Vitamin D and bone health in postmenopausal women

Osteoporosis, a disease of increased skeletal fragility, is becoming increasingly common as the U.S. population ages. Adequate vitamin D and calcium intake is the cornerstone of osteoporosis prevention and treatment. Age-related changes in vitamin D and calcium metabolism increase the risk of vitamin D insufficiency and secondary hyperparathyroidism. Although longitudinal data have suggested a role of vitamin D intake in modulating bone loss in perimenopausal women, studies of vitamin D and calcium supplementation have failed to support a significant effect of vitamin D and calcium during early menopause. There is a clearer benefit in vitamin D and calcium supplementation in older postmenopausal women. Vitamin D intake between 500 and 800 IU daily, with or without calcium supplementation, has been shown to increase bone mineral density (BMD) in women with a mean age of approximately 63 years. In women older than 65, there is even more benefit with vitamin D intakes of between 800 and 900 IU daily and 1200-1300 mg of calcium daily, with increased bone density, decreased bone turnover, and decreased nonvertebral fractures. The decreases in nonvertebral fractures may also be influenced by vitamin D-mediated decreases in body sway and fall risk. There are insufficient available data supporting a benefit from vitamin D supplementation alone, without calcium, to prevent osteoporotic fracture in postmenopausal women.     

Effect of withdrawal of calcium and vitamin D supplements on bone mass in elderly men and women

BACKGROUND: Supplementation with calcium and vitamin D reduces bone loss and prevents fractures in elderly people, but it is not known whether any lasting benefit remains if the supplements are discontinued. OBJECTIVE: The objective was to determine whether gains in bone mineral density (BMD) induced by calcium and vitamin D supplementation persist after supplement withdrawal. DESIGN: Two-hundred ninety-five healthy, elderly men and women (aged >/=68 y) who had completed a 3-y randomized, placebo-controlled trial of calcium and vitamin D supplementation were followed for an additional 2 y during which no study supplements were given. BMD was measured by dual-energy X-ray absorptiometry, and biochemical variables related to calcium metabolism and bone turnover were measured. RESULTS: In the 128 men, supplement-induced increases in spinal and femoral neck BMD were lost within 2 y of supplement discontinuation, but small benefits in total-body BMD remained. In the 167 women, there were no lasting benefits in total-body BMD or at any bone site. Consistent with the observations on BMD, the bone turnover rates in both men and women (as measured by serum osteocalcin concentrations) returned to their original higher concentrations within the same 2-y period. CONCLUSION: Discontinued calcium and vitamin D supplementation has limited cumulative effect on bone mass in men and women aged >/=68 y.     

Importance of calcium, vitamin D and vitamin K for osteoporosis prevention and treatment

Throughout the life cycle the skeleton requires optimum development and maintenance of its integrity to prevent fracture. Bones break because the loads placed on them exceed the ability of the bone to absorb the energy involved. It is now estimated that one in three women and one in twelve men aged >55 years will suffer from osteoporosis in their lifetime and at a cost in the UK of > 1.7 pounds x 10(9) per year. The pathogenesis of osteoporosis is multifactorial. Both the development of peak bone mass and the rate of bone loss are determined by key endogenous and exogenous factors. Ca supplements appear to be effective in reducing bone loss in women late post menopause (>5 years post menopause), particularly in those with low habitual Ca intake (<400 mg/d). In women early post menopause (<5 years post menopause) who are not vitamin D deficient, Ca supplementation has little effect on bone mineral density. However, supplementation with vitamin D and Ca has been shown to reduce fracture rates in the institutionalised elderly, but there remains controversy as to whether supplementation is effective in reducing fracture in free-living populations. Re-defining vitamin D requirements in the UK is needed since there is evidence of extensive hypovitaminosis D in the UK. Low vitamin D status is associated with an increased risk of falling and a variety of other health outcomes and is an area that requires urgent attention. The role of other micronutrients on bone remains to be fully defined, although there are promising data in the literature for a clear link between vitamin K nutrition and skeletal integrity, including fracture reduction.     

Calcium intake and hip fracture risk in men and women: a meta-analysis of prospective cohort studies and randomized controlled trials

BACKGROUND: The role of total calcium intake in the prevention of hip fracture risk has not been well established. OBJECTIVE: The objective of the study was to assess the relation of calcium intake to the risk of hip fracture on the basis of meta-analyses of cohort studies and clinical trials. RESULTS: In women (7 prospective cohort studies, 170,991 women, 2,954 hip fractures), there was no association between total calcium intake and hip fracture risk [pooled risk ratio (RR) per 300 mg total Ca/d = 1.01; 95% CI: 0.97, 1.05]. In men (5 prospective cohort studies, 68,606 men, 214 hip fractures), the pooled RR per 300 mg total Ca/d was 0.92 (95% CI: 0.82, 1.03). On the basis of 5 clinical trials (n = 5666 women, primarily postmenopausal, plus 1074 men) with 814 nonvertebral fractures, the pooled RR for nonvertebral fractures between calcium supplementation (800-1600 mg/d) and placebo was 0.92 (95% CI: 0.81, 1.05). On the basis of 4 clinical trials with separate results for hip fracture (6,504 subjects with 139 hip fractures), the pooled RR between calcium and placebo was 1.64 (95% CI:1.02, 2.64). Sensitivity analyses including 2 additional small trials with <100 participants or per-protocol results did not substantially alter results. CONCLUSIONS: Pooled results from prospective cohort studies suggest that calcium intake is not significantly associated with hip fracture risk in women or men. Pooled results from randomized controlled trials show no reduction in hip fracture risk with calcium supplementation, and an increased risk is possible. For any nonvertebral fractures, there was a neutral effect in the randomized trials.     

Effect of vitamin D supplementation on bone and vitamin D status among Pakistani immigrants in Denmark: a randomised double-blinded placebo-controlled intervention study

Severe vitamin D deficiency is common among Muslim immigrants. The dose necessary to correct the deficiency and its consequence for bone health are not known for immigrants. The aim was to assess the effect of relatively low dosages of supplemental vitamin D on vitamin D and bone status in Pakistani immigrants. This 1-year-long randomised double-blinded placebo-controlled intervention with vitamin D3 (10 and 20 microg/d) included girls (10.1-14.7 years), women (18.1-52.7 years) and men (17.9-63.5 years) of Pakistani origin living in Denmark. The main endpoints were serum 25-hydroxyvitamin D (S-25OHD), parathyroid hormone, bone turnover markers and bone mass. The study showed that supplementation with 10 and 20 microg vitamin D3 per d increased S-25OHD concentrations similarly in vitamin D-deficient Pakistani women (4-fold), and that 10 microg increased S-25OHD concentrations 2-fold and 20 microg 3-fold in Pakistani men. S-25OHD concentrations increased at 6 months and were stable thereafter. Baseline S-25OHD concentrations tended to be lower in girls and women than in men; females achieved about 46 nmol/l and men 55 nmol/l after supplementation. Serum intact parathyroid hormone concentrations decreased at 6 months, but there was no significant effect of the intervention on bone turnover markers and dual-energy X-ray absorptiometry measurements of the whole body and lumbar spine.     

Bone and gastric bypass surgery: effects of dietary calcium and vitamin D

OBJECTIVE: To examine bone mass and metabolism in women who had previously undergone Roux-en-Y gastric bypass (RYGB) and determine the effect of supplementation with calcium (Ca) and vitamin D. RESEARCH METHODS AND PROCEDURES: Bone mineral density and bone mineral content (BMC) were examined in 44 RYGB women (> or = 3 years post-surgery; 31% weight loss; BMI, 34 kg/m(2)) and compared with age- and weight-matched control (CNT) women (n = 65). In a separate analysis, RYGB women who presented with low bone mass (n = 13) were supplemented to a total 1.2 g Ca/d and 8 microg vitamin D/d over 6 months and compared with an unsupplemented CNT group (n = 13). Bone mass and turnover and serum parathyroid hormone (PTH) and 25-hydroxyvitamin D were measured. RESULTS: Bone mass did not differ between premenopausal RYGB and CNT women (42 +/- 5 years), whereas postmenopausal RYGB women (55 +/- 7 years) had higher bone mineral density and BMC at the lumbar spine and lower BMC at the femoral neck. Before and after dietary supplementation, bone mass was similar, and serum PTH and markers of bone resorption were higher (p < 0.001) in RYGB compared with CNT women and did not change significantly after supplementation. DISCUSSION: Postmenopausal RYGB women show evidence of secondary hyperparathyroidism, elevated bone resorption, and patterns of bone loss (reduced femoral neck and higher lumbar spine) similar to other subjects with hyperparathyroidism. Although a modest increase in Ca or vitamin D does not suppress PTH or bone resorption, it is possible that greater dietary supplementation may be beneficial.     

Pakistani immigrant children and adults in Denmark have severely low vitamin D status

OBJECTIVE: To determine vitamin D and bone status in adolescent girls, pre-menopausal women and men of Pakistani origin, to single out determinants of vitamin D status and to determine the association between vitamin D status, bone metabolism and bone status. SUBJECTS/METHODS: Cross-sectional study, Copenhagen (55 degrees N), January-November. Serum 25-hydroxyvitamin D (S-25OHD), serum intact parathyroid hormone (S-iPTH), bone turnover markers and whole body and lumbar spine bone mineral density were measured. Sun, smoking and clothing habits, age, body mass index (BMI), and vitamin D and calcium from food and from supplements were recorded. Thirty-seven girls (median age, range: 12.2 years, 10.1-14.7), 115 women (36.2 years, 18.1-52.7) and 95 men (38.3 years, 17.9-63.5) of Pakistani origin (immigrants or descendants with Pakistani parents) took part in the study. RESULTS: Median concentration of S-25OHD was 10.9, 12.0 and 20.7 nmol/l for girls, women and men, respectively. Forty-seven per cent of the girls, 37% of the women and 24% of the men had elevated S-iPTH, and there was a negative relationship between S-iPTH and S-25OHD. Use of vitamin D-containing supplements had a positive association with S-25OHD for men (P=0.04) and women (P=0.0008). Twenty-one per cent of the women and 34% of the men had osteopenia. Neither S-25OHD nor S-iPTH was associated with lumbar spine or whole body bone mineral content. CONCLUSIONS: Severely low vitamin D status and elevated S-iPTH is common among Pakistani immigrants in Denmark. The low vitamin D status is not associated with bone markers or bone mass among relatively young Pakistanis.     

Calcium, vitamin D and involutional osteoporosis

PURPOSE OF REVIEW: Previous studies suggest that combined calcium and vitamin D supplementation decreases the risk of fractures in older people, particularly those living in care homes, but trials of vitamin D alone in fracture prevention have generated inconsistent results. This review examines the physiological functions of calcium and vitamin D, and the contrasting views of what constitutes an adequate dietary calcium intake and vitamin D sufficiency in adults, and highlights the results of recent large studies of calcium and vitamin D supplementation. RECENT FINDINGS: The RECORD study shows that calcium (1000 mg/day) and vitamin D (800 IU/day), either alone or in combination, are ineffective in the secondary prevention of osteoporotic fractures in older men and women living in the community. The Northern and Yorkshire Study also suggests that calcium (1000 mg/day) and vitamin D (800 IU/day) are of no benefit in the primary prevention of fractures in community-dwelling older women. Furthermore, the Wessex study demonstrated no reduction in fractures in older people living in the community treated with annual IM injections of vitamin D (300 000 IU). SUMMARY: The latest studies highlight that vitamin D, either alone or in combination with calcium supplementation, is ineffective in the primary or secondary prevention of fractures in community-dwelling older people. In contrast, calcium and vitamin D supplementation prevents fractures in institutionalized elderly people, who commonly have vitamin D deficiency and secondary hyperparathyroidism.     

Prevention of fractures in older people with calcium and vitamin D

The greatest cause of fracture in older people is osteoporosis which contributes to increased morbidity and mortality in older people. A number of meta-analyses have been performed assessing the effectiveness of calcium supplementation alone, vitamin D supplementation alone and the combined therapy on bone loss and fracture reduction in older people. The results of these meta-analyses indicate that vitamin D supplementation alone is unlikely to reduce fracture risk, calcium supplementation alone has a modest effect in reducing total fracture risk, but compliance with calcium supplements is poor in the long term. The combination of calcium supplementation with vitamin D supplementation, particularly in those at risk of marginal and low vitamin D status reduces total fractures, including hip fractures. Therefore older people would be recommended to consume adequate dietary calcium (>1100 mg/day) together with maintaining adequate vitamin D status (>60 nmol/L 25(OH)D) to reduce risk of fracture. It is a challenge to consume sufficient dietary calcium from dietary sources, but the increasing range of calcium fortified foods could assist in increasing the dietary calcium intake of older people. In addition to the usual dairy based food sources, vitamin D supplements are likely to be required for older people with reduced mobility and access to sunlight.     

Management of Postmenopausal Osteoporosis

Postmenopausal osteoporosis is a very common disease, and approximately half of all women aged >50 years will experience an osteoporotic fracture during the remainder of their lifetime. The predominant cause of postmenopausal osteoporosis is the decline in estrogen levels, which causes an increase in bone turnover, and results in a loss of bone mass throughout the entire skeleton. Fragility fractures, either vertebral or nonvertebral, have a considerable adverse effect on quality of life in women with osteoporosis and place a significant burden on society in terms of healthcare costs.Management of postmenopausal osteoporosis includes alteration of modifiable risk factors (e.g. lifestyle and propensity to fall), ensuring adequate calcium and vitamin D intake, and pharmacological treatment to decrease fracture risk by slowing or preventing bone loss and preserving bone strength. Raloxifene (Evista®), a selective estrogen receptor modulator that partially mimics the effects of estrogen on bone and lipid metabolism and acts as an antiestrogen in the breast and endometrium, is indicated for the prevention and treatment of postmenopausal osteoporosis. Raloxifene increases bone mineral density at vertebral and nonvertebral sites, and decreases the risk of vertebral fracture to a similar extent to the bisphosphonates alendronate and risedronate. However, effects on nonvertebral fracture risk, including the risk of hip fracture, have not been observed.Raloxifene appears to reduce breast cancer risk (in women at average risk) and cardiovascular risk (in women at increased risk) without stimulating the endometrium, and does not cause vaginal bleeding or breast pain. However, the drug causes hot flashes in some women, and increases the risk of venous thromboembolic events by about the same amount as hormone replacement therapy (HRT).In economic models, raloxifene is cost effective compared with no treatment, HRT, calcitonin, or alendronate for the prevention or treatment of postmenopausal osteoporosis.In conclusion, raloxifene is a valuable and cost-effective therapy for preventing the progression of osteoporosis and for reducing vertebral fracture risk in osteoporotic postmenopausal women. The tendency for raloxifene to cause hot flashes, and its apparent lack of effect on hip fracture risk, may preclude its use in women with vasomotor symptoms and in patients at high risk for hip fracture. Results from large ongoing trials are needed to confirm the effects of raloxifene on breast cancer and cardiovascular disease. However, the effects of raloxifene on breast cancer and cardiovascular risk without stimulating the endometrium make the drug an attractive therapy for the prevention and treatment of postmenopausal osteoporosis.     

Osteoporosis: the role of micronutrients

Osteoporosis and low bone mass are currently estimated to be a major public health threat. Adequate nutrition plays a major role in the prevention and treatment of osteoporosis; the micronutrients of greatest importance are calcium and vitamin D. Calcium has been shown to have beneficial effects on bone mass at all ages, although the results are not always consistent. Higher doses than the current US recommendation (600 IU) of vitamin D in the elderly (age > or = 65 y) may actually be required for optimal bone health (800-1000 IU/d). The elderly can clearly benefit from increased vitamin D intakes; however, the potential importance of vitamin D in peak bone mass is just being investigated. Vitamin D has been related to falls, with supplementation reducing the number of falls. There are clear fracture benefits demonstrated in randomized clinical trials of calcium and vitamin D supplementation. The other micronutrient needs for optimizing bone health can be easily met by a healthy diet that is high in fruits and vegetables to ensure adequate intakes for magnesium, potassium, vitamin C, vitamin K, and other potentially important nutrients. Healthcare professionals need to be aware of the importance of adequate calcium and vitamin D intakes (easily monitored by serum 25(OH)D) for optimal bone health, as well as the prevention of falls and fractures. In addition, a healthy diet that includes 5 servings a day of fruits and vegetables should optimize the intake of micronutrients required for bone health.     

The role of nutrition on optimizing peak bone mass

The growth years provide an important window of opportunity for building peak bone mass. More than one-fourth of adult bone mass is acquired between the ages of 12 to 14 years in girls and 13 to 15 years in boys. Although genetics determine 60-80% of peak bone mass, lifestyle choices including diet and physical activity are also predictors of bone accrual during growth. Calcium and vitamin D are two nutrients that are most likely to be deficient. Dietary calcium predicts 10-15% of skeletal calcium retention during adolescence with race and sexual maturity in the models. Boys retain more calcium than girls and black girls retain more calcium than whites girls. The role of Vitamin D status on peak bone mass is not well understood. Results of randomized, controlled trials are mixed and the effects of vitamin D supplementation on calcium absorption in children has not been studied. Dietary salt increases urinary calcium excretion. Exercise can enhance the effect of dietary calcium through enhanced bone geometry.     

Calcium, vitamin D supplementation, and physical function in the Women's Health Initiative

OBJECTIVES: The Women's Health Initiative (WHI) randomized trial of calcium/vitamin D supplementation found reduced bone loss with active treatment compared to placebo. Now we examine whether the treatment affected self-reported physical functioning and objective measures of physical functioning. DESIGN: A randomized, double-blind, placebo-controlled trial of 1,000 mg calcium carbonate plus 400 IU vitamin D(3) per day or matching placebo pills. SUBJECTS/SETTING: The study included 33,067 women (50 to 79 years old) at 40 US study centers. MAIN OUTCOME MEASURES: Physical functioning was assessed by questionnaire at enrollment in WHI, 1 year prior to calcium/vitamin D trial randomization and at study close-out (average follow-up 7.1 years). Objective physical performance and self-reported exercise measures were collected at WHI baseline (1 year prior to calcium/vitamin D enrollment) and 2 years and 4 years after calcium/vitamin D trial enrollment in a subsample (n=3,137). STATISTICAL ANALYSES PERFORMED: Calcium/vitamin D effects were tested in unadjusted and interaction linear models for each of the physical function measures. Covariates were baseline total calcium intake, fracture risk score, treatment arm in the hormone therapy and dietary modification trials (ie, active drug or placebo, low-fat diet intervention or usual diet, respectively) and age. RESULTS: Neither intention to treat nor high adherence analyses produced substantial effects of calcium/vitamin D compared to placebo on physical functioning or performance. The interaction analyses also did not result in differences because of calcium/vitamin D. CONCLUSIONS: As the first long-term randomized trial to examine the effectiveness of calcium and vitamin D in protecting against decline of physical functioning in older women, the results did not support benefit.     

Calcium,vitamin D,milk consumption,and hip fractures: a prospective study among postmenopausal women

BACKGROUND: Short trials of calcium supplementation show that it reduces loss of bone density in postmenopausal women; longer observational studies do not generally find a lower risk of hip fracture with higher-calcium diets. Fewer studies have focused on vitamin D in preventing postmenopausal osteoporosis or fractures. OBJECTIVE: We assessed relations between postmenopausal hip fracture risk and calcium, vitamin D, and milk consumption. DESIGN: In an 18-y prospective analysis in 72 337 postmenopausal women, dietary intake and nutritional supplement use were assessed at baseline in 1980 and updated several times during follow-up. We identified 603 incident hip fractures resulting from low or moderate trauma. Relative risks (RRs) from proportional hazards models were controlled for other dietary and nondietary factors. RESULTS: Women consuming > or = 12.5 microg vitamin D/d from food plus supplements had a 37% lower risk of hip fracture (RR = 0.63; 95% CI: 0.42, 0.94) than did women consuming < 3.5 microg/d. Total calcium intake was not associated with hip fracture risk (RR = 0.96; 95% CI: 0.68, 1.34 for > or = 1200 compared with < 600 mg/d). Milk consumption was also not associated with a lower risk of hip fracture (P for trend = 0.21). CONCLUSIONS: An adequate vitamin D intake is associated with a lower risk of osteoporotic hip fractures in postmenopausal women. Neither milk nor a high-calcium diet appears to reduce risk. Because women commonly consume less than the recommended intake of vitamin D, supplement use or dark fish consumption may be prudent.     

Osteoporosis and African American women

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

Acute alcohol use among patients with acute hip fractures: a descriptive incidence study in southeastern Finland

AIM: To assess the very recent use of alcohol among patients admitted to two Finnish hospitals due to an acute hip fracture. METHOD: Very recent use of alcohol was recorded according to the patient's or the relatives' report. Ethanol was measured in blood samples taken at admission. Serum gamma-glutamyltransferase, aspartate aminotransferase and alanine aminotransferase, and vitamin D concentration were measured. Reported use of medication, vitamin D, and/or calcium supplementation was recorded. RESULTS: Complete data were obtained on 222 of 375 eligible patients; 71% of those enrolled were women. The mean age of women was 80.5 years (SD 10) and of men 73 years (SD 12) (P < 0.001). The fracture type was femoral neck in 50%, trochanteric in 41%, and subtrochanteric in 9%. The use of alcohol within 24 h before the accident leading to hip fracture was reported by 21.5% of men and 7% of women; positive serum alcohol levels were noted in 17% (19% of men and 16% of women) and 2.2% had a level of >1.0 mg/l. Recent alcohol use was more common among patients in the age group of 65-74 years than among older patients (P < 0.001). The use of alcohol was associated strongly with tobacco use (P = 0.00012) but had no association with vitamin D levels. Alcohol users used less medication than non-users (P < 0.01). Women seemed to conceal their use of alcohol more than men (P < 0.005). CONCLUSIONS: Alcohol consumption was common among patients with an acute hip fracture, being more common in younger than in older patients. Use of alcohol in the 24 h prior to the injury was reported by 21.5% of men and 7% of women. Alcohol concentration in blood was positive in 19% of men and 16% of women.     

Effects of protein-rich supplementation and nandrolone on bone tissue after a hip fracture

BACKGROUND & AIMS: Osteoporosis is a major health problem worldwide. Low weight is a major risk factor for low bone mass and fractures. The aim of this study was to investigate the effects on bone tissue of protein-rich supplementation alone or in combination with nandrolone decanoate in lean elderly women after a hip fracture. METHODS: Sixty elderly women with BMI <24 kg/m(2) admitted to hospital due to a femoral neck fracture were randomised to a control group, to receive a protein-rich formula or to receive the same formula with an addition of nandrolone decanoate for 6 months. All patients received additional calcium and vitamin D. The effects after 6 and 12 months were measured by means of bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA), and with biochemical bone markers. Osteocalcin and C-terminal telopeptide of collagen-1 (CTX) were used to estimate bone formation and bone resorption, respectively. RESULTS: The analyses showed an increase in total body BMD at 6 and 12 months in patients who received protein-rich supplementation. Nandrolone decanoate did not appear to have any additional effect on BMD. Osteocalcin increased in all groups while no significant changes were found for CTX. CONCLUSION: The overall results of the study indicated that protein-rich supplementation given to lean elderly female hip fracture patients increased the total body BMD.     

Predictors of bone mineral density in a convenience sample of young Caucasian adults living in southern Ontario

Osteoporosis is a major public health concern in Canada and worldwide. Although much is known about bone health in older adults, little is known about bone health in young, healthy Canadian men and women. The objectives of this research were to describe bone mineral density (BMD) of young, healthy adults living in southern Ontario, Canada, and to identify predictors of BMD in this population. Two-hundred and fifty-eight Caucasian men and women aged 18-33 years completed health and physical activity questionnaires along with a calcium and vitamin D specific food frequency questionnaire. Height and mass were measured. BMD of the total hip, femoral neck, spine, and total body was measured using dual energy X-ray absorptiometry. Among men, body mass, weight-bearing physical activity, and calcium intake were significant predictors of BMD. Among women, body mass, calcium intake, and family history of osteoporosis significantly predicted log BMD. The predictors of BMD in young Canadian men and women identified in this study may inform the development of longitudinal studies designed to examine the influence of lifestyle factors on BMD in young adults.     

妊娠期糖尿病母亲新生儿低骨密度危险因素分析及相关模型构建

目的 探究影响妊娠期糖尿病(gestational diabetes mellitus,GDM)母亲新生儿低骨密度的危险因素,并构建预测模型.方法 选取2017年1月至2019年12月在广西壮族自治区江滨医院进行产检与分娩的200例GDM孕妇及其所产新生儿作为研究对象,根据新生儿是否出现低骨密度分为低骨密度组(50例)...     

Patient assessment in the diagnosis, prevention, and treatment of osteoporosis.

Assessment of the patient with osteoporosis includes history and physical examination, laboratory testing, and imaging studies. Information gathered during this assessment assists clinicians in targeting strategies to prevent fractures. The medical history should contain items such as personal and family history of fractures, lifestyle, intake of substances such as vitamin D, calcium, corticosteroids, and other medications. The physical examination can reveal relevant information such as height loss and risk of falls. Bone mineral density (BMD), most commonly determined by dual-energy x-ray absorptiometry, best predicts fracture risk in patients without previous fracture. BMD testing is most efficient in women over 65 years old but is also helpful for men and women with risk factors. Serial BMD tests can identify individuals losing bone mass, but clinicians should be aware of what constitutes a significant change. Laboratory testing can detect other risk factors and can provide clues to etiology. Selection of laboratory tests should be individualized, as there is no consensus regarding which tests are optimal. Biochemical markers of bone turnover have a potential role in fracture risk assessment and in gauging response to therapy, but are not widely used at present. Clinicians should be aware of problems with vitamin D measurement, including seasonal variation, variability among laboratories, and the desirable therapeutic range. Careful assessment of the osteoporotic patient is essential in developing a comprehensive plan that reduces fracture risk and improves quality of life.