Diabetic peripheral neuropathy is highly associated with nontraumatic fractures in Korean patients with type 2 diabetes mellitus.

OBJECTIVE: Patients with type 2 diabetes mellitus are at greater risk of bone fractures than nondiabetics. However, the risk factors for fractures in patients with diabetes have not been fully evaluated. This study was designed to evaluate the relative frequency of fractures at different sites and the diabetes-associated factors that affect nontraumatic bone fracture in patients with type 2 diabetes. PATIENTS AND DESIGN: This retrospective case-control study recruited 144 patients with type 2 diabetes, who presented with nontraumatic fractures between March 2004 and March 2009 and 150 age-, gender-, body mass index (BMI)- and duration of diabetes-matched control subjects. Nontraumatic fractures were confirmed using patients' medical records and radiological findings. All subjects were examined for their diabetes status and associated factors for fracture, including bone mineral density (BMD). RESULTS: Of 150 reported bone fractures, the hip was the most frequent fracture site (32·7%), followed by the upper extremity (19·3%). Nontraumatic fractures were associated with diabetic retinopathy, diabetic peripheral neuropathy, stroke history, previous fracture and insulin treatment (P < 0·05). In multivariate analyses, independently associated factors for bone fracture were diabetic peripheral neuropathy [odds ratio (OR) = 37·3, 95% confidence interval (CI) = 1·46-652·57] and previous fracture (OR = 9·54, 95% CI = 1·18-77·37; P < 0·05). CONCLUSIONS: The hip was the most frequent site of nontraumatic fracture, and diabetic peripheral neuropathy was significantly associated with an increased risk of nontraumatic fractures in patients with type 2 diabetes.

Defining ethnic and racial differences in osteoporosis and fragility fractures.

BACKGROUND: Osteoporotic fractures are a major public health issue. The literature suggests there are variations in occurrence of fractures by ethnicity and race. QUESTIONS/PURPOSES: My purpose is to review current literature related to the influence of ethnicity and race on the (1) epidemiology of fracture; (2) prevalence of osteoporosis by bone mineral density; (3) consequences of osteoporotic hip fracture; (4) differences in risk fracture for fracture; and (5) disparities in screening, diagnosis, and treatment of osteoporosis. METHODS: Current literature was selectively reviewed related to osteoporosis, ethnicity, and race. RESULTS: Ethnicity and race, like sex, influence the epidemiology of fractures, with highest fracture rates in white women. Bone mineral density is higher in African Americans; however, these women are more likely to die after hip fracture, have longer hospital stays, and are less likely to be ambulatory at discharge. Consistent risk factors for fracture across ethnicity include older age, lower bone mineral density, previous history of fracture, and history of two or more falls. Ethnic and racial disparities exist in the screening, diagnosis, and treatment of osteoporosis. CONCLUSIONS: Across ethnic and racial groups, more women experience fractures than the combined number of women who experience breast cancer, myocardial infarction, and coronary death in 1 year. Prevention efforts should target all women, irrespective of their race/ethnicity, especially if they have multiple risk factors.

Low risk of vertebral fracture in Mexican American women.

Ethnicity is important in assessing risk for osteoporotic fractures, and should be considered in decision-making about the use of prophylactic treatments. Few data are available, however, on fracture risks among Hispanic patients. To assess the risk of vertebral fracture in Mexican Americans, we determined the prevalence of vertebral fracture among 822 patients, aged 15 to 86 years, who underwent spinal roentgenography in a study of low-back pain. After adjusting for age, use of steroids, drug or alcohol abuse, and recent trauma, the odds ratio for Mexican American women compared with non-Hispanic whites was 0.55 (95% confidence interval, 0.32 to 0.95), indicating a substantially lower risk. These results are concordant with earlier data documenting a reduced risk of hip fracture among Mexican American women. Thus, recommendations for prophylactic treatments for osteoporosis may be different for Mexican Americans than for non-Hispanic whites.

Bone fragility in Asian and Caucasian men.

Hip and vertebral fractures are a public health problem in men of Asian and Caucasian origin. Inferences regarding gender and racial/ethnic differences in fracture rates must be made cautiously as problems in case ascertainment and classification of hip fractures, and problems in defining what constitutes a vertebral 'fracture' have not been solved. However, methodological issues probably do not entirely account for the heterogeneity of fracture patterns. There is likely to be a wide variation in fracture rates from country to country in Asia as reported in studies in Europe. The reasons for this heterogeneity are unknown. Caucasian men lose similar amounts of bone as Caucasian women during ageing from the endosteal surface of the bone. Net bone loss is less in men than women because men form more periosteal bone during ageing than do women. The extent of periosteal and endosteal bone modelling and remodelling have not been studied in Asian men and women. Nor have there been hypothesis-driven studies designed to compare periosteal apposition and endosteal bone loss in Asian males compared to Caucasian males. Sex hormone deficiencies contribute to abnormalities in skeletal size and mass during growth, remodelling imbalance and bone loss during ageing in men. The larger peak bone size and greater periosteal apposition with ageing in men compared to women is most likely to be androgen-dependent in Caucasians and Asians. Androgen deficiency may also partly account for reduced bone formation and negative bone balance at the basic multicellular unit (BMU). Oestrogen deficiency during growth is associated with reduced bone mass and increased leg length in males and females. Oestrogen deficiency during ageing may account for trabecular bone loss in men by increasing remodelling rate. There have been no anti-fracture efficacy studies done in Asian males. Studies on the pathophysiology of osteoporosis in males have given insight into the pathophysiology of osteoporosis in females. Similarly, collaborative research efforts between groups around the world will facilitate comparative studies in Asian and Caucasian communities. The results of this work will provide important insights into the pathophysiology of bone fragility in both groups.

Type 2 diabetes is associated with vertebral fractures in a sample of clinic- and hospital-based Latinos.

Latinos are the fastest growing ethnic population in the United States and type 2 diabetes is a major health burden in this population, but little effort has been made to study the prevalence of diabetic vertebral fragility in Latinos. We performed a cross-sectional study to determine vertebral fracture prevalence in a hospital-based population of South Texas residents (N = 296). We defined fractures in X-rays as a >20% reduction in vertebral body height. Numerous variables were recorded, including age, body mass index, indicators of diabetes management and others. 71% of the sample (N = 296) was Latino. The prevalence of vertebral fracture was increased in diabetic subjects relative to non-diabetic subjects (diabetic 27.9%, non-diabetic 13.8%) and, regardless of sex and diabetics status, decreased in Latinos relative to non-Latinos (Latino 16.7%, non-Latino 26.4%). These data suggest that vertebral fractures may be a growing concern for diabetic Latinos as well as diabetics of any racial/ethnic background.

High prevalence of asymptomatic vertebral fractures in Chinese women with systemic lupus erythematosus.

OBJECTIVE: To investigate the prevalence of vertebral fractures and to identify risk factors associated with vertebral fractures in Chinese women with systemic lupus erythematosus (SLE). METHODS: One hundred fifty-two consecutive patients with SLE were recruited in this cross-sectional study. Bone mineral density (BMD) measurements of the hip and spine were performed using the same dual energy X-ray absorptiometry (DEXA). Lateral radiographs of the spine (T5-L4) were assessed for vertebral fractures using a method described by Genant. Inflammatory and biochemical markers included C-reactive protein, receptor activator of nuclear factor-kappaB ligand, serum ss-CrossLaps assay for C-terminal telopeptides of type 1 collagen, and osteoprotegerin (OPG). RESULTS: Asymptomatic vertebral fractures occurred in 20.4% of patients with SLE. Univariate analyses of variables associated with fractures were older age, higher body mass index (BMI), lower BMD spine, lower BMD hips, higher serum C3 and C4, longer estrogen exposure, higher levels of OPG, and the use of sunscreen. Multivariate analysis showed older age (p = 0.017), higher BMI (p < 0.036), and lower BMD of the spine were significantly associated with vertebral fractures in the thoracic and/or lumbar spine (odds ratio 1.068, 1.166, 0.005; p = 0.018, p = 0.025, p = 0.003, respectively). CONCLUSION: Asymptomatic vertebral fractures occur in 20.4% of patients with SLE and 30% of these patients have normal BMD. The current method using DEXA to predict the presence of vertebral fracture has limited value and there is a need for assessment of bone quality. Vertebral morphometry in patients with SLE is recommended and early therapeutic intervention is necessary to prevent vertebral fractures in patients with SLE.

Skeletal health among African Americans with recent-onset rheumatoid arthritis.

OBJECTIVE: African Americans with rheumatoid arthritis (RA) may be at increased fracture risk. We applied the World Health Organization (WHO) Fracture Risk Assessment Tool (FRAX) and National Osteoporosis Foundation (NOF) guidelines to a cohort of African Americans with early RA to identify which patients were recommended for osteoporosis treatment. METHODS: Risk factors and bone mineral density (BMD) were assessed in a cohort of African Americans with RA. The WHO FRAX tool estimated 10-year fracture risk. Patients were risk stratified using FRAX without BMD to identify which individuals might be most efficiently targeted for BMD testing. RESULTS: Participants (n = 324) had a mean age of 51 years and included 81% women. There were no associations of RA disease characteristics with BMD. The proportion of patients recommended for osteoporosis treatment varied from 3-86%, depending on age and body mass index (BMI). Ten-year fracture risk calculated with BMI only was generally the same or higher than fracture risk calculated with BMD; adding BMD data provided the most incremental value to risk assessment in patients 55-69 years of age with low/normal BMI, and in those > or =70 years of age with BMI > or =30 kg/m2. CONCLUSION: A high proportion of African Americans with RA were recommended for treatment under the 2008 NOF guidelines. FRAX without BMD identified low-risk patients accurately. Systematic application of FRAX to screen high-risk groups such as patients with RA may be used to target individuals for BMD testing and reduce the use of unnecessary tests and treatments.

The relationship of absolute poverty and bone mineral density in postmenopausal Iranian women.

OBJECTIVE: It is increasingly recognized that socioeconomic inequalities play an important role in bone health, with significantly higher fracture rates being reported in lower income groups. But the relationship between absolute poverty and bone mineral density (BMD) and/or osteoporosis has not been investigated. METHODS: A total of 1135 postmenopausal women under absolute poverty lines who received financial support from the Imam Khomeini Relief Foundation (IKRF) and 406 randomly selected healthy postmenopausal women were screened for osteoporosis using BMD testing. RESULTS: At all BMD sites, women under the absolute poverty lines had the lowest mean BMD values (p < 0.0001). According to the WHO criteria, 252 subjects under absolute poverty lines (22.4%) and 35 healthy postmenopausal women from the general population (8.7%) were considered osteoporotic (p < 0.0001). After adjustment for lifestyle factors for osteoporosis in logistic regression models, absolute poverty was associated with the age-adjusted prevalence of femoral neck osteoporosis and lumbar osteoporosis [OR = 2.50 (CI, 1.38-4.51; p = 0.002); OR = 2.40 (CI, 1.56-3.70; p < 0.0001), respectively]. CONCLUSION: Postmenopausal women under the absolute poverty lines had lower BMDs at all skeletal sites, independent of established osteoporosis risk factors.

Cortical bone remodeling rates in a sample of African American and European American descent groups from the American Midwest: comparisons of age and sex in ribs.

This study employs regression analysis to explore population and sex differences in the pattern of age-associated bone loss, as reflected by histomorphometric variables that are measures of intracortical and endocortical bone remodeling. A comparison of an African American sample from the Washington Park Cemetery in St. Louis, Missouri, and a European American rib sample composed of cadavers, autopsies, and forensic cases from Missouri reveals the existence of complex age-associated patterns for differences in measures of intracortical remodeling and cortical area. Females from the two samples express similar bone dimensions and dynamics. The African American females appear to lose more bone than their male counterparts, but this difference is absent in the European American sample. When age-associated patterns are considered, it is in the younger cohorts that African Americans exhibit greater relative cortical area than European Americans, but this is reversed in the older ages, when the latter group manifests greater bone mass. The European American males consistently differ in the slopes and intercepts for the variables compared to the other groups, and differences are highly significant with African American females, with the former group maintaining bone mass while the latter exhibit a more rapid bone loss. Achieving larger relative cortical area due to smaller endosteal area, coupled with better bone quality due to lower intracortical porosity early in life, may be a mechanism by which African Americans, especially females, maintain adequate bone mass in older ages, which buffers them from bone loss and related fragility fractures despite higher rates of intracortical remodeling and endosteal expansion later in life. These results suggest that both genetic and environmental factors are responsible for the differences in bone remodeling and bone mass observed between these samples.

Osteoporosis and African American women.

The incidence of osteoporosis and related fractures in African American women is half that of Caucasian women. African American women who sustain osteoporosis-related fractures have increased disability and decreased survival. Given the exponential increase in hip fracture rate among African American women over the age of 70 years, the risk of osteoporosis among this population may be underestimated. This review focuses on racial differences in women's bone mineral density (BMD) and bone metabolism and on various explanations for these observed differences. Environmental risk factors for osteoporosis and related fractures among African American women and modalities for prevention and treatment of osteoporosis are discussed. African American women begin menopause with higher BMD and have lower rates of women's bone loss after menopause, which account for their decreased incidence of osteoporosis and related fractures. The risk factors for osteoporosis among African American women are similar to those found in Caucasian women. Lifestyle interventions, such as calcium and vitamin D supplementation, smoking cessation, and increased physical activity, should be encouraged to enhance peak bone mass and to decrease bone loss. These interventions and other treatment modalities, such as hormone replacement therapy, bisphosphonates, and selective estrogen receptor modulators, should be studied further in African American women.

External rotation of the hip. A predictor of risk for stress fractures.

External rotation of the hip was found to have a statistically significant correlation with the incidence of stress fractures, in a prospective study among Israeli infantry recruits of possible anthropomorphic predictors of risk for stress fractures. Soldiers in whom hip external rotation was greater than 65 degrees were at a higher risk for tibial and total stress fractures than those with external rotations of less than 65 degrees. The mean hip external rotation in this study of 57 degrees +/- 9.3 degrees was higher than in statistics reported in the American literature. The existence of a larger subpopulation with hip external rotation greater than 65 degrees may partially explain why the reported incidence of stress fractures in the Israeli army is higher than that of the American army.

Calcaneal ultrasound attenuation in older African-American and Caucasian-American women.

The lower fracture rates among African-American women relative to Caucasian women may reflect their higher bone mass. However, bone mass is not the only determinant of bone strength: the quality and microarchitecture of the bone are also important. Quantitative ultrasound is believed to measure properties of bone strength that are independent of bone mass. To test the hypothesis that there are racial differences in quantitative ultrasound measures of bone, we recruited 154 African-American women age > or = 65 years. A random sample of 300 Caucasian women participating in the Study of Osteoporotic Fractures in Pittsburgh, Pennsylvania, was chosen for comparison. The Walker Sonix UBA 575+ was used to measure calcaneal broadband ultrasonic attenuation (BUA). Duplicate BUA measurements were obtained with a reproducibility of 5%. We measured bone mineral density (BMD) of the hip and calcaneus using single (calcaneus) or dual (hip) energy X-ray absorptiometry. The correlation between BUA and calcaneal BMD was similar in Caucasians (r = 0.66, p < 0.001) and African-Americans (r = 0.58, p < 0.001). Age-adjusted BUA (dB/MHz) was higher among the African-American women than Caucasian women (69.1 and 66.2, respectively), but these differences were not statistically significant, (p = 0.12). Adjustment for calcaneal BMD completely attenuated the racial differences in BUA. BMD at the femoral neck and calcaneus was higher among the African-American women, even after adjusting for age, height and weight. In conclusion, our results suggest that racial differences in rates of fracture cannot be explained by differences in bone quality as assessed by ultrasound attenuation.

Sex and ethnic differences in bone architecture.

Technologic developments and applications such as dual energy x-ray absorptiometry, magnetic resonance imaging, and computed tomography have enabled researchers to assess bone quantity (ie, bone mineral density) and bone quality (ie, bone architecture), which are two important and independent contributions to bone strength. Recent studies on sex differences in bone architecture indicate that a number of biomechanical variables lead to increased bone strength in males compared with females. Ethnic differences in bone architecture are less clear-cut, indicating a need to identify and test the social and biologic variables that race and ethnicity represent. New methods using magnetic resonance imaging technology may become important in creating efficient and reliable in vivo methods of assessing features of bone architecture that are relevant to fracture risk and contribute to the elucidation of sex and ethnic differences in osteoporosis.

Differences between lactase deficient and non-lactase deficient women with spinal osteoporosis.

Both osteoporosis and lactase deficiency are seen commonly in the United States. Since the latter may lead to avoidance of calcium sources and may exacerbate the bone disease in populations at risk, we studied lactose tolerance and histomorphometrically analyzed undecalcified transiliac bone biopsies in a consecutive group of postmenopausal women with the osteoporotic spinal compression fracture syndrome. Oral lactose tolerance tests prior to the biopsy clearly separated two groups. Sixty-five percent had abnormal test results. The bone biopsies in the lactase deficient group showed more osteoid volume and osteoid seam widths on examined trabecular bone. Analysis of tetracycline-labeled bone revealed significant increases in both single, double, combined single and double tetracycline labels, and the percent osteoid labeled with tetracycline. There was no difference in the calcification rates. These findings indicate different mineralization activity in lactase deficient patients, possibly reflecting their lower dietary calcium intake.