Aging and bone metabolism in African American and Caucasian women

Menopausal hormone therapy and risk of sarcoidosis: a population-based nested case-control study in Sweden

Sarcoidosis incidence peaks in women between 50 and 60 years old, which coincides with menopause, suggesting that certain sex hormones, mainly estrogen, may play a role in disease development. We investigated whether menopausal hormone therapy (MHT) was associated with sarcoidosis risk in women and whether the risk varied by treatment type. We performed a nested case-control study (2007-2020) including incident sarcoidosis cases from the Swedish National Patient Register (n = 2593) and matched (1:10) to general population controls (n = 20,003) on birth year, county, and living in Sweden at the time of sarcoidosis diagnosis. Dispensations of MHT were obtained from the Swedish Prescribed Drug Register before sarcoidosis diagnosis/matching. Adjusted odds ratios (aOR) of sarcoidosis were estimated using conditional logistic regression. Ever MHT use was associated with a 25% higher risk of sarcoidosis compared with never use (aOR 1.25, 95% CI 1.13-1.38). When MHT type and route of administration were considered together, systemic estrogen was associated with the highest risk of sarcoidosis (aOR 1.51, 95% CI 1.23-1.85), followed by local estrogen (aOR 1.25, 95% CI 1.11-1.42), while systemic estrogen-progestogen combined was associated with the lowest risk compared to never users (aOR 1.12, 95% CI 0.96-1.31). The aOR of sarcoidosis did not differ greatly by duration of MHT use. Our findings suggest that a history of MHT use is associated with increased risk of sarcoidosis, with women receiving estrogen administered systemically having the highest risk.

Reproductive and hormonal risk factors for sarcoidosis: a nested case–control study

Background

Sarcoidosis incidence peaks in females around the fifth decade of life, which coincides with menopause, suggesting hormonal factors play a role in disease development. We investigated whether longer exposure to reproductive and hormonal factors is associated with reduced sarcoidosis risk.

Methods

We conducted a matched case–control study nested within the Mammography Screening Project. Incident sarcoidosis cases were identified via medical records and matched to controls on birth and questionnaire date (1:4). Information on hormonal factors was obtained through questionnaires prior to sarcoidosis diagnosis. Multilevel modelling was used to estimate adjusted odds ratios with 95% credible intervals (OR; 95% CI).

Results

In total, 32 sarcoidosis cases and 124 controls were included. Higher sarcoidosis odds were associated with older age at menarche (OR 1.19: 95% CI 0.92–1.55), natural menopause versus non-natural (OR 1.53: 95% CI 0.80–2.93), later age at first pregnancy (OR 1.11: 95% CI 0.76–1.63) and ever hormone replacement therapy (HRT) use (OR 1.40: 95% CI 0.76–2.59). Lower odds were associated with older age at menopause (OR 0.90: 95% CI 0.52–1.55), longer duration of oral contraceptive use (OR 0.70: 95% CI 0.45–1.07), longer duration of HRT use (OR 0.61: 95% CI 0.22–1.70), ever local estrogen therapy (LET) use (OR 0.83: 95% CI 0.34–2.04) and longer duration of LET use (OR 0.78: 95% CI 0.21–2.81). However, the CIs could not rule out null associations.

Conclusion

Given the inconsistency and modest magnitude in our estimates, and that the 95% credible intervals included one, it still remains unclear whether longer estrogen exposure is associated with reduced sarcoidosis risk.

Vitamin D and Abdominal Aortic Calcification in Older African American Women, the PODA Clinical Trial

Abdominal aortic calcification (AAC) detected on lateral vertebral fracture assessment is associated with increased cardiovascular risk. Vitamin D deficiency and toxicity have been linked with vascular calcification. The objective of this study was to determine the effect of high-dose vitamin D on the progression of AAC. The Physical Performance, Osteoporosis and vitamin D in African American Women (PODA) is a randomized, clinical trial examining the effect of vitamin D. There were 14.7% subjects with AAC in the vitamin D group, compared to 12.1% in the placebo group at baseline. The prevalence of extended AAC at baseline was 6.4% in the vitamin D group and 3.5% in the placebo group. The extended calcification scores over time were not different between groups. There was no association between AAC and serum 25(OH)D. However, PTH was associated with an increase in AAC in the placebo group.

Inter-population variation of histomorphometric variables used in the estimation of age-at-death

Population variation of several microscopic structures used in age-at-death estimation was assessed for three different population samples. The aim of the study was to determine if the need exists for population-specific standards when dealing with individuals of African and European origin. A total sample 223 bone sections from the anterior cortex of the femur (n = 99 black South Africans, n = 94 white South Africans and n = 30 Danish individuals) were analysed using a stereological protocol. Variables assessed included the average number of osteons per grid area (OPD), osteon size and Haversian canal size. ANCOVA was employed for assessment of statistically significant differences. The results indicated that OPD differed significantly between the three groups, but that osteon size was similar for all individuals. Haversian canal size showed unpredictable changes with age and high levels of variation, making it unsuitable to use for age estimation as a single factor. As there are conflicting opinions in the literature on whether to use population-specific equations for the estimation of age-at-death or not, this paper provided additional insight into the use of specific variables and its related variation between groups.

Screening for Vitamin D Deficiency in Black Americans: Comparison of Total, Free, Bioavailable 25 Hydroxy Vitamin D Levels with Parathyroid Hormone Levels and Bone Mineral Density

OBJECTIVES

There is debate surrounding the adequacy of total and free 25 hydroxy vitamin D [25(OH)D] levels in black Americans who have inherently high bone mineral density [BMD] and low serum concentration of vitamin D binding proteins [VDBP].

DESIGN

Retrospective analysis of serum samples and BMD analyses from the African American Health Study [AAHS] cohort.

SETTING

The AAHS is a population-based longitudinal study initiated to examine issues of disability and frailty among urban-dwelling black Americans in the city of Saint Louis, Missouri.

PARTICIPANTS

122 men and 206 women, age 60.2 ± 4.3 years.

INTERVENTION

Retrospective analysis.

MEASUREMENTS

Total 25(OH)D, VDBP, PTH, and BMD of the lumbar spine and hip by dual energy x-ray photometry (DXA). Free and bioavailable vitamin D levels were calculated using serum concentrations and affinity constants for the VDBP (Gc1F and Gc1S) phenotypes.

RESULTS

Serum total 25(OH)D levels were 14.6 ± 8.9 ng/mL (36 ± 22 nmol/L). Vitamin D insufficiency was estimated by compensatory elevations of PTH above the normal range (> 65 pg/mL). PTH levels were within the normal reference range in > 95% of the samples at total 25(OH)D levels ≥ 20 ng/mL (≥50 nmol/L). There was no difference in the correlation of the reciprocal relationship of vitamin D vs parathyroid hormone between the VDBP phenotypes. Receiver operating characteristic curve analyses indicated that serum total 25(OH)D discriminated sufficiency from insufficiency at least as well as the calculated levels of the free and bioavailable vitamin D. Very low levels of total 25(OH)D (≤ 8 ng/mL, ≤20 nmol/L) were associated with decreased BMD (p=0.02), but higher levels of 25(OH)D did not show statistical differences in BMD.

CONCLUSION

Total 25(OH)D levels of ≤ 8ng/mL (≤20 nmol/L) are associated with clinically significant changes in BMD, whereas total 25(OH)D levels ≥ 20 ng/mL (≥50 nmol/L) suppressed PTH and were not associated with deficiencies in BMD. Lower levels of 25(OH)D may be acceptable for bone health in black than in white Americans.

Lifelong challenge of calcium homeostasis in male mice lacking TRPV5 leads to changes in bone and calcium metabolism

Trpv5 plays an important role in calcium (Ca²⁺) homeostasis, among others by mediating renal calcium reabsorption. Accordingly, Trpv5 deficiency strongly stresses Ca²⁺ homeostasis in order to maintain stable serum Ca²⁺. We addressed the impact of lifelong challenge of calcium homeostasis on the bone phenotype of these mice.

Aging significantly increased serum 1,25(OH)₂D₃ and PTH levels in both genotypes but they were more elevated in Trpv5^−/− mice, whereas serum Ca²⁺ was not affected by age or genotype. Age-related changes in trabecular and cortical bone mass were accelerated in Trpv5^−/− mice, including reduced trabecular and cortical bone thickness as well as reduced bone mineralization. No effect of Trpv5 deficiency on bone strength was observed. In 78-week-old mice no differences were observed between the genotypes regarding urinary deoxypyridinoline, osteoclast number, differentiation and activity as well as osteoclast precursor numbers, as assessed by flow cytometry.

In conclusion, life-long challenge of Ca²⁺ homeostasis present in Trpv5^−/− mice causes accelerated bone aging and a low cortical and trabecular bone mass phenotype. The phenotype of the Trpv5^−/− mice suggests that maintenance of adequate circulatory Ca²⁺ levels in patients with disturbances in Ca²⁺ homeostasis should be a priority in order to prevent bone loss at older age.

Cognitive Function and Salivary DHEA Levels in Physically Active Elderly African American Women

Serum and plasma dehydroepiandrosterone sulfate (DHEAS) concentration has been associated with several health parameters associated with aging including cognitive function, bone mineral density, and muscular strength. However, the effectiveness of salivary DHEA for the prediction of cognitive function, bone mineral density, and muscular strength in older adults is currently unknown. Thirty elderly African American females provided early morning salivary samples and DHEA levels were determined using a commercially available immunoassay. Participants completed testing for psychomotor and executive function via Trail Making Tests (TMT) A and B, respectively. Bone ultrasound attenuation (BUA) was used to bone density and an isometric mid-thigh pull (IMTP) was used to determine isometric strength. Age significantly correlated with time on TMT A (r=0.328) and B (r=0.615) but was not related to DHEA, BUA, or IMTP outcomes. Elevated DHEA was associated with longer time to completion for TMT A (χ (2) = 5.14) but not to TMT B. DHEA levels were not associated with BUA or IMTP outcomes. While elevated levels of DHEA were correlated with impaired psychomotor function, salivary DHEA is not associated with executive function, bone mineral density, or isometric strength in elderly African American women.

Evidence that increased ovarian aromatase activity and expression account for higher estradiol levels in African American compared with Caucasian women

CONTEXT

Serum estradiol levels are significantly higher across the menstrual cycle in African American (AAW) compared with Caucasian women (CW) in the presence of similar FSH levels, yet the mechanism underlying this disparity is unknown.

OBJECTIVE

The objective of the study was to determine whether higher estradiol levels in AAW are due to increased granulosa cell aromatase mRNA expression and activity.

DESIGN

The design of the study included daily blood sampling and dominant follicle aspirations at an academic medical center during a natural menstrual cycle.

SUBJECTS

Healthy, normal cycling AAW (n = 15) and CW (n = 14) aged 19-34 years participated in the study.

MAIN OUTCOME MEASURES

Hormone levels in peripheral blood and follicular fluid (FF) aspirates and aromatase and FSH receptor mRNA expression in granulosa cells were measured.

RESULTS

AAW had higher FF estradiol [1713.0 (1144.5-2032.5) vs 994.5 (647.3-1426.5) ng/mL; median (interquartile range); P < .001] and estrone [76.9 (36.6-173.4) vs 28.8 (22.5-42.1) ng/mL; P < .001] levels than CW, independent of follicle size. AAW also had lower FF androstenedione to estrone (7 ± 1.8 vs 15.8 ± 4.1; mean ± SE; P = .04) and T to estradiol (0.01 ± 0.002 vs 0.02 ± 0.005; P = .03) ratios, indicating enhanced ovarian aromatase activity. There was a 5-fold increase in granulosa cell aromatase mRNA expression in AAW compared with CW (P < .001) with no difference in expression of FSH receptor. FSH, inhibin A, inhibin B, and AMH levels were not different in AAW and CW.

CONCLUSIONS

Increased ovarian aromatase mRNA expression, higher FF estradiol levels, and decreased FF androgen to estrogen ratios in AAW compared with CW provide compelling evidence that racial differences in ovarian aromatase activity contribute to higher levels of estradiol in AAW across the menstrual cycle. The absence of differences in FSH, FSH receptor expression, and AMH suggest that population-specific genetic variation in CYP19, the gene encoding aromatase, or in factors affecting its expression should be sought.

Socioeconomic status, race, and bone turnover in the Midlife in the US Study

Among a group of 940 US adults, economic adversity and minority race status were associated with higher serum levels of markers of bone turnover. These results suggest that higher levels of social stress may increase bone turnover.

INTRODUCTION

To determine socioeconomic status (SES) and race differences in levels of bone turnover.

METHODS

Using data from the Biomarker Substudy of the Midlife in the US (MIDUS) study (491 men, 449 women), we examined cross-sectional associations of SES and race with serum levels of bone turnover markers (bone-specific alkaline phosphatase [BSAP], procollagen type I N-terminal propeptide [PINP], and N-telopeptide [Ntx]) separately in men and women. Linear multivariable regression was used to control for body weight, menopausal transition stage, and age.

RESULTS

Among men, low family poverty-to-income ratio (FPIR) was associated with higher turnover, but neither education nor race was associated with turnover. Men with FPIR <3 had 1.808 nM BCE higher Ntx (P = 0.05), 3.366 U/L higher BSAP (P = 0.02), and 7.066 higher PINP (P = 0.02). Among women, neither education nor FPIR was associated with bone turnover, but Black women had 3.688 nM BCE higher Ntx (P = 0.001), 5.267 U/L higher BSAP (P = 0.005), and 11.906 μg/L higher PINP (P = 0.008) compared with non-Black women.

CONCLUSIONS

Economic adversity was associated with higher bone turnover in men, and minority race status was associated with higher bone turnover in women, consistent with the hypothesis that higher levels of social stresses cause increased bone turnover. The magnitude of these associations was comparable to the effects of some osteoporosis medications on levels of turnover.

Estrogen levels are higher across the menstrual cycle in African-American women compared with Caucasian women

CONTEXT

Previous studies have suggested that estrogen levels may be higher in African-American women (AAW) compared with Caucasian women (CW), but none have systematically examined estrogen secretion across the menstrual cycle or in relation to other reproductive hormones.

OBJECTIVE

The objective of the study was to compare estradiol (E2), progesterone (P), gonadotropins, androstenedione (a'dione), inhibins, and SHBG levels between AAW and CW across the menstrual cycle.

DESIGN, SETTING, AND SUBJECTS

Daily blood samples were collected from regularly cycling AAW (n = 27) and CW (n = 27) for a full menstrual cycle, and serial ultrasounds were performed.

MAIN OUTCOME MEASURES

Comparison of E2, P, LH, FSH, SHBG, inhibin A, inhibin B, and a'dione levels.

RESULTS

AAW and CW were of similar age (27.2 ± 0.6 yr, mean ± sem) and body mass index (22.7 ± 0.4 kg/m(2)). All subjects grew a single dominant follicle and had comparable cycle (25-35 d) and follicular phase (11-24 d) lengths. E2 levels were significantly higher in AAW compared with CW (P = 0.02) with the most pronounced differences in the late follicular phase (225.2 ± 14.4 vs. 191.5 ± 10.2 pg/ml; P = 0.02), midluteal phase (211.9 ± 22.2 vs.150.8 ± 9.9, P < 0.001), and late luteal phase (144.4 ± 13.2 vs. 103.5 ± 8.5, P = 0.01). Although LH, FSH, inhibins A and B, P, a'dione, and SHBG were not different between the two groups, the a'dione to E2 ratio was lower in AAW (P < 0.001).

CONCLUSIONS

Estradiol is higher in AAW compared with CW across the menstrual cycle. Higher estradiol in the face of similar androstenedione and FSH levels suggests enhanced aromatase activity in AAW. Such differences may contribute to racial disparities in bone mineral density, breast cancer, and uterine leiomyomas.

High prevalence of low vitamin D and musculoskeletal complaints in women with breast cancer

Reduced vitamin D levels may play a significant role in the development of fractures and musculoskeletal pains reported in patients on aromatase inhibitors (AIs) for breast cancer. In this study, we evaluated the vitamin D status in postmenopausal women with non-metastatic breast cancer who were about to start AI therapy. This study was conducted on community dwelling postmenopausal subjects, aged 35-80 years, with early non-metastatic breast cancer (up to stage IIIA), who were about to start therapy using third generation AIs. Symptoms of joint and muscle pains were obtained using a modified Leuven menopausal questionnaire. 25-hydroxyvitamin D [25(OH)D] was evaluated by radioimmunoassay while bone mineral density (BMD) of the lumbar spine and the proximal femur by dual energy x-ray absorptiometry (DXA). Of the 145 participants (mean age = 60.96 ± 0.88 years), 63 of 145 (43.5%) had baseline levels of 25(OH)D of < 20 ng/mL (deficient), 50 of 145 (34.5%) had levels between 20 and 29 ng/mL (insufficient), and only 32 of 145 (22%) had ≥ 30 ng/mL (sufficient); thus, 113 of 145 (78%) had low 25(OH)D levels (i.e., < 30 ng/mL). Arthralgias and myalgias were found in 61.3% and 43% of patients, respectively; and of those, 83.3% and 88.1% had 25(OH)D of < 30 ng/mL, respectively. Prevalence of vitamin D deficiency is high in breast cancer women and this may increase the risk of bone loss and fractures in those who are going to start AIs. Moreover, musculoskeletal pains are common in breast cancer women, even before the initiation of AIs and in association with low vitamin D in the majority. Future studies may be needed to establish the contribution of low vitamin D, if any, on the prevalence of musculoskeletal pains in women on AIs.

Estrogen therapy and bone mineral density in African-American and Caucasian women

Controlling for body size and composition, the authors examined the association between estrogen therapy and bone mineral density in older African-American and Caucasian women. In 1992-1998, 443 African-American and 989 Caucasian women aged 45-87 years were assessed for medication use, laboratory variables, behavioral characteristics, and bone mineral density. The mean age was 61.3 (95% confidence interval: 60.3, 62.3) years in African Americans and 71.0 (95% confidence interval: 70.4, 71.7) years in Caucasians (P < 0.001). All measures of body size and composition were significantly greater in the African-American women compared with Caucasian women (P < 0.001). As expected, African Americans had significantly higher bone mineral density at all 4 sites independent of age, weight, body composition, estrogen use, and lifestyle factors. Although Caucasians were significantly more likely to currently use estrogen (48.9% vs. 33.9%; P < 0.001), African Americans not using estrogen had significantly higher bone mineral density at all sites except the spine than Caucasians who were using estrogen. Regression models including age and lean mass explained the most variation in bone mineral density (R(2) range = 0.13-0.37). Results suggest that higher levels of bone mineral density in African-American women were not due to estrogen use.

Utilization of preoperative patient factors to predict postoperative vitamin D deficiency for patients undergoing gastric bypass

INTRODUCTION

Vitamin D deficiency occurring after gastric bypass procedures can predispose patients to calcium and parathyroid hormone (PTH) level abnormalities. The aim of the study is to identify preoperative patient risk factors for postoperative vitamin D deficiency.

METHODS

We retrospectively reviewed patients who underwent Roux-en-Y gastric bypass procedures between 2005 and 2006. Patient demographics, laboratory values of calcium, vitamin D, and PTH were followed at quarterly intervals for 1 year.

RESULTS

One hundred forty-five patients were included in the study. The mean age for the group was 44 years with an average body mass index of 49.5 kg/m(2). Eighty-six percent of patients were female and 23% was African-American. Forty-two percent of the patients had vitamin D deficiency (<20 ng/mL) either preoperatively or at year 1. The mean calcium levels decreased from 9.39 to 9.16 mg/dL (p < 0.001) while the mean PTH levels increased from 25.7 to 43.9 ng/mL (p < 0.001). A logistic regression model recognized preoperative vitamin D levels, race, and bypass limb length to be the only significant factors (p < 0.05) for postoperative vitamin D deficiency.

CONCLUSION

It is important to recognize patients who are at risk for vitamin D deficiency before surgery so that early intervention could be in place to minimize further postoperative deficiency.

Lean body mass, not estrogen or progesterone, predicts peak bone mineral density in premenopausal women

Estrogen and body fat content are important predictors of bone mineral density (BMD) in postmenopausal women, but their association with BMD in premenopausal women is less clear. Mounting evidence suggests that dietary fats can have detrimental effects on bone health. In a cross-sectional sample of healthy 30- to 40-y-old women (n = 242), we investigated the predictors of BMD at the hip and spine by multilevel multiple regression analyses. Predictor variables in the models included dietary intake of various fats, serum concentrations of sex steroids, blood chemistries and markers of metabolic syndrome, anthropometric variables, and ethnicity. Among these premenopausal women, lean body mass was the strongest independent predictor (P < 0.0001) and African-American ethnicity (P < 0.05) was another positive independent predictor of BMD at the hip and spine. Dietary fats were not independent predictors of BMD of hip and spine. Lean body mass and being African-American explained 33% of the variance in hip BMD. Lean body mass, African-American ethnicity, and serum concentrations of triglycerides (a negative predictor, P = 0.0001) explained 28% of the variance in spine BMD. In contrast, luteal phase serum concentrations of estradiol, progesterone, and testosterone were not predictors of BMD. It remains to be determined whether efforts to increase lean body mass in premenopausal women with normal levels of endogenous estrogen may be an effective preventive strategy to preserve bone health.

Fracture rates in urban South African children of different ethnic origins: the Birth to Twenty cohort

Fracture rates were compared in children of different ethnic backgrounds from Johannesburg, South Africa. More white children fracture than black and mixed ancestry children. Reasons for this may be due to greater sports participation by whites and genetic protective factors in blacks. This has to be further investigated.

INTRODUCTION

Fracture rates in childhood are as high as those in the elderly. Recent research has been undertaken to understand the reasons for this, but there is little information available on ethnic differences in childhood fracture rates.

METHODS

Using the birth to twenty longitudinal cohort of children, we retrospectively obtained information on fractures and their sites from birth to 14.9 years of age on 2031 participants. The ethnic breakdown of the children was black (B) 78%, white (W) 9%, mixed ancestry (MA) 10.5% and Indian (I) 1.5%.

RESULTS

Four hundred and forty-one (22%) children had sustained a fracture one or more times during their lifetime (males 27.5% and females 16.3%; p < 0.001). The percentage of children fracturing differed between the ethnic groups (W 41.5%, B 19%, MA 21%, I 30%; p < 0.001). Of the 441 children reporting fractures, 89(20%) sustained multiple fractures. The most common site of fracture was the upper limb (57%).

CONCLUSION

More white children fracture than black and mixed ancestry children. This is the first study to show ethnic differences in fracture rates among children. The reasons for these differences have to be further elucidated. Greater sports participation by whites and genetic protective factors in blacks may be contributing factors.

Screening for chronic kidney disease complications in US adults: racial implications of a single GFR threshold

BACKGROUND AND OBJECTIVES

An ideal and effective screening tool should perform equally across ethnic groups. The objective of this study was to determine whether the widely advocated creatinine-based estimated GFR (eGFR) threshold of 60 ml/min per 1.73 m(2) identifies the typical metabolic abnormalities related to chronic kidney disease equally well in minority and nonminority adults.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This objective was addressed using data for 8918 minority and nonminority adult participants in the National Health and Nutrition Examination Survey 2003 through 2006, which used stratified, multistage, probability sampling methods to assemble a nationwide probability sample of the noninstitutionalized population of the United States. Metabolic abnormalities including BP, potassium, hemoglobin, bicarbonate, uric acid, calcium, phosphorus, and parathyroid hormone were defined by fifth or 95th percentile values.

RESULTS

Among participants with eGFR <60 ml/min per 1.73 m(2), black individuals were more likely than white individuals to have low hemoglobin (adjusted odds ratio [aOR] 3.76; 95% confidence interval [CI] 1.94 to 7.28), elevated uric acid (aOR 2.15; 95% CI 1.26 to 3.68), and elevated parathyroid hormone (aOR 3.93; 95% CI 2.33 to 6.66).

CONCLUSIONS

Metabolic consequences of reduced eGFR are more common in black individuals and seem to be present at levels well above 60 ml/min per 1.73 m(2); thus, black individuals should be screened for the metabolic complications of chronic kidney at higher GFR levels.

The impact of clothing style on bone mineral density among women in Turkey

To investigate the effect of veiled clothing style on bone mineral density (BMD). The BMD measurements were performed on the femoral neck and the lumbar spines of adult female population with two different types of clothing taking calcium daily in the normal range according to the proper technique utilizing dual energy X-ray absorptiometry (DEXA). In the lumbar spine measurements, the BMD was measured 1.0020 +/- 0.177 gr/cm2 in cases with veiled clothing style while it was measured 1.0793 +/- 0.169 gr/cm2 in cases with unveiled clothing style (P = 0.049, t = 1.98). In the femoral neck measurements, the BMD was measured 0.8428 +/- 0.146 gr/cm2 in cases with veiled clothing style while it was measured 0.8532 +/- 0.177 in cases with unveiled clothing style (P = 0.548, t = 0.457). Although a decrease in BMD values was observed in both regions with veiled clothing style, only the change in the lumbar spine BMD measurements was statistically significant. These findings suggest that the veiled clothing style may have an adverse effect on BMD by interfering with the sun exposure which is believed to have a key role in bone strength.

Diet, smoking and anthropometric indices and postmenopausal bone fractures: a prospective study

OBJECTIVE

Bone fractures are an important cause of morbidity and mortality among the elderly in the US. The present study assesses the possible role of a number of risk factors for postmenopausal bone fractures.

METHODS

We analysed the relationships of anthropometric, demographic and lifestyle factors with the risk of bone fracture among 6250 postmenopausal women in a prospective cohort study, the New York University Women's Health Study.

RESULTS

After an average of 7.6 years of follow-up, 1025 new incident bone fractures were reported, including 34 hip and 159 wrist fractures (incidence rates; 71.6 and 334.7 per 105 woman-years, respectively). The risk of fracture increased with increasing age, body height and total fat intake, while it was significantly lower among obese and African American women. The relative risk among African Americans was 0.45 (95% CI: 0.32-0.63) compared with non-African Americans. Women taller than 170 cm had a 64% increase in risk of fractures, as compared with those under 155 cm. These associations were generally more pronounced when fractures were limited to those at the hip and wrist.

CONCLUSIONS

The present study provides an indication for a potential role of dietary fat in the development of postmenopausal fractures and further evidence to support protective effects of obesity, short stature and African American ethnicity.