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1.
PLoS One ; 19(2): e0285963, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38358995

RESUMO

INTRODUCTION: The COVID-19 pandemic disproportionately affected older adults, particularly those with pre-existing chronic health conditions. To address the health disparity and challenges faced by under-resourced African American older adults in South Los Angeles during this period, we implemented a hybrid (virtual/in-person), pre-post, community-based participatory intervention research project utilizing a faith-based lay health advisor model (COVID-19 Health Ambassador Program (CHAP)). We recruited COVID-19 Health Ambassadors (CHAs) and African American older adults (participants) from faith-based organizations who partook in CHA-led meetings and follow-ups that educated and supported the participants. This paper seeks to evaluate this intervention's implementation using the Consolidated Framework for Implementation Research (CFIR) as a reporting tool with an emphasis on fidelity, challenges, and adaptations based on data collected via stakeholder interviews and surveys. RESULTS: CHAP was delivered to 152 participants by 19 CHAs from 17 faith-based organizations. CHAs assisted with chronic disease management, resolved medication-related challenges, encouraged COVID-19 vaccination, reduced psychological stress and addressed healthcare avoidance behaviors such as COVID-19 vaccine hesitancy among the participants. Challenges encountered include ensuring participant engagement and retention in the virtual format and addressing technological barriers for CHAs and participants. Adaptations made to better suit the needs of participants included providing communication tools and additional training to CHAs to improve their proficiency in using virtual platforms in addition to adapting scientific/educational materials to suit our participants' diverse cultural and linguistic needs. CONCLUSION: The community-centered hybrid approach in addition to our partnership with faith-based organizations and their respective COVID-19 health ambassadors proved to be essential in assisting underserved African American older adults manage chronic health conditions and address community-wide health disparities during the COVID-19 pandemic. Adaptability, cultural sensitivity, and teamwork are key to implementing health interventions especially in underserved populations.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Desigualdades de Saúde , Idoso , Humanos , Negro ou Afro-Americano , COVID-19/epidemiologia , COVID-19/prevenção & controle , Pandemias , Pesquisa Participativa Baseada na Comunidade
2.
Front Public Health ; 11: 1268961, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38035278

RESUMO

Introduction: A high quality diet is vital in promoting wellbeing and ensuring good health, particularly for those living with chronic conditions. Older African Americans, already burdened with a higher prevalence of chronic conditions, also face a higher risk for suboptimal diets. The COVID-19 pandemic had lasting effects on access to healthy food for all Americans, but some demographic groups were disproportionately affected. Older African Americans, who already experienced reduced access to healthy food pre-pandemic, were particularly afflicted, but the full extent of the pandemic's impact on their food insecurity and food environment remains unclear. Methods: To address this gap, we conducted a study among 102 older African Americans in South Los Angeles between October 2021 and July 2022 during the COVID-19 pandemic. Participants completed surveys on dietary intake, food insecurity, and neighborhood food environment. We measured dietary quality using the healthy eating index (HEI)-2015. The analysis included descriptive, bivariate chi-square, t-tests, analysis of variance, and multiple linear and logistic regression. Results: While overall dietary quality was suboptimal, most participants met the guidelines for fruit and vegetable consumption. Food insecurity was associated with lower overall diet quality and lower total fruit and whole fruit intake. However, there was no association between food environment and diet quality. Discussion: In light of our findings, further intervention is critical to improving diet quality, especially among older African Americans living with chronic conditions in the post-pandemic era.


Assuntos
Negro ou Afro-Americano , Dieta , Insegurança Alimentar , Pandemias , Humanos , Doença Crônica , COVID-19/epidemiologia , Estados Unidos
4.
Artigo em Inglês | MEDLINE | ID: mdl-37336866

RESUMO

OBJECTIVES: Unhealthy diets and inadequate exercise are associated with chronic health conditions and excess mortality. Older African Americans do not meet dietary and exercise guidelines, and this may have worsened during the COVID-19 pandemic due to individual and environmental factors, including food insecurity. Studies evaluating these dynamics are essential for developing interventions. This narrative details a study protocol and data collection experiences during the pandemic. METHODS: Participants > 55 years African American old completed detailed food frequency, exercise, and food access questionnaires between October 2020 and July 2021. Observations of the study administrators (authors of this manuscript) for the duration of the study are presented. Details on the study design and reflections on the opportunities, challenges, and lessons learned are summarized. Future manuscripts will report data analysis of study findings. RESULTS: A total of 123 older African American adults participated in the study, and 118 (70% female) completed all three questionnaires. More than 50% of the participants had at least two primary chronic conditions. About 85% were fully vaccinated against COVID-19. Applying community-based participatory approaches, leveraging partnerships, and exercising flexibility approaches were pivotal to successfully implementing the study protocol. CONCLUSIONS: Despite challenges related to the COVID-19 pandemic, detailed data on older African American adults' diet and exercise habits were obtained. Our study design and experiences will benefit future researchers. More importantly, results from our study will inform interventions and policies aimed at minimizing consequences associated with poor diet and exercise habits during the pandemic among this vulnerable population.

5.
Artigo em Inglês | MEDLINE | ID: mdl-37047890

RESUMO

Confusing health messages and environmental changes intended to prevent the spread of the COVID-19 virus have affected the dietary behavior of older African Americans. We investigated the impact of COVID-19-related factors on diet quality and the relationship between food access and diet quality. We surveyed 150 African Americans aged 55 years and above during the COVID-19 pandemic. The data obtained included socio-demographic and health information, and COVID-19-related knowledge and perceptions. Dietary intake data was obtained using the Diet History Questionnaire III. Analyses included bivariate and multivariable statistics. Overall, based on United States Department of Agriculture guidelines, the diet quality of older African Americans was poor. Lower knowledge and a lower perceived threat of COVID-19 were significantly associated with poor diet quality. Additionally, older African Americans with chronic diseases and food insecurity had poor diet quality. The COVID-19 pandemic has highlighted the fragility of diet quality. The combined impact of poor knowledge and perceived threat of COVID-19, chronic disease, and food insecurity contribute to poor diet quality in this population. This study adds to the well-known need for strategies to support the right to a healthy diet, particularly during COVID-19 and future pandemics. Proactive interventions to counteract the potential consequences of poor diets are needed.


Assuntos
Negro ou Afro-Americano , COVID-19 , Dieta , Insegurança Alimentar , Avaliação Nutricional , Humanos , Negro ou Afro-Americano/psicologia , Negro ou Afro-Americano/estatística & dados numéricos , COVID-19/epidemiologia , COVID-19/psicologia , Dieta/normas , Dieta/estatística & dados numéricos , Ingestão de Alimentos , Pandemias , Estados Unidos/epidemiologia , Idoso , Pessoa de Meia-Idade , Avaliação Geriátrica/estatística & dados numéricos , Conhecimentos, Atitudes e Prática em Saúde/etnologia , Acesso a Alimentos Saudáveis/normas , Acesso a Alimentos Saudáveis/estatística & dados numéricos
6.
Artigo em Inglês | MEDLINE | ID: mdl-36768041

RESUMO

BACKGROUND: The COVID-19 pandemic transformed healthcare delivery with the expansive use of telemedicine. However, health disparities may result from lower adoption of telehealth among African Americans. This study examined how under-resourced, older African Americans with chronic illnesses use telehealth, including related sociodemographic and COVID-19 factors. METHODS: Using a cross-sectional design, 150 middle-aged and older African Americans were recruited from faith-based centers from March 2021 to August 2022. Data collected included sociodemographics, comorbidities, technological device ownership, internet usage, and attitudes toward COVID-19 disease and vaccination. Descriptive statistics and multivariable regression models were conducted to identify factors associated with telehealth use. RESULTS: Of the 150 participants, 32% had not used telehealth since the COVID-19 pandemic, with 75% reporting no home internet access and 38% having no cellular/internet network on their mobile device. Age, access to a cellular network on a mobile device, and wireless internet at home were significantly associated with the utilization of telehealth care. Higher anxiety and stress with an increased perceived threat of COVID-19 and positive attitudes toward COVID-19 vaccination were associated with telehealth utilization. DISCUSSION: Access and integration of telehealth services were highlighted as challenges for this population of African Americans. To reduce disparities, expansion of subsidized wireless internet access in marginalized communities is necessitated. Education outreach and training by healthcare systems and community health workers to improve uptake of telehealth currently and post-COVID-19 should be considered.


Assuntos
COVID-19 , Telemedicina , Pessoa de Meia-Idade , Humanos , Idoso , COVID-19/epidemiologia , Negro ou Afro-Americano , Vacinas contra COVID-19 , Estudos Transversais , Los Angeles , Pandemias
7.
BMC Med Educ ; 22(1): 808, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36419030

RESUMO

BACKGROUND: There is a critical need for a diverse pool of academic leaders to increase the number and diversity of the medical workforce. Physician Assistant/Associate (PA) is a growing medical profession. Although the master's degree is the terminal degree for PAs, a growing number of PAs obtain a variety of doctoral degrees. However, there is no standardized training for academic PA leaders. The purpose of this study was to identify factors associated with PA academic leadership. Specifically, this study explored the following factors: doctoral degree credentials, gender and underrepresented minority status. METHODS: Using the 2019 Physician Assistant Education Association Faculty and Directors survey, we assessed the relationship between academic leadership groups [Program Director (PD), Academic Director (AD), and Clinical Director (CD)] doctoral degree, gender, and underrepresented minority in medicine (URIM) status. Multivariable logistic regression models were used to determine the predictors of being in a leadership role. Results with p < 0.05 were considered statistically significant. RESULTS: Of the 956 participants, 71% were female, 4% Hispanic, 86% White, 4% Black, 2% Asian, and 1% Native Hawaiian/Pacific Islander/American Indian/Alaska Native. Overall, 9% were URIM. Mean age was 45.6 (SD = 10.2) years. Average time in PA education was 2.9 years (SD = 1.4). Approximately 50% (n = 472) had a leadership role (PD-24%, AD-10%, CD-16%). Of all leaders, 68% were female, 9% were URIM, and 19% had a doctoral degree. Having a doctoral degree increased the odds of being a PD [AOR 2.38, CI [1.57-3.59], p = < 0.0001, AD and CD = non-significant]. More time in PA education increased the odds of being a PD [AOR 1.10, CI [1.07-1.12, p = < 0.0001] and AD [AOR 1.06, CI [1.03-1.09], p = < 0.0001], but not a CD. Gender and URIM status were not significantly associated with leadership roles. URIMs had doctorate degrees at higher rates than non-URIMs. CONCLUSION: PA academic leaders differ by doctoral degree attainment but not by gender and URIM status. URIM faculty are grossly underrepresented in the PA professorate, but disproportionately have doctoral degrees. Academic training opportunities for all PA academic leaders and strategies to increase URIM faculty are needed.


Assuntos
Educação Médica , Assistentes Médicos , Feminino , Humanos , Pessoa de Meia-Idade , Masculino , Liderança , Estudos Transversais , Docentes de Medicina
9.
BMC Public Health ; 22(1): 907, 2022 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-35524229

RESUMO

BACKGROUND: Vaccination is a powerful tool in the fight against seasonal influenza, among underserved, middle-age and older, Latinx adults. Yet, vaccine hesitancy and inconsistent uptake in this population continues to represent a substantial challenge to public health. A better understanding of factors impacting influenza vaccination behaviors in this group could result in more effective messaging and initiatives promoting universal vaccination among Latinx. METHODS: In this cross-sectional survey, we explore correlates of influenza vaccination uptake among underserved, Latinx, older adults. Our focus was on the role of socio-demographics, living arrangements, financial strain, access and satisfaction with medical care, and the presence of major chronic conditions in terms of vaccine uptake. Middle-aged and older Latinx residents diagnosed with diabetes and/or hypertension (n=165), were recruited from the South Los Angeles Service Plan Area (SPA), a historically under-resourced community. Bi-variate and multi-variate logistical regression were performed on survey data to explore independent correlates of influenza vaccination. RESULTS: Almost half of underserved Latinx older adults in our study (45%) reported influenza vaccination within the 12 months prior to the study. The majority (~85%) reported receiving this recommendation from their primary care provider. However, thirty percent (30%) of those receiving this advice did not get the vaccine. A decreased likelihood of vaccination was significantly associated with living alone (p-value=0.026), lacking Medicare coverage (0.028), or higher levels of financial strain (0.020). Difficulty accessing medical care (p-value=0.008) or dissatisfaction with these experiences (p-value=0.001) were also strongly associated with decreased likelihood of vaccination. Participants diagnosed with COPD had 9.5 (CI: 1.76 - 51.3) higher odds of being vaccinated compared to those without; no correlation was detected for other chronic conditions. CONCLUSION: The high number of unvaccinated Latinx participants receiving a vaccine recommendation from a provider is consistent with studies among other ethnic/racial minority older adults and highlights the pivotal role of the provider in influenza vaccine adoption. Additional findings reflect negative impact of Social Determinates of Health on preventive care efforts in this group. Further efforts to quantify these associations are needed to explore structural and human factors impacting influenza vaccine uptake.


Assuntos
Vacinas contra Influenza , Influenza Humana , Idoso , Doença Crônica , Estudos Transversais , Humanos , Vacinas contra Influenza/uso terapêutico , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Medicare , Pessoa de Meia-Idade , Estados Unidos , Vacinação
10.
Gerontol Geriatr Med ; 8: 23337214211057730, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35340364

RESUMO

African Americans and Hispanics are disproportionately burdened by cardiovascular risk factors including hypertension, diabetes mellitus, and obesity. There is evidence that fruits and vegetables have protective benefits for cardiovascular health. Factors associated with fruit and vegetable intake among older minority adults are not well established. A cross-sectional analysis of African American and Hispanic adults >55 years with diagnosis of hypertension and/or diabetes was conducted. Daily intake of fruits and vegetables was analyzed by socio-demographic, health status, health behaviors, and access to fruits and vegetables. 77% of participants did not meet the United States Department of Agriculture ≥5 a day serving guidelines. Fruit and vegetable consumption was not associated with having hypertension or diabetes. Body mass index >25 and regular exercise were significantly associated with more vegetable intake, but not fruit. African Americans consumed significantly less fruits and vegetables than Hispanics. Among those with access to fruits and vegetables, 78% did not meet the guidelines. Many older African American and Hispanic adults with cardiovascular disease risk factors do not meet the fruit and vegetable intake guidelines. Inadequate intake is worse among African Americans, sedentary, and non-overweight/obese adults. Studies are needed to understand the barriers associated with fruit and vegetable intake in this population.

11.
Health Promot Perspect ; 12(4): 399-409, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36852204

RESUMO

Background: The purpose of this study is to determine whether underserved middle-aged and older African Americans are receiving a colorectal cancer (CRC) screening test (sigmoidoscopy or colonoscopy) and if recommended by their provider. Additionally, we examined correlates of both provider recommendation and uptake of CRC screening. Methods: Seven hundred forty African American individuals, aged 55 and older, participated in this local community cross-sectional survey. We used a multivariate technique of logistic regression. Results: One out of three participants reported that they never received a sigmoidoscopy or colonoscopy for CRC screening. More than 31% indicted that their providers never suggested CRC testing. However, participants who indicated that their providers recommended sigmoidoscopy/colonoscopy were almost 49 times (odds ratio [OR]: 48.9, 95% confidence interval [CI]: 29.5-81.2) more likely to obtain it compared to their counterparts who were not advised to have these procedures. Our data suggest that African American men were significantly less likely than women to receive recommendations from their providers (OR: 0.70, 95% CI: 0.50-0.91). Furthermore, controlling for other variables, the following factors: 1) living arrangement (OR: 1.44, 95% CI: 1.02-2.04), 2) health maintenance organization (HMO) membership (OR: 1.84, 95% CI: 1.28-2.67), 3) number of providers (OR: 1.15, 95% CI: 1.01-1.32), 4) satisfaction with access to and quality of care (OR: 1.24, 95% CI: 1.03-1.51), 5) depressive symptoms (OR: 0.92, 95% CI: 0.86-0.98), and 6) gastrointestinal conditions (OR: 1.73, 95% CI: 1.16-2.58) were associated with obtaining a sigmoidoscopy or colonoscopy test. Conclusion: Our findings suggest that the absence of a provider recommendation is the primary barrier preventing underserved older African Americans from obtaining CRC screening. In addition, our data revealed significant association between obtaining CRC screening and some of the predisposing characteristics of participants, satisfaction with access to and quality of care, and physical and mental health. These findings are consistent with this notion that disparities in health care for African Americans can be traced back to four primary factors: patients, healthcare providers, the healthcare system, and society as a whole, and emphasize the need for establishing theory-driven, culturally-sensitive, and cost-effective CRC screening interventions that recognize and address the constraints to cancer screening experienced by this segment of population.

12.
Clin Nutr ESPEN ; 46: 336-342, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34857217

RESUMO

BACKGROUND AND AIMS: Nutritionally adequate diets can slow the progression of diabetes, but adherence to recommended dietary choices can be hindered by food insecurity. We examined the relationship between dietary quality, food insecurity, and glycemic control among adults with Type 2 Diabetes. METHODS: We analyzed data from the National Health and Nutrition Examination Survey (2011-2016) for 1682 adults =>20 years old with Type 2 diabetes. Glycemic control was measured by HbA1c. Dietary quality was computed using the Healthy Eating Index 2015 score. Food security was assessed by a questionnaire. We analyzed the data using multinomial regression models. RESULTS: About 16% of the population had an HbA1c ≥ 9; 31.8% had food insecurity; 68.3% consumed a poor quality diet. About 24% consumed a poor quality diet and had food insecurity. In the multinomial model, an HbA1c of 8-<9% was associated with poor diet quality (adjusted odds ratio (AOR) = 5.2, 95% confidence interval (CI) = 1.4-19.2, p = 0.01) and food insecurity (AOR = 8.5, 95% CI = 1.4-52.0, p = 0.02). Those with both factors had higher odds of both an HbA1c 8-<9% (AOR = 6.1, 95% CI = 1.5-24.8, p = 0.01) and HbA1c ≥ 9% (AOR = 6.7, 95% CI = 2.0-22.2, p < 0.01). Other risk factors for poor glycemic control were being Black or Hispanic, having no regular source of care, and ever having visited a diabetes specialist (p < 0.05). CONCLUSIONS: Poor glycemic control among adults with diabetes was associated with poor quality of diet and/or food insecurity, being Black, Hispanic, and lacking a regular source of care. There is a need for policies that improve access to healthy food in patients with type 2 diabetes, particularly among minority populations.


Assuntos
Diabetes Mellitus Tipo 2 , Adulto , Estudos Transversais , Dieta , Segurança Alimentar , Controle Glicêmico , Humanos , Inquéritos Nutricionais , Adulto Jovem
13.
Artigo em Inglês | MEDLINE | ID: mdl-34299695

RESUMO

Chronic low back pain is one of the most common, poorly understood, and potentially disabling chronic pain conditions from which older adults suffer. The existing low back pain research has relied almost exclusively on White/Caucasian participant samples. This study examines the correlates of chronic low back pain among a sample of underserved urban African American and Latino older adults. Controlling for age, gender, race/ethnicity, education, living arrangement, and number of major chronic conditions, associations between low back pain and the following outcome variables are examined: (1) healthcare utilization, (2) health-related quality of life (HR-QoL) and self-rated quality of health; and (3) physical and mental health outcomes. METHODS: We recruited nine hundred and five (905) African American and Latino older adults from the South Los Angeles community using convenience and snowball sampling. In addition to standard items that measure demographic variables, our survey included validated instruments to document HR-QoL health status, the Short-Form McGill Pain Questionnaire-2, Geriatric Depression Scale, sleep disorder, and healthcare access. Data analysis includes bivariate and 17 independent multivariate models. RESULTS: Almost 55% and 48% of the Latino and African American older adults who participated in our study reported chronic low back pain. Our data revealed that having low back pain was associated with three categories of outcomes including: (1) a higher level of healthcare utilization measured by (i) physician visits, (ii) emergency department visits, (iii) number of Rx used, (iv) a higher level of medication complexity, (v) a lower level of adherence to medication regimens, and (vi) a lower level of satisfaction with medical care; (2) a lower level of HR-QoL and self-assessment of health measured by (i) physical health QoL, (ii) mental health QoL, and (iii) a lower level of self-rated health; and (3) worse physical and mental health outcomes measured by (i) a higher number of depressive symptoms, (ii) a higher level of pain, (iii) falls, (iv) sleep disorders, (v) and being overweight/obese. DISCUSSION: Low back pain remains a public health concern and significantly impacts the quality of life, health care utilization, and health outcomes of underserved minority older adults. Multi-faceted and culturally sensitive interventional studies are needed to ensure the timely diagnosis and treatment of low back pain among underserved minority older adults. Many barriers and challenges that affect underserved African American and Latino older adults with low back pain simply cannot be addressed in over-crowded EDs. Our study contributes to and raises the awareness of healthcare providers and health policymakers on the necessity for prevention, early diagnosis, proper medical management, and rehabilitation policies to minimize the burdens associated with chronic low back pain among underserved older African American and Latino patients in an under-resourced community such as South Los Angeles.


Assuntos
Dor Lombar , Qualidade de Vida , Negro ou Afro-Americano , Idoso , Estudos Transversais , Hispânico ou Latino , Humanos , Dor Lombar/epidemiologia
14.
Am J Hosp Palliat Care ; 38(6): 601-609, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33535787

RESUMO

BACKGROUND: Numerous studies have documented multilevel racial inequalities in health care utilization, medical treatment, and quality of care in minority populations in the United States. Palliative care for people with serious illness and hospice services for people approaching the end of life are no exception. It is also well established that Hispanics and non-Hispanic Blacks are more likely than non-Hispanic Whites to have less knowledge about advance care planning and directives, hospice, and palliative care. Both qualitative and quantitative research has identified lack of awareness of palliative and hospice services as one of the major factors contributing to the underuse of these services by minority populations. However, an insufficient number of racial/ethnic comparative studies have been conducted to examine associations among various independent factors in relation to awareness of end-of-life, palliative care and advance care planning and directives. AIMS: The main objective of this analysis was to examine correlates of awareness of palliative, hospice care and advance directives in a racially and ethnically diverse large sample of California adults. METHODS: This cross-sectional study includes 2,328 adults: Hispanics (31%); non-Hispanic Blacks (30%); and non-Hispanic Whites (39%) from the Survey of California Adults on Serious Illness and End-of-Life 2019. Using multivariate analysis, we adjusted for demographic and socio-economic variables while estimating the potential independent impact of health status, lack of primary care providers, and recent experiences of participants with a family member with serious illnesses. RESULTS: Hispanic and non-Hispanic Black participants are far less likely to report that they have heard about palliative and hospice care and advance directives than their non-Hispanic White counterparts. In this study, 75%, 74%, and 49% of Hispanics, non-Hispanic Blacks, and non-Hispanic White participants, respectively, claimed that they have never heard about palliative care. Multivariate analysis of data show gender, age, education, and income all significantly were associated with awareness. Furthermore, being engaged with decision making for a loved one with serious illnesses and having a primary care provider were associated with awareness of palliative care and advance directives. DISCUSSION: Our findings reveal that lack of awareness of hospice and palliative care and advance directives among California adults is largely influenced by race and ethnicity. In addition, demographic and socio-economic variables, health status, access to primary care providers, and having informal care giving experience were all independently associated with awareness of advance directives and palliative and hospice care. These effects are complex, which may be attributed to various historical, social, and cultural mechanisms at the individual, community, and organizational levels. A large number of factors should be addressed in order to increase knowledge and awareness of end-of-life and palliative care as well as completion of advance directives and planning. The results of this study may guide the design of multi-level community and theoretically-based awareness and training models that enhance awareness of palliative care, hospice care, and advance directives among minority populations.


Assuntos
Cuidados Paliativos na Terminalidade da Vida , Adulto , Diretivas Antecipadas , California , Estudos Transversais , Hispânico ou Latino , Humanos , Cuidados Paliativos , Estados Unidos
16.
Bone ; 48(5): 1103-8, 2011 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-21241839

RESUMO

Muscle and bone form a functional unit. While muscle size is a useful surrogate of mechanical load on bone, the independent contributions to bone strength of muscle force, muscle size, gravitational load (body weight), and physical activity have not been assessed. Three hundred twenty-one healthy participants (32% black, 47% male), aged 5-35 years were assessed. Peak dorsiflexion muscle torque (ft-lbs) of the ankle was assessed using isometric dynamometry. Tibia peripheral quantitative computed tomography measures included polar section modulus (Zp; mm(3)), periosteal and endosteal circumference (mm), cortical area (mm(2)), and volumetric bone mineral density (vBMD; mg/cm(3)) at the 38% site, and muscle cross-sectional area (CSA; mm(2)), at the 66% site. Physical activity (average hours per week) was assessed by questionnaire. Log linear regression was used to assess determinants of muscle specific force (MSF; torque relative to muscle CSA) and Zp adjusted for age and tibia length. MSF was greater in blacks than whites (p<0.05) and lower in females than males (p<0.001). Zp was greater in blacks than whites (p=0.002) in Tanner stages 1-4, but the difference was attenuated in Tanner 5 (interaction, p=0.02); R(2)=0.87. Muscle CSA, muscle torque, body weight, and physical activity were added to the model and each load covariate was independently and significantly (all, p<0.02) associated with Zp (R(2)=0.92), periosteal circumference, and cortical area. Inclusion of these measures attenuated but did not eliminate the significant race differences. Only muscle CSA was positively associated with endosteal circumference, while none of the load covariates were associated with vBMD. In conclusion, bone geometry is associated with several factors that define the mechanical load on bone, independent of age, tibia length, maturation, race, and sex. Race differences in Zp were not explained by these measures of mechanical load. Given that inclusion of muscle torque, body weight, and physical activity resulted in a nominal increase in the R(2), muscle size is an adequate surrogate for the mechanical load on bone in healthy participants.


Assuntos
Osso e Ossos/anatomia & histologia , Osso e Ossos/fisiologia , Saúde , Adolescente , Adulto , Fenômenos Biomecânicos/fisiologia , Desenvolvimento Ósseo/fisiologia , Criança , Pré-Escolar , Demografia , Módulo de Elasticidade/fisiologia , Feminino , Humanos , Masculino , Análise Multivariada , Músculos/anatomia & histologia , Músculos/fisiologia , Especificidade de Órgãos , Grupos Raciais , Torque , Suporte de Carga/fisiologia , Adulto Jovem
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