Bone mineral density testing and osteoporosis education improve lifestyle behaviors in premenopausal women: a prospective study.

One way to decrease the risk of osteoporosis is to maximize peak bone mass. Peak bone mass may be moderately influenced by lifestyle behaviors: increasing calcium and exercise, decreasing alcohol intake and smoking may increase peak bone mass. We examined the effects of osteoporosis education and bone mineral density (BMD) testing on self-reported lifestyle behaviors in 669 premenopausal women enrolled in a prospective study to assess determinants of peak bone mass. Study participants completed a questionnaire that assessed lifestyle behaviors, received pamphlets about osteoporosis, and had BMD testing. One year later, the women completed a similar questionnaire. After education about osteoporosis and BMD testing, women reported that they were less likely to smoke (odds ratio [OR] = 0.55; 95% confidence interval [95% CI]: 0.28-1.0), consume alcohol (OR = 0.13; 95% CI: 0.04-0.34), and caffeinated beverages (OR = 0. 43; 95% CI: 0.27-0.68). Women were more likely to use calcium supplements (OR = 4.3; 95% CI: 3.04-6.2), vitamin D supplements (OR = 12.6; 95% CI: 7.4-22.9), and drink at least one glass of milk a day (OR = 13.3; 95% CI: 7.8-23.9). Further, women with low bone mass were more likely to use calcium supplements (OR = 1.7; 95% CI: 1.2-2.3) and vitamin D supplements (OR = 1.6; 95% CI:1.1-2.2) compared with women who had normal bone mass. Thus, our intervention improved self-reported lifestyle behaviors in premenopausal women. Such behaviors may ultimately increase peak bone mass and decrease the risk of developing osteoporosis.     

Diet,bone mass,and osteocalcin: A cross-sectional study

To determine the relationships among nutrient intake, bone mass, and bone turnover in women we have investigated these issues in a population-based, crosssectional, observational study in one county in central Sweden. A total of 175 women aged 28–74 at entry to the study were included. Dietary assessment was made by both a semiquantitative food frequency questionnaire and by four 1-week dietary records. Dual energy X-ray absorptiometry was performed at five sites: total body, L2–L4 region of the lumbar spine, and three regions of the proximal femur. Serum concentrations of osteocalcin (an osteoblast-specific protein reflecting bone turnover) were measured by a radioimmunoassay. Linear regression models, with adjustment for possible confounding factors, were used for statistical analyses. A weak positive association was found between dietary calcium intake as calculated from the semiquantitative food frequency questionnaire and total body bone mineral density (BMD) among premenopausal women. No association emerged between dietary calcium intake and sitespecific bone mass, i.e., lumbar spine and femoral neck, nor was an association found between dietary calcium intake and serum osteocalcin. BMD at some of the measured sites was positively associated with protein and carbohydrates and negatively associated with dietary fat. In no previous studies of diet and bone mass have dietary habits been ascertained so carefully and the results adjusted for possible confounding factors. Neither of the two methods of dietary assessment used in this study revealed any effect of calcium intake on BMD at fracture-relevant sites among these healthy, mostly middle-aged women. A weak positive association was found between calcium intake estimates based on the food frequency questionnaire and total body BMD. In this study population the preventive effect of high dietary calcium on osteoporosis is probably very weak. The independent significance of protein, carbohydrates, and fat is uncertain.     

Potential risk factors for development of postmenopausal osteoporosis — Examined over a 12-year period

In a longitudinal study, we investigated the influence of risk factors on bone mass at menopause and postmenopausal bone loss in 121 healthy postmenopausal women. These women had completed a 2-year prospective study in 1979 and a follow-up examination in 1989. Measurements of the bone mineral content in the distal forearm (single photon absorptiometry) were performed 9 times during the initial study and once at the follow-up examination. Bone mass at menopause (initial measurement), rate of early postmenopausal bone loss, and the subsequent rate of bone loss over 10 years were thus determined. In addition, the bone mineral density of the lumbar spine and proximal femur was measured by dual-energy X-ray absorptiometry (DXA) in 1989. Information about risk factors was assessed by standardized questionnaires and included reproductive history and lifestyle factors (intake of calcium and vitamin D supplements, consumption of alcohol and caffeine, smoking habits, and physical activity). Lactation, oral contraceptive use, and dietary calcium intake above 1500 mg per day was associated with significantly increased bone mass at menopause. The number of pregnancies reduced the rate of early postmenopausal bone loss, whereas moderate alcohol consumption reduced the subsequent rate of bone loss. Smoking significantly reduced femoral bone mineral density. In conclusion, the present prospective study showed that some of the examined putative risk factors positively influenced bone mass at menopause, especially calcium intake, whereas the postmenopausal bone loss was virtually unaffected. Assessment of risk factors in postmenopausal women thus seems to have limited value for reducing future risk of osteoporosis.     

Is caffeine consumption a risk factor for osteoporosis?

High caffeine consumption has been proposed as a risk factor for osteoporotic fracture, but the evidence associating high caffeine intake with low bone density is inconsistent. We therefore examined the influence of caffeine consumption on bone mineral at six skeletal sites in an age-stratified random sample of white women residing in Rochester, Minnesota. After age adjustment, there was no association between overall caffeine consumption and bone mineral at five of the six sites. In the femoral shaft, however, there was a statistically significant interaction between age and caffeine consumption so that high caffeine intake was associated with slight reductions in bone mineral among elderly subjects but with modestly increased bone mineral at younger ages. When caffeine intake was categorized by source, no consistent influence of coffee, tea, or other caffeinated beverage consumption could be detected on bone mineral. Caffeine intake was, however, positively associated with cigarette smoking and alcohol consumption. After adjusting for age, caffeine consumption was not correlated with biochemical indices of bone turnover, circulating concentrations of estradiol and estrone, or other dietary and musculoskeletal variables. These data suggest that caffeine intake in the range consumed by a representative sample of white women is not an important risk factor for osteoporosis. Among elderly women, however, in whom calcium balance performance is impaired, high caffeine intake may predispose to cortical bone loss from the proximal femur.     

Association between caffeine intake and bone mass among young women: potential effect modification by depot medroxyprogesterone acetate use

Summary This study assessed associations between habitual caffeine intake and bone mass among young women. Analyses of the entire study population revealed no significant associations, while analyses restricted to women using depot medroxyprogesterone acetate (DMPA) showed modest inverse associations between caffeine intake and bone mineral content (BMC). Introduction Some previous investigations among postmenopausal women suggest an inverse relationship between caffeine intake and bone mass, yet studies of this association among young women are few. Methods The association between habitual caffeine intake and bone mass was evaluated prospectively in a population-based cohort of 625 females, aged 14 to 40 years, adjusting for relevant biological and lifestyle factors. Caffeinated beverage intake was self-reported, and bone mineral content (BMC) and bone mineral density (BMD) were measured at baseline and every 6 months throughout a 24-month follow-up period using dual-energy x-ray absorptiometry. Results Cross-sectional analyses revealed no significant differences in mean BMC or BMD at baseline. Mean percentage and absolute changes in BMC and BMD were not associated with caffeine use. Repeated measures analyses similarly showed no significant association between caffeine intake at baseline and mean BMC or BMD measured during follow-up. However, among women using depot medroxyprogesterone acetate (DMPA), modest inverse associations between caffeine and BMC (but not BMD) were detected. Conclusions Our data suggest that heavy habitual consumption of caffeinated beverages does not adversely impact bone mass among young women in general. Greater caffeine intake may be associated with lower BMC among DMPA users. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

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.     

Interactions of interleukin-6 promoter polymorphisms with dietary and lifestyle factors and their association with bone mass in men and women from the Framingham Osteoporosis Study.

Lifestyle and dietary factors may influence the association of IL-6 polymorphisms with bone mass. In 1574 unrelated men and women from the Framingham Offspring Cohort, we observed significant hip BMD differences between IL-6 -174 genotypes only in older women, those without estrogens, and those with a poor calcium intake. Hence, association of IL-6 polymorphisms with BMD may be limited to discrete population subgroups. INTRODUCTION: Interleukin (IL)-6 plays a central role in the pathogenesis of osteoporosis. Two functional variants in the IL-6 promoter have previously been associated with IL-6 expression, bone resorption levels, and BMD in late postmenopausal women, but results were conflicting in different populations. We hypothesized that the association between IL-6 promoter alleles and BMD may be affected by interactions with lifestyle and dietary factors known to influence bone turnover. MATERIALS AND METHODS: Among the Offspring Cohort of the Framingham Heart Study, 1574 unrelated men and women were genotyped for IL-6 -572 and -174 alleles. Interaction analyses with years since menopause, estrogen status, physical activity, smoking, dietary calcium, vitamin D, and alcohol intake were based on BMD measurements at the hip. RESULTS AND CONCLUSIONS: In models that considered only the main effects of IL-6 polymorphisms, no significant association with BMD was observed in either gender. In contrast, p values (0.003-0.096 by ANOVA) suggestive of an interaction between IL-6 -174 genotypes and years since menopause, estrogen status, dietary calcium, and vitamin D intake were observed in women (n = 819). In turn, BMD was significantly lower with genotype -174 GG compared with CC, and intermediate with GC, in women who were more than 15 years past menopause and in those without estrogens or with calcium intake <940 mg/day. In estrogen-deficient women with poor calcium intake, BMD differences between genotypes CC and GG were 10.2% at femoral neck (p = 0.012), 12.0% at trochanter (p = 0.012), and 16.8% at Ward's area (p = 0.0014). In contrast, no such interactions were observed in men (n = 755). In conclusion, IL-6 genetic variation was prominently associated with hip BMD in late postmenopausal women, those without estrogen replacement therapy, and those with inadequate calcium intake. In contrast, IL-6 polymorphisms are unlikely to be significant determinants of bone mass in other women or men.     

Low bone mass in premenopausal parous women: identification and the effect of an information and bone density feedback program.

The aims of this study of premenopausal parous women were to determine whether low bone mass could be accurately identified by clinical risk factors and to describe the effect of an information and bone mineral density (BMD) feedback program on lifestyle behavior. The subjects were a convenience sample of 271 women who took part in a cohort study of cot death in 1988, and in a population-based study of the determinants of bone mass in 1996. These subjects were provided with BMD feedback according to their T-score. Those with a score < -1.0 at either the femoral neck or lumbar spine were sent a letter indicating that their BMD was low (n = 72), whereas those scoring above -1.0 at both sites (n = 199) were told that their BMD was normal. Both groups were given a comprehensive osteoporosis information leaflet. In late 1997 we were able to contact 256 subjects (95%). In logistic regression, the presence or absence of low BMD was correctly classified in 79% of cases (p < 0.0001) by a model containing body mass index, fracture history, smoking, breastfeeding history, and sports participation. The model had poor sensitivity (38%) but high specificity (93%). At follow-up, those with low BMD had similar smoking cessation rates (16 vs 17%, p = 0.93) but higher rates of increased calcium intake (61 vs 9%), calcium supplement use (39 vs 4%), and increased physical activity (41 vs 17%) (all p < 0.001) in comparison with those with normal BMD. We conclude that a feedback program can alter self-reported behavior in young women for at least 12 mo and that the magnitude of effect is greatest in those with low BMD. Identification of these subjects by clinical risk factors is good but suboptimal, suggesting that measurement of BMD may be necessary to target most accurately and effectively those at highest risk.     

Correlates of Quantitative Ultrasound in the Women’s Healthy Lifestyle Project

Quantitative ultrasound (QUS) assessment of bone is a strong predictor of hip fractures and is currently an FDA-approved tool to identify women at risk of osteoporosis. However, few studies have investigated the lifestyle and genetic correlates of QUS in women. This study investigated the cross-sectional associates of several lifestyle, demographic and genetic factors with calcaneal QUS parameters (broadband ultrasound attenuation (BUA) and speed of sound (SOS)) in 393 women aged 45–53 years. Leisure-time and historical physical activity, dietary calcium and protein, body composition, vitamin D receptor genotypes, menopause status, other health behaviors, calcaneal QUS parameters and bone mineral density (BMD) were assessed at a single clinic visit. Lean mass, recent physical activity and African-American race were the strongest correlates of SOS whereas dietary protein, calcium and recent physical activity were the strongest correlates of BUA. These predictors explained 13% and 6% of the variance in SOS and BUA, respectively. Smoking, alcohol intake, education, hormone replacement therapy, calcium and vitamin D supplements, historical physical activity and vitamin D receptor genotypes were not significantly associated with BUA or SOS. Lean body mass and premenopausal status were the strongest correlates of lumbar BMD whereas lean body mass, physical activity, African-American race and body mass index were significantly related to femoral neck BMD. Physical activity remained predictive of SOS after controlling for lumbar BMD. The spectrum and magnitude of risk factors for SOS and BUA, including lean body mass, physical activity, race, protein and calcium intake, parallel previously observed predictors of BMD. Received: 25 November 1998 / Accepted: 1 April 1999     

Dietary essential amino acid supplements increase bone strength by influencing bone mass and bone microarchitecture in ovariectomized adult rats fed an isocaloric low-protein diet.

This study was designed to investigate whether the administration of dietary essential amino acid supplements in adult rats made osteoporotic by estrogen deficiency and reduced protein intake could reverse the deleterious effects caused by these maneuvers. This animal model was selected to mimic the situation observed in elderly women in whom estrogen deficiency and/or low-protein intake (but also calcium and vitamin D deficiency) are known to contribute to the pathogenesis of osteoporosis. Six-month-old rats were ovariectomized (OVX) and fed an isocaloric 2.5% casein diet for 10 weeks or sham-operated (SHAM) and fed an isocaloric 15% casein diet. The animals fed the 2.5% casein diet were given isocaloric supplements of essential amino acids in similar relative proportion to that of casein at doses of 2.5% or 5% of total diet for an additional 16 weeks. Vertebrae, femur, and tibia bone mineral density (BMD); ultimate strength; and microtomographic histomorphometry were evaluated before and after dietary essential amino acid supplements. Essential amino acid supplements increased vertebrae, femur, and tibia bone strength in OVX rats fed a low-protein diet. The mechanical changes induced by this dietary isocaloric supplement were associated with the prevention of a further BMD decrease or even with some increases and changes in microarchitecture such as from a rod to a plate trabecular spacial configuration and increased cortical thickness. Higher insulin-like growth factor (IGF) I levels, as well as greater bone formation and reduced bone resorption as assessed by biochemical markers of bone remodeling, were found in rats receiving essential amino acid supplements. In conclusion, dietary essential amino acid supplements increased bone strength through modifications of BMD, trabecular architecture, and cortical thickness possibly by an IGF-I-mediated process.     

Determinants of bone mineral density in Chinese men

Osteoporotic fractures are increasing among Asian populations in both genders, but the risk factors for low bone mineral density (BMD) in Asian men is unclear. To determine the hormonal and lifestyle risk factors for low BMD in Asian men, we studied 407 community-dwelling southern Chinese men aged 50 years and above. Medical history and lifestyle habits were obtained with a structured questionnaire. Dietary calcium and phytoestrogen intake were assessed by a semi-quantitative questionnaire. BMD at the spine and hip were measured by dual-energy X-ray absorptiometry (DXA). Fasting blood was analyzed for 25(OH)D, parathyroid hormone (PTH), total and bioavailable estradiol (bio-E) and testosterone (bio-T). The mean age of the cohort was 68.42±10.4 (50–96) years. In the linear regression model, weight, age, body mass index (BMI), bio-E, PTH, cigarette smoking and weight-bearing exercise were significant determinants of total hip BMD. Together they explained 55% of the total variance of hip BMD, with body weight being the most important determining factor. With age and weight adjustment, height, bio-T and flavonoid intake were identified as additional determinants of total hip BMD. Strategies to prevent bone loss and osteoporosis in Asian men should include lifestyle modification and maintenance of hormonal sufficiency.     

Effect of dietary protein on bone loss in elderly men and women: the Framingham Osteoporosis Study.

Few studies have evaluated protein intake and bone loss in elders. Excess protein may be associated with negative calcium balance, whereas low protein intake has been associated with fracture. We examined the relation between baseline dietary protein and subsequent 4-year change in bone mineral density (BMD) for 391 women and 224 men from the population-based Framingham Osteoporosis Study. BMD (g/cm2) was assessed in 1988-1989 and in 1992-1993 at the femur, spine, and radius. Usual dietary protein intake was determined using a semiquantitative food frequency questionnaire (FFQ) and expressed as percent of energy from protein intake. BMD loss over 4 years was regressed on percent protein intake, simultaneously adjusting for other baseline factors: age, weight, height, weight change, total energy intake, smoking, alcohol intake, caffeine, physical activity, calcium intake, and, for women, current estrogen use. Effects of animal protein on bone loss also were examined. Mean age at baseline (+/-SD) of 615 participants was 75 years (+/-4.4; range, 68-91 years). Mean protein intake was 68 g/day (+/-24.0; range, 14-175 g/day), and mean percent of energy from protein was 16% (+/-3.4; range, 7-30%). Proportional protein intakes were similar for men and women. Lower protein intake was significantly related to bone loss at femoral and spine sites (p < or = 0.04) with effects similar to 10 lb of weight. Persons in the lowest quartile of protein intake showed the greatest bone loss. Similar to the overall protein effect, lower percent animal protein also was significantly related to bone loss at femoral and spine BMD sites (all p < 0.01) but not the radial shaft (p = 0.23). Even after controlling for known confounders including weight loss, women and men with relatively lower protein intake had increased bone loss, suggesting that protein intake is important in maintaining bone or minimizing bone loss in elderly persons. Further, higher intake of animal protein does not appear to affect the skeleton adversely in this elderly population.     

The relation between lifestyle factors and biochemical markers of bone turnover among early postmenopausal women

We examined the associations of two biochemical markers of bone turnover with lifestyle factors in 340 postmenopausal women in Hawaii, ages 45–59 years, from the Early Postmenopausal Intervention Cohort. Physical activity, calcium supplement use, smoking and alcohol use in the prior 2 weeks were measured and examined as independent variables in multiple regression analyses with bone turnover markers as dependent variables, adjusted for weight, height, whole body bone mass, serum estradiol, years since menopause, and ethnicity. Calcium supplement and alcohol use were significantly associated with reduced levels of urinary type I collagen cross-linked N-telopeptides (NTX). The mean NTX level was 12% lower among women using ≥250 mg of calcium supplements per day as compared with other women, and 20% lower among alcohol users compared with nonusers. Both calcium supplement use and alcohol intake were associated with lower mean serum osteocalcin (a marker of bone formation) and NTX z-scores. By contrast, smoking was associated with lower osteocalcin levels, without any effect on NTX. The osteocalcin level was 12% lower among smokers compared with nonsmokers. In addition, the z-score difference between NTX and osteocalcin was significantly associated with smoking, with a shift towards more NTX than osteocalcin. Physical activity was not significantly associated with either of the markers. These findings suggest that biochemical markers may help to identify lifestyle factors that affect bone, and provide estimates of the relative magnitude of these effects on bone formation and resorption, independent of each other.     

Sexual differences in bone markers and bone mineral density of normal Chinese

We measured bone mineral density (BMD) at lumbar (L2–L4) vertebrae and proximal femurs of 385 healthy Chinese women aged 40–70 years and 156 healthy Chinese men aged 20–85, and four markers—bone alkaline phosphatase isozyme (BAP), procollagen-I C terminal propeptide (PICP), osteocalcin (BGP) in serum, and a bone resorption marker, urinary cross-linked N-telopeptide of type I collagen (NTX), of these subjects. The results indicate that in postmenopausal women, levels of all the markers increased with age. In men, serum BAP, PICP, and urinary NTX decreased significantly, and serum BGP decreased with borderline significance (P=0.08). With increasing age, bone density decreased at both sites in post-menopausal women and at the proximal femur in men. The lumbar bone density showed no significant age-related changes in men. In premenopausal women, BMD at either site showed no significant change with increasing age. Despite the different trends between men and women of agerelated changes in BMD and bone markers, bone density of both proximal femur and spine in both sexes correlated inversely with levels of the bone markers in a manner independent of age or body weight. The meaning of opposite age effects on bone markers in men and women needs further investigation. In addition, higher bone marker levels, implying faster bone turnover rate, are associated with lower BMD in both sexes.     

Bone mineral density measured by dual-energy X-ray absorptiometry in healthy finnish women

Summary A cross-sectional study of 351 healthy Finnish women aged 20–76 years was done to establish reference values of bone mineral density (BMD) using dual-energy X-ray absorptiometry (DEXA). The effects of age and of several physical and lifestyle factors on BMD of the lumbar spine and proximal femur (femoral neck, trochanter, and Ward's triangle area) were investigated. Altogether 58 women were excluded from the final analysis due to significant spinal osteoarthritis or other diseases or drugs known to influence calcium or bone metabolism. The precision of the method was 0.9, 1.2, 2.7, and 2.4% in the lumbar, femoral neck, Ward's triangle and trochanter area, respectively. Lumbar BMD was increased by 30% (P<0.001) in 15 patients with osteoarthritis (21% of women 50 years or older), but it was apparently unaffected in 5 cases with aortic calcification. Except for the trochanter area, BMD diminished along with age, and this was significant after the menopause. The peak of mean BMD was observed at the age of 31–35 years in the spine and at the age of 20–25 years in the femoral neck and Ward's triangle. BMD was in a positive relationship to weight both in premenopausal and postmenopausal women and to the use of oral contraceptives in premenopausal women and to that of estrogen replacement therapy in postmenopausal women. Labors and pregnancies had a weak positive effect on BMD in premenopausal women. As compared with nonusers premenopausal women who had used alcohol showed a slightly decreased BMD of Ward's triangle. In postmenopausal women there was a positive correlation between alcohol intake and BMD.     

Differences in bone mineral status between urban and rural Chinese men and women

BACKGROUND: Few studies have investigated differences in bone health and associated lifestyle factors between urban and rural populations in countries, such as China, undergoing rapid nutrition transition. Such a study may help to identify risk factors of osteoporosis and provide evidence for future preventive strategies. OBJECTIVE: To determine primarily whether differences in bone mineral content (BMC) and bone mineral density (BMD) exist between urban and rural Chinese men and women and secondly whether any urban-rural differences could be explained by body size or lifestyle factors. METHODS: In total, 490 men and 689 women aged 50-70 were included in the study. 535 of them were from urban Shanghai and 644 from surrounding rural areas. Anthropometric measurements were conducted and spine lumber 1-4 BMC measurements were determined by dual-energy X-ray absorptiometry (DEXA). Information on socioeconomic status, medical history, smoking and drinking habits and physical activity were collected. RESULTS: Urban men and women had significantly higher spine BMC, BMD and bone area than their rural counterparts (P<0.01). After controlling body size, the differences between urban-rural spine BMC and BMD remained in women (P<0.001), but were no longer significant in men. The urban and rural differences of BMC and BMD in women could not be explained by including the lifestyle factors such as income, intake of milk, vitamin D and calcium, total physical activity level, walking and social activity. CONCLUSION: This study found the significant differences in both spine BMC and BMD between urban and rural men and women in Shanghai, China. This difference could be explained by the body size in men; however, it remained unexplained in women after adjusting for body size and certain lifestyle risk factors.     

Randomised double blind placebo controlled trial investigating the effect of calcium and vitamin D supplementation on bone mineral density and bone metabolism in adult patients with cystic fibrosis

BACKGROUND: Low bone mineral density (BMD) is prevalent in adults with cystic fibrosis and might be related to calcium and vitamin D malabsorption from the gastrointestinal tract. The aim of this study was to investigate the effect of calcium and vitamin D supplementation on BMD and bone metabolism in these subjects. METHODS: Patients were invited to participate if they had a BMD Z score of -1 or less in the lumbar spine, proximal femur or distal forearm. Patients were randomised to receive calcium 1 g+vitamin D 800 IU or placebo daily, in addition to their regular vitamin D supplements (900 IU/day). BMD and bone biochemical markers were measured before and after 1 year of treatment. RESULTS: After 12 months, the treatment group (n=15) showed a reduced rate of bone loss compared with the control group (n=15) in the lumbar spine (mean difference 1.9% [CI -0.9% to 4.6%]), total hip (mean difference 0.7% [CI -2.2% to 3.5%]) and distal forearm (mean difference 1.7% [CI -2.2% to 5.5%]), but these changes did not reach statistical significance. There was also a trend towards a reduction in bone turnover in the treatment group. CONCLUSIONS: Calcium and vitamin D supplementation reduced the rate of bone turnover and bone loss in adult patients with cystic fibrosis, but these changes did not reach statistical significance. These data suggest that a longer term trial of this simple intervention would be justified.     

Diet and lifestyle associated with increased bone mineral density: cross-sectional study of Japanese elderly women at an osteoporosis outpatient clinic

Background Several studies have already demonstrated that lifestyle characteristics, such as physical activity, smoking, and alcohol intake, are associated with bone mineral density (BMD). Coffee intake was shown to be negatively associated with BMD, whereas tea drinking was reported to be associated with increased BMD. A review of the literature, however, revealed that few studies have described the association between BMD and lifestyle, including characteristic Japanese foods such as fish, natto, and Japanese green tea. The aim of this study was to identify lifestyle factors associated with BMD. Methods A total of 632 women age ≥60 years were enrolled in this study. Subjects were interviewed about their lifestyle by means of a questionnaire regarding the consumption pattern of dietary items. BMD was measured at the lumbar spine by dual energy X-ray absorptiometry. Results The BMD was higher in subjects with the habits of alcohol drinking, green tea drinking, and physical activity and lower in those with the habits of smoking and cheese consumption. Multiple regression analysis showed that factors associated with BMD were smoking, alcohol consumption, green tea drinking, and physical activity after adjusting for age and body mass index (BMI). Conclusions In this cross-sectional study at an osteoporosis outpatient clinic, patients with the habits of alcohol drinking, green tea drinking, and physical activity had significantly higher BMD, and those who smoked had significantly lower BMD than patients without each habit after adjusting for age, BMI, and other variables regarding lifestyle.     

Lifestyle influences on 9-year changes in BMD in young women.

The effects of dietary calcium intake and physical activity on longitudinal changes in BMD over a mean of 9.4 years were examined in 62 healthy young women. Proximal femur BMD declined, lumbar spine BMD increased, and physical activity was associated with BMD change at intertrochanter and total hip sites. INTRODUCTION: Maximizing premenopausal BMD is an important strategy for the prevention of osteoporosis and resultant fractures later in life. MATERIALS AND METHODS: Young women who previously participated in a placebo-controlled 2-year calcium intervention study at a mean age of 18.5 +/- 0.3 years were remeasured at 27.8 +/- 1.0 years of age. DXA (Hologic QDR 1000W) was used to measure changes in BMD, and lifestyle factors were ascertained by questionnaire. RESULTS AND CONCLUSIONS: Early decline in BMD at the neck of femur (-3.3%/decade) and the converse gain in BMD at the lumbar spine (+4.3%/decade) and intertrochanter (+1.9%/decade) suggest site-specific changes in BMD in young premenopausal women. No effect of previous calcium supplementation was seen on current BMD or changes in BMD (p > 0.10). Lifestyle predictors of change in BMD were determined using hierarchical regression analysis after forced correction for the covariates baseline BMD and previous calcium supplementation. Physical activity was positively associated with change in BMD at total hip and intertrochanter sites (beta-coefficients, beta = 0.26 and 0.26 respectively; p < 0.05). Calcium intake was negatively associated with change in BMD at the lumbar spine (beta = -0.27, p < 0.05). Parity was negatively associated with change in BMD at all sites (beta = -0.40 to -0.26, p < 0.05). These data show that BMD is already declining at the proximal femur in these healthy young women. Physical activity assists in maintenance of BMD at some sites and thus may contribute to lifelong fracture prevention. There was no positive association between calcium intake and change in BMD.     

Differences in mineral homeostasis, volumetric bone mass and femoral neck axis length in black and white South African women

In South Africa, appendicular and lumbar spine bone mineral density (BMD) have been found to be similar in black and white women. However, femoral BMD has been found to be higher in black than in white women. Two different techniques were used to recalculate BMD to eliminate the possible confounding influence of ethnic differences in height on areal BMD measurements. Volumetric bone mineral apparent density (BMAD) values were calculated and bone mineral content (BMC) was corrected for body and bone size. This report analyses differences in BMD (corrected for height and weight), BMAD, BMC (corrected for body and bone size), femoral neck axis length (FNAL), mineral homeostasis and bone turnover (BT) in a group of 20 to 49-year-old premenopausal (105 whites and 74 blacks) and 45 to 64-year-old postmenopausal (50 whites and 65 blacks) female South African nurses. The corrected BMD and BMC findings were congruous, showing that both pre- and postmenopausal blacks and whites have similar distal radius and lumbar spine bone mass but that whites have lower femoral neck bone mass than blacks. In contrast, BMAD findings suggest that pre- and postmenopausal whites have lower bone mass at the lumbar spine and femoral neck than blacks but similar bone mass at the distal radius to blacks. There is a greater rate of decline in BMD in postmenopausal whites than in blacks. BMD at the femoral neck was 12.1% lower in premenopausal whites and 16.5% lower in postmenopausal whites than in blacks. There was a positive association between femoral neck BMD and weight in premenopausal blacks (R ²=0.5,p=0.0001) but not in whites. Blacks had shorter FNAL than whites in both the pre- and postmenopausal groups. Blacks had lower serum 25-hydroxyvitamin D (25-(OH)D) and higher 1,25-dihydroxyvitamin D (1,25-(OH)₂D) levels than whites. There were no ethnic differences in biochemical markers of bone formation (serum alkaline phosphatase and osteocalcin) or bone resorption (urine hydroxyproline and pyridinoline), or in dietary calcium intake in either the pre- or postmenopausal groups. In the postmenopausal group, whites had higher ionized serum calcium (p=0.003), similar serum albumin, lower serum parathyroid hormone (p=0.003) and higher urinary calcium excretion (p=0.0001) than blacks. These results suggest that the higher peak femoral neck BMD in South African blacks than in whites might be determined by greater weight-bearing in blacks and that the significantly lower femoral neck BMD in postmenopausal whites than in blacks is determined by lower peak femoral neck BMD and a faster postmenopausal decline in BMD in whites. The higher incidence of femoral neck fractures in South African whites than in blacks is probably determined by the lower femoral neck BMD and longer FNAL in whites. The greater rate of decline in BMD in postmenopausal whites than in blacks is associated with an increase in urinary calcium excretion in whites. Measurement of biochemical markers of BT has not contributed to the understanding of ethnic differences in BMD and skeletal metabolism in our subjects.