Obesity and fracture in men and women: an epidemiologic perspective

Interaction between Muscle and Bone

The clinical significance of sarcopenia and osteoporosis has increased with the increase in the population of older people. Sarcopenia is defined by decreased muscle mass and impaired muscle function, which is related to osteoporosis independently and dependently. Numerous lines of clinical evidence suggest that lean body mass is positively related to bone mass, which leads to reduced fracture risk. Genetic, endocrine and mechanical factors affect both muscle and bone simultaneously. Vitamin D, the growth hormone/insulin-like growth factor I axis and testosterone are physiologically and pathologically important as endocrine factors. These findings suggest the presence of interactions between muscle and bone, which might be very important for understanding the physiology and pathophysiology of sarcopenia and osteoporosis. Muscle/bone relationships include two factors: local control of muscle to bone and systemic humoral interactions between muscle and bone. As a putative local inducer of muscle ossification, we found Tmem119, a parathyroid hormone-responsive osteoblast differentiation factor. Moreover, osteoglycin might be one of the muscle-derived humoral bone anabolic factors. This issue may be important for the development of novel drugs and biomarkers for osteoporosis and sarcopenia. Further research will be necessary to clarify the details of the linkage of muscle and bone.

Association between metabolic syndrome and bone fractures: a meta-analysis of observational studies

BACKGROUND

Emerging epidemiological evidence suggest an association between metabolic syndrome and fractures. However, whether metabolic syndrome is an independent risk or protective factor of fractures remains controversial. Our goal is to provide a quantitative assessment of the association between metabolic syndrome and bone fractures by conducting a meta-analysis of observational studies.

METHODS

The PubMed and Embase database were searched through to March 2013 to identify studies that met pre-established inclusion criteria. Reference lists of retrieved articles were also reviewed. Summary effect estimates with 95% confidence intervals (CI) were derived using a fixed or random effects model, depending on the heterogeneity of the included studies.

RESULTS

Eight epidemiologic studies involving 39,938 participants were included in the meta-analysis. In overall analysis, metabolic syndrome was not associated with prevalent fractures [pooled odds ratio (OR) 0.93, 95% CI 0.84 - 1.03] in cross-sectional studies or incident fractures [pooled relative risk (RR) 0.88, 95% CI 0.37 - 2.12] in prospective cohort studies. No evidence of heterogeneity was found in cross-sectional studies (p = 0.786, I2 = 0.0%). A substantial heterogeneity was detected in cohort studies (p = 0.001, I2 = 85.7%). No indication of significant publication bias was found either from Begg's test or Egger's test. Estimates of total effects were substantially consistent in the sensitivity and stratification analyses.

CONCLUSIONS

The present meta-analysis of observational studies suggests that the metabolic syndrome has no explicit effect on bone fractures.

A United Kingdom perspective on the relationship between body mass index (BMI) and bone health: a cross sectional analysis of data from the Nottingham Fracture Liaison Service

OBJECTIVES

This study examines the relationship between high BMI, a diagnosis of osteoporosis and low trauma fractures.

METHOD

This is a cross sectional analysis using data collected from the Nottingham Fracture Liaison Service. A total of 4288 participants with a low trauma fracture from 1 January 2007 to 31 August 2012 were analysed. Logistic regression adjusted for potential confounders was used investigate osteoporosis and BMI. Fracture types were compared between those who were obese and non-obese.

RESULTS

A total of 30% (1285) were obese. Prevalence of osteoporosis was 13.4%, 24.9%, and 40.4% in the obese, overweight and normal category respectively. Being obese has an odds ratio of 0.23 (95% CI 0.19-0.28, p<0.01) of having osteoporosis compared to a normal BMI category. When variable BMI cut offs were used (BMI 25, 30 and 35) to calculate the positive predictive value of patients not having osteoporosis, it was 80.5%, 86.3% and 88.3%. Examining fracture types, obese patients when compared with the non-obese category, were more likely to fracture their ankle (OR 1.48, p<0.01) and upper arm (OR 1.48, p<0.001), but were less likely to fracture their wrist (OR 0.65, p<0.001). In the elderly (>70years), obesity no longer influenced ankle or wrist fractures but there is an increased risk of upper arm fractures (OR 1.46, p=0.005).

CONCLUSION

Higher BMD in obesity is not protective against fractures as there are a significant number of fractures in this group which may be due to body habitus, mechanism of injury and the effect of adiposity on bone. A low trauma osteoporotic fracture will need to be redefined in light of these findings.

Bone loss after bariatric surgery: causes, consequences, and management

Bariatric surgery is an effective and increasingly common treatment for severe obesity and its many comorbidities. The side-effects of bariatric surgery can include detrimental effects on bone and mineral metabolism. Bone disease in patients who have had bariatric surgery is affected by preoperative abnormalities in bone and mineral metabolism related to severe obesity. Changes that arise after bariatric surgery are specific to procedure type: the most pronounced abnormalities in calciotropic hormones and bone loss are noted after procedures that result in the most malabsorption. The most consistent site for bone loss after all bariatric procedures is at the hip. There are limitations of dual-energy x-ray absorptiometry technology in this population, including artefact introduced by adipose tissue itself. Bone loss after bariatric surgery is probably multifactorial. Proposed mechanisms include skeletal unloading, abnormalities in calciotropic hormones, and changes in gut hormones. Few data for fracture risk in the bariatric population are available, and this is a crucial area for additional research. Treatment should be geared toward correction of nutritional deficiencies and study of bone mineral density in high-risk patients. We explore the skeletal response to bariatric surgery, potential mechanisms for changes, and strategies for management.

Cytokines and Hormones That Contribute to the Positive Association between Fat and Bone

The positive association between body weight and bone density has been established in numerous laboratory and clinical studies. Apart from the direct effect of soft tissue mass on bone through skeletal loading, a number of cytokines and hormones contribute to the positive association between adipose and bone tissue, acting either locally in sites where cells of the two tissues are adjacent to each other or systemically through the circulation. The current review describes the effects of such local and systemic factors on bone physiology. One class of factors are the adipocyte-secreted peptides (adipokines), which affect bone turnover through a combination of direct effects in bone cells and indirect mechanisms mediated by the central nervous system. Another source of hormones that contribute to the coupling between fat and bone tissue are beta cells of the pancreas. Insulin, amylin, and preptin are co-secreted from pancreatic beta cells in response to increased glucose levels after feeding, and are also found in high circulating levels in obesity. A number of peptide hormones secreted from the gastrointestinal tract in response to feeding affect both fat and bone cells and thus can also act as mediators of the association between the two tissues. The current review focuses on results of laboratory studies investigating possible mechanism involved in the positive association between fat mass and bone mass.

A meta-analysis of the association of fracture risk and body mass index in women

Several recent studies suggest that obesity may be a risk factor for fracture. The aim of this study was to investigate the association between body mass index (BMI) and future fracture risk at different skeletal sites. In prospective cohorts from more than 25 countries, baseline data on BMI were available in 398,610 women with an average age of 63 (range, 20-105) years and follow up of 2.2 million person-years during which 30,280 osteoporotic fractures (6457 hip fractures) occurred. Femoral neck BMD was measured in 108,267 of these women. Obesity (BMI ≥ 30 kg/m(2) ) was present in 22%. A majority of osteoporotic fractures (81%) and hip fractures (87%) arose in non-obese women. Compared to a BMI of 25 kg/m(2) , the hazard ratio (HR) for osteoporotic fracture at a BMI of 35 kg/m(2) was 0.87 (95% confidence interval [CI], 0.85-0.90). When adjusted for bone mineral density (BMD), however, the same comparison showed that the HR for osteoporotic fracture was increased (HR, 1.16; 95% CI, 1.09-1.23). Low BMI is a risk factor for hip and all osteoporotic fracture, but is a protective factor for lower leg fracture, whereas high BMI is a risk factor for upper arm (humerus and elbow) fracture. When adjusted for BMD, low BMI remained a risk factor for hip fracture but was protective for osteoporotic fracture, tibia and fibula fracture, distal forearm fracture, and upper arm fracture. When adjusted for BMD, high BMI remained a risk factor for upper arm fracture but was also a risk factor for all osteoporotic fractures. The association between BMI and fracture risk is complex, differs across skeletal sites, and is modified by the interaction between BMI and BMD. At a population level, high BMI remains a protective factor for most sites of fragility fracture. The contribution of increasing population rates of obesity to apparent decreases in fracture rates should be explored.

What's in a name revisited: should osteoporosis and sarcopenia be considered components of "dysmobility syndrome?"

Sarcopenia and osteoporosis are age-related declines in the quantity and quality of muscle and bone respectively, with shared pathogeneses and adverse health consequences. Both absolute and relative fat excess, i.e., obesity and sarcopenic obesity, contribute to disability, falls, and fractures. Rather than focusing on a single component, i.e., osteoporosis, sarcopenia, or obesity, we realized that an opportunity exists to combine clinical factors, thereby potentially allowing improved identification of older adults at risk for disability, falls, and fractures. Such a combination could be termed dysmobility syndrome, analogous to the approach taken with metabolic syndrome. An arbitrary score-based approach to dysmobility syndrome diagnosis is proposed and explored in a small cohort of older adults. Further evaluation of such an approach in large population-based and prospective studies seems warranted.

Of fracture thresholds and bone mineral density reference data: does one size really fit all?

Men who fracture have greater mean bone mineral density (BMD) than women who fracture, and to some this suggests that BMD fracture "thresholds" are greater in men than women, justifying use of a male BMD reference standard. Others disagree and argue that because BMD distribution in men is right-shifted (higher) compared with women, anything that occurs with equal probability for men and women will occur at a greater mean BMD in men. If the latter is true, it supports using a common (female) BMD reference standard. We directly tested this latter principle and, indirectly, the validity of using a constant BMD reference standard, in 51,326 women (3722 major fractures) and 4691 men (276 fractures), by comparing mean BMD in fracture vs nonfracture groups defined by sex, age, race and body mass index because these 4 factors affect both mean BMD and risk of fractures. Among those who fractured, mean BMD for all measurement sites were significantly greater in men vs women, youngest vs oldest, whites vs Asian, and heaviest vs the lightest (all p < 0.001). However, the same BMD pattern was seen in those who did not fracture and the absolute difference in BMD between those who fractured and those who did not was essentially constant regardless of sex, age, race, or weight class (all p-interaction nonsignificant). This finding suggests that use of a common reference standard for BMD (i.e., young white women) for men, and indeed all subgroups defined by osteoporosis risk factors, is reasonable and consistent with empiric observations.

Divergent effects of obesity on bone health

Historically, obesity was thought to be advantageous for maintaining healthy bones due to the greater bone mineral density observed in overweight individuals. However, recent observations of increased fracture in some obese individuals have led to concern that common metabolic complications of obesity, such as type 2 diabetes, metabolic syndrome, impaired glucose tolerance, insulin resistance, hyperglycemia, and inflammation may be associated with poor bone health. In support of this hypothesis, greater visceral fat, a hallmark of insulin resistance and metabolic syndrome, is associated with lower bone mineral density. Research is needed to determine if and how visceral fat and/or poor metabolic health are causally associated with bone health. Clinicians should consider adding a marker metabolic health, such as waist circumference or fasting plasma glucose concentration, to other known risk factors for osteoporosis and fracture.

Osteoarthritis and osteoporosis: what is the overlap?

Osteoarthritis (OA) and osteoporosis (OP) are highly prevalent health problems, associated with considerable morbidity. In the past, attention was focused on a supposed inverse relationship between OA and OP, since both disorders usually affect the elderly, but were regarded to rarely coexist in a single person. However, recent studies have revealed several factors which contribute to the pathogenesis of both disorders. These insights might contribute to the development of shared new treatment options in the near future. Increased subchondral bone loss is a characteristic feature of OP and the early stage of OA, and this finding is the rationale for studies on the effect of anti-osteoporotic drugs in OA. In addition, inflammation and unfavourable body composition have been recognized as contributing factors for both disorders. Underweight is a risk factor for OP, while obesity stimulates the development of OA, by mechanical overloading of weight-bearing joints but also by supposed unfavourable effects of adipokines.

The association between fracture site and obesity in men: a population-based cohort study

A site-dependent association between obesity and fracture has been reported in postmenopausal women. In this study we investigated the relationship between body mass index (BMI) and fracture at different skeletal sites in older men (≥65 years). We carried out a population-based cohort study using data from the Sistema d'Informació per al Desenvolupament de l'Investigació en Atenció Primària (SIDIAP(Q) ) database. SIDIAP(Q) contains the primary care and hospital admission computerized medical records of >1300 general practitioners (GPs) in Catalonia (Northeast Spain), with information on a representative 30% of the population (>2 million people). In 2007, 186,171 men ≥65 years were eligible, of whom 139,419 (74.9%) had an available BMI measurement. For this analysis men were categorized as underweight/normal (BMI < 25 kg/m(2) , n = 26,298), overweight (25 ≤ BMI < 30 kg/m(2) , n = 70,851), and obese (BMI ≥ 30 kg/m(2) , n = 42,270). Incident fractures in the period 2007 to 2009 were ascertained using International Classification of Diseases, 10th edition (ICD-10) codes. A statistically significant reduction in clinical spine and hip fractures was observed in obese (relative risk [RR], 0.65; 95% confidence interval [CI], 0.53-0.80 and RR, 0.63; 95% CI, 0.54-0.74, respectively), and overweight men (RR, 0.77; 95% CI, 0.64-0.92 and RR, 0.63; 95% CI 0.55-0.72, respectively) when compared with underweight/normal men. Additionally, obese men had significantly fewer wrist/forearm (RR, 0.77; 95% CI, 0.61-0.97) and pelvic (RR, 0.44; 95% CI, 0.28-0.70) fractures than underweight/normal men. Conversely, multiple rib fractures were more frequent in overweight (RR, 3.42; 95% CI, 1.03-11.37) and obese (RR, 3.96; 95% CI, 1.16-13.52) men. In this population-based cohort of older men, obesity was associated with a reduced risk of clinical spine, hip, pelvis, and wrist/forearm fracture and increased risk of multiple rib fractures when compared to normal or underweight men. Further work is needed to identify the mechanisms underlying these associations.

Relationship of adiposity to bone volumetric density and microstructure in men and women across the adult lifespan

Recent evidence suggests that adipose tissue may negatively impact bone health, challenging the traditional paradigm that increased fat mass, through mechanical loading or endogenous estrogen production, is beneficial to the skeleton. We hypothesized that it is primarily the visceral compartment of body fat that is detrimental to bone metabolism, resulting in impaired bone density and architecture. In an age-stratified population sample of 218 women and 291 men (age 20-97 years), we assessed visceral (VAT) and subcutaneous (SAT) adipose tissue areas at the L2-L3 interspace level by single slice quantitative computed tomography (QCT) and measured total body fat mass (TBF) by dual-energy X-ray absorptiometry. We then correlated these findings with volumetric bone mineral density (vBMD) at the femoral neck (FN) and lumbar spine (LS) assessed by central QCT, and with vBMD and microstructural parameters at the ultradistal radius (UDR) by high resolution peripheral QCT (HRpQCT). In unadjusted analyses in postmenopausal women, TBF and SAT were positively correlated with total, trabecular, and cortical vBMD at the FN, LS, and UDR and with trabecular microstructure at the UDR. By contrast, VAT was not correlated with vBMD at the FN or LS but was positively correlated with UDR total and trabecular vBMD but not cortical vBMD. Adjustment for age or for bioavailable estradiol and testosterone levels reduced these correlations, while adjustment for body weight eliminated most positive associations. Assessment of the VAT/SAT ratio, however, demonstrated a negative relationship with vBMD at the FN and LS in postmenopausal women, a relationship eliminated when adjusted for age. Correlations between skeletal parameters and adipose measurements in pre-menopausal women and older men were weaker and mostly non-significant. In younger men, VAT was negatively associated with vBMD, cortical thickness, and trabecular microstructure at the UDR, and with LS vBMD and FN cortical vBMD. These associations generally remained after adjustment, with some negative associations (e.g., UDR cortical area) being accentuated. Similar results were found when the VAT/SAT ratio was correlated with FN vBMD in younger men; in contrast, VAT/SAT was positively correlated with FN vBMD in older men and this relationship was strengthened by age-adjustment. Together, our data suggest that adiposity has associations with bone that are age-, gender-, menopausal status-, adipose depot-, and bone compartment-specific. These novel observations warrant further investigations to establish any causal relationships.

Association between abdominal obesity and fracture risk: a prospective study

CONTEXT

Higher body weight is associated with greater bone mineral density (BMD) and lower fracture risk. However, the relationship between abdominal fat mass (aFM) and fracture risk is unclear because of limited prospective data. The present study sought to examine the association between aFM, BMD, and fracture risk.

METHODS

The study was designed as a prospective investigation, in which a sample of 1126 participants (360 men and 766 women) aged 50 years or older had been continuously followed up for an average of 5 years. The mean age of participants was 71 years (range, 57-94 years). At baseline, BMD at the femoral neck and lumbar spine and aFM were measured by dual-energy X-ray absorptiometry. The incidence of low-trauma and nonpathological fractures was ascertained prospectively from X-ray reports.

RESULTS

During the follow-up period, 19 men and 107 women had sustained a fracture. In women, each 1-kg lower aFM was associated with a 50% higher risk of fracture (hazard ratio [HR], 1.50; 95% confidence interval [CI], 1.10-2.05) after adjustment for age, femoral neck BMD, falls, stature, physical activity, and prior fracture. Subgroup analysis by fracture type found that the association was mainly observed in clinical vertebral fracture (HR, 1.96; 95% CI, 1.22-3.13). In men, although there was no statistically significant association between aFM and fracture risk (HR, 1.15; 95% CI, 0.58-2.25), the strength of this finding is affected negatively by the low number of fractures.

CONCLUSIONS

Lower abdominal fat was significantly associated with an higher fracture risk in women.

The relationships among total body fat, bone mineral content and bone marrow adipose tissue in early-pubertal girls

Investigation of the physiologic relevance of bone marrow adipose tissue (BMAT) during growth may promote understanding of the bone-fat axis and confluence with metabolic factors. The objective of this pilot investigation was two-fold: (1) to evaluate the relationships among total body fat, bone mineral content (BMC) and femoral BMAT during childhood and underlying metabolic determinants and (2) to determine if the relationships differ by race. Participants included white and non-Hispanic black girls (n=59) ages 4–10 years. Femoral BMAT volume was measured by magnetic resonance imaging, BMC and body fat by dual-energy X-ray absorptiometry. Metabolic parameters were assessed in the fasted state. Total fat and BMC were positively associated with BMAT; however, simultaneous inclusion of BMC and body fat in the statistical model attenuated the association between BMC and BMAT. Differences in BMAT volume were observed, non-Hispanic black girls exhibiting marginally greater BMAT at age eight (P=0.05) and white girls exhibiting greater BMAT at age ten (P<0.001). Metabolic parameters conferred differential impact by race, such that, a positive association for BMAT and leptin (P=0.02) and adiponectin (P=0.002) in white girls while BMAT and insulin were inversely related in non-Hispanic black girls (P=0.008). Our findings revealed a positive relationship between BMAT, body fat and BMC, although body fat, respective to leptin, contributed partly to the relationship between BMAT and BMC. Despite large differences in total fat between non-Hispanic black and white, the relationship between BMAT and BMC was similar to white girls. However, this relationship appeared to be impacted through different mechanisms according to race.

Obesity and bone

Recent studies indicate that fractures in obese postmenopausal women and older men contribute significantly to the overall fracture burden. The effect of obesity is to some extent site-dependent, the risk being increased for some fractures and decreased for others, possibly related to different patterns of falling and the presence or absence of soft tissue padding. Risk factors for fracture in obese individuals appear to be similar to those in the nonobese population, although falls may be particularly important in the obese. There is some evidence that the morbidity associated with fractures in obese individuals is greater than in the nonobese; however, a recent study indicates that the mortality associated with fracture is lower in obese and overweight people than in those of normal weight. The evidence base for strategies to prevent fractures in obese individuals is weak and is an important area for future research.

Higher prevalence of morphometric vertebral fractures in patients with recent coronary events independently of BMD measurements

Cardiovascular disease and osteoporosis are important causes of morbi-mortality in the elderly and may be mutually related. Low bone mineral density (BMD) may be associated with increased risk of cardiovascular events. We investigated the prevalence of low bone mass and fractures in metabolic syndrome patients with acute coronary events. A case-control study was conducted with 150 individuals (30-80years-old) with metabolic syndrome. Seventy-one patients had had an acute coronary syndrome episode in the last 6months (cases) and the remaining 79 had no coronary event (controls). Cases and controls were matched for gender, BMI and age. DXA measurements and body composition were performed while spine radiographs surveyed for vertebral fractures and vascular calcification. Biochemical bone and metabolic parameters were measured in all patients. No statistically significant difference in BMD and the prevalence of osteopenia, osteoporosis and non-vertebral fractures was observed between cases and controls. The prevalence of vertebral fractures and all fractures was higher in the cases (14.1 versus 1.3%, p=0.003 and 22.5versus7.6%, p=0.010, respectively). Male gender (OR=0.22 95% CI 0.58 to 0.83, p=0.026) and daily intake of more than 3 portions of dairy products (OR=0.19 95% CI 0.49 to 0.75, p=0.017) were associated with lower prevalence of fractures. Cases had higher risk for fractures (OR=4.97, 95% CI 1.17 to 30.30, p=0.031). Bone mass and body composition parameters were not associated with cardiovascular risk factors or bone mineral metabolism. Patients with fragility fractures had higher OPG serum levels than those without fractures (p<0.001). Our findings demonstrated that patients with recent coronary events have a higher prevalence of vertebral fractures independently of BMD.

Cost-effectiveness of bone densitometry among Caucasian women and men without a prior fracture according to age and body weight

We used a microsimulation model to estimate the threshold body weights at which screening bone densitometry is cost-effective. Among women aged 55-65 years and men aged 55-75 years without a prior fracture, body weight can be used to identify those for whom bone densitometry is cost-effective.

INTRODUCTION

Bone densitometry may be more cost-effective for those with lower body weight since the prevalence of osteoporosis is higher for those with low body weight. Our purpose was to estimate weight thresholds below which bone densitometry is cost-effective for women and men without a prior clinical fracture at ages 55, 60, 65, 75, and 80 years.

METHODS

We used a microsimulation model to estimate the costs and health benefits of bone densitometry and 5 years of fracture prevention therapy for those without prior fracture but with femoral neck osteoporosis (T-score ≤ -2.5) and a 10-year hip fracture risk of ≥3%. Threshold pre-test probabilities of low BMD warranting drug therapy at which bone densitometry is cost-effective were calculated. Corresponding body weight thresholds were estimated using data from the Study of Osteoporotic Fractures (SOF), the Osteoporotic Fractures in Men (MrOS) study, and the National Health and Nutrition Examination Survey (NHANES) for 2005-2006.

RESULTS

Assuming a willingness to pay of $75,000 per quality adjusted life year (QALY) and drug cost of $500/year, body weight thresholds below which bone densitometry is cost-effective for those without a prior fracture were 74, 90, and 100 kg, respectively, for women aged 55, 65, and 80 years; and were 67, 101, and 108 kg, respectively, for men aged 55, 75, and 80 years.

CONCLUSIONS

For women aged 55-65 years and men aged 55-75 years without a prior fracture, body weight can be used to select those for whom bone densitometry is cost-effective.

Prevalence of low bone mass in postmenopausal Kuwaiti women residents in the largest province of Kuwait

We measured bone mineral density (BMD) in Kuwaiti women residents in the largest province of Kuwait state to highlight the BMD changes with each age, in particular when they reach the postmenopausal stage. Healthy Kuwaiti females between the ages of 10 and 89 years, who were residents in the largest province of Kuwait, were included in the study. After measurements of their height and weight, their bone mineral density of L2-L4 lumbar spine and femur (neck and total) was measured using dual-energy X-ray absorptiometry. Out of the studied 903 female subjects, 811 fulfilled the inclusion criteria. Their mean ± SEM age and body mass index (BMI) were respectively 47 ± 1 years and 30.8 ± 0.2 kg/m(2). Out of these 811 subjects, 454 were postmenopausal, and their age and BMI were 55.0 ± 0.3 years and 32.0 ± 0.3 kg/m(2), respectively. We have demonstrated that osteoporotic BMD of the spine and femur neck occurred in 20.2 and 12.5 % of postmenopausal Kuwaiti females, whereas osteopenic BMD of the spine and femur neck was observed at a frequency of 35.4 and 42.8 % of women, respectively. When the subjects were subdivided as per BMI, it was notable that overweight and obese had significantly higher BMD than normal weight postmenopausal women. BMD of the spine, femur neck, and femur total demonstrated significant positive correlations with body weight and BMI, whereas they demonstrated significant negative correlations with age. Low BMD of the femur neck and spine, reflected by the combination of osteopenia and osteoporosis, seemed to occur in more than half (55.3-55.6 %) of postmenopausal Kuwaiti women.

OBJECTIVES

Most of the studies on assessment of prevalence of low bone mass were focused in Caucasian population. Data on subjects of the Mediterranean area are limited. We measured bone mineral density (BMD) in Kuwaiti women residents in the largest province of Kuwait state to highlight the BMD changes with each age, in particular when they reach the postmenopausal stage.

SUBJECTS AND METHODS

Kuwaiti female subjects of different age groups between 10 and 89 years, who were residents in the largest province of Kuwait (Hawalli), were included in the study. They were included if they had been healthy over the last 12 months, had no past history of bone disease, and are not taking any prescription medication that may affect bone density. Their bone mineral density of L2-L4 lumbar spine and femur (neck and total) was measured using dual-energy X-ray absorptiometry.

RESULTS

Out of the studied 903 female subjects, 811 fulfilled the inclusion criteria and were included in the study. Their mean ± SEM age and body mass index (BMI) were respectively 47 ± 1 years and 30.8 ± 0.2 kg/m(2). Out of these 811 subjects, 454 were postmenopausal, and their age and BMI were 55.0 ± 0.3 years and 32.0 ± 0.3 kg/m(2), respectively. We have demonstrated that osteoporotic BMD of the spine and femur neck occurred in 20.2 and 12.5 % of postmenopausal Kuwaiti females, respectively, whereas osteopenic BMD of the spine and femur neck was observed at a frequency of 35.4 and 42.8 % of women. When subjects were subdivided as per BMI, it was notable that overweight and obese postmenopausal women had significantly higher BMD of lumbar spine, femur neck, and femur total than normal weight postmenopausal women. Bone mineral densities of the spine, femur neck, and femur total demonstrated significant positive correlations with body weight and BMI, whereas they demonstrated significant negative correlations with age.

CONCLUSION

Low BMD of the femur neck and spine, reflected by the combination of osteopenia and osteoporosis, seemed to occur in more than half (55.3-55.6 %) of postmenopausal Kuwaiti women residents at the largest province of Kuwait.