Socioeconomic status over the life-course and adult bone mineral density: the Midlife in the U.S. Study

Proteins and pathways involved in inflammation are longitudinally associated with total body bone mineral density among primarily Hispanic overweight/obese adolescents and young adults

BMD, an important marker of bone health, is regulated by a complex interaction of proteins. Plasma proteomic analyses can contribute to identification of proteins associated with changes in BMD. This may be especially informative in stages of bone accrual and peak BMD achievement (ie, adolescence and young adulthood), but existing research has focused on older adults. This analysis in the Study of Latino Adolescents at Risk for Type 2 Diabetes (SOLAR; n = 304; baseline age 8-13, 100% Hispanic) explored associations between baseline proteins (n = 653 proteins) measured with Olink plasma protein profiling and repeated annual DXA measures of BMD (average of 3.2 visits per participant). Covariate-adjusted linear mixed effect regression models were applied to estimate longitudinal protein-BMD associations using an adjusted p value cutoff (p < .00068). Identified proteins were imported into the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database to determine significantly enriched protein pathways. Forty-four proteins, many of which are involved in inflammatory processes, were associated with longitudinal changes in total body BMD, including several proteins previously linked to bone health such as osteopontin (SPP1) and microfibrillar-associated protein 5 (MFAP5; both p < .00068). These 44 proteins were associated with enrichment of pathways including PI3K-Akt signaling pathway and cytokine-cytokine receptor interaction, supporting results from existing proteomics analyses in older adults. To evaluate whether protein associations were consistent into young adulthood, linear mixed effect models were repeated in a young adult cohort (n = 169; baseline age 17-22; 62.1% Hispanic) with 346 available overlapping Olink protein measures. While there were no significant overlapping longitudinal protein associations between the cohorts, these findings suggest differences in protein regulation at different ages and provide novel insight on longitudinal protein associations with BMD in overweight/obese adolescents and young adults of primarily Hispanic origin, which may inform the development of biomarkers for bone health in youth.

Lipid accumulation product, poverty income ratio, and bone mineral density in U.S. adults: a mediation analysis based on NHANES (2009-2020)

Objective

This study aims to investigate the relationship between the lipid accumulation product (LAP) index and total femur bone mineral density (BMD), while also examining the mediating role of the poverty-income ratio (PIR).

Methods

Using the most recent data from the National Health and Nutrition Examination Survey (NHANES) spanning 2009 to 2020, multivariate logistic regression models were employed in this study to investigate the relationship between the LAP index and total femur BMD. Saturation effects and potential non-linear associations were examined using a smooth curve-fitting approach to determine saturation levels. Interaction tests and subgroup analyses were also performed. Additionally, a mediation analysis was conducted to explore the mediating role of PIR.

Results

Three thousand two hundred and twenty three participants aged 20 years or older were recruited for this study. Multivariate regression analysis demonstrated a greater total femur BMD in individuals with a high LAP index. Additionally, analysis of the saturation effect and smooth curve fitting identified a clear saturation effect between the LAP index and total femur BMD. A saturation value of 16.05 was determined when investigating the relationship between the LAP index and total femur BMD. Subgroup analysis revealed no significant interaction effects after adjusting for covariates. Moreover, mediation analysis indicated that the LAP index had a substantial direct effect on total femur BMD (p < 0.0001), with PIR partially mediating this relationship (1.115%, p = 0.0280).

Conclusion

The results of this investigation demonstrated a saturation effect between the LAP index and total femur BMD, which may have been mediated by PIR.

Lifetime employment trajectories and cancer

Working life is associated with lifestyle, screening uptake, and occupational health risks that may explain differences in cancer onset. To better understand the association between working life and cancer risk, we need to account for the entire employment history. We investigated whether lifetime employment trajectories are associated with cancer risk. We used data from 6809 women and 5716 men, average age 70 years, from the Survey of Health, Ageing, and Retirement in Europe. Employment history from age 16 to 65 was collected retrospectively using a life calendar and trajectories were constructed using sequence analysis. Associations between employment trajectories and self-reported cancer were assessed using logistic regression. We identified eight employment trajectories for women and two for men. Among women, the risk of cancer was higher in the trajectories "Mainly full-time to home/family", "Full-time or home/family to part-time", "Mainly full-time", and "Other" compared with the "Mainly home/family" trajectory. Among men, the risk of cancer was lower in the "Mainly self-employment" trajectory compared with "Mainly full-time". We could show how employment trajectories were associated with cancer risk, underlining the potential of sequence analysis for life course epidemiology. More research is needed to understand these associations and determine if causal relationships exist.

Relationship between urinary sodium excretion and bone mineral density in pediatrics: population-based study from KNHANES V 2010-2011

OBJECTIVES

Osteoporosis poses a growing public health challenge worldwide. While calcium and vitamin D may influence bone mineral density (BMD), the effect of sodium (Na) intake, particularly in pediatrics, remains unexplored. This study aimed to evaluate the relationship between urinary Na excretion and BMD in a Korean pediatric population.

METHODS

A total of 2,018 participants (1,084 males and 934 females) aged 10-18 years were included from the data obtained from Korea National Health and Nutrition Examination Survey V (2010-2011).

RESULTS

Daily Na intake was about 4,560 mg and 3,600 mg in boys and girls, respectively. The mean intake of Na per day was positively correlated with the increment of urine Na/Cr ratio quartile (p<0.001). The BMD z-score [lumbar spine (LS), femur neck (FN), and whole body except head (WB)] in the group with high Na/Cr ratio (4th quartile, 4Q) was significantly less than in those with low Na/Cr ratio (1st quartile, 1Q) (p<0.001). Moreover, the LS (p=0.028), FN (p=0.002) and WB (p=0.056) in the 4Q group showed 2.0 times, 2.8 times, and 1.9 times greater risk of low BMD z-scores than in the 1Q group, even after adjusting for other confounding factors, such as age, sex, BMI, vitamin D, moderate activity, and household incomes.

CONCLUSIONS

Our findings suggest a strong negative association between urine Na excretion and BMD among Korean children and adolescents. The results underscore the importance of public health interventions targeting Na intake. Further longitudinal studies are recommended to clarify the long-term effects of Na on bone health in younger populations.

Psychological Disorders Linked to Osteoporosis Diagnoses in a Population-Based Cohort Study of Middle and Older Age United States Adults

BACKGROUND AND OBJECTIVES

Although it is well established that psychological disorders and osteoporosis risk are linked, how the relationship manifests is not. This study examines depressive symptoms and a history of psychological problems as potential risk factors for osteoporosis diagnosis, adjudicating between 4 theoretical models rarely tested together. We analyze these models across multiple domains (i.e., demographic, socioeconomic, and health-related), while accounting for bone mineral density (BMD) scans, which have been shown to improve health equity across sex and racial/ethnic identities.

RESEARCH DESIGN AND METHODS

Data from the 2012-2016, nationally representative, population-based, cohort Health and Retirement Study (N = 18,224-18,359) were used to estimate 4 logistic regression models with the outcome of osteoporosis diagnosis. Approximately 50% of the sample identified as female and 50% as male, while about 81% identified as White/European American, 11% as Black/African American, and 8% as another race/ethnicity. The key independent variables were depressive symptoms-measured using two common scales-and a history of psychological problems.

RESULTS

A history of psychological problems and one depressive symptoms measure were associated with the odds of osteoporosis diagnosis in the presence of other known risk factors for osteoporosis.

DISCUSSION AND IMPLICATIONS

Support for the theoretical models was limited. Evidence suggests possible directionality; a history of psychological distress may be a risk factor for osteoporosis, though we cannot rule out the other direction. Public health professionals and healthcare providers should consider a history of psychological problems as a risk factor for osteoporosis when deciding whether to recommend a BMD scan.

Association between the atherogenic index of plasma and bone mineral density among adult women: NHANES (2011-2018)

Background

Studies on the relationship between the atherogenic index of plasma (AIP) and bone mineral density (BMD) among adult women in the United States are limited. The purpose of this study was to explore this association using a sizable, nationally representative sample.

Methods

Data from the 2011 to 2018 National Health and Nutrition Examination Survey (NHANES) were used in this observational study. The AIP was computed as log10 (triglycerides/high-density lipoprotein cholesterol). Total BMD was measured via dual-energy X-ray densitometry. We constructed multiple linear regression models to evaluate the correlation between the AIP and BMD. The non-linear relationship was characterized by smooth curve fitting and generalized additive models. We also conducted subgroup and interaction analyses.

Results

In this study, we included 2,362 adult women with a mean age of 38.13 ± 12.42 years. The results of multiple linear regression analysis, the AIP and total BMD showed a negative association (β = -0.021, 95%CI: -0.037, -0.006). The curve fitting analysis and threshold effect analysis showed a non-linear relationship between the two variables, and the inflection point of the AIP was found to be -0.61. The total BMD decreased significantly when the AIP reached this value (β = -0.03, 95%CI: -0.04, -0.01). The results of the subgroup analysis showed that AIP and total BMD had a strong negative relationship in participants who were below 45 years old (β = -0.023; 95% CI: -0.041, -0.004), overweight (BMI ≥ 25 kg/m2) (β = -0.022; 95% CI: -0.041, -0.002), had a higher education level (β = -0.025; 95% CI: -0.044, -0.006), and had no partners (β = -0.014; 95% CI: -0.06, -0.009).

Conclusions

We found a negative correlation between the AIP and total BMD. Clinicians should pay attention to patients with high AIP, which might indicate a low BMD and has reference significance in preventing osteoporosis.

Lifetime Employment Trajectories and Cancer: A Population-Based Cohort Study

Working life is associated with lifestyle, screening uptake, and occupational health risks that may explain differences in cancer onset. To better understand the association between working life and cancer risk, we need to account for the entire employment history. We investigated whether lifetime employment trajectories are associated with cancer risk. We used data from 6,809 women and 5,716 men, average age 70 years, from the Survey of Health, Ageing, and Retirement in Europe. Employment history from age 16 to 65 was collected retrospectively using a life calendar and trajectories were constructed using sequence analysis. Associations between employment trajectories and self-reported cancer were assessed using logistic regression. We identified eight employment trajectories for women and two for men. Among women, the risk of cancer was higher in the trajectories "Mainly full-time to home/family", "Full-time or home/family to part-time", "Mainly full-time", and "Other" compared with the "Mainly home/family" trajectory. Among men, the risk of cancer was lower in the "Mainly self-employment" trajectory compared with "Mainly full-time". We could show how employment trajectories were associated with cancer risk, underlining the potential of sequence analysis for life course epidemiology. More research is needed to understand these associations and determine if causal relationships exist.

Endocrine Health and Health Care Disparities in the Pediatric and Sexual and Gender Minority Populations: An Endocrine Society Scientific Statement

Endocrine care of pediatric and adult patients continues to be plagued by health and health care disparities that are perpetuated by the basic structures of our health systems and research modalities, as well as policies that impact access to care and social determinants of health. This scientific statement expands the Society's 2012 statement by focusing on endocrine disease disparities in the pediatric population and sexual and gender minority populations. These include pediatric and adult lesbian, gay, bisexual, transgender, queer, intersex, and asexual (LGBTQIA) persons. The writing group focused on highly prevalent conditions-growth disorders, puberty, metabolic bone disease, type 1 (T1D) and type 2 (T2D) diabetes mellitus, prediabetes, and obesity. Several important findings emerged. Compared with females and non-White children, non-Hispanic White males are more likely to come to medical attention for short stature. Racially and ethnically diverse populations and males are underrepresented in studies of pubertal development and attainment of peak bone mass, with current norms based on European populations. Like adults, racial and ethnic minority youth suffer a higher burden of disease from obesity, T1D and T2D, and have less access to diabetes treatment technologies and bariatric surgery. LGBTQIA youth and adults also face discrimination and multiple barriers to endocrine care due to pathologizing sexual orientation and gender identity, lack of culturally competent care providers, and policies. Multilevel interventions to address these disparities are required. Inclusion of racial, ethnic, and LGBTQIA populations in longitudinal life course studies is needed to assess growth, puberty, and attainment of peak bone mass. Growth and development charts may need to be adapted to non-European populations. In addition, extension of these studies will be required to understand the clinical and physiologic consequences of interventions to address abnormal development in these populations. Health policies should be recrafted to remove barriers in care for children with obesity and/or diabetes and for LGBTQIA children and adults to facilitate comprehensive access to care, therapeutics, and technological advances. Public health interventions encompassing collection of accurate demographic and social needs data, including the intersection of social determinants of health with health outcomes, and enactment of population health level interventions will be essential tools.

Childhood Family Environment and Osteoporosis in a Population-Based Cohort Study of Middle-to Older-Age Americans

Demographic and early-life socioeconomic and parental investment factors may influence later-life health and development of chronic and progressive diseases, including osteoporosis, a costly condition common among women. The "long arm of childhood" literature links negative early-life exposures to lower socioeconomic attainment and worse adult health. We build on a small literature linking childhood socioeconomic status (SES) and bone health, providing evidence of whether associations exist between lower childhood SES and maternal investment and higher risk of osteoporosis diagnosis. We further examine whether persons identifying with non-White racial/ethnic groups experience underdiagnosis. Data from the nationally representative, population-based cohort Health and Retirement Study (N = 5,490-11,819) were analyzed for participants ages 50-90 to assess these relationships. Using a machine learning algorithm, we estimated seven survey-weighted logit models. Greater maternal investment was linked to lower odds of osteoporosis diagnosis (odds ratio [OR] = 0.80, 95% confidence interval [CI] = 0.69, 0.92), but childhood SES was not (OR = 1.03, 95% CI = 0.94, 1.13). Identifying as Black/African American (OR = 0.56, 95% CI = 0.40, 0.80) was associated with lower odds, and identifying as female (OR = 7.22, 95% CI = 5.54, 9.40) produced higher odds of diagnosis. There were differences in diagnosis across intersectional racial/ethnic and sex identities, after accounting for having a bone density scan, and a model predicting bone density scan receipt demonstrated unequal screening across groups. Greater maternal investment was linked to lower odds of osteoporosis diagnosis, likely reflecting links to life-course accumulation of human capital and childhood nutrition. There is some evidence of underdiagnosis related to bone density scan access. Yet results demonstrated a limited role for the long arm of childhood in later-life osteoporosis diagnosis. Findings suggest that (1) clinicians should consider life-course context when assessing osteoporosis risk and (2) diversity, equity, and inclusivity training for clinicians could improve health equity. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Retrospective reports of socioeconomic disadvantage in childhood and mortality risk: are associations consistent across measures and sex?

Although prior research has established associations between childhood socioeconomic disadvantage and all-cause mortality, there is still limited research investigating (1) the consistency between subjective and objective reports of childhood socioeconomic status, (2) sex differences in the associations between childhood socioeconomic disadvantage and all-cause mortality, and (3) potential mediators within these associations. Drawing on data from the Midlife in the United States (MIDUS) cohort (N = 7425), we examined the associations between three distinct indicators of childhood socioeconomic disadvantage and all-cause mortality risk, and whether these associations differ for males and females. Among males only, lower perceived relative childhood financial status, lower levels of parents' education, and receipt of welfare during childhood were associated with excess mortality risk, adjusted for age and minority status, with adjusted hazard ratios ranging from 1.24 (95% confidence interval (CI): 1.02, 1.51) for perceived childhood financial status to 1.28 (95% CI: 1.11, 1.47) for welfare in childhood. When additionally adjusted for education, substance use, depression, and underlying health conditions, only childhood welfare status maintained an association with mortality (AHR, 1.17; 95% CI, 1.02-1.35). Mediation analyses among males revealed that education, substance use, depression, and underlying health conditions accounted for substantial proportions of these associations, ranging from 31.03 to 57.63%, across indicators of childhood socioeconomic disadvantage. Future research is needed to clarify the developmental mechanisms that lead to sex differences and identify effective strategies to intervene on the relation between childhood socioeconomic position and excess mortality risk among males.

Structural Inequity and Socioeconomic Status Link to Osteoporosis Diagnosis in a Population-Based Cohort of Middle-Older-Age Americans

Socioeconomic status (SES) is an important social determinant of health inequities that has been linked to chronic conditions, including osteoporosis, but research tends to focus on socioeconomic disadvantage rather than how socioeconomic advantage may facilitate these inequities. This study accounts for structural inequities and assesses the relationship between early-life and later-life SES, and risk of osteoporosis diagnosis. Data come from the nationally representative, population-based cohort Health and Retirement Study and include individuals ages 50 to 90. The outcome variable is osteoporosis diagnosis. Logistic regression models of the relationship between SES and osteoporosis diagnosis are estimated, accounting for demographic, health, and childhood variables. Higher levels of childhood and adult SES link to lower odds of osteoporosis diagnosis. Structural inequities in income and underdiagnosis of osteoporosis among persons identifying as Black/African American were detected. Accounting for bone density scan access, inequities in osteoporosis diagnosis appear to stem from barriers to accessing health care due to financial constraints. The important role of SES and evidence of structural inequities leading to underdiagnosis suggest the critical importance of clinicians receiving Diversity, Equity, and Inclusion training to reduce health inequities.

Socioeconomic status influences on bone mineral density in American men: findings from NHANES 2011-2020

The association between socioeconomic status (SES) and bone mineral density (BMD) in men remains controversial. We showed that SES was positively associated with BMD in American men. Confounding factors like race/ethnicity and age could affect the association.

INTRODUCTION

Based on the data from the National Health and Nutrition Examination Survey (NHANES), 2011-2020, this article aims to investigate the association of SES (poverty income ratio (PIR) and education level) with the BMD in American men.

METHODS

We evaluated the association of SES with BMD in 4446 men aged ≥ 20 years (mean age, 41.0 ± 13.4 years) from the NHANES 2011-2020. BMD was measured by dual-energy X-ray absorptiometry (DXA) at the lumbar spine. We used multivariate linear regression models to examine the relationship between SES and total spine BMD, adjusted for a large range of confounding factors.

RESULTS

Compared with other PIR quarters, individuals in the highest quarter of PIR were more likely to be older and white and had fewer smoking or drinking behaviors. After adjusting for race/ethnicity, age, drinking and smoking behavior, body mass index (BMI), total protein, serum calcium, serum uric acid, cholesterol, serum phosphorus, and blood urea nitrogen, PIR was positively correlated with total spine BMD (β = 0.004 95% CI: 0.001-0.007, P = 0.006). Individuals with the highest degree (college degree or above) had a 0.057 g/cm² greater BMD than that of the lowest degree (less than 9th grade) (β = 0.057 95% CI: 0.037-0.077, P < 0.001).

CONCLUSIONS

Our study indicates that SES was positively associated with the lumbar BMD among American men. Clinicians, healthcare providers, and policymakers should consider the unequal SES of men when implementing osteoporosis prevention and treatment strategies.

Atopic Eczema-Associated Fracture Risk and Oral Corticosteroids: A Population-Based Cohort Study

BACKGROUND

Evidence suggests adults with atopic eczema have increased fracture risk. However, it is unclear whether oral corticosteroids explain the association.

OBJECTIVE

To assess to what extent oral corticosteroids mediate the relationship between atopic eczema and fractures.

METHODS

We conducted a cohort study using English primary care (Clinical Practice Research Datalink) and hospital admissions (Hospital Episode Statistics) records (1998-2016) including adults (18 years old and older) with atopic eczema matched (age, sex, and general practice) with up to 5 adults without atopic eczema. We used Cox regression to estimate hazard ratios (HRs) for specific major osteoporotic fractures (hip, spine, pelvis, or wrist) and for any-site fracture comparing individuals with atopic eczema with those without, adjusting for 6 different definitions of time-updated oral corticosteroid use (ever any prescription, ever high-dose, and recent, cumulative, current, or peak dose).

RESULTS

We identified 526,808 individuals with atopic eczema and 2,569,030 without. We saw evidence of an association between atopic eczema and major osteoporotic fractures (eg, spine HR 1.15, 99% CI 1.08-1.22; hip HR 1.11, 99% CI 1.08-1.15) that remained after additionally adjusting for oral corticosteroids (eg, cumulative corticosteroid dose: spine HR 1.09, 99% CI 1.03-1.16; hip HR 1.09, 99% CI 1.06-1.12). Fracture rates were higher in people with severe atopic eczema than in people without even after adjusting for oral corticosteroids (eg, spine HR [99% CI]: confounder-adjusted 2.31 [1.91-2.81]; additionally adjusted for cumulative dose 1.71 [1.40-2.09]).

CONCLUSIONS

Our findings suggest that little of the association between atopic eczema and major osteoporotic fractures is explained by oral corticosteroid use.

Assessing the roles of demographic, social, economic, environmental, health-related, and political factors on risk of osteoporosis diagnosis among older adults

Chronic stress from social/environmental pressures has been proposed to affect bone health through increased inflammation. We demonstrate that inflammation from prolonged stress does not cause changes to bone health through inflammation but instead impacts access to health care, social inequalities, and overall health, which in turn impact bone health.

PURPOSE

The study provides a comprehensive assessment of how determinants of health across demographic, psychological, mobility-related, health, environmental, and economic domains are associated with the diagnosis of osteoporosis and tests three hypotheses: (1) a diverse set of variables across domains will predict osteoporosis, (2) chronic inflammation as a result of stress (represented by high-sensitivity C-reactive protein) will not be associated with osteoporosis, and (3) the model developed will have high accuracy in predicting osteoporosis.

METHODS

Logistic regression and Cox proportional hazards models of osteoporosis diagnosis were estimated using data from 14,792 and 13,169 participants (depending on model) in the 2012-2016 waves of the Health and Retirement Study, including the Biomarker Study, the Contextual Data Resource, and validated measures of childhood socioeconomic status. Predictive accuracy was assessed using k-Nearest Neighbors Discriminant Analysis.

RESULTS

Demographic, environmental, and health-related factors were associated with osteoporosis diagnosis, and predictive accuracy of the models was good. High-sensitivity C-reactive protein was not associated with osteoporosis diagnosis.

CONCLUSION

Social determinants identified indicate access to health care, inequalities in the greater social environment (e.g., access to resources), and overall health (i.e., underlying medical conditions) are key components for developing osteoporosis and indicate underlying health inequities in this sample. There is a need to further address the interplay between primary health care and social determinants of health.

Increase in Epinephrine Administration for Food-Induced Anaphylaxis in Pediatric Emergency Departments from 2007 to 2015

BACKGROUND

Epinephrine is underused in the treatment of anaphylaxis, despite being the first-line treatment, which reflects the challenges in diagnosing anaphylaxis and understanding the appropriate therapy.

OBJECTIVE

To describe trends in epinephrine administration for patients visiting the pediatric emergency department (ED) with food-induced anaphylaxis (FIA) from 2007 to 2015.

METHODS

This retrospective cohort study included children 0 to 17 years of age with FIA from 46 children's hospitals in the United States between 2007 and 2015. Multivariable regression was used to identify factors associated with epinephrine administration.

RESULTS

A total of 15,318 cases of FIA cases were seen in the pediatric EDs from 2007 to 2015. Among these ED visits, 7,600 (49.6%) had at least 1 dose of epinephrine administered in the ED. Administration of epinephrine for anaphylaxis in the pediatric ED increased by 4% each year (odds ratio [OR] 1.04; 95% CI 1.03-1.05; P < .001). Sensitivity analysis by census region demonstrated that hospitals in the Northeast and the West were associated with an increase in epinephrine administration per year (Northeast OR 1.18, 95% CI 1.13-1.22, P < .001; West OR 1.14, 95% CI 1.10-1.18, P < .001).

CONCLUSIONS

Epinephrine administration for FIA in the pediatric ED has increased over time, reflecting the need for continued advocacy for the optimal management of FIA. Further research is warranted to identify optimal strategies for proper recognition and early administration of epinephrine for anaphylaxis.

Factors influencing peak bone mass gain

Bone mass is a key determinant of osteoporosis and fragility fractures. Epidemiologic studies have shown that a 10% increase in peak bone mass (PBM) at the population level reduces the risk of fracture later in life by 50%. Low PBM is possibly due to the bone loss caused by various conditions or processes that occur during adolescence and young adulthood. Race, gender, and family history (genetics) are responsible for the majority of PBM, but other factors, such as physical activity, calcium and vitamin D intake, weight, smoking and alcohol consumption, socioeconomic status, age at menarche, and other secondary causes (diseases and medications), play important roles in PBM gain during childhood and adolescence. Hence, the optimization of lifestyle factors that affect PBM and bone strength is an important strategy to maximize PBM among adolescents and young people, and thus to reduce the low bone mass or osteoporosis risk in later life. This review aims to summarize the available evidence for the common but important factors that influence bone mass gain during growth and development and discuss the advances of developing high PBM.

Childhood socioeconomic status, comorbidity of chronic kidney disease risk factors, and kidney function among adults in the midlife in the United States (MIDUS) study

Background

There is a lack of empirical effort that systematically investigates the clustering of comorbidity among known risk factors (obesity, hypertension, diabetes, hypercholesterolemia, and elevated inflammation) of chronic kidney disease (CKD) and how different types of comorbidity may link differently to kidney function among healthy adult samples. This study modeled the clustering of comorbidity among risk factors, examined the association between the clustering of risk factors and kidney function, and tested whether the clustering of risk factors was associated with childhood SES.

Methods

The data were from 2118 participants (ages 25–84) in the Midlife in the United States (MIDUS) Study. Risk factors included obesity, elevated blood pressure (BP), high total cholesterol levels, poor glucose control, and increased inflammatory activity. Glomerular filtration rate (eGFR) was estimated from serum creatinine, calculated with the CKD-EPI formula. The clustering of comorbidity among risk factors and its association with kidney function and childhood SES were examined using latent class analysis (LCA).

Results

A five-class model was optimal: (1) Low Risk (class size = 36.40%; low probability of all risk factors), (2) Obese (16.42%; high probability of large BMI and abdominally obese), (3) Obese and Elevated BP (13.37%; high probability of being obese and having elevated BP), (4) Non-Obese but Elevated BP (14.95%; high probability of having elevated BP, hypercholesterolemia, and elevated inflammation), and (5) High Risk (18.86%; high probability for all risk factors). Obesity was associated with kidney hyperfiltration, while comorbidity between obesity and hypertension was linked to compromised kidney filtration. As expected, the High Risk class showed the highest probability of having eGFR < 60 ml/min/1.73 m² (P = .12; 95%CI = .09–.17). Finally, higher childhood SES was associated with reduced probability of being in the High Risk rather than Low Risk class (β = − 0.20, SE = 0.07, OR [95%CI] = 0.82 [0.71–0.95]).

Conclusion

These results highlight the importance of considering the impact of childhood SES on risk factors known to be associated with CKD.

Secular decline in limb bone strength among South African Africans during the 19th and 20th centuries

OBJECTIVES

South African Africans have been reported to have experienced negative or null secular trends in stature and other measures of skeletal structure across the 19th and 20th centuries, presumably due to poor living conditions during a time of intensifying racial discrimination. Here, we investigate whether any secular trend is apparent in limb bone strength during the same period.

MATERIALS AND METHODS

Cadaver-derived skeletons (n = 221) were analyzed from female and male South African Africans who were born between 1839 and 1970, lived in and around Johannesburg, and died between 1925 and 1991 when they were 17-90 years of age. For each skeleton, a humerus and femur were scanned using computed tomography, and mid-diaphyseal cross-sectional geometric properties were calculated and scaled according to body size.

RESULTS

In general linear mixed models accounting for sex, age at death, and skeletal element, year of birth was a significant (p < .05) negative predictor of size-standardized mid-diaphyseal cortical area (a proxy for resistance to axial loading) and polar moment of area (a proxy for resistance to bending and torsion), indicating a temporal trend toward diminishing limb bone strength. No significant interactions were detected between year of birth and age at death, suggesting that the decline in limb bone strength was mainly due to changes in skeletal maturation rather than severity of age-related bone loss.

DISCUSSION

Limb bone strength is thus potentially another feature of the skeletal biology of South African Africans that was compromised by poor living conditions during the 19th and 20th centuries.

Factors associated with bone mineral content in adults: a population-based study

OBJECTIVE

To determine the association among bone mineral content, sociodemographic, anthropometric and behavioral factors, and health status of Brazilian adults.

METHODS

This was a cross-sectional, population-based study including 701 individuals from both sexes aged between 20 and 59 years. DEXA was used to evaluate dependent variable. The associations were evaluated using linear regression models stratified by sex.

RESULTS

When mean bone mineral content values were compared, we found significant differences related to sex and all the independent variables evaluated. In the adjusted models, we identified an inverse association between bone mineral content and age in both sexes. Among men, to be overweight and/or obese, be highly educated, and have almost sufficiency of 25(OH)D were associated with higher bone mineral content values. On the other hand, among women, to be non-white skin color, overweight and/or obese were associated with better bone health. The main factors associated with low total bone mineral density were advanced age, white skin color, low level of formal education, eutrophy, and 25(OH)D deficiency.

CONCLUSION

Our results may help to identify adults who are at higher risk, and these findings should be used as guidelines for prevention and early diagnosis.

Levels of Knowledge, Beliefs, and Practices Regarding Osteoporosis and the Associations with Bone Mineral Density among Populations More Than 40 Years Old in Malaysia

Osteoporosis is a skeletal disorder commonly found among the elderly, in which the bones become weak, brittle, and more susceptible to fracture. Adequate knowledge and positive attitude towards the disease and osteoprotective activities may prevent osteoporosis, but comprehensive studies to verify this hypothesis are limited in Malaysia. This study aims to bridge the research gap by determining the levels of knowledge, beliefs, and practices regarding osteoporosis and their associations with bone mineral density (BMD) among men and women ≥ 40 years in Klang Valley, Malaysia. In this cross-sectional study, 786 Malaysians (382 men, 404 women) completed a questionnaire on knowledge, beliefs, and osteoprotective practices, and underwent BMD scan using a dual-energy X-ray absorptiometry device. The current study found moderate levels of knowledge and beliefs regarding osteoporosis but poor osteoprotective practices. Osteoporosis knowledge, beliefs, and practices were significantly different based on subjects' demographic characteristics (p < 0.05). Osteoporosis knowledge and beliefs were correlated significantly with osteoprotective practices (p < 0.05). Bone health status of the subjects was associated positively with calcium supplement intake, and negatively with exercise barriers and smoking status of the subjects (p < 0.05). However, no significant correlation was noted between osteoporosis knowledge and bone health (p > 0.05). Conclusively, despite some correlations between individual components, the detachment between bone health knowledge and beliefs, and osteoprotective practices among Malaysians is apparent. Integrating all three components into a comprehensive osteoporosis prevention program is warranted.

Bone mineral density, vitamin D status, and calcium intake in healthy female university students from different socioeconomic groups in Turkey

Peak bone mass is reached in late adolescence. Low peak bone mass is a well recognized risk factor for osteoporosis later in life. Our data do not support a link between vitamin D status, bone mineral density (BMD), and socioeconomic status (SES). However, there was a marked inadequacy of daily calcium intake and a high presence of osteopenia in females with low SES.

PURPOSE

Our aims were to (1) examine the effects of different SES on BMD, vitamin D status, and daily calcium intake and (2) investigate any association between vitamin D status and BMD in female university students.

SUBJECTS AND METHODS

A questionnaire was used to obtain information about SES, daily calcium intake, and physical activity in 138 healthy, female university students (age range 18-22 years). Subjects were stratified into lower, middle, and higher SES according to the educational and occupational levels of their parents. All serum samples were collected in spring for 25-hydroxyvitamin D concentration (25OHD). Lumbar spine and total body BMD was obtained by dual-energy X-ray absorptiometry (DXA) scan (Lunar DPX series). Osteopenia was defined as a BMD between - 1.0 and - 2.5 standard deviations (SDs) below the mean for healthy young adults on lumbar spine DXA.

RESULTS

No significant difference was found between the three socioeconomic groups in terms of serum 25OHD concentration, BMD levels, or BMD Z scores (p > 0.05). Both the daily intake of calcium was significantly lower (p = 0.02), and the frequency of osteopenia was significantly higher in girls with low SES (p = 0.02). There was no correlation between serum 25OHD concentration and calcium intake and BMD values and BMD Z scores (p > 0.05). The most important factor affecting BMD was weight (β = 0.38, p < 0.001).

CONCLUSIONS

Low SES may be associated with sub-optimal bone health and predispose to osteopenia in later life, even in female university students.

Socioeconomic status and bone mineral density in adults by race/ethnicity and gender: the Louisiana osteoporosis study

Low bone mineral density (BMD) and osteoporosis have become a public health problem. We found that non-Hispanic white, black, and Asian adults with extremely low education and personal income are more likely to have lower BMD. This relationship is gender-specific. These findings are valuable to guide bone health interventions.

INTRODUCTION

The evidence is limited regarding the relationship between socioeconomic status (SES) and bone mineral density (BMD) for minority populations in the USA, as well as the relationship between SES and BMD for men. This study explored and examined the relationship between SES and BMD by race/ethnicity and gender.

METHODS

Data (n = 6568) from the Louisiana Osteoporosis Study (LOS) was examined, including data for non-Hispanic whites (n = 4153), non-Hispanic blacks (n = 1907), and non-Hispanic Asians (n = 508). General linear models were used to estimate the relationship of SES and BMD (total hip and lumbar spine) stratified by race/ethnicity and gender. Adjustments were made for physiological and behavioral factors.

RESULTS

After adjusting for covariates, men with education levels below high school graduate experienced relatively low hip BMD than their counterparts with college or graduate education (p < 0.05). In addition, women reporting a personal annual income under $20,000 had relatively low hip and spine BMD than their counterparts with higher income level(s) (p < 0.05).

CONCLUSIONS

Establishing a conclusive positive or negative association between BMD and SES proved to be difficult. However, individuals who are at an extreme SES disadvantage are the most vulnerable to have relatively low BMD in the study population. Efforts to promote bone health may benefit from focusing on men with low education levels and women with low individual income.

Bone Mineral Density in the Noninstitutionalized Elderly: Influence of Sociodemographic and Anthropometric Factors

Objective. Analysis of bone mineral density (BMD) in the elderly and its associated factors according to sex. Methods. A cross-sectional study is presented herein, with a random sample of 132 noninstitutionalized elderly people. Individuals who did not use diuretics were excluded. BMD was obtained from examination of total body densitometry and its association with sociodemographic variables, lifestyle, anthropometric, and body composition was verified. Results. Mean BMD for men was 1.17 ± 0.12 g/cm(2) and for women was 1.04 ± 0.11 g/cm(2). Higher education was associated with higher BMD values in men (p < 0.05). There was a reduction in BMD in the age group 75-79 years of age in women and over 80 years of age in men (p < 0.05). Underweight was associated with significantly low BMD for both sexes (p < 0.01), while normal weight was associated with low BMD in women (p < 0.001). Discussion. The elderly with low schooling and in older age groups are more probable to also present low BMD. Lower levels of body mass index also indicated towards low BMD.

Oral health behaviors and bone mineral density in South Korea: the 2008-2010 Korean National Health and Nutrition Examination Survey

The purpose of this study was to examine the association between oral health behaviors and bone mineral density (BMD) by using data from the Korean National Health and Nutrition Examination Survey conducted in 2008-2010. We included 6,620 subjects (3,140 men aged more than 50 years and 3,480 postmenopausal women). BMD was measured at three sites-namely, the lumbar spine, total femur, and femur neck. Oral health behaviors were assessed by use of a self-administered questionnaire in the Korean National Health and Nutrition Examination Survey. After adjustment for all covariates, BMD of the lumbar spine and femur neck tended to increase as the frequency of tooth brushing increased in men (p trend = 0.020 and p trend = 0.028, respectively). Women using secondary oral products had increased lumbar spine BMD compared with women who did not use secondary oral products. However, after adjustment for all covariates, no significant relationship was observed between BMD and the use of secondary oral products. As the frequency of tooth brushing and the number of secondary oral products used increased, the prevalence of osteoporosis decreased. The frequency of tooth brushing is associated with increased lumbar spine and femur neck BMD in South Korean men.

Bone health and its correlates in Korean prostate cancer patients receiving androgen deprivation therapy

PURPOSE

This study aimed to examine bone health status, identify factors associated with bone mineral density (BMD), and determine potential risk factors for osteoporosis in Korean prostate cancer patients receiving androgen deprivation therapy (ADT).

METHODS

Using a cross-sectional descriptive design, we recruited 139 men with prostate cancer receiving ADT at two university-based hospitals in South Korea. Participants completed a self-reported questionnaire and underwent dual energy X-ray absorptiometry testing. BMD (gm/cm(2)), bone health status (normal BMD, osteopenia, and osteoporosis), and lifestyle variables (physical activity, smoking, and alcohol consumption) were measured.

RESULTS

The prevalence in our sample was 49.6% for osteopenia and 17.3% for osteoporosis. In multivariate linear regression analyses, BMD was positively associated with body mass index, number of comorbidities, and level of physical activity and negatively associated with being unemployed or retired, having a lower monthly income, and being treated with gonadotropin-releasing hormone therapy alone. In logistic regression analyses, potential risk factors for osteoporosis were low monthly income (OR = 4.33, p = 0.011), receipt of radiation therapy (OR = 4.69, p = 0.018), and lack of regular physical activity (OR = 2.63, p = 0.035).

CONCLUSIONS

Our results suggest that a proportion of prostate cancer survivors who are receiving ADT warrant monitoring to prevent osteoporosis, particularly men of lower economic status and those having lower levels of physical activity. Nurses can play an important role in screening these high risk groups.

Socioeconomic disparities in osteoporosis prevalence: different results in the overall Korean adult population and single-person households

OBJECTIVES

The present study was conducted in order to examine the association between socioeconomic status (SES) and osteoporosis prevalence in Korea and to assess whether different associations are found in single-person households.

METHODS

A cross-sectional population-based study was conducted using the Korea National Health and Nutrition Examination Survey, from 2008 to 2011. The study subjects were people aged ≥ 50 years with osteoporosis as defined by bone mineral density. Multivariate logistic models were used to estimate prevalence odds ratios (pORs) and 95% confidence intervals (CIs). Gender differences in the likelihood of osteoporosis were analyzed based on household income, education level, and residential area.

RESULTS

There were 8221 osteoporosis patients aged ≥ 50 years, of whom 927 lived in single-person households. There was a gender-specific association between osteoporosis prevalence and all three SES factors that we analyzed: income, education, and residential area. After adjusting for age, SES, and health behaviors, including body mass index (BMI), low household income was only significantly associated with osteoporosis in men, whereas education level had an inverse relationship with osteoporosis only in women (p = 0.01, p < 0.001, respectively). However, after controlling for age and BMI, rural residency was only associated with osteoporosis in women living in single-person households (pOR, 1.59; 95% CI, 1.05 to 2.43).

CONCLUSIONS

The Korean adult population showed a gender-specific relationship between SES and osteoporosis prevalence, with a different pattern found in single-person households.

Adult bone strength of children from single-parent families: the Midlife in the United States Study

Bone health may be negatively impacted by childhood socio-environmental circumstances. We examined the independent associations of single-parent childhood and parental death or divorce in childhood with adult bone strength indices. Longer exposure to a single-parent household in childhood was associated with lower bone strength in adulthood.

INTRODUCTION

Because peak bone mass is acquired during childhood, bone health may be negatively impacted by childhood socio-environmental disadvantage. The goal of this study was to determine whether being raised in a single-parent household is associated with lower bone strength in adulthood.

METHODS

Using dual-energy X-ray absorptiometry data from 708 participants (mean age 57 years) in the Midlife in the United States Biomarker Project, we examined the independent associations of composite indices of femoral neck bone strength relative to load (in three failure modes: compression, bending, and impact) in adulthood with the experience of single-parent childhood and parental death or divorce in childhood.

RESULTS

After adjustment for gender, race, menopause transition stage, age, and body mass index, each additional year of single-parent childhood was associated with 0.02 to 0.03 SD lower indices of adult femoral neck strength. In those with 9-16 years of single-parent childhood, the compression strength index was 0.41 SD lower, bending strength index was 0.31 SD lower, and impact strength index was 0.25 SD lower (all p values < 0.05). In contrast, parental death or divorce during childhood was not by itself independently associated with adult bone strength indices. The magnitudes of these associations were unaltered by additional adjustment for lifestyle factors and socioeconomic status in childhood and adulthood.

CONCLUSIONS

Independent of parental death or divorce, growing up in a single-parent household is associated with lower femoral neck bone strength in adulthood, and this association is not entirely explained by childhood or adult socioeconomic conditions or lifestyle choices.

Early life adversity and adult biological risk profiles

OBJECTIVES

To determine whether there is a relationship between early life adversity (ELA) and biological parameters known to predict health risks and to examine the extent to which circumstances in midlife mediate this relationship.

METHODS

We analyzed data on 1180 respondents from the biomarker subsample of the second wave of the National Survey of Midlife Development in the United States. ELA assessments were based on childhood socioeconomic disadvantage (i.e., on welfare, perceived low income, and less educated parents) and other stressors (e.g., parental death, parental divorce, and parental physical abuse). The outcome variable was cumulative allostatic load (AL), a marker of biological risk. We also incorporate information on adult circumstances, including than following: education, social relationships, and health behaviors.

RESULTS

Childhood socioeconomic adversity and physical abuse were associated with increased AL (B = 0.094, standard error = 0.041, and B = 0.263, standard error = 0.091 respectively), with nonsignificant associations for parental divorce and death with AL. Adult education mediated the relationship between socioeconomic ELA and cumulative AL to the point of nonsignificance, with this factor alone explaining nearly 40% of the relationship. The association between childhood physical abuse and AL remained even after adjusting for adult educational attainments, social relationships, and health behaviors. These associations were most pronounced for secondary stress systems, including inflammation, cardiovascular function, and lipid metabolism.

CONCLUSIONS

The physiological consequences of early life socioeconomic adversity are attenuated by achieving high levels of schooling later on. The adverse consequences of childhood physical abuse, on the other hand, persist in multivariable-adjusted analysis.

Racial/ethnic and socioeconomic differences in bone loss among men

As men age, they lose bone and are susceptible to fracture. Despite having lower fracture rates than women, men have worse fractures than women do. Racial/ethnic and socioeconomic status (SES) disparities in fracture rates exist, yet data on rates of bone loss by race/ethnicity and SES among men are limited. We examined annualized percentage change in bone mineral density (%ΔBMD) at the hip (N = 681), spine (N = 663), and forearm (N = 636) during 7 years of follow-up among men aged 30-79 years at baseline. Multivariable models tested whether race/ethnicity, income, or genetic ancestry predicted annualized %ΔBMD after controlling for an extensive set of covariates. Annualized %ΔBMD ranged from -0.65(0.04)% (femoral neck) to +0.26(0.03)% (1/3 distal radius), and changes were consistent across age groups with the exception of the ultradistal radius, where annualized declines increased with age. Neither self-identified race/ethnicity nor genetic ancestry were associated with annualized %ΔBMD. In contrast, income was strongly associated (dose-response) with annualized %ΔBMD at total hip (independent of confounders, self-identified race/ethnicity, and genetic ancestry). Fully adjusted least-square mean change in annualized %ΔBMD at the total hip were -0.24(0.12)% and -0.16(0.06)% steeper among men with low and moderate incomes, respectively, than among men with higher incomes (overall p = 0.0293). Results show a linear decline in bone that begins relatively early in life among men, that rates of bone loss do not vary with race/ethnicity (self-identified or "objectively" measured), and that income plays an important role in relation to bone loss at the hip. These data suggest that fracture risk in men may be driven in part by income-related differences in bone loss, but also, that the known higher fracture risk among white men is not the result of racial/ethnic differences in bone loss, but rather, early life exposures that lead to attainment of higher peak bone mass among minorities.

Multisystem dysregulation and bone strength: findings from the study of midlife in the United States

CONTEXT

Accumulated dysregulation across multiple physiological systems, or allostatic load (AL), has been proposed as the biological pathway from psychosocial adversity to poor health.

OBJECTIVE

The objective of the study was to examine whether AL, constructed using biomarkers and medication data from seven systems (sympathetic, parasympathetic, hypothalamic-pituitary-adrenal axis, cardiovascular regulation, inflammation, and lipid and glucose metabolism), is associated with lower bone strength in a national sample.

DESIGN

This was a cross-sectional study.

SETTING AND PARTICIPANTS

Seven hundred three community-dwelling men and women from the Study of Midlife in the United States participated in the study.

OUTCOME MEASURES

Bone mineral density (BMD) was measured in the femoral neck and lumbar spine. Femoral neck BMD was combined with bone size and body size to create composite indices of femoral neck strength relative to load in three failure modes: compression, bending, and impact.

RESULTS

In mixed-effects linear regression controlling for clustering within families and adjusted for age, gender, race/ethnicity, body mass index, menopausal transition stage, childhood socioeconomic status, adult finances, education level, and study center, each SD increment in AL score was associated with between 0.10 and 0.11 SD decrements in lumbar spine BMD and each of the three composite strength indices (all values of P < .05). Gender modified the association of AL only with femoral neck BMD; each SD increment in AL score was associated with 0.21 SD decrement in femoral neck BMD in men (P < .01) but not in women.

CONCLUSIONS

Accumulation of dysregulation across systems was modestly associated with lower bone strength. This study adds to the accumulating evidence that multisystem dysregulation, or AL, predicts a variety of adverse health outcomes.

Insulin resistance and bone strength: findings from the study of midlife in the United States

Although several studies have noted increased fracture risk in individuals with type 2 diabetes mellitus (T2DM), the pathophysiologic mechanisms underlying this association are not known. We hypothesize that insulin resistance (the key pathology in T2DM) negatively influences bone remodeling and leads to reduced bone strength. Data for this study came from 717 participants in the Biomarker Project of the Midlife in the United States Study (MIDUS II). The homeostasis model assessment of insulin resistance (HOMA-IR) was calculated from fasting morning blood glucose and insulin levels. Projected 2D (areal) bone mineral density (BMD) was measured in the lumbar spine and left hip using dual-energy X-ray absorptiometry (DXA). Femoral neck axis length and width were measured from the hip DXA scans, and combined with BMD and body weight and height to create composite indices of femoral neck strength relative to load in three different failure modes: compression, bending, and impact. We used multiple linear regressions to examine the relationship between HOMA-IR and bone strength, adjusted for age, gender, race/ethnicity, menopausal transition stage (in women), and study site. Greater HOMA-IR was associated with lower values of all three composite indices of femoral neck strength relative to load, but was not associated with BMD in the femoral neck. Every doubling of HOMA-IR was associated with a 0.34 to 0.40 SD decrement in the strength indices (p<0.001). On their own, higher levels of fasting insulin (but not of glucose) were independently associated with lower bone strength. Our study confirms that greater insulin resistance is related to lower femoral neck strength relative to load. Further, we note that hyperinsulinemia, rather than hyperglycemia, underlies this relationship. Although cross-sectional associations do not prove causality, our findings do suggest that insulin resistance and in particular, hyperinsulinemia, may negatively affect bone strength relative to load.

Socioeconomic status in relation to incident fracture risk in the Study of Women's Health Across the Nation

We examined baseline and annual follow-up data (through annual follow-up visit 9) from a cohort of 2,234 women aged 42 to 52 years at baseline. Independent of financial status, higher educational level was associated with lower fracture incidence among non-Caucasian women but not among Caucasian women.

INTRODUCTION

This study was conducted to determine the associations of education and income with fracture incidence among midlife women over 9 years of follow-up.

METHODS

We examined baseline and annual follow-up data (through annual follow-up visit 9) from 2,234 participants of the Study of Women's Health Across the Nation, a cohort of women aged 42 to 52 years at baseline. We used Cox proportional hazards regression models to examine the associations of socioeconomic predictors (education, family-adjusted poverty-to-income ratio, and difficulty paying for basics) with time to first incident nontraumatic, nondigital, noncraniofacial fracture.

RESULTS

Independent of family-adjusted poverty-to-income ratio, higher educational level was associated with decreased time to first incident fracture among non-Caucasian women but not among Caucasian women (p(interaction) 0.02). Compared with non-Caucasian women who completed no more than high school education, non-Caucasian women who attained at least some postgraduate education had 87% lower rates of incident nontraumatic fracture (adjusted hazard ratio 0.13, 95% confidence interval [CI] 0.03-0.60). Among non-Caucasian women, each additional year of education was associated with a 16% lower odds of nontraumatic fracture (adjusted odds ratio 0.84, 95% CI 0.73-0.97). Income, family-adjusted poverty-to-income ratio, and degree of difficulty paying for basic needs were not associated with time to first fracture in Caucasian or non-Caucasian women.

CONCLUSIONS

Among non-Caucasian midlife women, higher education, but not higher income, was associated with lower fracture incidence. Elucidation of the mechanisms underlying the possible protective effects of higher educational level on nontraumatic fracture incidence may allow us to better target individuals at risk of future fracture.

Marital histories, marital support, and bone density: findings from the Midlife in the United States Study

We examined the association between marital life history and bone mineral density (BMD) in a national sample from the US. In men, being stably married was independently associated with better lumbar spine BMD, and in women, more spousal support was associated with better lumbar spine BMD.

INTRODUCTION

Adult bone mass may be influenced by stressors over the life course. We examined the association between marital life history and bone mineral density (BMD) net socioeconomic and behavioral factors known to influence bone mass. We sought evidence for a gender difference in the association between marital history and adult BMD.

METHODS

We used data from 632 adult participants in the Midlife in the United States Study to examine associations between marital history and BMD, stratified by gender, and adjusted for age, weight, menopausal stage, medication use, childhood socioeconomic advantage, adult financial status, education, physical activity, smoking, and alcohol consumption.

RESULTS

Compared to stably married men, men who were currently divorced, widowed, or separated, men who were currently married but previously divorced, widowed, or separated, and never married men had 0.33 (95% CI: 0.01, 0.65), 0.36 (95% CI: 0.10, 0.83), and 0.53 (95% CI: 0.23, 0.83) standard deviations lower lumbar spine BMD, respectively. Among men married at least once, every year decrement in age at first marriage (under age 25) was associated with 0.07 SD decrement in lumbar spine BMD (95% CI: 0.002, 0.13). In women, greater support from the spouse was associated with higher lumbar spine BMD.

CONCLUSIONS

Our findings suggest that marriage before age 25 and marital disruptions are deleterious to bone health in men, and that marital quality is associated with better bone health in women.

FRAX provides robust fracture prediction regardless of socioeconomic status

We investigated the fracture risk assessment tool (FRAX) Canada calibration and discrimination according to income quintile in 51,327 Canadian women, with and without a competing mortality framework. Our data show that, under a competing mortality framework, FRAX provides robust fracture prediction and calibration regardless of socioeconomic status (SES).

INTRODUCTION

FRAX® predicts 10-year fracture risk. Social factors may independently affect fracture risk. We investigated FRAX calibration and discrimination according to SES.

METHODS

Women aged ≥50 years with baseline femoral neck bone mineral density (BMD) were identified from the Manitoba Bone Density Program, Canada (n = 51,327), 1996-2011. Mean household income, extracted from 2006 census files, was categorized into quintiles. Ten-year fracture probabilities were calculated using FRAX Canada. Incident non-traumatic fractures were studied in relation to income quintile in adjusted Cox proportional hazards models. We compared observed versus predicted fractures with and without a competing mortality framework.

RESULTS

During mean 6.2 ± 3.7 years of follow up, there were 6,392 deaths, 3,723 women with ≥1 major osteoporotic fracture (MOF), and 1,027 with hip fractures. Lower income was associated with higher risk for death, MOF, and hip fracture in adjusted models (all p < 0.005). More women in income quintile 1 (lowest) versus quintile 5 experienced death (19 vs. 8%), MOF (10 vs. 6%), or hip fracture (3.0 vs. 1.3 %) (all p ≤ 0.001). Adjustment for competing mortality mitigated the effect of SES on FRAX calibration, and good calibration was observed. FRAX provided good fracture discrimination for MOF and hip fracture within each income quintile (all p < 0.001). Area under the curve was slightly lower for income quintiles 1 versus 5 for FRAX with BMD to predict MOF (0.68, 95% CI 0.66-0.70 vs. 0.71, 95% CI 0.69-0.74) and hip fracture (0.79, 95% CI 0.76-0.81 vs. 0.87, 95% CI 0.84-0.89).

CONCLUSION

Increased fracture risk in individuals of lower income is offset by increased mortality. Under a competing mortality framework, FRAX provides robust fracture prediction and calibration regardless of SES.

Childhood socioeconomic status and adult femoral neck bone strength: findings from the Midlife in the United States Study

PURPOSE

Bone acquisition in childhood impacts adult bone mass, and can be influenced by childhood socioeconomic conditions. Socioeconomic status is also associated with body weight which affects the load that bone is exposed to in a fall. We hypothesized that socioeconomic advantage in childhood is associated with greater bone strength relative to load in adulthood.

METHODS

Hip dual x-ray absorptiometry scans from 722 participants in the Midlife in the United States Study were used to measure femoral neck size and bone mineral density, and combined with body weight and height to create composite indices of femoral neck strength relative to load in different failure modes: compression, bending, and impact. A childhood socioeconomic advantage score was created for the same participants from parental education, self-rated financial status relative to others, and not being on welfare. Multiple linear regression was used to determine the association of childhood socioeconomic advantage with femoral neck composite strength indices, stratified by gender and race (white/non-white), and adjusted for study site, age, menopause status in women, education, and current financial advantage.

RESULTS

Childhood socioeconomic advantage was independently associated with higher indices of all three composite strength indices in white men (adjusted standardized effect sizes, 0.19 to 0.27, all p values<0.01), but not in the other three race/gender groups. Additional adjustment for adult obesity, physical activity in different life stages, smoking, and heavy drinking over the life-course significantly attenuated the associations in white men.

CONCLUSIONS

Socioeconomic disadvantage in childhood is associated with lower hip strength relative to load in white men, and these influences are dampened by healthy lifestyle choices.