Nutrition, mild hyperparathyroidism, and bone mineral density in young Japanese women

BACKGROUND: The adverse effects of poor nutrition on the bones of young Asian women have not been fully elucidated. OBJECTIVE: The purpose of this study was to investigate possible associations of vitamin D nutrition, calcium intake, and other nutrients with bone metabolism and bone mass in young Japanese women. DESIGN: The subjects were 108 female college students aged 19-25 y. Dietary nutrients were measured by using the duplicate sampling method on 3 weekdays. Serum 25-hydroxyvitamin D [25(OH)D], intact parathyroid hormone, and bone turnover markers were also measured. Bone mineral density (BMD) of the spine and femur was measured by dual-energy X-ray absorptiometry. RESULTS: The proportions of the subjects with low 25(OH)D (< 30 nmol/L) and high intact parathyroid hormone (> or = 6.9 pmol/L) concentrations were 32.4% and 15.7%, respectively. Serum 25(OH)D concentrations (P = 0.0265) and calcium intake (P = 0.0103) were inversely associated with serum intact parathyroid hormone. In addition to weight and physical activity, the presence of mild hyperparathyroidism was associated with a low BMD of the lumbar spine (P = 0.0062) and the femoral neck (P = 0.0250), and a low calcium intake was associated with a low BMD of the femoral neck (P = 0.0044). CONCLUSIONS: Low calcium intake (based on low BMD of the femoral neck only) and mild hyperparathyroidism (based on low BMD of both the femoral neck and lumbar spine), partly explained by low vitamin D nutrition and a low calcium intake, are important predictors of low BMD in young Japanese women. Effects of poor nutrition and mild hyperparathyroidism on bone peak bone mass in young women should be further investigated in longitudinal studies.     

Association between urinary potassium, urinary sodium, current diet, and bone density in prepubertal children

BACKGROUND: Our understanding of the role of nutrients in bone development in children is limited. OBJECTIVE: We examined the associations between urinary potassium, urinary sodium, usual dietary intake, and bone mineral density (BMD) in prepubertal children. DESIGN: This was a cross-sectional study of 330 boys and girls aged 8 y. Urinary measures were assessed in a single, timed, overnight urine specimen. Usual diet was assessed with a food-frequency questionnaire completed by a parent or guardian. BMD at the femoral neck, lumbar spine, and total body was measured by dual-energy X-ray absorptiometry. RESULTS: Urinary potassium correlated significantly with BMD at all sites (femoral neck: r = 0.20, P < 0.001; lumbar spine: r = 0.19, P = 0.001; total body: r = 0.24, P < 0.001). After adjustment for confounders (primarily lean body mass), this association was lower in magnitude but remained significant at 2 sites with a consistent trend at the third (femoral neck: P = 0.15; lumbar spine: P = 0.046; total body: P = 0.028). Urinary sodium was not associated with BMD at any site. No nutrient or food intake estimate was associated with BMD, although urinary potassium correlated significantly with potassium intake (r = 0.14, P = 0.016) and fruit and vegetable intake (r = 0.12, P = 0.033). CONCLUSIONS: Urinary potassium was associated with both dietary intake and BMD independent of lean body mass in these well-nourished, calcium-replete young children. These findings should be confirmed in further longitudinal studies. Nevertheless, this association is likely to represent dietary intake of potassium and suggests that measurement of urinary potassium is superior to food-frequency questionnaires for assessing potassium intake in this age group.     

Nutritional associations with bone loss during the menopausal transition: evidence of a beneficial effect of calcium, alcohol, and fruit and vegetable nutrients and of a detrimental effect of fatty acids

BACKGROUND: The menopausal transition is characterized by rapid bone loss. Few data exist on the role of nutrition. OBJECTIVE: The objective of the study was to ascertain which dietary factors influence perimenopausal skeletal loss. DESIGN: A longitudinal study was conducted of 891 women aged 45-55 y at baseline and 50-59 y at follow-up 5-7 y later. Bone mineral density (BMD) was measured by using dual-energy X-ray absorptiometry at the lumbar spine and femoral neck (FN). Nutrient intakes were assessed after the baseline visit and 5 y later, by using the same food-frequency questionnaire. RESULTS: After adjustment for energy intake and other confounders, higher intakes of calcium were correlated with change in FN BMD (ie, reduced loss) (r = 0.073, P < 0.05), and the intake of modest amounts of alcohol was associated with less lumbar spine bone loss (P < 0.01 for quartile of alcohol intake). Greater FN BMD loss was associated with increased intake of polyunsaturated fatty acids (r = -0.110, P < 0.01), monounsaturated fatty acids (r = -0.069, P < 0.05), retinol (r = -0.067; P < 0.05), and vitamin E (r = -0.110; P < 0.01). The latter 2 nutrients were highly correlated with polyunsaturated fatty acids. For premenopausal women, calcium and nutrients found in fruit and vegetables (vitamin C, magnesium, and potassium) were associated with FN BMD, and calcium, vitamin C, and magnesium were associated with change in FN BMD. CONCLUSIONS: Although menopausal status and hormone replacement therapy use dominate women's bone health, diet may influence early postmenopausal bone loss. Fruit and vegetable intake may protect against premenopausal bone loss.     

Previous milk consumption is associated with greater bone density in young women

BACKGROUND: Dietary calcium and milk intakes at specific ages may influence bone mineral measures at specific sites during development of peak bone mass. OBJECTIVE: Relations of previous milk intake and current calcium intake to current bone mineral measures were investigated in young women. DESIGN: A food-frequency interview and recall of previous milk intake from early childhood to 12 y of age and during adolescence (13-19 y) were completed in a cross-sectional analysis in young women (age 18-31 y; n = 224). Three levels of previous milk intake were defined: 1) infrequently or never, 2) sometimes, and 3) at every or almost every meal. Total body (TB), femoral neck, radius (R), and spine (S) bone mineral density (BMD) and bone mineral content (BMC) were determined by using dual-energy X-ray absorptiometry. RESULTS: Childhood and adolescent milk intakes were positively correlated (r = 0.66). Childhood and adolescent milk intakes correlated with current calcium intakes (r = 0.26 and 0.33, respectively). Adolescent milk intake correlated with RBMD (r = 0.16). When weight was controlled for, adolescent milk intake correlated with TBBMD (r = 0.16), TBBMC (r = 0.21), SBMC (r = 0.16), RBMD (r = 0.18), and RBMC (r = 0.15). Current calcium intakes correlated with SBMC (r = 0.17). Regression analyses supported these results. CONCLUSIONS: Results were consistent with the hypothesis that higher milk intake during adolescence is associated with greater total body, spine, and radial bone mineral measures during development of peak bone mass, whereas current calcium intakes may influence SBMC. In addition, milk intake at a younger age may contribute to similar habits of milk intake later in life.     

Resemblance in dietary habits and calcaneal ultrasound attenuation in malay mother-daughter pairs

The relationship between dietary habits and bone health status was evaluated in 61 pairs of premenopausal mothers and their biological daughters aged 10-19 years. Subjects were volunteers living in Kuala Lumpur. Bone status of the calcaneus was assessed using Quantitative Ultrasound (QUS) which measured the Broadband Ultrasound Attenuation (BUA; in units of dB/MHz) of the bone. Daily nutrient intake of all subjects was evaluated using a 3-day dietary record. Reproductive history, food intake habits, and physical activity level were assessed using questionnaires. Bone health status of mothers (mean BUA of 98.0 ± 15.8 dB/MHz) was significantly higher (p<0.001) compared to their daughters (mean BUA of 86.4 ± 17.0 dB/MHz). BUA (r=0.30, p<0.05), weight (r=0.30, p<0.05) and BMI (r=0.32, p<0.05) were significantly correlated within mother-daughter pairs. Lifestyle characteristics such as calcium intake and physical activity were not correlated. However, other dietary habits (energy intake, milk intake and frequency of skipping meals) in daughters were significantly correlated with their mothers. This study suggests that mothers play an important role in influencing the dietary habits of their daughters, which in turn may affect their bone health status.     

Mother-daughter pairs: spinal and femoral bone densities and dietary intakes

Bone mineral density (BMD) of the lumbar spine (L1-L4) and femur (femoral neck, Ward's triangle, and trochanter) was measured in 37 healthy, white mother-daughter pairs by dual-photon absorptiometry. Mothers and daughters were aged 52 +/- 7 and 25 +/- 4 y (mean +/- SD), respectively. Three-day dietary intakes were evaluated. Significant correlations between mother-daughter pairs for BMD of all lumbar and femoral areas [except for L2 (r = 0.26, P = 0.054)] indicated familial resemblances in bone mineralization. Total calcium intake was significantly correlated with three BMD values for the daughters (L2, femoral neck, and trochanter) but not for the mothers. When mothers were classified as pre- (n = 20) or postmenopausal (n = 17), correlation coefficients for BMD were higher for premenopausal mothers and their daughters and lower for postmenopausal mothers and their daughters, except for the trochanter. The results suggest that the nature of inheritance of bone mass of women may have at least two components, one influencing the level of peak bone mass and one related to bone loss at menopause.     

Familial resemblance of bone mineralization, calcium intake, and physical activity in early-adolescent daughters, their mothers, and maternal grandmothers

OBJECTIVE: To describe familial relationships among bone mineral density (BMD), calcium intake, and physical activity in early-adolescent daughters, their premenopausal mothers, and postmenopausal maternal grandmothers. SUBJECTS: Healthy, early-adolescent daughter and premenopausal mother pairs (n=72) were enrolled in the study. In addition, a cohort of 22 postmenopausal maternal grandmothers were measured for comparison of related triads (n=22). DESIGN: Cross-sectional measurements of hip (three sites) and lumbar spine BMD by dual energy x-ray absorptiometry (DXA), body height and weight, menstrual function, current calcium intake, and current and past physical activity patterns were assessed using recalls and questionnaires. STATISTICAL ANALYSIS: Correlational analysis was used to establish relationships between bone characteristics and body size, menstrual function, calcium intake, and physical activity. Multiple regression analyses with backward elimination were used to examine heritability of bone characteristics in daughter-mother and mother-grandmother pairs and daughter-mother-grandmother triads. Quick cluster analysis and cross-tabulation with Pearson's chi(2) were used to evaluate familial patterns for bone characteristics and lifestyle practices. RESULTS: Height, weight, and lumbar spine BMD were significantly correlated within mother-daughter pairs. Current and past calcium intakes were not related within pairs or triads or to BMD in the daughters or the grandmothers. A weak inverse relationship between calcium intake and the hip trochanter and lumbar spine BMD was observed in the mothers (R(2)=-0.25; P=.05). Physical activity, independent of calcium intake, was strong predictor of BMD for daughters and mothers. Among the daughters, the hertiability estimates for trochanter and lumbar spine BMD were 0.56 and 0.70, respectively (P<.01). The heritability estimate for premenopausal mothers were significant for lumbar spine BMD (h(2)=0.66; P<.01). Daughter-mother-grandmother triads with low physical activity had low femoral neck BMD whereas those with high physical activity had high femoral neck BMD (P<.001). APPLICATIONS: Making physical activity a part of the daily routine, in addition to an adequate intake of calcium and bone-related nutrients, is an important goal for maintaining or improving bone health for women of all ages.     

Vitamin D supplementation and bone mineral density in early postmenopausal women

BACKGROUND: Increased vitamin D intake may preserve or increase bone mineral density (BMD) in older persons. OBJECTIVE: A 2-y double-blind study was undertaken to determine whether weekly administration of 10 000 units of vitamin D(2) maintained or increased BMD in younger postmenopausal women more efficiently than did calcium supplements alone. DESIGN: One hundred eighty-seven women who were >or= 1 y postmenopausal were randomly assigned to take either 1000 mg Ca/d after the evening meal or 1000 mg Ca/d plus 10 000 U vitamin D(2)/wk in a double-blind, placebo-controlled format. The BMD of the proximal forearm, lumbar spine, femoral neck, Ward's triangle, and femoral trochanter was measured at 6-mo intervals by osteodensitometry. RESULTS: During the 2-y period, there was no significant difference in the change in BMD at any site between the subjects taking calcium supplements and those taking calcium plus vitamin D(2). Both groups significantly (P < 0.005) gained BMD in Ward's triangle and the femoral trochanter but significantly (P < 0.005) lost bone in the proximal radius. There was no significant change in the lumbar spine or femoral neck BMD. CONCLUSION: In younger postmenopausal women ( age: 56 y) whose average baseline serum 25-hydroxyvitamin D concentration was well within the normal range, the addition of 10 000 U vitamin D(2)/wk to calcium supplementation at 1000 mg/d did not confer benefits on BMD beyond those achieved with calcium supplementation alone.     

Bone density in axial and appendicular skeleton in patients with lactose intolerance: influence of calcium intake and vitamin D status

BACKGROUND: Lactose intolerance (LI) is a common enzymatic insufficiency, manifesting by poor tolerance of dairy products, leading to low calcium intake and poor calcium absorption from dairy products. These changes might lead to an impairment of bone metabolism [1]. OBJECTIVES: To evaluate the impact of LI on quantitative bone parameters in axial and appendicular skeletal sites. To assess the impact of calcium intake from dairy and non-dairy nutritional sources, calcium regulating hormones and bone turnover on quantitative bone parameters in LI patients. METHODS: We evaluated calcium intake and bone status in sixty-six patients with LI, 49 women and 17 men, aged 20 to 78. Bone mass was assessed at the lumbar spine (LS), total hip (TH) and femoral neck (FN) by dual-energy x-ray absorptiometry (DEXA) and at the radius, tibia, phalanx by quantitative ultrasound. Serum calcium, albumin, inorganic phosphate, calcium regulating hormones and markers of bone turnover were evaluated. RESULTS: Total daily calcium intake was below the recommended by the American Dietetic Association [2] in all study participants (mean 692 mg/day +/- 162). Elevated level of urinary deoxypyridinoline crosslinks (DPD) was observed in 63 (96%) patients and was negatively correlated with total daily calcium intake (r = -0.998, p = 0.025) and with nondairy calcium intake (r = -0.34, p = 0.015). Parathyroid hormone (PTH) level in the upper third of normal range (45-65 ng/L) was observed in 11 (17%) patients. Parathyroid hormone (PTH) was inversely correlated with total calcium intake (r = -0.4, p = 0.001), dairy calcium intake (r = -0.83, p = 0.05), non-dairy calcium intake (r = -0.29, p = 0.043), 25OHD(3) serum level (r = -0.3, p = 0.007) and positively correlated with bone turnover markers (deoxypyridinoline crosslinks [DPD], r = 0.36, p = 0.01 and bone specific alkaline phosphatase [BSAP] r = 0.36, p = 0.01). Decrease in quantitative bone parameters compared to age-matched controls was observed in the axial and in the appendicular skeleton in men and in postmenopausal women: mean z-score for LS -0.87 +/- 0.22 and -1.32 +/- 0.65, p = 0.004 and 0.015, tibia -1.15 +/- 0.53 and -0.44 +/- 0.044, p < 0.001 and 0.27, phalanx -0.98 +/- 0.22 and -0.52 +/- 0.98, p < 0.001. We observed decrease in bone mass in patients with serum PTH in the upper tertile of normal range in the FN (z-score -0.57 +/- 0.6 versus -0.03 +/- 0.9, p = 0.025), TH (-0.51 +/- 0.96 versus 0.04 +/- 0.9, p = 0.05) and radius (-1.84 +/- 0.27 versus -0.07 +/- 1.61, p = 0.025, respectively). z-scores in FN and TH positively correlated with serum 25OHD(3) level (r = 0.31, 0.29; p = 0.014, 0.019). In postmenopausal women serum 25OHD(3) level correlated also with LS z-scores (r = 0.52, p = 0.004); FN and TH z-scores negatively correlated with DPD level (r = -0.51, p = 0.02 and r = -0.55, p = 0.04). CONCLUSION: LI state may lead to increased bone turnover and decreased bone mass especially in men and postmenopausal women. Impaired vitamin D status and low calcium intake may be deleterious to bone in this condition.     

Dietary acid load is not associated with lower bone mineral density except in older men

High dietary acid load may be detrimental to bone mineral density (BMD), although sufficient calcium intake might neutralize this effect. In observational studies, the association between BMD and dietary acid load, estimated by net endogenous acid production (NEAP) and potential renal acid load (PRAL), has been inconsistent, and the potential modifying effect of calcium intake has not been assessed. We therefore examined the cross-sectional associations of estimated NEAP and PRAL with BMD in the Framingham Osteoporosis Study. We hypothesized that higher estimated NEAP and PRAL would be associated with lower BMD, but only among those with total calcium intake < 800 mg/d. BMD of the femoral neck and lumbar spine was measured, and estimated NEAP and PRAL were calculated via FFQ among 1069 Framingham Original (1988-1989, 1992-1993; 62% women, mean age 76 y) and 2919 Offspring (1996-2001; 56% women, mean age 60 y) cohort participants. Cohort- and sex-specific ANCOVA was used to calculate multivariable-adjusted mean BMD for estimated NEAP and PRAL quartiles. Assuming no uncontrolled confounding, estimated NEAP, but not PRAL, was inversely associated with femoral neck BMD (P-trend = 0.04) in Original cohort men, whereas neither was associated with lumbar spine BMD. Estimated NEAP and PRAL were not associated with BMD at any site among Original cohort women or Offspring cohort men and women. There were no significant interactions between either estimated NEAP or PRAL and total calcium intake. These results suggest that, with a possible exception of older men, dietary acid load does not have a measureable negative effect on bone health, regardless of total calcium intake.     

Growth hormone favorably affects bone turnover and bone mineral density in patients with short bowel syndrome undergoing intestinal rehabilitation

BACKGROUND: Patients with short bowel syndrome (SBS) have a high prevalence of metabolic bone disease due to nutrient malabsorption and potential effects of parenteral nutrition (PN). Human growth hormone (hGH) has been shown in some studies to have anabolic effects on bone, but hGH effects on bone in patients with SBS are unknown. METHODS: Adults with PN-dependent SBS underwent a 7-day period of baseline studies while receiving usual oral diet and PN and then began receiving modified diets designed to improve nutrient absorption and daily oral calcium/vitamin D supplements (1500 mg elemental calcium and 600 IU vitamin D, respectively). Subjects were randomized to receive in a double-blind manner either subcutaneous (sc) saline placebo as the control or hGH (0.1 mg/kg/d for 3 weeks, then 0.1 mg/kg 3 days a week for 8 subsequent weeks). Open-label hGH was given from week 13 to week 24 in subjects who required PN after completion of the 12-week double-blind phase. Markers of bone turnover (serum osteocalcin and urinary N-telopeptide [NTX]), vitamin D nutriture (serum calcium, 25-hydroxyvitamin D [25-OH D] and parathyroid hormone [PTH] concentrations), and intestinal calcium absorption were measured at baseline and at weeks 4 and 12. Dual x-ray absorptiometry (DXA) of the hip and spine was performed to determine bone mineral density (BMD) at baseline and weeks 12 and 24. RESULTS: The majority of subjects in each group exhibited evidence of vitamin D deficiency at baseline (25-OH D levels<30 ng/mL; 78% and 79% of control and hGH-treated subjects, respectively). Subjects treated with hGH demonstrated a significant increase from baseline in serum osteocalcin levels at 12 weeks (+62%; p<.05). The levels of NTX were increased over time in the hGH-treated group; however, this did not reach statistical significance. Both NTX and osteocalcin remained unchanged in control subjects. BMD of the spine and total hip was unchanged in subjects treated with placebo or hGH at 24 weeks. However, femoral neck BMD was slightly but significantly decreased in the placebo group at this time point but remained unchanged from baseline in the hGH-treated subjects. CONCLUSIONS: hGH therapy significantly increased markers of bone turnover during the initial 3 months of therapy and stabilized femoral neck bone mass over a 6-month period in patients with severe SBS undergoing intestinal rehabilitation.     

Effects of dietary calcium compared with calcium supplements on estrogen metabolism and bone mineral density

BACKGROUND: High calcium intake has been associated with both high bone mineral density (BMD) and high urinary estrogen metabolites. However, the role of dietary calcium and calcium supplements on estrogen metabolism and BMD remains unknown. OBJECTIVE: The objective was to investigate the importance of the source of calcium intake on estrogen metabolism and BMD. DESIGN: The average total daily calcium intake from supplements and diet, urinary estrogen metabolites, and spine and proximal femur BMD were studied in 168 healthy postmenopausal white women. RESULTS: Women who obtained calcium primarily from the diet or from both the diet and supplements had significantly (P=0.03) lower ratios of nonestrogenic to estrogenic metabolites (2-hydroxyestrone 1/16 alpha-hydroxyestrone) than did those who obtained calcium primarily from supplements. Adjusted BMD z scores were significantly greater in the subjects who obtained calcium primarily from the diet or from both the diet and supplements than in those who obtained calcium primarily from calcium supplements at the spine (P=0.012), femoral neck (P=0.02), total femur (P=0.003), and intertrochanter (P=0.005). This difference was evident especially in those who obtained calcium primarily from the diet, whose total calcium intake was lower than that in those who obtained calcium primarily from supplements. CONCLUSION: Calcium from dietary sources is associated with a shift in estrogen metabolism toward the active 16 alpha-hydroxyl metabolic pathway and with greater BMD and thus may produce more favorable effects in bone health in postmenopausal women than will calcium from supplements.     

Menstrual history and bone density in young women

Adequate levels of reproductive and pituitary hormones are needed for the initiation and maintenance of regular menstrual cycles as well as for the achievement of peak bone mineral density (BMD). Therefore, in the absence of direct hormone measures, menstrual history may serve as a surrogate for the adequacy of hormonal functioning and be a marker for bone status in young women. In our cross-sectional study of white college women aged 19-26 years, we examined the association of six characteristics of menstrual history with bone density at the lumbar spine and the femoral neck. To characterize associations, we used multiple linear regression models that also accounted for the contribution of body mass index, dietary calcium intake, height, level of physical activity, smoking, and alcohol use. The associations between each of the six menstrual characteristics and BMD were stronger at the lumbar spine than at the femoral neck. Age at menarche explained the most variance at both the lumbar spine (partial r2 x 100 = 5.9%) and the femoral neck (partial r2 x 100 = 2.1%). For each year that menarche was delayed, bone density was lower by -0.023 g/cm2 (p = 0.0024) at the lumbar spine and -0.0129 g/cm2 (p = 0.0565) at the femoral neck. At the lumbar spine, a higher number of lifetime menstrual cycles was also significantly associated with increased bone density (adjusted beta = 0.0010, p = 0.0052, partial r2 x 100 = 4.4%). This association was not significant after adjusting for age at menarche. Neither reproductive years (age - age at menarche) nor a history of irregular cycles (either at menarche, in the past year, or ever) was associated with bone density at either site. Menstrual function appears to affect the bone density of these young women. Studies that include measures of reproductive and pituitary hormones are needed to further explore the role of hormones in the potential link between menstrual history and bone density.     

甲状旁腺激素基因多态性与钙摄入量对青春期女童骨量增长的交互作用

目的:探讨甲状旁腺激素(PTH)基因多态性与钙摄入量对青春期女童骨量增长的交互作用。方法:选择228名9～11.5岁未月经初潮的健康女童进行2年追踪,用双能X线骨密度仪(DEXA)检测对象追踪前后全身、左侧近端股骨(包括股骨颈、大转子、粗隆间和华氏三角区)、L1～L4腰椎骨矿含量和骨密度,采用PCR-RFLP技术检测PTH基因BstBⅠ位点多态性。结果:BB基因型女童L1～L4腰椎骨矿含量增长率、左侧近端股骨、粗隆间和L1-L4腰椎骨密度增长率均高于含b等位基因女童(P=0.022～0.047)。BB基因型女童在高钙摄入(>950mg/d)时,粗隆间骨矿含量(ITBMC)增长率较中等和低钙摄入时分别高29.4%和35.0%,股骨颈骨密度(FNBMD)增长率分别高66.7%和46.2%。而含b等位基因女童的ITBMC和FNBMD增长率在不同钙摄入量之间没有显著性差异。结论:PTH基因BstBⅠ多态性与钙摄入量对青春期女童骨量增长存在交互作用,BB基因型女童高钙摄入可促进其骨量增长。     

High vitamin C intake is associated with lower 4-year bone loss in elderly men

Vitamin C is essential for collagen formation and normal bone development. We evaluated associations of total, supplemental, and dietary vitamin C intake with bone mineral density (BMD) at the hip [femoral neck, trochanter], spine, and radial shaft and 4-y BMD change in elderly participants from the Framingham Osteoporosis Study. Energy-adjusted vitamin C intakes were estimated from the Willett FFQ in 1988-89. Mean BMD and 4-y BMD change was estimated, for men and women, by tertile/category of vitamin C intake, adjusting for covariates. We tested for interaction with smoking, calcium, and vitamin E intake. Among 334 men and 540 women, the mean age was 75 y and mean vitamin D intake was 8.25 mug/d (women) and 8.05 mug/d (men). We observed negative associations between total and supplemental vitamin C intake and trochanter-BMD among current male smokers (P-trend = 0.01). Among male nonsmokers, total vitamin C intake was positively associated with femoral neck BMD (P-trend = 0.04). Higher total vitamin C intake was associated with less femoral neck and trochanter-BMD loss in men with low calcium (all P-trend 相似文献   

Plasma Fatty Acids and Quantitative Ultrasound,DXA and pQCT Derived Parameters in Postmenopausal Spanish Women

Different factors may contribute to the development of osteopenia or osteoporosis. Fatty acids are key nutrients for health, and a number of studies have reported an association between bone mineral density (BMD) and fatty acid intake. We aimed to investigate the relationships between serum levels of different fatty acids and bone parameters determined by quantitative bone ultrasound (QUS), peripheral quantitative computed tomography (pQCT), and dual-energy X-ray absorptiometry (DXA) in a sample of Spanish postmenopausal women. We enrolled a total of 301 postmenopausal women (median age 59 years; interquartile range (IQR) 7) in this study. All participants underwent full densitometric screening, including calcaneal quantitative ultrasound (QUS), peripheral quantitative computed tomography (pQCT), and dual-energy X-ray absorptiometry (DXA), as well as plasma fatty acid measurement. After adjustment for potential confounders, plasma n-3 polyunsaturated fatty acid (PUFA) levels correlated with BMD in the spine (r = 0.150; p = 0.014) and femoral neck (r = 0.143; p = 0.019). By multiple linear regression, an independent statistically significant positive relationship was observed between BMD in the spine and BMI (β = 0.288; p = 0.001) as well as total plasma n-3 PUFAs (β = 0.155; p = 0.009). The plasma n-3 PUFA level was also a significant and positive predictor of BMD at the femoral neck (β = 0.146; p = 0.009). Independent risk factors for low BMD (T-score ≤ 1) were determined by logistic regression analysis, and a relatively high level of plasma n-3 PUFAs (OR = 0.751; 95% CI 0.587-0.960, p = 0.022) was identified as a protective factor against low bone mass. In this single-center sample of Spanish postmenopausal women, we reported a significant positive and statistically independent association between BMD and plasma levels of n-3 PUFAs.     

Vitamin D and attainment of peak bone mass among peripubertal Finnish girls: a 3-y prospective study

BACKGROUND: Little is known about the effect of vitamin D status on bone gain in adolescents. OBJECTIVE: The objective was to examine whether vitamin D status is associated with accrual of bone mineral density (BMD) and bone mineral apparent density (BMAD). DESIGN: This 3-y prospective study examined the association between changes in BMD or BMAD and serum 25-hydroxyvitamin D [25(OH)D] in 171 healthy Finnish girls aged 9-15 y. Lumbar spine and femoral neck BMDs were measured by dual-energy X-ray absorptiometry. RESULTS: Baseline 25(OH)D correlated significantly with the unadjusted 3-y change in BMD at the lumbar spine (r = 0.35, P < 0.001) and femoral neck (r = 0.32, P < 0.001) in all participants. The difference from baseline in adjusted 3-y BMD accumulation between those with severe hypovitaminosis D [25(OH)D < 20 nmol/L] and those with a normal vitamin D status [25(OH)D > or = 37.5 nmol/L] was 4% (12.7%, 13.1%, and 16.7% for the lowest, middle, and highest tertiles of 25(OH)D, respectively; P for trend = 0.01) at the lumbar spine in the girls with advanced sexual maturation at baseline (n = 129). Moreover, the adjusted change in lumbar spine BMD was 27% greater in the highest vitamin D intake tertile than in the lowest tertile in the same girls (P for trend = 0.016). CONCLUSIONS: Pubertal girls with hypovitaminosis D seem to be at risk of not reaching maximum peak bone mass, particularly at the lumbar spine. Dietary enrichment or supplementation with vitamin D should be considered to ensure an adequate vitamin D status.     

Associations between body morphology and bone mineral density in premenopausal women

To investigate whether body morphology, obesity and its long time evolution were associated with lumbar and femoral bone mineral density (BMD) in premenopausal women of the same age. Design: Cross-sectional study. Subjects: 72 healthy premenopausal women born in 1950 (42 years) with a regular physical activity. Measurements: BMD measured by dual-X-ray absorptiometry (DEXA) at lumbar spine and proximal femur; body weight, body mass index (BMI), BMI at 20 years (BMI-20), increase in BMI since age of 20 (BMI->20), body circumferences (breast, waist, hip) and their ratios (WHR, BHR, WBR), smoking and alcohol intake. Results: Lumbar spine BMD did not correlate with any anthropometric measurement. Femoral BMDs correlated positively with weight, BMI, BMI-20, breast, waist, WHR and BHR. The BMI-20 explained the 5% and the current BMI the 13% of variance of total femur BMD. After adjustment for weight or BMI, breast circumference and BHR remained significantly correlated with all femoral BMDs sites except neck. Weight was the best predictor for neck BMD (R² = 0.08; p < 0.02), and BHR for Ward's triangle (R² = 0.12; p < 0.01) and trochanter (R² = 0.10; p < 0.001). Alcohol intake, cigarette smoking, and age of menarche were not related to BMDs. Conclusion: In premenopausal women of the same age, lumbar spine BMD was not associated with any anthropometric measurement. Greater BHR and its long time of evolution may be determinants of greater femoral BMD (trabecular), whereas body weight may be determinant of femoral neck BMD (cortical). Further studies are needed to determine whether large breast to hip ratio may be considered as a protective factor for femoral osteoporosis.     

Dietary soy isoflavones and bone mineral density: results from the study of women's health across the nation

Isoflavones are naturally occurring selective estrogen receptor modulators, with potential bone protective effects. To study the relation between soy isoflavone intake and bone mineral density (BMD), the authors analyzed baseline data from the Study of Women's Health Across the Nation, a US community-based cohort study of women aged 42-52 years. Their 1996-1997 analysis included African-American (n = 497), Caucasian (n = 1,003), Chinese (n = 200), and Japanese (n = 227) participants. Genistein and daidzein intakes were highly correlated (r = 0.98); therefore, analyses were conducted by using genistein. Median intakes of genistein (measured in micrograms/day) by African Americans and Caucasians were too low to pursue relational analyses further. For Chinese and Japanese women, median genistein intakes were 3,511 and 7,151 microg/day, respectively. Ethnic-specific, linear models were used to predict BMD as a function of energy-adjusted tertile of intake, controlled for relevant covariates. For Chinese women, no association between genistein and BMD was found. Premenopausal, but not perimenopausal, Japanese women whose intakes were greater had higher spine and femoral neck BMD. Adjusted mean spinal BMD of those in the highest tertile of intake was 7.7% greater than that of women in the lowest tertile (p = 0.02); femoral neck BMD was 12% greater in the highest versus the lowest tertile (p < 0.0001).     

Is caffeine associated with bone mineral density in young adult women?

BACKGROUND: By increasing the urinary excretion of calcium, caffeine consumption may reduce bone mineral density (BMD) and subsequently increase the risk for osteoporotic fracture. Although negative associations between caffeine consumption and BMD have been reported for postmenopausal women, in particular for those who consume low amounts of dietary calcium, the relation between caffeine and BMD in younger women is unclear. Therefore, we evaluated the association between caffeine consumption and BMD in a cross-sectional study of 177 healthy white women, age 19-26 years, who attended a Midwestern university. METHODS: Average caffeine intake (milligrams per day) was calculated from self-reports of the consumption of coffee, decaffeinated coffee, tea, colas, chocolate products, and select medications during the previous 12 months (mean caffeine intake = 99. 9 mg/day). BMD (grams per square centimeter) at the femoral neck and the lumbar spine was measured by dual-energy X-ray absorptiometry. RESULTS: After adjusting in linear regression models for potential confounders, including height, body mass index, age at menarche, calcium intake, protein consumption, alcohol consumption, and tobacco use, caffeine consumption was not a significant predictor of BMD. For every 100 mg of caffeine consumed, femoral neck BMD decreased 0.0069 g/cm(2) (95% confidence in terval [CI] = -0.0215, 0. 0076) and lumbar spine BMD decreased 0.0119 g/cm(2) (95% CI = -0. 0271, 0.0033). No single source of caffeine was significantly associated with a decrease in BMD. Furthermore, the association between caffeine consumption and BMD at either site did not differ significantly between those who consumed low levels of calcium (< or =836 mg/day) and those who consumed high levels of calcium (>836 mg/day). CONCLUSIONS: Caffeine intake in the range consumed by young adult women is not an important risk factor for low BMD.