific. Prenatal exposure to triclosan, a non-paraben phenol with antimicrobial properties, was one of the most strongly associated EDCs with telomere length; telomere length was 20% (95% CI 5%-33%) shorter among boys in the highest quartile of maternal biomarker concentrations compared to the lowest quartile. In contrast, we observed longer telomere length associated with increased gestational concentrations of mono-isobutyl phthalate, and among boys, with increased concentrations of mono-2-ethylhexyl phthalate. In this birth cohort, we observed associations between maternal gestational exposure to select EDC biomarkers and telomere length, most of which were sex-specific. These findings need to be confirmed in future studies.


Assuntos
Disruptores Endócrinos , Poluentes Ambientais , Exposição Materna , Ácidos Ftálicos , Homeostase do Telômero , Encurtamento do Telômero , Triclosan , Disruptores Endócrinos/toxicidade , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Fenóis , Gravidez , Fatores Sexuais , Telômero , Homeostase do Telômero/efeitos dos fármacos , Encurtamento do Telômero/efeitos dos fármacos
18.
Artigo em Alemão | MEDLINE | ID: mdl-32125462

RESUMO

BACKGROUND: Asthma is one of the most common chronic diseases in both children and adults. Asthma first occurring in adulthood (adult-onset asthma, AOA) is associated with poorer prognosis compared to childhood-onset asthma (COA), which urgently calls for more research in this area. The aim of this work was to analyze the data on asthma collected in the German National Cohort and compare it with the German Health Interview and Examination Survey for Adults (DEGS), in particular regarding AOA. MATERIAL AND METHODS: Our analysis was based on the dataset of the main questionnaire at mid-term of the German National Cohort baseline examination, comprising 101,723 participants. Variables considered in the analyses were self-reported diagnosis of asthma, age at first diagnosis, asthma treatment in the past 12 months, age, and sex. RESULTS: In the midterm dataset, 8.7% of women and 7.0% of men in the German National Cohort reported that they had ever been diagnosed with asthma. Approximately one third of participants with asthma received their initial diagnosis before their 18th birthday. COA affected 2.2% of women and 2.8% of men, whereas AOA affected 6.5% of women and 4.2% of men. During the previous 12 months, 33% of COA cases and 60% of AOA cases were medically treated. CONCLUSION: The proportion of persons affected by asthma in the German National Cohort, as well as observed patterns regarding age and gender, corresponds to other data sources such as DEGS. However, in our analysis, the proportion of individuals with AOA was higher than described in the literature. The increase in cumulative asthma diagnoses with age is markedly steeper in younger participants, indicating a rising trend over time.


Assuntos
Asma/diagnóstico , Adulto , Fatores Etários , Idade de Início , Asma/epidemiologia , Criança , Doença Crônica , Estudos de Coortes , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Inquéritos e Questionários
19.
Artigo em Alemão | MEDLINE | ID: mdl-32157352

RESUMO

BACKGROUND: Data on self-reported cardiovascular and metabolic diseases are available for the first 100,000 participants of the population-based German National Cohort (GNC, NAKO Gesundheitsstudie). OBJECTIVES: To describe assessment methods and the frequency of self-reported cardiovascular and metabolic diseases in the German National Cohort. MATERIALS AND METHODS: Using a computer-based, standardized personal interview, 101,806 participants (20-75 years, 46% men) from 18 nationwide study centres were asked to use a predefined list to report medical conditions ever diagnosed by a physician, including cardiovascular or metabolic diseases. For the latter, we calculated sex-stratified relative frequencies and compared these with reference data. RESULTS: With regard to cardiovascular diseases, 3.5% of men and 0.8% of women reported to have ever been diagnosed with a myocardial infarction, 4.8% and 1.5% with angina pectoris, 3.5% and 2.5% with heart failure, 10.1% and 10.4% with cardiac arrhythmia, 2.7% and 1.8% with claudicatio intermittens, and 34.6% and 27.0% with arterial hypertension. The frequencies of self-reported diagnosed metabolic diseases were 8.1% and 5.8% for diabetes mellitus, 28.6% and 24.5% for hyperlipidaemia, 7.9% and 2.4% for gout, and 10.1% and 34.3% for thyroid diseases. Observed disease frequencies were lower than reference data for Germany. CONCLUSIONS: In the German National Cohort, self-reported cardiovascular and metabolic diseases diagnosed by a physician are assessed from all participants, therefore representing a data source for future cardio-metabolic research in this cohort.


Assuntos
Doenças Cardiovasculares/epidemiologia , Doenças Metabólicas/epidemiologia , Estudos de Coortes , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Autorrelato , Inquéritos e Questionários
20.
Artigo em Alemão | MEDLINE | ID: mdl-32078705

RESUMO

BACKGROUND: A nationwide assessment of the respiratory status on the basis of standardized lung function measurements has so far not been available in Germany. The present work describes the lung function tests in the German National Cohort (GNC) and presents initial results based on the GNC Midterm Baseline Dataset. MATERIAL AND METHODS: The assessment of lung function in the GNC comprised spirometry (level 1) and the determination of exhaled nitric oxide (FeNO, level 2). Our quality assurance concept included regular training of lung function test procedures at various GNC sites, interim evaluations of test quality, as well as regular calibration/measurement checks of test equipment. For spirometry, we established a stepwise procedure for offline quality control based on raw flow volume curves. RESULTS: In the present dataset (n = 101,734), spirometry was available for 86,893 study participants and FeNO was available for 15,228 participants. The average (±SD) FEV1 Z score (according to GLI 2012) was -0.321 ± 1.047, the FVC Z score was -0.153 ± 0.941, and the FEV1/FVC Z score was -0.337 ± 0.901. The difference in FEV1/FVC between current smokers and never-smokers increased with age. The average FeNO was 14.2 ÷ 2.0 ppb. Current smoking reduced FeNO levels by 43%, whereas respiratory allergy increased FeNO levels by 16% in nonsmokers. DISCUSSION: The results of spirometry and the FeNO measurements are in the expected range with regard to their distributions and correlates. The GNC provides a valuable basis for future investigations of respiratory health and its determinants as well as research into the prevention of respiratory diseases in Germany.


Assuntos
Testes Respiratórios , Asma , Expiração , Alemanha , Humanos , Espirometria
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