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

Dietary Inflammatory Index and Fractures in Midlife Women: Study of Women's Health Across the Nation

CONTEXT

While evidence suggests that chronic, low-grade inflammation is a risk factor for bone loss and fractures, the potential relation between an inflammatory dietary profile and greater fracture risk is uncertain.

OBJECTIVE

We examined whether a more inflammatory diet, consumed during pre- and early perimenopause, is associated with more incident fractures starting in the menopause transition (MT) and continuing into postmenopause.

METHODS

Dietary inflammatory potential was quantified using 2 energy-adjusted dietary inflammatory index scores: one for diet only (E-DII), and one for diet plus supplements (E-DII-S). We included 1559 women from the Study of Women's Health Across the Nation, with E-DII and E-DII-S scores from the baseline visit (during pre- or early perimenopausal), and up to 20 years of follow-up. We excluded women using bone-beneficial medications at baseline; subsequent initiators were censored at first use. The associations of E-DII or E-DII-S (each tested as separate exposures) with incident fracture were examined using Cox proportional hazards regression.

RESULTS

Adjusted for age, BMI, cigarette use, diabetes, MT stage, race/ethnicity, prior fracture, bone-detrimental medication use, aspirin or nonsteroidal anti-inflammatory drug use, and study site, greater E-DII and E-DII-S (tested separately) were associated with more future fractures. Each SD increment in E-DII and E-DII-S predicted 28% (P = .005) and 21% (P = .02) greater fracture hazard, respectively. Associations were essentially unchanged after controlling for bone mineral density.

CONCLUSION

A more pro-inflammatory diet in pre- and early perimenopause is a risk factor for incident fracture. Future studies should consider whether reducing dietary inflammation in midlife diminishes fracture risk.

Ethnic determinants of skeletal health in female patients with fragility fracture in a culturally diverse population

Background

Low bone density leads to fragility fracture, with significant impact on morbidity and mortality. While ethnic differences in bone density have been observed in healthy subjects, this has not yet been explored in fragility fracture patients.

Aims

To assess if ethnicity is associated with bone mineral density and serum markers of bone health in female patients who experience fragility fractures.

Methods

219 female patients presenting with at least one fragility fracture at a major tertiary hospital in Western Sydney Australia were studied. Western Sydney is a region with great cultural diversity, comprising people from over 170 ethnicities. Within this cohort, the three largest broad ethnic groups were Caucasians (62.1 %), Asians (22.8 %), and Middle Eastern patients (15.1 %). Location and nature of the presenting fracture and other relevant past medical history were obtained. Bone mineral density, measured by dual-energy X-ray absorptiometry, and bone-related serum markers were compared between ethnicities. Covariates (age, height, weight, diabetes, smoking, and at-risk drinking) were adjusted in multiple linear regression model.

Results

Although Asian ethnicity was associated with lower bone mineral density at the lumbar spine in fragility fracture patients, this association was no longer significant after adjustment for weight. Ethnicity (Asian or Middle Eastern) was not a determinant of bone mineral density at any other skeletal site. Caucasians had lower estimated glomerular filtration rate compared to Asian and Middle Eastern subjects. Serum parathyroid hormone concentrations were significantly lower in Asians compared to other ethnicities.

Conclusion

Asian ethnicity and Middle Eastern ethnicity were not major determinants of bone mineral density at the lumbar spine, femoral neck, or total hip.

Socio-economic inequalities in fragility fracture incidence: a systematic review and meta-analysis of 61 observational studies

Individuals with low socio-economic status (SES) have a more than 25% higher risk of fragility fractures than individuals with high SES. Body mass index and lifestyle appear to mediate the effect of SES on fracture risk. Strategies to prevent fractures should aim to reduce unhealthy behaviours through tackling structural inequalities.

INTRODUCTION

This systematic review and meta-analysis aimed to evaluate the impact of socio-economic status (SES) on fragility fracture risk.

METHODS

Medline, Embase, and CINAHL databases were searched from inception to 28 April 2021 for studies reporting an association between SES and fragility fracture risk among individuals aged ≥50 years. Risk ratios (RR) were combined in meta-analyses using random restricted maximum likelihood models, for individual-based (education, income, occupation, cohabitation) and area-based (Index of Multiple Deprivation, area income) SES measures.

RESULTS

A total of 61 studies from 26 different countries including more than 19 million individuals were included. Individual-based low SES was associated with an increased risk of fragility fracture (RR 1.27 [95% CI 1.12, 1.44]), whilst no clear association was seen when area-based measures were used (RR 1.08 [0.91, 1.30]). The strength of associations was influenced by the type and number of covariates included in statistical models: RR 2.69 [1.60, 4.53] for individual-based studies adjusting for age, sex and BMI, compared with RR 1.06 [0.92, 1.22] when also adjusted for health behaviours (smoking, alcohol, and physical activity). Overall, the quality of the evidence was moderate.

CONCLUSION

Our results show that low SES, measured at the individual level, is a risk factor for fragility fracture. Low BMI and unhealthy behaviours are important mediators of the effect of SES on fracture risk. Strategies to prevent fractures and reduce unhealthy behaviours should aim to tackle structural inequalities in society thereby reducing health inequalities in fragility fracture incidence.

Systematic review of major osteoporotic fracture to hip fracture incidence rate ratios worldwide: implications for Fracture Risk Assessment Tool (FRAX)-derived estimates

The Fracture Risk Assessment Tool (FRAX) is the most widely used tool for fracture prediction. It provides 10-year probabilities for hip and major osteoporotic fracture (MOF). It uses country-specific hip fracture incidence and life expectancy data, and for most countries, MOF/hip fracture incidence rate ratios (IRRs) from Malmo Sweden. However, the risk of MOF varies by age, sex, and geography. The objective is to compare the MOF/hip IRRs across countries, by sex and age. This systematic review targeted observational studies of MOF and hip fractures in individuals >50 years (PROSPERO 2019 CRD42019129259). One reviewer screened potential articles. Two reviewers completed duplicate and independent data abstraction, and assessed study quality based on population representativeness, study design and duration, definition of ethnicity, and fracture characteristics. We calculated the MOF/hip IRRs (95% confidence interval) and Z-values to compare IRRs in various countries to those for Sweden. We included 27 studies, of fair to good quality in the majority, from Europe (15), US and Canada (7), Asia (3), and Australia (2). The IRRs were twofold to 10-fold higher in younger compared to older age categories, and in women compared to men, with few exceptions. Within Europe, and using Sweden as a reference, MOF/Hip IRRs in women 50-54 years from Finland, Italy, Netherlands, Denmark, and UK were significantly lower by 38% to 60%. Findings were similar in men. At older ages, MOF/Hip IRRs were consistently lower in women from European countries compared to Sweden, by 10%-40% and 11%-51%, at 75-79 years and 85-89 years, respectively. Findings were heterogenous in men and in non-European countries. In conclusion, the MOF/hip fracture IRR may vary between countries. The variability at older ages may affect FRAX prediction when country-specific fracture IRRs are not used. Further research is needed to elucidate the implication of our findings to FRAX-derived MOF estimates in various countries. © 2021 American Society for Bone and Mineral Research (ASBMR).

Association between body composite indices and vertebral fractures in pre and postmenopausal women in Korea

The association between obesity and vertebral fracture remains controversial. This study aimed to investigate the association between obesity/abdominal obesity and vertebral fracture according to menopausal status. This nationwide population-based epidemiologic study collected data from the Korean National Health Insurance Services to investigate the association between obesity/abdominal obesity and vertebral fracture in pre and postmenopausal women who underwent national cancer screening in 2009. We used three body composite indices of obesity, body mass index, waist circumference and waist-to-height ratio, to classify participants into obesity and abdominal obesity groups. In both pre and postmenopausal groups, participants with obesity showed a higher risk of vertebral fracture and the association was stronger in those with abdominal obesity (p < 0.001). Participants with obesity showed a high risk of vertebral fracture, and the association was stronger in participants with abdominal obesity (p < 0.001). In both pre and postmenopausal groups, participants with obesity showed a higher risk of vertebral fracture (adjusted HR, 1.24; 95% CI, 1.19–1.30), (adjusted HR, 1.04; 95% CI, 1.03–1.05, and those with abdominal obesity showed even higher risk of vertebral fractures (adjusted HR, 1.35; 95% CI, 1.27–1.43), (adjusted HR, 1.13; 95% CI, 1.11–1.14). Vertebral fracture risk is higher in pre and postmenopausal women with obesity and even higher in those with abdominal obesity. Therefore, weight management can prevent vertebral fractures.

Physical Activity and Psychosocial Factors Associated With Risk of Future Fractures in Middle-Aged Men and Women

Identification of risk factors for fractures is important for improving public health. We aimed to identify which factors related to physical activity and psychosocial situation were associated with incident fractures among 30,446 middle-aged women and men, followed from 1991-1996 to 2016, in a prospective population-based cohort study. The association between the baseline variables and first incident fracture was assessed by Cox regression models, and significant risk factors were summed into fracture risk scores. Any first incident fracture affecting spine, thoracic cage, arms, shoulders, hands, pelvis, hips, or legs was obtained from the National Patient Register, using the unique personal identity number of each citizen. A total of 8240 subjects (27%) had at least one fracture during the follow-up of median 20.7 years. Age, female sex, body mass index, previous fracture, reported family history of fracture >50 years (all p < .001), low leisure-time physical activity (p = .018), heavy work (p = .024), living alone (p = .002), smoking (p < .001), and no or high alcohol consumption (p = .005) were factors independently associated with incident fracture. The fracture risk score (0-9 points) was strongly associated with incident fracture (p for trend <.001). Among men without risk factors, the incidence rate was 5.3/1000 person-years compared with 23.2 in men with six or more risk factors (hazard ratio [HR] = 5.5; 95% confidence interval [CI] 3.7-8.2). Among women with no risk factors, the incidence rate was 10.7 compared with 28.4 in women with six or more risk factors (HR = 3.1; 95% CI 2.4-4.0). Even moderate levels of leisure-time physical activity in middle age are associated with lower risk of future fractures. In contrast, heavy work, living alone, smoking, and no or high alcohol consumption increase the risk of fracture. Our results emphasize the importance of these factors in public health initiatives for fracture prevention. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Fluoride in Drinking Water, Diet, and Urine in Relation to Bone Mineral Density and Fracture Incidence in Postmenopausal Women

BACKGROUND

Although randomized controlled trials (RCTs) have demonstrated that high fluoride increases bone mineral density (BMD) and skeletal fragility, observational studies of low-dose chronic exposure through drinking water (<1.5mg/L, the maximum recommended by the World Health Organization) have been inconclusive.

OBJECTIVE

We assessed associations of fluoride in urine, and intake via diet and drinking water, with BMD and fracture incidence in postmenopausal women exposed to drinking water fluoride ≤1mg/L.

METHODS

Data were from participants in the Swedish Mammography Cohort-Clinical, a population-based prospective cohort study. At baseline (2004-2009), fluoride exposure was assessed based on urine concentrations (n=4,306) and estimated dietary intake (including drinking water) (n=4,072), and BMD was measured using dual energy X-ray absorptiometry. Incident fractures were ascertained via register-linkage through 2017. Residential history was collected to identify women with long-term consistent drinking water exposures prior to baseline.

RESULTS

At baseline, mean urine fluoride was 1.2mg/g creatinine (±1.9) and mean dietary intake was 2.2mg/d (±0.9), respectively. During follow-up, 850, 529, and 187 cases of any fractures, osteoporotic fractures, and hip fractures, respectively, were ascertained. Baseline BMD was slightly higher among women in the highest vs. lowest tertiles of exposure. Fluoride exposures were positively associated with incident hip fractures, with multivariable-adjusted hazard ratios of 1.50 (95% CI: 1.04, 2.17) and 1.59 (95% CI: 1.10, 2.30), for the highest vs. lowest tertiles of urine fluoride and dietary fluoride, respectively. Associations with other fractures were less pronounced for urine fluoride, and null for dietary fluoride. Restricting the analyses to women with consistent long-term drinking water exposures prior to baseline strengthened associations between fractures and urinary fluoride.

DISCUSSION

In this cohort of postmenopausal women, the risk of fractures was increased in association with two separate indicators of fluoride exposure. Our findings are consistent with RCTs and suggest that high consumption of drinking water with a fluoride concentration of ∼1mg/L may increase both BMD and skeletal fragility in older women. https://doi.org/10.1289/EHP7404.

Psychosocial stress and bone loss among postmenopausal women: results from the Women’s Health Initiative

Background

Bone loss is a major public health concern with large proportions of older women experiencing osteoporotic fractures. Previous research has established a relationship between psychosocial stressors and fractures. However, few studies have investigated bone loss as an intermediary in this relationship. This study investigates whether social stress is associated with bone loss during a 6-year period in postmenopausal women.

Methods

Data from 11 020 postmenopausal women from the USA was used to examine self-reported psychosocial stress in relation to change in bone mineral density (BMD) measured at the femoral neck, lumbar spine and total hip. Linear regression models were used to examine associations between social measures of psychosocial stress (social strain, social functioning and social support) and per cent change in BMD over 6 years.

Results

High social stress was associated with decreased BMD over 6 years. After adjustment for confounders, each point higher in social strain was associated with 0.082% greater loss of femoral neck BMD, 0.108% greater loss of total hip BMD and 0.069% greater loss of lumbar spine BMD (p<0.05). Low social functioning and low social support were associated with greater decreases in femoral neck BMD, and low social functioning was associated with greater decreases in total hip BMD.

Conclusion

The findings provide evidence for an association between high social stress and greater bone loss over 6 years of follow-up. In agreement with the prior literature, the findings for social strain and social functioning suggest that poor quality of social relationships may be associated with bone loss in postmenopausal women.

Socioeconomic status and risk of osteoporotic fractures and the use of DXA scans: data from the Danish population-based ROSE study

There is a need of studies exploring the link between socioeconomic status and DXA scans and osteoporotic fracture, which was the aim of the present study. No differences in socioeconomic status and risk of osteoporotic fractures were found. However, women with further/higher education and higher income are more often DXA-scanned.

INTRODUCTION

Lower socioeconomic status is known to be associated with a range of chronic conditions and with access to health care services. The link between socioeconomic status and the use of DXA scans and osteoporotic fracture, however, needs to be explored more closely. Therefore, the aim of this study was to examine the relationship between socioeconomic status and both DXA scan utilization and major osteoporotic fractures (MOF) using a population-based cohort of Danish women and national registers.

METHODS

The study included 17,155 women (65-81 years) sampled from the Risk-stratified Osteoporosis Strategy Evaluation study (ROSE). Information on socioeconomic background, DXA scans, and MOFs was retrieved from national registers. Competing-risk regression analyses were performed. Mean follow-up was 4.8 years.

RESULTS

A total of 4245 women had a DXA scan (24.7%) and 1719 (10.0%) had an incident MOF during follow-up. Analyses showed that women with basic education had a lower probability of undergoing DXA scans than women with further or higher education (greater than upper secondary education and vocational training education) (subhazard ratio (SHR) = 0.82; 95% CI 0.75-0.89, adjusted for age and comorbidity). Moreover, women with disposable income in the low and medium tertiles had a lower probability of undergoing DXA scans than women in the high-income tertile (SHR = 0.90; 95% CI 0.84-0.97 and SHR = 0.88, 95% CI 0.82-0.95, respectively, adjusted for age and comorbidity). No association between socioeconomic background and probability of DXA was found in adjusted analyses.

CONCLUSION

The study found no differences in risk of osteoporotic fractures depending on socioeconomic status. However, women with further or higher education as well as higher income are more often DXA-scanned.

Accelerated Aging: The Role of Socioeconomic, Social, Demographic, and Biological Factors on Bone Mineral Density

We investigate socioeconomic, social, demographic, and biological variables that are associated with chronic stress in the body to assess whether they have an effect on bone mineral density (BMD) as an indicator of accelerated aging. Multiple regression models were derived from data in the Midlife in the United States: A National Longitudinal Study of Health and Well-Being, Waves 1 (1995–1996) and 2 (2004–2006). Three BMD variables were used as outcomes: femoral, femoral neck, and spine T scores. The sample included 333 men and women aged 34–80. Poverty and C-reactive protein were related to BMD for spine T scores, partially consistent with hypotheses. But, marital status, perceived support of a partner, and education were not associated. Friend strain was discovered to have a relationship with BMD. More variables, and from a broader context, need to be examined together to understand what affects reduced BMD, given the high costs of accelerated aging.

Bone Health During the Menopause Transition and Beyond

The menopause transition is a critical period for bone health, with rapid losses in bone mass and strength occurring in a 3-year window bracketing the date of the final menstrual period. Declines in bone mass are accompanied by deleterious changes in bone macrostructure and microarchitecture, which may be captured by changes in composite strength indices and indices of trabecular thickness and connectivity. The onset of the rapid bone loss phase is preceded by changes in sex steroid hormones and increases in markers of bone resorption, measurements of which may be clinically useful in predicting the onset of the rapid loss phase and in identifying the women who will lose the most bone strength over the menopause transition.

Educational inequalities in fracture-related mortality using multiple cause of death data in the Skåne region, Sweden

Aim: To assess the absolute and relative educational inequalities in mortality from hip and non-hip fractures in Skåne region, Sweden. Methods: We conducted a population-based open cohort study. People aged 30-99 years, resident in the region during 1998-2013 (n = 999, 148) were followed until death, their 100^th birthday, relocation outside Skåne, or the end of 2014. We obtained individual-level data from the Statistics Sweden and the Swedish National Board of Health and Welfare's Cause of Death Register. Death certificates coded with any fracture diagnosis were defined as fracture-related deaths. Educational inequalities were assessed by slope and relative indices of inequality (SII and RII). Cox regression and additive hazard models were used to estimates these indices. Results: During a mean follow-up of 12.2 years, there were 5,121 fracture-related deaths, of which 3,110 were associated with hip fracture. Age-standardized, hip fracture-related mortality rates per 100,000 person-years were 31, 95% confidence interval (CI) (30, 32) and 23 (20, 26) in people with low and high levels of education, respectively (rate ratio 1.4, 95% CI (1.2, 1.5)). Corresponding mortality rates for non-hip-fracture related deaths were 20 (18, 21) and 16 (14, 19) (rate ratio 1.2, 95% CI (1.0, 1.4)). SII and RII revealed educational inequalities in hip fracture-related mortality in favour of highly educated people. For non hip fracture-related mortality, there were statistically significant educational inequalities in people aged <70 years. Conclusions: We found higher fracture-related mortality with lower education suggesting preventative and therapeutic interventions for fractures should pay special attention to people with low-level education.

Socio-Economic Status and Prevalence of Self-Reported Osteoporosis in Tehran: Results from a Large Population-Based Cross-Sectional Study (Urban HEART-2)

Osteoporosis is a widespread disease among older peoples. The aim of this study is to estimate the prevalence of self-reported osteoporosis and assessing its association with socio-economic status. A population-based cross-sectional study was conducted in Tehran, Iran in 2011. Participants were 45,990 individuals aged above 20 years from 22 urban districts. Osteoporosis was measured by self-administrative questionnaire. Wealth index was constructed using principal component analysis based on household assets. Chi-square test, chi square test for trend, and crude odds ratio were used to assess associations in univariate analysis. Multiple logistic regression utilized to estimate adjusted associations between self-reported osteoporosis and socio-economic status.The overall estimated prevalence of self-reported osteoporosis was 4% (95% CI 3.88-4.13), 1.19% in men, and 6.84% in women (P < 0.001). The prevalence increased considerably as age increased (P for trend < 0.001). In multivariable analysis, education and wealth status were negative, and smoking was positively associated with the prevalence of self-reported osteoporosis. No association was found between participants' skill levels and Townsend deprivation index with the prevalence of self-reported osteoporosis.The findings of the present study have improved understanding of the association between socioeconomic status and osteoporosis in the Iranian population. It is important to consider socioeconomic status in screening and prevention programs.

Associations between socioeconomic factors and proinflammatory cytokines in children, adolescents and young adults: a systematic review protocol

INTRODUCTION

There is now substantial evidence of a social gradient in bone health. Social stressors, related to socioeconomic status, are suggested to produce an inflammatory response marked by increased levels of proinflammatory cytokines. Here we focus on the particular role in the years before the achievement of peak bone mass, encompassing childhood, adolescence and young adulthood. An examination of such associations will help explain how social factors such as occupation, level of education and income may affect later-life bone disorders. This paper presents the protocol for a systematic review of existing literature regarding associations between socioeconomic factors and proinflammatory cytokines in those aged 6-30 years.

METHODS AND ANALYSIS

We will conduct a systematic search of PubMed, OVID and CINAHL databases to identify articles that examine associations between socioeconomic factors and levels of proinflammatory cytokines, known to influence bone health, during childhood, adolescence or young adulthood. The findings of this review have implications for the equitable development of peak bone mass regardless of socioeconomic factors. Two independent reviewers will determine the eligibility of studies according to predetermined criteria, and studies will be assessed for methodological quality using a published scoring system. Should statistical heterogeneity be non-significant, we will conduct a meta-analysis; however, if heterogeneity prevent numerical syntheses, we will undertake a best-evidence analysis to determine whether socioeconomic differences exist in the levels of proinflammatory cytokines from childhood through to young adulthood.

ETHICS AND DISSEMINATION

This study will be a systematic review of published data, and thus ethics approval is not required. In addition to peer-reviewed publication, these findings will be presented at professional conferences in national and international arenas.

A systematic review of socioeconomic status measurement in 13 years of U.S. injury research

OBJECTIVE

The purpose of this review was to assess the impact of socioeconomic status (SES) on injury and to evaluate how U.S. injury researchers have measured SES over the past 13years in observational research studies.

DESIGN & METHODS

This systematic review included 119 US injury studies indexed in PubMed between January 1, 2002 and August 31, 2015 that used one or more individual and/or area-level measures of SES as independent variables. Study findings were compared to the results of a previous review published in 2002.

RESULTS

Findings indicate SES remains an important predictor of injury. SES was inversely related to injury in 78 (66%) of the studies; inverse relationships were more consistently found in studies of fatal injury (77.4%) than in studies of non-fatal injury (58%). Approximately two-thirds of the studies (n=73, 61%) measured SES along a gradient and 59% used more than one measure of SES (n=70). Studies that used a gradient measure of SES and/or more than one measure of SES identified significant relationships more often. These findings were essentially equivalent to those of a similar 2002 review (Cubbin & Smith, 2002).

CONCLUSIONS

There remains a need to improve measurement of SES in injury research. Public health training programs should include best practices for measurement of SES, which include: measuring SES along a gradient, selecting SES indicators based on the injury mechanism, using the smallest geographic region possible for area-level measures, using multiple indicators when possible, and using both individual and area-level measures as both contribute independently to injury risk. Area-level indicators of SES are not accurate estimates of individual-level SES.

PRACTICAL APPLICATIONS

Injury researchers should measure SES along a gradient and incorporate individual and area-level SES measures that are appropriate to the injury outcome under study.

DNA methylation and the social gradient of osteoporotic fracture: A conceptual model

INTRODUCTION

Although there is a documented social gradient for osteoporosis, the underlying mechanism(s) for that gradient remain unknown. We propose a conceptual model based upon the allostatic load theory, to suggest how DNA methylation (DNAm) might underpin the social gradient in osteoporosis and fracture. We hypothesise that social disadvantage is associated with priming of inflammatory pathways mediated by epigenetic modification that leads to an enhanced state of inflammatory reactivity and oxidative stress, and thus places socially disadvantaged individuals at greater risk of osteoporotic fracture.

METHODS/RESULTS

Based on a review of the literature, we present a conceptual model in which social disadvantage increases stress throughout the lifespan, and engenders a proinflammatory epigenetic signature, leading to a heightened inflammatory state that increases risk for osteoporotic fracture in disadvantaged groups that are chronically stressed.

CONCLUSIONS

Our model proposes that, in addition to the direct biological effects exerted on bone by factors such as physical activity and nutrition, the recognised socially patterned risk factors for osteoporosis also act via epigenetic-mediated dysregulation of inflammation. DNAm is a dynamic modulator of gene expression with considerable relevance to the field of osteoporosis. Elucidating the extent to which this epigenetic mechanism transduces the psycho-social environment to increase the risk of osteoporotic fracture may yield novel entry points for intervention that can be used to reduce individual and population-wide risks for osteoporotic fracture. Specifically, an epigenetic evidence-base may strengthen the importance of lifestyle modification and stress reduction programs, and help to reduce health inequities across social groups.

MINI ABSTRACT

Our conceptual model proposes how DNA methylation might underpin the social gradient in osteoporotic fracture. We suggest that social disadvantage is associated with priming of inflammatory signalling pathways, which is mediated by epigenetic modifications, leading to a chronically heightened inflammatory state that places disadvantaged individuals at greater risk of osteoporosis.

Bone health after menopause

PURPOSE OF REVIEW

This article reviews recent publications (January 2014-June 2015) on bone health and menopause.

RECENT FINDINGS

Recent articles suggest that simple instruments, such as the osteoporosis self-assessment tool based on age and weight may identify women age 50-64 for bone mineral density (BMD) testing. Rescreening of women age 50-64 is not recommended because their overall risk of fracture is quite low. A novel risk factor for hip fracture among non-Caucasian women is socioeconomic status. Midlife women with low serum 25-hydroxyvitamin D (<20 ng/ml) have an increased risk of fracture over the menopausal transition and vitamin D supplementation is warranted. Wrist fractures are the most common fracture in women age 50-64. Women who experience a wrist fracture have an increased risk of subsequent fracture and should have a BMD scan. Results of studies using composite measures of femoral neck strength relative to load emphasize the need for osteoporotic research to move beyond BMD.

SUMMARY

This recent research has provided new and important findings improving our understanding of osteoporosis during the menopausal transition.

Fracture risk and mortality post-kidney transplantation

BACKGROUND

Fractures are associated with high morbidity and economic costs. There is a paucity of information on fractures after kidney transplantation outside the United States.

METHODS

Data were obtained from the Hospital Episode Statistics database on kidney transplants performed in England between 2001 and 2013 and post-transplant fracture-related hospitalization. Mortality data were obtained from the Office for National Statistics.

RESULTS

In total, 21 769 first kidney transplant procedures were analyzed with 112 512 patient-years follow-up. Overall, 836 (3.8%) kidney allograft recipients developed a fracture requiring hospitalization. Event rate was 9.99 for any fracture and 1.54 for a hip fracture per 1000 patient-years. Accounting for the competing risk of mortality, increasing age, female gender, white ethnicity, and a history of pre-transplant diabetes mellitus or previous fracture were associated with increased fracture risk post-kidney transplantation. Death occurred in 2407 (11.1%) kidney allograft recipients, with 173 deaths occurring post-fracture. In an extended Cox model, hip fracture as a time-varying factor was independently associated with an increased risk of death (hazard ratio, 3.288; 95% confidence intervals, 2.513-4.301; p < 0.001).

CONCLUSIONS

Fracture rates in English kidney transplant recipients are lower than previously reported in US cohorts. Sustaining a hip fracture is associated with an increased mortality risk. Our results can be used to power future fracture prevention trials.

Education, marital status, and risk of hip fractures in older men and women: the CHANCES project

The role of socioeconomic status in hip fracture incidence is unclear. In a diverse population of elderly, higher education was found to be associated with lower, whereas living alone, compared to being married/cohabiting, with higher hip fracture risk. Educational level and marital status may contribute to hip fracture risk.

INTRODUCTION

The evidence on the association between socioeconomic status and hip fracture incidence is limited and inconsistent. We investigated the potential association of education and marital status with hip fracture incidence in older individuals from Europe and USA.

METHODS

A total of 155,940 participants (79 % women) aged 60 years and older from seven cohorts were followed up accumulating 6456 incident hip fractures. Information on education and marital status was harmonized across cohorts. Hip fractures were ascertained through telephone interviews/questionnaires or through record linkage with registries. Associations were assessed through Cox proportional hazard regression adjusting for several factors. Summary estimates were derived using random effects models.

RESULTS

Individuals with higher education, compared to those with low education, had lower hip fracture risk [hazard ratio (HR) = 0.84, 95 % confidence interval (CI) 0.72-0.95]. Respective HRs were 0.97 (95 % CI 0.82-1.13) for men and 0.75 (95 % CI 0.65-0.85) for women. Overall, individuals living alone, especially those aged 60-69 years, compared to those being married/cohabiting, tended to have a higher hip fracture risk (HR = 1.12, 95 % CI 1.02-1.22). There was no suggestion for heterogeneity across cohorts (P heterogeneity > 0.05).

CONCLUSIONS

The combined data from >150,000 individuals 60 years and older suggest that higher education may contribute to lower hip fracture risk. Furthermore, this risk may be higher among individuals living alone, especially among the age group 60-69 years, when compared to those being married/cohabiting.

The social gradient of fractures at any skeletal site in men and women: data from the Geelong Osteoporosis Study Fracture Grid

Age-specific and age-standardized associations between socioeconomic status (SES) and fractures in adults showed a social gradient of fracture, irrespective of fracture site. Compared to the highest SES, males in the lowest SES group had a sixfold increased odds for any fracture, whilst females had a twofold increased odds.

INTRODUCTION

The effective identification of predisposing risk factors for fracture requires understanding any association with SES. These investigations should consider both sexes, span the adult age range and include any fractures. We investigated age- and sex-specific and age-standardized associations between SES and fractures at any skeletal site in Australians aged ≥ 50 years.

METHODS

Incident fractures that occurred 2006-2007 for adults aged ≥ 50 years were identified from radiological reports extracted for the Barwon Statistical Division, in south-eastern Australia. SES was determined by cross-referencing residential addresses with Australian Bureau of Statistics census data and then categorized in quintiles. We compared frequencies of observed vs. expected fractures for SES quintiles using χ (2) comparison, calculated age-specific fracture incidence across SES and compared age-standardized fracture rates in SES quintile 1 to quintile 5.

RESULTS

We identified 3943 incident fractures (69.4 % female); 47.4 % had occurred at major osteoporotic fracture (MOF) sites (hip, humerus, spine and forearm/wrist). Differences existed in observed vs. expected fractures across SES quintiles (p ≤ 0.001, sexes combined); all fractures showed an inverse association with SES (p ≤ 0.001, sexes combined). Compared to the highest SES quintile, individuals from the lowest SES quintile had between two to six times greater standardized fracture rates.

CONCLUSIONS

Disadvantaged men and women have an increased fracture incidence compared to their less disadvantaged counterparts. The large differences in fracture rates between SES groups warrant further research into designing appropriate, targeted interventions for those demographics at most risk.

Sex- and age-specific associations between income and incident major osteoporotic fractures in Canadian men and women: a population-based analysis

We investigated sex- and age-specific associations between income and fractures at the hip, humerus, spine, and forearm in adults aged ≥50 years. Compared to men with the highest income, men with the lowest income had an increased fracture risk at all skeletal sites. These associations were attenuated in women.

INTRODUCTION

Associations between income and hip fractures are contested, even less is known about other fracture sites. We investigated sex- and age-specific associations between income and major osteoporotic fractures (MOF) at the hip, humerus, spine, and forearm.

METHODS

Incident fractures were identified from administrative health data for adults aged ≥50 years in Manitoba, Canada, 2000-2007. Mean neighborhood (postal code area) annual household incomes were extracted from 2006 census files and categorized into quintiles. We calculated age-adjusted and age-specific sex-stratified fracture incidence across income quintiles. We estimated relative risks (RR) and 95% CI for income quintile 1 (Q1, lowest income) vs. income quintile 5 (Q5) and tested the linear trend across quintiles.

RESULTS

We identified 15,094 incident fractures (4736 hip, 3012 humerus, 1979 spine, and 5367 forearm) in 2718 men and 6786 women. For males, the RR of fracture for the lowest vs. highest income quintile was 1.63 (95% CI 1.42-1.87) and the negative trend was statistically significant (p < 0.0001); individual skeletal sites showed similar associations. For females, the RR of fracture for the lowest vs. highest income quintile was 1.14 (95% CI 1.01-1.28), with a statistically significant negative trend (p = 0.0291); however, the only skeletal site associated with income in women was the forearm (Q1 vs. Q5 RR 1.09, 95% CI 1.01-1.28).

CONCLUSIONS

Compared to men with the highest income, men with the lowest income had an increased fracture risk at all skeletal sites. These associations were attenuated in women. For men, these effect sizes seem large enough to warrant public health concern.

Birth weight is not associated with risk of fracture: results from two Swedish cohort studies

Development and growth in utero has been suggested to influence bone health. However, the relationship with risk of fracture in old age is largely unknown. Using Cox proportional hazards regression, we studied the association between birth weight and fractures at ages 50-94 among 10,893 men and women (48% women) from the Uppsala Birth Cohort Study (UBCoS, born 1915-29) and 1334 men from the Uppsala Longitudinal Study of Adult Men (ULSAM, born 1920-24). Measured birth weight was collected from hospital or midwives' records and fractures from the Swedish National Patient Register. We observed 2796 fractures (717 of these were hip fractures) in UBCoS and 335 fractures (102 hip fractures) in ULSAM. In UBCoS, the hazard ratio (HR) per 1 kg increase in birth weight, adjusted for sex and socioeconomic status at birth, was 1.01 [95% confidence interval (CI), 0.94-1.09] for any fracture and 1.06 (95% CI, 0.91-1.23) for hip fracture. Estimates in ULSAM were similar. We did not observe a differential association of birth weight with fractures occurring before age 70 or after age 70 years. Neither birth weight standardized for gestational age nor gestational duration was associated with fracture rate. In linear regression, birth weight was not associated with bone mineral density among 303 men who were 82-years-old in ULSAM but showed positive associations with total body bone mineral content (β per kg increase in birth weight, adjusted for social class and age, 133; 95% CI, 30-227). This association was attenuated after further adjustment for body mass index and height (β, 41; 95% CI, -43-126). We conclude that birth weight is associated with bone mineral content but this association does not translate into an association with risk of fracture in men and women aged 50-94 years.