Vitamin C supplement use and bone mineral density in postmenopausal women.

Vitamin C is known to stimulate procollagen, enhance collagen synthesis, and stimulate alkaline phosphatase activity, a marker for osteoblast formation. Studies of dietary vitamin C intake and the relation with bone mineral density (BMD) have been conflicting, probably because of the well-known limitations of dietary nutrient assessment questionnaires. The purpose of this study was to evaluate the independent relation of daily vitamin C supplement use with BMD in a population-based sample of postmenopausal women. Subjects were 994 women from a community-based cohort of whom 277 women were regular vitamin C supplement users. Vitamin C supplement use was validated. Daily vitamin C supplement intake ranged from 100 to 5,000 mg; the mean daily dose was 745 mg. Average duration of use was 12.4 years; 85% had taken vitamin C supplements for more than 3 years. BMD levels were measured at the ultradistal and midshaft radii, hip, and lumbar spine. After adjusting for age, body mass index (BMI), and total calcium intake, vitamin C users had BMD levels approximately 3% higher at the midshaft radius, femoral neck, and total hip (p < 0.05). In a fully adjusted model, significant differences remained at the femoral neck (p < 0.02) and marginal significance was observed at the total hip (p < 0.06). Women taking both estrogen and vitamin C had significantly higher BMD levels at all sites. Among current estrogen users, those also taking vitamin C had higher BMD levels at all sites, with marginal significance achieved at the ultradistal radius (p < 0.07), femoral neck (p < 0.07), and total hip (p < 0.09). Women who took vitamin C plus calcium and estrogen had the highest BMD at the femoral neck (p = 0.001), total hip (p = 0.05), ultradistal radius (p = 0.02), and lumbar spine. Vitamin C supplement use appears to have a beneficial effect on levels of BMD, especially among postmenopausal women using concurrent estrogen therapy and calcium supplements.     

Osteoporosis in elderly men and women: effects of dietary calcium, physical activity, and body mass index.

Dietary calcium intake and physical activity are considered practical measures for prevention of osteoporosis. However, their associations with bone mineral density (BMD) in the elderly are not clear. The present study examined the association between osteoporosis and these two factors in relation to body mass index (BMI) in a cross-sectional, epidemiological study involving 1075 women and 690 men, aged 69 +/- 6.7 years (mean +/- SD). Dietary calcium intake (median of 580 mg/day) was inversely related to age (p = 0.01), positively related to physical activity index (PAI) (p = 0.01), femoral neck BMD (p = 0.01) in women, and higher lumbar spine (p = 0.003) and femoral neck BMD (p = 0.03) in men. Quadriceps strength was negatively associated with age (p < 0.0001) and positively related to BMI (p < 0.0001) and BMD (p < 0.0001) in both men and women. The PAI was associated with quadriceps strength (p < 0.0001) and femoral neck and lumbar spine BMD in women (p < 0.001) and with femoral neck BMD in men (p = 0.04); however, these associations were not significant after adjusting for age, BMI, quadriceps strength, and dietary calcium. Women in the top tertile of quadriceps strength (> or =23 kg) and dietary calcium intake (> or =710 mg/day) had 15% higher BMD than those in the lowest tertiles (< or =15 kg and < or =465 mg/day); the difference was comparable in men (11%). Among subjects with the lowest tertiles of BMI (< or =23 kg/m2 for women and < or =24 kg/m2 for men), quadriceps strength (< or =15 kg for women and < or =28 kg for men), and dietary calcium intake (< or =465 mg/day), 64% and 40% of women and men, respectively, were classified as having osteoporosis (based on a 2.5-SD reduction from the young-normal mean). The prevalence was only 12% in women and 1.5% in men among those in the highest tertiles of the three factors. Adequate dietary calcium intake and maintaining a physically active lifestyle in late decades of life could potentially translate into a reduction in the risk of osteoporosis and hence improve the quality and perhaps quantity of life in the elderly population.     

Association of Selective Serotonin Reuptake Inhibitors and Bone Mineral Density in Elderly Women

Depression and osteoporosis are 2 common comorbidities in geriatric patients. There are concerns about the deleterious effects of selective serotonin reuptake inhibitor (SSRI) antidepressant use on bone mineral density (BMD). We examined the association between SSRI use and BMD in elderly women (≥65?yr) referred to a geriatric osteoporosis clinic for bone health evaluation. Cross-sectional analyses using the general linear model were performed on data collected retrospectively from August 2010 to April 2015. A total of 250 women were seen during the study period. Of these, 140 women had complete data on BMD measurements: 22 (15.7%) used an SSRI and 118 (84.3%) did not. The 2 groups, SSRI users and SSRI nonusers, did not differ significantly across any of the covariates tested (age, ethnicity, body mass index, and past and present osteoporosis treatment medications). After adjusting for covariates, there was no difference in the BMDs at the femoral neck (p?=?0.887) or the spine (p?=?0.275) between the 2 groups. Similarly, no difference was seen in the T-scores between SSRI users and nonusers at the femoral neck (p?=?0.924) or at the spine level (p?=?0.393). Our study did not show an association between SSRI use and BMD among elderly women referred for bone health evaluation. Other studies in the literature have been inconclusive, and therefore, robust longitudinal studies are needed to further assess the interaction between SSRI use and predictors of fracture such as BMD, bone turnover markers, and genes involved in bone turnover. Until then, clinicians should closely monitor the bone health of long-term SSRI users.     

Effects of current and discontinued estrogen replacement therapy on hip structural geometry: the study of osteoporotic fractures.

It is assumed that estrogen influences bone strength and risk of fractures by affecting bone mineral density (BMD). However, estrogen may influence the mechanical strength of bones by altering the structural geometry in ways that may not be apparent in the density. Repeated dual energy X-ray absorptiometry (DXA) hip scan data were analyzed for bone density and structural geometry in elderly women participating in the Study of Osteoporotic Fractures (SOF). Scans were studied with a hip structural analysis program for the effects of estrogen replacement therapy (ERT) on BMD and structural geometry. Of the 3,964 women with ERT-use data, 588 used ERT at both the start and end of the approximately 3.5-year study, 1,203 had past use which was discontinued by clinic visit 4, and 2,163 women had never used ERT. All groups lost BMD at the femoral neck, but the reduced BMD among users of ERT was entirely due to subperiosteal expansion and not bone loss, whereas both bone loss and expansion occurred in past or nonusers. BMD increased 0.8%/year at the femoral shaft among ERT users but decreased 0.8%/year among nonusers. Section moduli increased at both the neck and shaft among ERT users but remained unchanged in past and nonusers. Current, but not past, use of estrogen therapy in elderly women seems to increase mechanical strength of the proximal femur by improving its geometric properties. These effects are not evident from changes in femoral neck BMD.     

Risk factors for longitudinal bone loss in elderly men and women: the Framingham Osteoporosis Study.

Few studies have evaluated risk factors for bone loss in elderly women and men. Thus, we examined risk factors for 4-year longitudinal change in bone mineral density (BMD) at the hip, radius, and spine in elders. Eight hundred elderly women and men from the population-based Framingham Osteoporosis Study had BMD assessed in 1988-1989 and again in 1992-1993. BMD was measured at femoral neck, trochanter, Ward's area, radial shaft, ultradistal radius, and lumbar spine using Lunar densitometers. We examined the relation of the following factors at baseline to percent BMD loss: age, weight, change in weight, height, smoking, caffeine, alcohol use, physical activity, serum 25-OH vitamin D, calcium intake, and current estrogen replacement in women. Multivariate regression analyses were conducted with simultaneous adjustment for all variables. Mean age at baseline was 74 years +/-4.5 years (range, 67-90 years). Average 4-year BMD loss for women (range, 3.4-4.8%) was greater than the loss for men (range, 0.2-3.6%) at all sites; however, BMD fell with age in both elderly women and elderly men. For women, lower baseline weight, weight loss in interim, and greater alcohol use were associated with BMD loss. Women who gained weight during the interim gained BMD or had little change in BMD. For women, current estrogen users had less bone loss than nonusers; at the femoral neck, nonusers lost up to 2.7% more BMD. For men, lower baseline weight and weight loss also were associated with BMD loss. Men who smoked cigarettes at baseline lost more BMD at the trochanter site. Surprisingly, bone loss was not affected by caffeine, physical activity, serum 25-OH vitamin D, or calcium intake. Risk factors consistently associated with bone loss in elders include female sex, thinness, and weight loss, while weight gain appears to protect against bone loss for both men and women. This population-based study suggests that current estrogen use may help to maintain bone in women, whereas current smoking was associated with bone loss in men. Even in the elderly years, potentially modifiable risk factors, such as weight, estrogen use, and cigarette smoking are important components of bone health.     

Angiotensin converting enzyme inhibitor use is associated with higher bone mineral density in elderly Chinese

Hypertension and osteoporosis are two major chronic diseases affecting the elderly. A cross-sectional study of 3887 Chinese men (n = 1958) and women (n = 1929) was used to explore the association between angiotensin converting enzyme inhibitor (ACEI) use and bone mineral density (BMD). The participants were aged 65 years and above, and were recruited using a combination of private solicitation and public advertising from community centers, housing estates, and the general community in Hong Kong. Demographic, medical, and lifestyle information was obtained from face to face interviews using standardized questionnaire, and physical examination measurements included anthropometry, tibial, and brachial systolic blood pressures, femoral neck, total hip, and lumbar spine BMD. In multiple regression analyses, after adjusting for age, weight, height, thiazide, beta-blocker, calcium channel blocker, statin, corticosteroid, and calcium supplement use, history of diabetes, heart disease, peripheral vascular disease, cigarette smoking, alcohol intake, and physical activity level, ACEI use was associated with higher femoral neck BMD (+0.015 g/cm2, P = 0.035) in women, and higher femoral neck (+0.015 g/cm2, P = 0.017), total hip (+0.016 g/cm2, P = 0.021), and lumbar spine (+0.043 g/cm2, P < 0.001) BMD in men. Thiazide use was associated with higher BMD at all three sites in general, although associations with BMD increase at the total hip (P = 0.07) and femoral neck (P = 0.09) were weak in men. Calcium channel blocker use was only significantly associated with BMD increase at the lumbar spine (P = 0.03) in women, and beta-blocker use did not have significant associations with BMD at any site. This study suggests that in addition to thiazide diuretics ACEI may have possible benefits in treating not only hypertension but also osteoporosis among older Chinese.     

Sex differences in peak adult bone mineral density

Osteoporotic fractures are more common in women than men. Although accelerated bone loss following the menopause is recognized as of major importance, it is generally considered that a lower peak adult bone mass in females also contributes to their increased risk of osteoporosis in later life. To examine potential sex differences in peak adult bone mass we studied 29 pairs of dizygotic twins of differing within-pair sex in whom the female twin was premenopausal (mean age 37 years, range 21-55). Bone mineral density (BMD, g/cm2) was measured at the lumbar spine and femoral neck by dual-photon absorptiometry; 22 pairs also had BMD measured in the distal and 21 pairs in the ultradistal radius by single-photon absorptiometry. There was no significant difference in usual dietary calcium intake or tobacco consumption between the twin pairs. Consistent with accepted dogma, BMD at both radial sites were higher (+27%) in the males than their female cotwins. In contrast, there was no sex difference (male versus female) in BMD (mean +/- SEM) in the femoral neck (0.96 +/- 0.02 versus 0.97 +/- 0.03), and surprisingly, the females had a greater lumbar spine BMD than their male cotwins (1.19 +/- 0.03 versus 1.26 +/- 0.03, p less than 0.05). This difference was observed despite the fact that the males were taller (p = 0.033). If the femoral neck BMD values in the females were corrected for this difference in BMI, their values (0.99 +/- 0.03 g/cm2) were significantly higher than those in their male cotwin (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Associations between dietary flavonoid intakes and bone health in a scottish population

Flavonoids are bioactive polyphenols found particularly in fruit and vegetables, but little is known about their role in bone health in humans. The aim of this observational study was to investigate whether dietary flavonoid intake was associated with bone mineral density (BMD) and bone resorption in a large group of perimenopausal Scottish women. Over 3000 women completed a food frequency questionnaire as part of an osteoporosis screening study. The diets were analyzed for flavonoid intake using a food composition database. BMD was measured at the femoral neck (FN) and lumbar spine (LS) by dual‐energy X‐ray absorptiometry (DXA). Free pyridinoline (PYD) and deoxypyridinoline (DPD) were measured by high‐performance liquid chromatography (HPLC) in second early morning fasted urine samples. The mean flavonoid intake of the diet was 307 ±199 mg/d. The catechin family contributed the most to flavonoid intakes (55%), and the flavones the least (<1%). Associations were found between energy‐adjusted total flavonoid intakes and BMD at the FN and LS (FN r = 0.054, LS r = 0.036, p ≤ .05). Annual percent change in BMD was associated with intakes of procyanidins and catechins (p ≤ .05), and flavanones were negatively associated with bone‐resorption markers (PYD r = ?0.049, DPD r = –0.057, p ≤ .001). These associations were still seen after adjusting for confounders. It is concluded that dietary flavonoid intakes are associated with BMD, supporting the evidence from animal and cellular studies. © 2011 American Society for Bone and Mineral Research.     

Vitamin A intake and the risk of hip fracture in postmenopausal women: the Iowa Women’s Health Study

Excessive intake of vitamin A is postulated to have a detrimental effect on bone by inducing osteoporosis. This may lead to an increased risk of fracture, particularly in persons who are already at risk of osteoporosis. However, few studies have specifically examined the association of vitamin A intake through diet and supplement use, with fractures in a cohort of older, community-dwelling women. We prospectively followed a cohort of 34,703 postmenopausal women from the Iowa Womens Health Study to determine if high levels of vitamin A and retinol intake through food and supplement use were associated with an increased risk of hip or all fractures. A semiquantitative food frequency questionnaire was used to obtain the participants baseline vitamin A and retinol intake. Participants were followed for a mean duration of 9.5 years for incident self-reported hip and nonhip fractures. After multivariate adjustment, it was revealed that users of supplements containing vitamin A had a 1.18-fold increased risk of incident hip fracture (n=525) compared with nonusers (95% CI, 0.99 to 1.41), but there was no evidence of an increased risk of all fractures (n=6,502) among supplement users. There was also no evidence of a dose-response relationship in hip fracture risk with increasing amounts of vitamin A or retinol from supplements. Furthermore, our results showed no association between vitamin A or retinol intake from food and supplements, or food only, and the risk of hip or all fractures. In conclusion, we found little evidence of an increased risk of hip or all fractures with higher intakes of vitamin A or retinol among a cohort of older, postmenopausal women.     

Large-scale population-based study shows no evidence of association between common polymorphism of the VDR gene and BMD in British women.

The VDR is a candidate gene for osteoporosis. Here we studied five common polymorphisms of VDR in relation to calcium intake and vitamin D status in a population-based cohort of 3100 British women, but found no significant association with bone mass, bone loss, or fracture. INTRODUCTION: Population studies of vitamin D receptor (VDR) polymorphisms have produced conflicting results. We performed a comprehensive study dealing with all potential confounders in a large population to determine whether polymorphisms in the VDR gene influence bone health. MATERIALS AND METHODS: We studied 3100 women (50-63 years old) with bone markers, 25-hydroxyvitamin D, calcium, PTH, diet, and physical activity collected in 1998-2000. BMD was measured in 1990-1994 and 1998-2000. Fracture prevalence was assessed in 2002. Women were genotyped for five polymorphisms in the VDR gene: Cdx-2, Fok1, Bsm1, Apa1, and Taq1. The relationship between VDR and BMD, and interactions between VDR genotype, dietary calcium, and 25-hydroxyvitamin D, were examined using analysis of covariance. RESULTS: Compared with carriers of the G allele, homozygotes for the rare Cdx-2 A polymorphism (n = 136) had less bone loss (-0.5 +/- 1.2 versus -0.7 +/- 1.0%/year [SD]; p = 0.01) and lower PTH (3.0 +/- 1.6 versus 3.4 +/- 2.0 pM; p = 0.03) despite similar vitamin D status. The association was not significant after correction for multiple testing or adjustment for confounders. At low calcium intakes, AA homozygotes had greater femoral neck (FN) BMD compared with carriers of the G allele, but at higher calcium intakes, the association was reversed. At low calcium intake, homozygotes for the b allele of Bsm1 had greater BMD compared with carriers of the B allele, but at higher calcium intakes, there was no difference. Similar results were seen for the Taq1 polymorphism. There was no evidence of gene-nutrient interaction when adjusted for body weight. No interactions between genotypes and vitamin D status on BMD were observed. CONCLUSIONS: VDR does not seem to influence BMD or bone turnover in early postmenopausal white women with adequate calcium intake. Gene-nutrient interactions on BMD may be an indirect consequence of interactions between genotype and calcium intake on weight.     

Modifiable determinants of bone status in young women

The purpose of this study was to evaluate the contributions of exercise, fitness, body composition, and calcium intake during adolescence to peak bone mineral density and bone structural measurements in young women. University Hospital and 75 healthy, white females in the longitudinal Penn State Young Women's Health Study were included. Body composition, total body, and hip bone mineral density (BMD) were measured by dual-energy X-ray absorptiometry (DXA), exercise scores by sports-exercise questionnaire during ages 12-18 years, and estimated aerobic capacity by bike ergometry. Section modulus values (a measurement of bending strength) cross-sectional area (CSA), subperiosteal width, and cortical thickness were calculated from DXA scan data for the femoral neck and femoral shaft. Calcium intakes were calculated from 39 days of prospective food records collected at 13 timepoints between ages 12 and 20 years; supplemental calcium intakes were included. Section moduli at the femoral neck and shaft were correlated significantly with lean body mass, sports-exercise scores (R(2) = 0.07-0.19, p < 0.05), and aerobic capacity (R(2) = 0.06-0.57, p < 0.05). Sports-exercise scores correlated with BMD at the femoral neck and shaft. Average total daily calcium intake at age 12-20 years ranged from 486 to 1958 mg/day and was not significantly associated with total or regional peak BMD or bone structure measures at 20 years of age. It was shown that achievable levels of exercise and fitness have a favorable effect on BMD and section modulus of the femoral neck and femoral shaft in young adult women, whereas daily calcium intake of >500 mg in female adolescents appears to have little, if any effect.     

An investigation of the association between omega 3 FA and bone mineral density among older adults: results from the National Health and Nutrition Examination Survey years 2005–2008

Summary

The relation of omega 3 fatty acids (n-3 FA) with bone mineral density (BMD) was assessed among adults >60 years; NHANES data (2005–2008). The association of dietary n-3 FA with measures of hip BMD was equivocal, but n-3 FA supplement use was significantly associated with higher spine BMD—a finding that deserves further study.

Introduction

Associations between polyunsaturated fatty acids and bone mineral density are not well understood.

Purpose

To evaluate the cross-sectional relation between dietary omega 3 fatty acid intake (specifically docosahexaenoic acid, eicosapentaenoic acid, and octadecatetraenoic) and BMD at the hip and spine among older adults.

Methods

Omega 3 FA intake (g/day) was assessed from two 24-h recalls using the National Health and Nutrition Examination Survey (NHANES, in 2005–2008); and omega 3 FA supplement use (yes/no) via questionnaire. Multivariable regression models were developed to explain variance in femoral neck, total femur, and lumbar spine BMD among 2,125 men and women over 60 years.

Results

Mean age was 70 years. In adjusted models, dietary omega 3 FA were marginally associated with greater femoral neck BMD (p?=?0.0505), but not with total femur BMD (p?=?0.95) or lumbar spine BMD (p?=?0.74). Omega 3 supplement use was significantly positively associated with lumbar spine BMD (p?=?0.005) but not with femoral neck or total femur BMD.

Conclusions

Dietary intakes of omega 3 FA were marginally associated with femoral neck BMD; however, omega 3 supplement use was significantly associated with higher lumbar spine BMD in older adults. These results emphasize the need for assessment of total omega 3 intakes (diet and supplements) to provide a greater range of intake and a more accurate picture of the relation between omega 3 FA and BMD.     

Major Nutrient Patterns and Bone Mineral Density among Postmenopausal Iranian Women

Our understanding of the influence of overall nutrient intake on bone mineral density (BMD) is limited because most studies to date have focused on the intakes of calcium, vitamin D, or a few isolated nutrients. Therefore, we examined the association of major nutrient patterns with BMD in a sample of postmenopausal Iranian women. In this cross-sectional study, 160 women aged 50–85 years were studied and their lumbar spine and femoral neck BMDs were measured using dual-energy X-ray absorptiometry. Dietary intakes were assessed using a validated 168-item food frequency questionnaire, and daily intakes of 30 nutrients were calculated. All nutrient intakes were energy adjusted by the residual method and were submitted to principal component factor analysis to identify major nutrient patterns. Overall, three major nutrient patterns were identified, among which only the first pattern, which was high in folate, total fiber, vitamin B₆, potassium, vitamin A (as retinol activity equivalent), vitamin C, β-carotene, vitamin K, magnesium, copper, and manganese, had a significant association with BMD. After controlling for potential confounders, multivariate adjusted mean of the lumbar spine BMD of women in the highest tertile of the first pattern scores was significantly higher than those in the lowest tertile (mean difference 0.08; 95 % confidence interval 0.02–0.15; P = 0.01). A nutrient pattern similar to pattern 1, which is associated with high intakes of fruits and vegetables, may be beneficial for bone health in postmenopausal Iranian women.     

beta-Blocker use, BMD, and fractures in the study of osteoporotic fractures.

A role for osteoblastic beta-adrenoreceptors in bone regulation is suggested by the finding that beta-blockers increase bone mass in mice. We studied the association of beta-blocker use with BMD and fractures in the Study of Osteoporotic Fractures. beta-blocker use and BMD are unrelated in this cohort, and associations with fracture risk are inconsistent. INTRODUCTION: The central nervous system has been shown to regulate bone mass in mice, possibly by way of the beta(2)-adrenoreceptors on osteoblasts. beta-blockers have been shown to increase bone mass in mice. Because these agents are widely used therapeutically, it is possible that they may influence fracture epidemiology in humans, and they are a potential therapy for osteoporosis. MATERIALS AND METHODS: We have studied the association of beta-blocker use with BMD and fracture rates in the Study of Osteoporotic Fractures. beta-blocker use was recorded at the fourth visit, in 8412 women, of whom 1099 were users, and these women were followed for 7 years. RESULTS: Users had significantly higher weight, more thiazide use, more estrogen use, less glucocorticoid use, more statin use, and more hypertension than nonusers, and they smoked less. Total hip BMD at the fourth visit was higher in the beta-blocker users (0.746 versus 0.735 g/cm(2), p = 0.02), but adjustment for weight alone, or together with these other variables, eliminated this difference (p = 0.62). There was no effect of beta-blocker use on loss of hip BMD over a mean follow-up of 4 years (p = 0.48). Os calcis BMD at visit 4 was also higher in those taking beta-blockers (0.385 versus 0.375 g/cm(2), p = 0.005), but weight adjustment eliminated this difference (p = 0.14). The frequencies of hip or any fracture (since age 50) were similar in users and nonusers (p = 0.80 and p = 0.51, respectively). Over a mean follow-up of 7 years, there were 2167 total fractures, including 431 at the wrist and 585 at the hip. Among beta-blocker users, hazards ratios were 0.92 (0.81, 1.05) for any fracture, 0.74 (0.54, 1.01) for wrist fracture, and 0.76 (0.58, 0.99) for hip fracture. Adjustment for weight and other factors previously shown to influence hip fracture incidence in this cohort made little difference to the outcome. When fracture data were analyzed for nonselective and beta(1)-selective agents separately, trends toward fewer fractures were confined to the users of selective beta(1)-blockers. CONCLUSIONS: beta-Blocker use and BMD are unrelated in this cohort, and associations with fracture risk are inconsistent. Therefore, a history of use of these drugs is not useful in assessing fracture risk, nor do they have a role in osteoporosis management at this time. The relationship between beta-blocker use and hip fracture deserves further study.     

High serum retinyl esters are not associated with reduced bone mineral density in the Third National Health And Nutrition Examination Survey, 1988-1994.

Hypervitaminosis A is sometimes associated with abnormalities of calcium metabolism and bone mineral status. A recent study found a negative association between reported dietary vitamin A intake and bone mineral density (BMD). Some segments of the U.S. population have high fasting serum retinyl ester concentrations, a physiological marker that may reflect high and possibly excessive vitamin A intake. We examined the association between fasting serum retinyl esters and BMD in the Third National Health and Nutrition Examination Survey, 1988-1994 (NHANES III), a large, nationally representative sample of the U.S. population. BMD was measured for the femoral neck, trochanter, intertrochanter, and total hip on all nonpregnant participants aged > or = 20 years; 5,790 participants also had complete data on fasting serum retinyl esters and covariates including age, body mass index (BMI), smoking, alcohol consumption, dietary supplement use, diabetes, physical activity, and, among women, parity, menopausal status, and the use of oral contraceptives or estrogen-replacement therapy. The sample included non-Hispanic white, non-Hispanic black, and Mexican American men and women. We examined the association between fasting serum retinyl esters and BMD at each site, controlling for covariates with multiple linear regression. We examined the association with osteopenia and osteoporosis with multiple logistic regression. Although the prevalences of high fasting serum retinyl esters concentration and low BMD were both substantial in this sample, there were no significant associations between fasting serum retinyl esters and any measure of bone mineral status.     

Risk factors for low bone mineral density and the 6-year rate of bone loss among premenopausal and perimenopausal women

Risk factors that are associated with lower bone mineral density (BMD) may not necessarily be associated with increased bone loss among premenopausal and perimenopausal women. We determined risk factors for lower premenopausal and perimenopausal BMD while simultaneously determining risk factors for increased 6-year rate of bone loss among women aged 24–50 years within a population-based prospective cohort study. BMD of the lumbar spine and femoral neck, reported as t scores, were measured five times within the 6-year study among 614 women who were between the ages of 24 and 44 in 1992/1993. Rates of bone loss were calculated from the repeated BMD measurements. Risk factors for lower BMD over time at the lumbar spine included history of any fracture (P=0.005). The major risk factor for lower BMD over time at the femoral neck was family history of osteoporosis (P<0.002). The major protective factor for greater BMD over time at both skeletal sites was additional body weight (P<0.0001). Other protective factors for greater BMD over time at the femoral neck were modest alcohol consumption (P=0.0002) and high-school sports participation (P=0.002). Risk factors for greater bone loss at either skeletal site included postmenopausal status (P<0.0001 at the lumbar spine; P=0.01 at the femoral neck), and the reporting of a reproductive cancer (P<0.0001 at the lumbar spine; P=0.0008 at the femoral neck). Body weight was protective against bone loss at both skeletal sites (P<0.0001). Baseline age, calcium intake, smoking, and current physical activity were not associated with BMD or bone loss. The understanding of the relative importance of risk factors for both low BMD and bone loss may assist in the identification of women at greater risk for subsequent low postmenopausal BMD.     

Relationship between bone mineral density and dietary intakes in the elderly

Dietary protein and/or calorie insufficiencies represent an important problem in elderly patients. The biological and clinical implications, and particularly the influence on bone mass of undernutrition in the elderly, have not been completely defined, although several studies have demonstrated a high prevalence of dietary insufficiencies in patients with a recent fracture of the proximal femur. In the present study the relationship between dietary intakes, physical performance and bone mineral density (BMD) was examined in hospitalized elderly patients. The study comprised 74 patients (48 women, mean age 82 years; and 26 men, mean age 80 years) who were hospitalized for various medical indications. They were divided into two groups according to their dietary protein intakes, evaluated during the first 28 days in hospital while on a regular diet. The first group consisted of 26 patients (14 women and 12 men) whose protein intake was equal to or greater than 1 g per kilogram of ideal body weight. The second group consisted of 48 patients (34 women and 14 men) who consumed less than 1 g of protein per kilogram of ideal body weight. The two groups differed also in their energy, carbohydrate, lipid and calcium intakes. Patients in the group with the higher protein intake displayed higher BMD at the level of the femoral neck as measured by dual-photon absorptiometry. The men in this group also had higher lumbar spine BMD. After 4 weeks in hospital the women with a higher protein intake had significantly enhanced bicipital and quadricipital muscle strength and better performance as indicated by the increased capacity to climb stairs. These results indicate that lower dietary intakes in hospitalized elderly patients without fractures are associated with lower physical performance and lower femoral neck BMD. Thus, the role of dietary factors, including protein, in the risk of proximal femoral fractures deserves further investigation.     

Detrimental effect of oral contraceptives on parameters of bone mass and geometry in a cohort of 248 young women

The aim of this cross-sectional analysis was to examine the skeletal effects of low-dose monophasic oral contraceptive (OC) use in a cohort of 248 young Caucasian women aged 18-24 years. Areal bone mineral density (BMD) of the femoral neck and lumbar spine was evaluated by dual-energy X-ray absorptiometry. Volumetric BMD, bone mineral content (BMC), and bone geometry were assessed in the tibia by peripheral quantitative computed tomography (pQCT). The women were allocated into ever or never OC users, and also into 5 different OC groups according to duration and time of initiation of OC use. Women with >2 years of OC use and OC initiation within 3 years after menarche were characterized by 10% lower femoral neck areal BMD (P<0.001), 5% lower spine areal BMD (not significant, P=0.101), 7% lower distal tibial total BMC (P<0.05), and 6% lower total BMC at the tibial shaft (P<0.05) relative to never users. In addition, women who had ever used OCs had lower bone mass at the femoral neck and tibial shaft, despite similar age, height, weight, BMI, hours of exercise, and calcium intake compared with never users. At the tibial shaft, OC users showed reduced total cross-sectional area, and increased cortical BMD. In conclusion, our data suggest that OC use is associated with a detrimental effect on bone mass in young women, and provide further insight into the pathophysiological mechanisms involved.     

Bone mineral density and fractures among alcohol-dependent women in treatment and in recovery

Women are at higher risk for osteoporosis, but most of the literature examining the effect of alcohol abuse on bone mineral density (BMD) has been in men. The aim of this study was to determine differences in BMD and fracture prevalence among women in treatment for alcohol abuse, in recovery and non-alcohol-dependent women. This cross-sectional study was completed at two residential substance abuse centers in Iowa (USA). The patients were Caucasian women, aged 18-70 years, in treatment for alcohol abuse and dependence ( n=228); in recovery and abstaining from alcohol ( n=156); and women with no history of alcohol abuse ( n=447). The main outcome measures were femoral neck and lumbar spine BMD measured by dual-energy X-ray absorptiometry (DXA); self-reported lifetime fracture prevalence. After adjusting for age and menopausal status, women in treatment had BMDs that were 7.7% ( p<0.01) and 6.3% ( p<0.01) lower at the femoral neck and lumbar spine, respectively, than non-alcohol-abusing women, and 4.8% lower at both bone sites ( p<0.01) than women in recovery. Femoral neck BMD of women in recovery was 3.1% lower ( p<0.01) than in non-alcohol-dependent women; however, the difference was not significant following multivariate analysis. Women in treatment and recovery reported more fractures during childhood and early adolescence than non-alcohol-dependent women ( p<0.01). Women in recovery also reported significantly greater numbers of fractures following sobriety than their paired non-alcohol-dependent counterparts. Alcohol abuse and dependence was associated with lower femoral neck and lumbar spine BMD. Women with histories of alcohol dependence had a higher lifetime prevalence of fractures, including time periods before the onset of problem drinking and following abstinence, suggesting that factors other than acute intoxication contributed to the greater fracture prevalence.     

Spine and femur densitometry at the menopause: Are both sites necessary in the assessment of the risk of osteoporosis?

Summary The aim of our study was to compare the results provided by the measurement of vertebral and femoral bone mineral density (BMD) for assessing the individual risk of osteoporosis as defined by either low BMD and/or rapid bone loss. Vertebral and femoral BMD were measured twice at a mean interval of 21 months in 85 normal, early post-menopausal women who had passed a natural menopause 6 months to 3 years previously. According to the measurement site, 36% (spine), 29% (femoral neck), 35% (Ward's triangle), and 25% (trochanter) fall in the at risk category, defined by a BMD value of 1 SD or more below the normal values for premenopausal women. Based on vertebral BMD, 39–48% of the women at risk had a normal femoral BMD. On the other hand, 24–37% of the women classified at risk based on femoral BMD maintained a low risk at the vertebral level. The annual rate of bone loss was significantly greater for the Ward's triangle (-2.7±3.8%) and femoral neck (-2.1±2.5%) than for the spine (-1.5±2.1%) and trochanter (-1.5±3.4%). There was a significant relationship between the rate of loss measured at the spine and femoral levels (r=0.34–0.58). Among the 21 women with a rapid vertebral bone loss, 48–67% had a low bone loss at the femoral level and vice versa. The ratio between mean rate of loss and the precision of the measurement sites was greater for the spine (1.6) compared with the femur (1.1–0.71). Our results indicate that vertebral and femoral BMD measurements produce discordant results in assessing the individual risk for osteoporosis.