Importance of albumin, 25(OH)-vitamin D and IGFBP-3 as risk factors in elderly women and men with hip fracture

Sarcopenia in patients with hip fracture: A multicenter cross-sectional study

BACKGROUND

Sarcopenia is prevalent in older persons and is a risk factor for falls, fractures, and mortality. The aim of this study was to determine a) the feasibility of determining sarcopenia in patients with acute hip fracture, b) the prevalence of sarcopenia and c) associations of sarcopenia with nutritional status and comorbidities.

METHODS

A multicenter cross-sectional study on sarcopenia in male and female patients with acute hip fracture. Participants were previously ambulatory and living in the community. Sarcopenia was assessed postoperatively with muscle mass estimated by anthropometry using triceps skinfold, arm circumference, height, weight and sex. Grip strength was measured by Jamar dynamometer and pre-fracture mobility was by self-report using the New Mobility Score.

RESULTS

Out of 282 patients, 202 were assessed for sarcopenia of whom 74 (37%) were diagnosed as sarcopenic. Sarcopenia was associated with age, odds ratio (OR) 1.4 per 5 years, 95% confidence interval (CI) [1.1, 1.8], ASA Physical Status Classification System score, OR 2.3 per point, 95% CI [1.3, 4.3] and number of medications at discharge, OR 1.2 per medication, 95% CI [1.0, 1.3] and inversely associated with BMI, OR 0.8, 95% CI [0.7, 0.9] and serum albumin, OR 0.9, 95% CI [0.8,1.0].

CONCLUSIONS

Thirty-seven percent of assessed subjects were diagnosed with sarcopenia. Our data demonstrates that the prevalence of sarcopenia is associated with older age, malnutrition and comorbidities. Determining sarcopenia at the bedside was feasible in postoperative hip fracture patients by using grip strength, estimation of muscle mass by anthropometry and self-reported mobility.

Hypoalbuminaemia-a marker of malnutrition and predictor of postoperative complications and mortality after hip fractures

OBJECTIVE

Our aim was to determine the effect of hypoalbuminaemia as a marker of malnutrition on the 30-day postoperative complication rate and mortality in patients receiving surgical treatment for hip fractures using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database.

METHODS

We analyzed all patients admitted with hip fractures receiving surgical treatment from 2011 to 2013. Patients were dichotomized based on their albumin levels; hypoalbuminaemia (albumin <3.5g/dL), and nonhypoalbuminaemia (albumin >3.5g/dL). Patient demographics, postoperative complications, and length of stay were analysed. Logistic regression analysis was conducted to assess the ability of albumin level for predicting postoperative complications, length of stay, and mortality.

RESULTS

A total of 10,117 patients with hip fractures were identified with 5414 patients with normal albumin levels, and 4703 with low albumin. Multivariate analysis showed that when controlling for comorbidities; hypoalbuminaemia alone was a predictor of postoperative complications (death, unplanned intubation, being on a ventilator >48h, sepsis, and blood transfusion), and increased length of stay (6.90±7.23 versus 8.44±8.70, CI 0.64-1.20, P<0.001).

CONCLUSION

Hypoalbuminaemia alone can predict postoperative outcomes in patients with hip fractures. Furthermore, patients with hypoalbuminaemia had a longer hospital length of stay. Further studies are needed to assess whether nutritional support can improve postoperative complications in patients with hypoalbuminaemia.

Are Albumin Levels a Good Predictor of Mortality in Elderly Patients with Neck of Femur Fractures?

BACKGROUND

Neck of femur (NOF) fractures are associated with significant morbidity and mortality in elderly people with multiple co-morbidities; making management of this patient subgroup challenging. Predictors of an increase in morbidity and mortality would therefore provide a useful framework for the assessment and management of this demographic. Within the current literature, hypoalbuminaemia (<35g/dl) has been highlighted as being a good biochemical predictor of short-term mortality (<12 months). Our aims were to assess whether there was an association between low albumin levels and mortality and whether the severity adversely affects outcomes.

MATERIALS AND METHODS

Patients admitted to our large district hospital between January 2011 and December 2012 who had sustained a NOF fracture, were over 65 years old and had a pre-operative albumin level were included. This retrospective, longitudinal, observational study concluded in July 2014. Demographic and pre-operative function and albumin data was collated retrospectively. An association with mortality was made.

RESULTS

471 patients had usable data. Mean pre-operative albumin level was 29.5g/dl (SD 6.22g/dl) in patients who died and 32.8g/dl (SD 6.43g/dl) in patients who survived during the study period. Pre-operative albumin level was significantly associated with survival (hazard ratio 0.957: 95% CI (0.937, 0.978); p<0.001). Thus, a reduction of 1g/dl in pre-operative albumin is associated with an increased hazard of death of 4.3%.

CONCLUSIONS

Early identification of patients with hypoalbuminaemia on admission with a venous blood sample and timely input from orthogeriatrians could optimise these patients pre- and post-operatively. This may enable rates of morbidity and mortality to fall. Hypoalbuminaemia may be a reasonable predictor of shorter-term mortality in this patient subgroup. However, this may reflect existing co-morbidities rather than an isolated cause. This study supports an association between hypoalbuminaemia and poorer outcome for patients with NOF fractures.

Evaluation of food products fortified with oyster shell for the prevention and treatment of osteoporosis

Production and evaluation of different diet formulas fortified with oyster shell for the prevention and treatment of osteoporosis. Eighty-eight female albino rats were recruited and divided into 11 groups (8 rats each). Group 1 represented negative control while the remaining groups were ovariectomized. Group 2 acted as positive control. Groups 3-5 were fed on basal diet. Groups 6-8 were fed on lentil soup while groups 9-11 were fed on vegetable soup. Group 4, 7, 10 were fed on diets fortified with oyster shell. Groups 5, 8 and 11 were fed on diet formulas fortified with calcium citrate. All calcium fortified diet formulas, especially lentil soup, have minimized risk factors associated with osteoporosis as indicated from the significant increase in tibial weight, total protein, total calcium and phosphorus with noticeable reduction in ALP activity compared to positive group. Maximum recovery was observed for diet fortified with oyster shell. These data suggest that food products fortified with oyster shell as natural and inexpensive source could be beneficial for the prevention and treatment of osteoporosis.

Interactions between vitamin D and IGF-I: from physiology to clinical practice

The interplay between vitamin D and IGF-I is complex and occurs at both endocrine and paracrine/autocrine levels. Vitamin D has been shown to increase circulating IGF-I and IGFBP-3, with the consistent finding of a positive correlation between vitamin D and IGF-I serum values in population-based cohorts of healthy subjects. The modulation of IGF-I and IGFBP-3 concentrations by vitamin D may impact recombinant human (rh) GH dosing for the treatment of GHD. It might also underlie some of the extra-skeletal beneficial effects ascribed to vitamin D. On the other hand, IGF-I stimulates renal production of 1,25-dihydroxyvitamin D, which increases calcium and phosphate availability in the body and suppresses PTH secretion. This effect is responsible for an altered calcium-phosphate balance in uncontrolled acromegaly and might also account for the improvement in bone metabolism associated with rhGH treatment in patients with GHD. Data on the paracrine/autocrine vitamin D-IGF-I interactions are abundant, but mostly not linked to one another. As a result, it is not possible to draw a comprehensive picture of the physiological and/or pathological interrelations between vitamin D, IGF-I and IGF-binding proteins (IGFBP) in different tissues. A potential role of vitamin D action is related to its association with carcinogenesis, a paradigm being breast cancer. Current evidence indicates that, in breast tumours, vitamin D modulates the IGF-I/IGFBP ratio to decrease proliferation and increase apoptosis.

Influence of anabolic steroid on tibial fracture healing in rabbits - a study on experimental model

INTRODUCTION

Anabolic steroid is an established drug for treating catabolic states. The said drug has been shown to restore the lean body mass, to prevent osteoporosis and to correct the impaired immune response, but only few studies have evaluated the effect of the same on fracture healing.

METHODS

Fracture was produced by an impact device in 24 rabbits which were divided into experimental (I) and control (II) groups of 12 animals each. The experimental groups were further divided into the subgroups IA and IB of equal animals, which received Nandrolone Decanoate 10 mg/kg intramuscularly, biweekly for 2 weeks and 4 weeks respectively.

RESULTS AND CONCLUSION

Radiographs taken on the post fracture day15 and 40 showed better healing in the Nandrolone Decanoate administrated groups as a dense periosteal bone formation and prevention of the local osteoporosis. Histochemical examination of the callus and high serum alkaline phosphatase levels on day 15 and 40 confirmed better mineralization in experimental animals.

Efficacy of optimization of vitamin D in preventing osteoporosis and osteoporotic fractures: A systematic review

Increased intake or supplementation of vitamin D is often recommended for normal bone health; however, its preventive effect on osteoporosis has not been fully evaluated. The aim of this review is to gather evidence of the efficacy of the optimization of vitamin D nutrition in preventing osteoporosis and osteoporotic fractures. PubMed was used for searching the relevant literature using the MeSH terms "Bone Density (limited to "human", "female", and "English" literature)" or "Fractures (limited to "human", "age ≥45 years", and "English" literature)", and "Vitamin D". The searches yielded 19 randomized controlled trials (RCTs), nine cohort studies, 19 case-control studies, 19 cross-sectional studies, and one meta-analysis. We attempted to answer three questions: 1) does increased vitamin D intake prevent bone loss in peri- and postmenopausal women?, 2) does increased vitamin D intake prevent osteoporotic fractures in the elderly?, and 3) does increased vitamin D in take positively affect peak bone mass attainment in young women? The answer to questions 1 and 2 is that a vitamin D intake of 10-17.5 μg/day (400-700 IU/day) or more is effective in preventing bone loss in late postmenopausal women and an intake of 17.5-20 μg/day (700-800 IU/day) or more together with a calcium supplement reduces the risk of osteoporotic fractures. For question 3, some lines of evidence support the negative effect of low vitamin D nutrition on the attainment of peak bone mass in young women. Further studies are needed to clarify the effect of vitamin D in this age group.

Mortality after hip fracture in Japan: the role of nutritional status

PURPOSE

To assess factors that influence 4-year mortality following hip fracture surgery in a Japanese population.

METHODS

Records of 129 hips in 24 men and 103 women aged 50 to 103 (mean, 79) years who underwent surgery for femoral neck or trochanteric fractures were reviewed. Clinical data reviewed included age, gender, body mass index (BMI), side of fracture, fracture type, fracture stability, surgery type, interval from admission to surgery, length of hospital stay, number of pre-fracture comorbidities, pre-fracture ambulatory level, pre-fracture place of residence, preoperative dementia, preoperative skeletal traction, blood haemoglobin level, serum albumin level, number of postoperative complications, and postoperative delirium. Univariate and multiple logistic regression analyses were performed to identify the relative contribution of the variables to mortality. Receiver operating characteristic (ROC) curves were used to identify optimal cut-off levels.

RESULTS

The 4-year mortality was 48%. Multiple logistic regression analysis showed that serum albumin level (p = 0.0004, odds ratio [OR] = 5.8541) and BMI (p = 0.0192, OR = 1.1693) significantly influenced mortality; the cut-off points were 36 g/l and 18.9 kg/m square, respectively, based on the ROC curves. Kaplan-Meier curves showed that survival rates were significantly worse in patients with values below these cut-off points.

CONCLUSION

Serum albumin level and BMI on admission are predictive of mortality after hip fracture surgery.

Hip fracture risk in relation to vitamin D supplementation and serum 25-hydroxyvitamin D levels: a systematic review and meta-analysis of randomised controlled trials and observational studies

BACKGROUND

Vitamin D supplementation for fracture prevention is widespread despite conflicting interpretation of relevant randomised controlled trial (RCT) evidence. This study summarises quantitatively the current evidence from RCTs and observational studies regarding vitamin D, parathyroid hormone (PTH) and hip fracture risk.

METHODS

We undertook separate meta-analyses of RCTs examining vitamin D supplementation and hip fracture, and observational studies of serum vitamin D status (25-hydroxyvitamin D (25(OH)D) level), PTH and hip fracture. Results from RCTs were combined using the reported hazard ratios/relative risks (RR). Results from case-control studies were combined using the ratio of 25(OH)D and PTH measurements of hip fracture cases compared with controls. Original published studies of vitamin D, PTH and hip fracture were identified through PubMed and Web of Science databases, searches of reference lists and forward citations of key papers.

RESULTS

The seven eligible RCTs identified showed no significant difference in hip fracture risk in those randomised to cholecalciferol or ergocalciferol supplementation versus placebo/control (RR = 1.13[95%CI 0.98-1.29]; 801 cases), with no significant difference between trials of <800 IU/day and > or = 800 IU/day. The 17 identified case-control studies found 33% lower serum 25(OH)D levels in cases compared to controls, based on 1903 cases. This difference was significantly greater in studies with population-based compared to hospital-based controls (chi(2)(1) (heterogeneity) = 51.02, p < 0.001) and significant heterogeneity was present overall (chi(2)(16) (heterogeneity) = 137.9, p < 0.001). Serum PTH levels in hip fracture cases did not differ significantly from controls, based on ten case-control studies with 905 cases (chi(2)(9) (heterogeneity) = 149.68, p < 0.001).

CONCLUSIONS

Neither higher nor lower dose vitamin D supplementation prevented hip fracture. Randomised and observational data on vitamin D and hip fracture appear to differ. The reason for this is unclear; one possible explanation is uncontrolled confounding in observational studies. Post-fracture PTH levels are unrelated to hip fracture risk.

Declining incidence of hip fractures and the extent of use of anti-osteoporotic therapy in Denmark 1997-2006

SUMMARY

The incidence of hip fractures in Denmark declined by about 20% from 1997 to 2006 in both men and women aged 60 and over. The decrease in hip fracture rates was much too large to be explained by the extent of anti-osteoporotic medication used in the country.

INTRODUCTION

The purpose of this study is to clarify (1) if hip fracture rates decline in Denmark despite low treatment rates and (2) if changes in age-specific rates could be explained by anti-osteoporotic medications.

METHODS

National registers were used to obtain incidence rates for hip fractures in men and women aged 60+ and aggregated national data on number of users of anti-osteoporotic medications for 1997-2006. The potential contribution of anti-osteoporotic treatment to prevented hip fractures was estimated.

RESULTS

Incidence rates declined by 20% in men and 22% in women. Use of specific anti-osteoporotic medications had increased from 1.8% in 60+-year-old women and 0.2% in 60+-year-old men to 7.3% and 1.3%, respectively. The decrease risk in men was nearly the same as in women, despite a six times lower treatment prevalence. The number of prevented hip fractures that could be attributed to therapy was 1.3% in men and 3.7% in women.

CONCLUSIONS

The decrease in hip fractures is much too large to be explained by the extent of anti-osteoporotic medication. Interestingly, the decrease in fracture rates also applied to men, despite much lower treatment rates. Potential explanations include smoking habits, obesity, national home visit programmes, improved general health and vitamin D supplementation.

Validated treatments and therapeutic perspectives regarding nutritherapy

Nutritherapy seeks to prevent or correct disease by the use of nutritional supplements including vitamins, trace elements, or macronutrients. This chapter of the "Les Entretiens du Carla" reviews the potential of nutritherapy for the prevention or improvement of sarcopenia, which is the progressive reduction in muscle mass and muscle strength prevalent in late-life. It is critical that we review nutrients and their potential to maintain muscle mass and strength which ultimately will help minimize falls and fractures among the older population. Evidence from randomized-controlled trials will be reviewed for muscle mass as well as important sarcopenia-related endpoints including lower extremity strength and function, as well as falls and fall-related fractures. This chapter will focus on vitamin D as a compelling strategy with evidence for strength gain, fall and fracture prevention from double-blind randomized controlled trials. The other strategy discussed is increased protein intake although longer-term trials and evidence for clinically important endpoints are limited. Today, there is no consistent data on other micronutrients or macronutrients with an established potential to combat sarcopenia.

Serum albumin and total lymphocyte count as predictors of outcome in hip fractures

BACKGROUND & AIMS

Hip fractures are a significant cause of mortality and morbidity in the elderly. Malnutrition is a significant contributor to this, however no consensus exists as to the detection or management of this condition. We hypothesise that results of admission serum albumin and total lymphocyte count (TLC), as markers of Protein Energy Malnutrition (PEM) can help predict clinical outcome in hip fracture patients aged over 60 years.

METHODS

This retrospective study evaluated the nutritional status of patients with hip fractures using albumin and TLC assays and analysed their prognostic relevance. Clinical outcome parameters studied were delay to operation, duration of in-patient stay, re-admission and in-patient, 3- and 12-month mortality.

RESULTS

Four hundred and fifteen hip fracture patients were evaluated. Survival data were available for 377 patients at 12 months. In-hospital mortality for PEM patients was 9.8%, compared with 0% for patients without. Patients with PEM had a higher 12-month mortality compared to patients who had normal values of both laboratory parameters (Odds Ratio 4.6; 95% CI: 1.0-21.3). Serum albumin (Hazard Ratio 0.932, 95% CI: 0.9-1.0) and age (Hazard Ratio 1.04, 95% CI: 1.0-1.1) were found to be significant independent prognostic factors of mortality by Cox regression analysis.

CONCLUSIONS

These results highlight the relevance of assessing the nutritional status of patients with hip fractures at the time of admission and emphasises the correlation between PEM and outcome in these patients.

Serum 25-hydroxyvitamin D levels and rate of hip bone loss in older men

CONTEXT

Vitamin D deficiency is common among older adults, but the association between 25-hydroxyvitamin D [25(OH)D] levels and rates of bone loss is uncertain.

OBJECTIVE

Our aim was to test the hypothesis that lower 25(OH)D levels are associated with higher rates of hip bone loss in older men.

DESIGN AND SETTING

We conducted a prospective cohort study in six U.S. centers.

PARTICIPANTS

A total of 1279 community-dwelling men aged 65 yr or older with 25(OH)D levels (liquid chromatography-tandem mass spectroscopy) and hip bone mineral density (BMD) (dual-energy x-ray absorptiometry) at baseline and repeat hip BMD an average of 4.4 yr later participated in the study.

MAIN OUTCOME MEASURE(S)

We measured the annualized percentage rate of change in hip BMD.

RESULTS

After adjustment for multiple potential confounders, the average rate of decline in total hip BMD was -0.59%/yr among men with 25(OH)D levels below 15.0 ng/ml, -0.54%/yr among men with 25(OH)D levels 15.0-19.9 ng/ml, -0.35%/yr among men with 25(OH)D levels 20.0-29.9 ng/ml, and -0.37%/yr among men with 25(OH)D levels of at least 30 ng/ml (P trend = 0.008 for multivariable model). Evidence was strong to support an association among men aged 75 yr and older (P trend <0.001), but not among younger men (P trend = 0.55). Findings were similar when 25(OH)D level was expressed in quintiles and when BMD at hip subregions was substituted for total hip BMD.

CONCLUSIONS

In this cohort of community-dwelling older men, men with 25(OH)D levels below 20 ng/ml had greater subsequent rates of hip bone loss, but rates of loss were similar among men with higher levels. These results lend support to the view that low 25(OH)D levels are detrimental to BMD in older men.

Nutritional determinants of bone health

Osteoporosis is a major public health problem. The aging population will require vigilant prevention, education, and treatment to maintain bone density and reduce the risk of fractures and falls. Nutritional requirements of elderly persons can have a profound effect on bone health. Calcium, vitamin D, and protein are vital nutrients for optimal bone health. Adequate calcium is essential for bone maintenance. Vitamin D research shows a link between reduced falls and fractures. Related macro- and micronutrients play an important role in bone mass integrity and quality. Adequate nutrition for older adults needs to be encouraged to promote and maintain bone health.

Severe vitamin D deficiency in Swiss hip fracture patients

BACKGROUND

Most clinical guidelines for the prevention of hip fractures recommend 800 IU vitamin D per day. This dose shifted serum 25-hydroxyvitamin D levels (25(OH)D) in previous studies to between 60 and 100 nmol/l.

AIM

To measure 25(OH)D levels and prevalence of vitamin D supplementation in individuals age 65+ with acute hip fracture.

METHODS

222 consecutive hip fracture patients were investigated over a 12 month period. Mean age of patients was 86 years and 77% were women.

RESULTS

Mean serum 25(OH)D levels were low among hip fracture patients admitted from home (34.6 nmol/l), from assisted living (27.7 nmol/l), and from nursing homes (24 nmol/l). Severe vitamin D deficiency below 30 nmol/l was present in 60%, 80% were below 50 nmol/l, and less than 4% reached desirable levels of at least 75 nmol/l. Consistently, only 10% of hip fracture patients had any vitamin D supplementation on admission to acute care with significantly higher 25(OH)D levels among individuals supplemented with 800-880 IU/day (63.5 nmol/l). Controlling for age and gender, vitamin D supplementation, type of dwelling, and season were independently and significantly associated with 25(OH)D levels.

CONCLUSION

These data provide evidence that current guidelines for the prevention of hip fractures need further effort to be translated into clinical practice.

Serum 25-hydroxyvitamin D and hip fracture risk in older U.S. white adults

We used serum 25(OH)D data from NHANES III and incident hip fracture cases identified using linked mortality and Medicare records, and found that serum 25(OH)D was significantly related to reduced hip fracture risk in non-Hispanic white adults >or=65 yr of age.

INTRODUCTION

The role of vitamin D status in reducing fracture risk is unclear. We examined the relationship between serum 25 hydroxyvitamin D [25(OH)D] and incident hip fracture risk in older non-Hispanic white adults.

MATERIALS AND METHODS

The study sample consisted of 1917 white men and women >or=65 yr of age who were examined in the third National Health and Nutrition Examination Survey (NHANES III, 1988-1994), a nationally representative survey. Incident hip fractures were ascertained using linked mortality and Medicare records that were obtained for NHANES III participants. Serum 25(OH)D values were measured with a radioimmunoassay kit. Cox proportional hazards models were used to estimate the relative risk (RR) of hip fracture by serum 25(OH)D level.

RESULTS

There were 156 incident hip fracture cases in the sample. Cases were older, had lower BMD and body mass index, more prevalent spine or wrist fractures and weight loss before baseline, and ate fewer kilocalories and less calcium than noncases. After adjusting for these differences, serum 25(OH)D values exceeding 60 nM were significantly related to hip fracture risk. For example, the multivariate-adjusted RR was 0.64 (95% CI, 0.46-0.89) among individuals with serum 25(OH)D values >or=62.5 nM compared with those with values below this level. When grouped into quartiles, the multivariate-adjusted RR for the second, third, and fourth versus the first quartile of serum 25(OH)D were 0.50 (95% CI, 0.25-1.00), 0.41 (95% CI, 0.24-0.70), and 0.50 (95% CI, 0.29-0.86), respectively.

CONCLUSIONS

Serum 25(OH)D was related to a significantly lower hip fracture risk in this cohort of older white adults, even after adjusting for several relevant confounding variables. The relationship did not seem to be linear across all values. Our results support other studies suggesting that serum 25(OH)D values exceeding 60 nM are associated with health benefits.

Predictors of low bone mineral density in the elderly: the role of dietary intake, nutritional status and sarcopenia

OBJECTIVES

The aims of this study were to investigate the relationship between sarcopenia, dietary intake, nutritional indices and hip bone mineral density (BMD) in the elderly, and to estimate the risk of low BMD due to specific independent predictor thresholds.

SUBJECTS AND METHODS

Body mass index (BMI), serum albumin, energy and protein intake were studied in 352 elderly outpatients (216 women aged 73.5+/-5.3 years and 136 men aged 73.9+/-5.6 years). BMD at different hip sites and appendicular skeletal muscle mass (ASMM) were assessed by dual-energy X-ray absorptiometry.

RESULTS

The prevalence of osteoporosis was 13% in men and 45% in women, while the prevalence of sarcopenia (50%) and hypoalbuminemia (5%) were similar in both genders. BMI, albumin and ASMM were significantly associated with BMD in both genders: so was protein intake, but only in men. By multiple regression analysis, the variables that retained their independent explanatory role on total hip BMD, were BMI and protein intake in men, and BMI and albumin in women. By logistic regression analysis, men risked having a low BMD with a BMI <22 (OR=12) and a protein intake <65.7 g/day (OR=3.7). Women carried some risk already in the BMI 25-30 class (OR=5), and a much greater risk in the BMI <22 class (OR=26). Albumin <40 g/l also emerged as an independent risk factor (OR=2.6).

CONCLUSIONS

BMI in both genders, albumin in women and protein intake in men have an independent effect on BMD. BMI values <22 are normal for younger adults but carry a higher risk of osteoporosis in the elderly, particularly in women. Age-related sarcopenia does not seem to be involved in bone mass loss.

Age-related decrease in serum 25-hydroxyvitamin D concentrations in the frail elderly: a longitudinal study

Several cross-sectional studies have demonstrated an age-related decrease in serum 25-hydroxyvitamin D [25(OH)D] concentrations. No prospective studies, however, have been conducted to examine this correlation to date. The objectives of this study were to measure age-related changes in serum 25(OH)D concentrations and to identify predictors of change in serum 25(OH)D concentrations in the frail elderly during a 2-year follow-up period. Eighty elderly subjects (48 women and 32 men) were selected from people utilizing the long-term care insurance system in a community in Japan. All subjects participated in both the baseline and follow-up (2 years later) medical examinations. Baseline measurements included age, height, body mass index, and weight. Additionally, levels of activities of daily living (Barthel index), grip strength, lifestyle, serum 25(OH)D, intact parathyroid hormone (PTH), albumin, total protein, and creatinine concentrations were also determined at baseline. The average age of the subjects was 82.1 years (SD, 8.8). The 2-year decrease in serum 25(OH)D concentrations was calculated to be 6 nmol/l. Multiple linear regression analyses found that the 2-year change (Delta) in the log-transformed 25(OH)D was associated with Deltaalbumin (beta = 0.503, R (2) = 0.288, P < 0.0001), and Deltalog-transformed intact PTH was associated with baseline creatinine (beta = 0.453, R (2) = 0.142, P = 0.0006) and Deltalog-transformed 25(OH)D (beta = -0.512, R (2) = 0.103, P = 0.0037). In conclusion, serum 25(OH)D concentrations decreased in the 2-year follow-up. This information is useful for the maintenance of vitamin D status and prevention of vitamin D insufficiency in the frail elderly.

Gastric banding induces negative bone remodelling in the absence of secondary hyperparathyroidism: potential role of serum C telopeptides for follow-up

OBJECTIVE

Data about the consequences of laparoscopic adjustable gastric banding (LAGB) on phospho-calcic and bone metabolism remain scarce.

SUBJECTS

We studied a group of 37 obese premenopausal women (age: 24-52 y; mean BMI = 43.7 kg/m2) who underwent LAGB.

METHODS

Serum calcium, phosphate, alkaline phosphatase, parathormone (PTH), vitamin D3, serum C-telopeptides, IGFBP-3 and IGF-1 were measured at baseline, 6, 12, 18 and 24 months after surgery. Body composition, bone mineral content (BMC) and density (BMD) were measured using dual-X-ray absorptiometry (DXA) at baseline, 6, 12 and 24 months after surgery.

RESULTS

There was no clinically significant decrease of calcemia; PTH remained stable. Serum telopeptides increased by 100% (P < 0.001) and serum IGFBP-3 decreased by 16% (P < 0.001) during the first 6 months, and then stabilized, whereas IGF-1 remained stable over the 2 y. BMC and BMD decreased, especially at the femoral neck; this decrease was significantly correlated with the decrease of waist and hip circumference.

CONCLUSIONS

We concluded that there was no evidence of secondary hyperparathyroidism 24 months after LAGB. The observed bone resorption could be linked to the decrease of IGFBP-3, although this decrease could be attributable to other confounding factors. Serum telopeptides seem to be a reliable marker of bone metabolism after gastric banding. DXA must be interpreted cautiously during major weight loss, because of the artefacts caused by the important variation of fat tissue after LAGB.

Dietary protein: an essential nutrient for bone health

Nutrition plays a major role in the development and maintenance of bone structures resistant to usual mechanical loadings. In addition to calcium in the presence of an adequate vitamin D supply, proteins represent a key nutrient for bone health, and thereby in the prevention of osteoporosis. In sharp opposition to experimental and clinical evidence, it has been alleged that proteins, particularly those from animal sources, might be deleterious for bone health by inducing chronic metabolic acidosis which in turn would be responsible for increased calciuria and accelerated mineral dissolution. This claim is based on an hypothesis that artificially assembles various notions, including in vitro observations on the physical-chemical property of apatite crystal, short term human studies on the calciuric response to increased protein intakes, as well as retrospective inter-ethnic comparisons on the prevalence of hip fractures. The main purpose of this review is to analyze the evidence that refutes a relation of causality between the elements of this putative patho-physiological "cascade" that purports that animal proteins are causally associated with an increased incidence of osteoporotic fractures. In contrast, many experimental and clinical published data concur to indicate that low protein intake negatively affects bone health. Thus, selective deficiency in dietary proteins causes marked deterioration in bone mass, micro architecture and strength, the hallmark of osteoporosis. In the elderly, low protein intakes are often observed in patients with hip fracture. In these patients intervention study after orthopedic management demonstrates that protein supplementation as given in the form of casein, attenuates post-fracture bone loss, increases muscles strength, reduces medical complications and hospital stay. In agreement with both experimental and clinical intervention studies, large prospective epidemiologic observations indicate that relatively high protein intakes, including those from animal sources are associated with increased bone mineral mass and reduced incidence of osteoporotic fractures. As to the increased calciuria that can be observed in response to an augmentation in either animal or vegetal proteins it can be explained by a stimulation of the intestinal calcium absorption. Dietary proteins also enhance IGF-1, a factor that exerts positive activity on skeletal development and bone formation. Consequently, dietary proteins are as essential as calcium and vitamin D for bone health and osteoporosis prevention. Furthermore, there is no consistent evidence for superiority of vegetal over animal proteins on calcium metabolism, bone loss prevention and risk reduction of fragility fractures.

The Problem of Low Levels of Vitamin D and Osteoporosis

Osteoporosis and fragility fractures are common in the elderly population and represent a large public health burden. Non-pharmacological recommendations for the management of osteoporosis include modification of lifestyle behaviours, increased weight-bearing exercise and consumption - through dietary or supplement sources - of adequate amounts of calcium and vitamin D. Although current guidelines include recommendations on calcium and vitamin D intake, patients frequently do not take sufficient amounts, even when supplements are provided free of charge. Vitamin D is essential for mineral metabolism, and low levels are associated with impaired skeletal metabolism and neuromuscular function. Nutritional sources of vitamin D are limited, and supplementation is usually necessary. A high prevalence of low vitamin D levels has been reported in a number of populations worldwide, including women being treated for osteoporosis and those with fragility fractures. At present, bisphosphonates are the most commonly prescribed pharmacological treatments for osteoporosis, and alendronic acid is the most frequently prescribed bisphosphonate. A nitrogen-containing bisphosphonate, alendronic acid has demonstrated anti-fracture efficacy at vertebral and non-vertebral skeletal sites, including the hip, in addition to long-term safety and efficacy. Weekly administration of alendronic acid takes advantage of the pharmacokinetics of the drug and osteoclast biology to optimise treatment, and may improve patient adherence. Combining alendronic acid 70mg and colecalciferol (vitamin D(3)) 2800 IU in a single, once-weekly tablet has the advantage of combining the proven efficacy of an established bisphosphonate, alendronic acid, with the amount of vitamin D currently recommended for osteoporosis management.

Vitamin D and intact PTH status in patients with hip fracture

INTRODUCTION

The prevalence of hypovitaminosis D in patients with acute hip fracture was examined in a population on Sado Island in Japan. There were 85 cases of hip fracture among this population in 2004, giving an overall incidence of hip fracture of 121.4 per 100,000 population per year. This study included 50 of the 85 cases, and these cases were defined as the hip fracture group. Patients older than 70 years without established osteoporosis who were admitted to the hospital on the island during almost the same period for treatment of an orthopedic condition other than a hip fracture were defined as the control group.

MATERIALS AND METHODS

The levels of serum 25-hydroxyvitamin D (25-OHD), intact parathyroid hormone (intact PTH), alkaline phosphatase (ALP), albumin, and the number of remaining teeth were examined in each group. In the hip fracture group, serum calcium, serum phosphorus, urine N-terminal cross-linking telopeptide of type I collagen (NTx), bone mineral density (BMD) of the nonfractured hip, the presence of a vertebral fracture on X-ray, severity of dementia, and physical activity level were also examined.

RESULTS

Both the serum 25-OHD and serum albumin levels were significantly lower in patients with hip fracture than in controls, and the intact PTH level was significantly higher in patients with hip fracture. The number of remaining teeth was correlated with age, and was also significantly correlated with 25-OHD. In the hip fracture group, 62% of the subjects had hypovitaminosis D (25-OHD <20 ng/ml) and one-fifth of cases with hypovitaminosis D showed elevated PTH levels (>65 pg/ml). On the other hand, in the control group, hypovitaminosis D occurred in 18.9% of the subjects, and only one case showed elevated PTH. The serum 25-OHD level showed a decrease as the severity of dementia progressed and the activity level decreased.

CONCLUSION

Our results indicate that about two-thirds (62%) of hip fracture patients had vitamin D insufficiency, suggesting that this condition may be closely associated with hip fracture in elderly people. Therefore, the serum 25-OHD level may be a useful index for the risk of hip fracture in elderly people.

Factors associated with the lumbar spine and proximal femur bone mineral density in older men

Bone mass is a major determinant of fracture, but there have been few comprehensive studies of the correlates of bone mineral density (BMD) in older men. The objective of the current cross-sectional analysis was to determine the factors associated with BMD of the lumbar spine and proximal femur in a large population-based sample of older men enrolled in The Osteoporotic Fractures in Men Study, "Mr.OS." We enrolled 5,995 men 65 years of age or older, 89% Caucasian, in Mr.OS at six US clinical centers. Demographic, medical and family history and lifestyle information was obtained by interview and physical function and anthropometric data by examination. Spine and hip BMD was measured using dual-energy X-ray absorptimetry. The multivariable linear regression models predicted 19 and 10% of the overall variance in BMD of the femoral neck and spine, respectively. African-American men had 6 to 11% higher BMD than Caucasian men independent of multiple factors. Hip BMD declined with advancing age, while spine BMD increased. Body weight (per 10 kg) and self report of diabetes were each associated with 2 to 4% higher BMD, while history of a non-trauma fracture and current use of selective serotonin reuptake inhibitors, but not other antidepressants, were associated with at least 4% lower BMD. Both maternal and paternal histories of fracture were associated with 1.4-1.7% lower BMD. Osteoarthritis, physical activity, grip strength, alcohol intake, and dietary calcium were positively related to BMD, while a history of chronic lung disease, prostate cancer, and kidney stones was associated with lower BMD. Smoking, caffeine intake, and thiazide diuretics were not related to BMD in older men. A number of lifestyle and behavioral characteristics and medical conditions were associated with BMD in older men. Identification of these correlates could improve methods to identify men at risk for fracture and improve our understanding of fracture etiology.

The need for clinical guidance in the use of calcium and vitamin D in the management of osteoporosis: a consensus report

A European Union (EU) directive on vitamins and minerals used as ingredients of food supplements with a nutritional or physiological effect (2002/46/EC) was introduced in 2003. Its implications for the use of oral supplements of calcium and vitamin D in the prevention and treatment of osteoporosis were discussed at a meeting organized with the help of the World Health Organization (WHO) Collaborating Center for Public Health Aspects of Rheumatic Diseases (Liège, Belgium) and the support of the WHO Collaborating Center for Osteoporosis Prevention (Geneva, Switzerland). The following issues were addressed: Is osteoporosis a physiological or a medical condition? What is the evidence for the efficacy of calcium and vitamin D in the management of postmenopausal osteoporosis? What are the risks of self-management by patients in osteoporosis? From their discussions, the panel concluded that: (1) osteoporosis is a disease that requires continuing medical attention to ensure optimal therapeutic benefits; (2) when given in appropriate doses, calcium and vitamin D have been shown to be pharmacologically active (particularly in patients with dietary deficiencies), safe, and effective for the prevention and treatment of osteoporotic fractures; (3) calcium and vitamin D are an essential, but not sufficient, component of an integrated management strategy for the prevention and treatment of osteoporosis in patients with dietary insufficiencies, although maximal benefit in terms of fracture prevention requires the addition of antiresorptive therapy; (4) calcium and vitamin D are a cost-effective medication in the prevention and treatment of osteoporosis; (5) it is apparent that awareness of the efficacy of calcium and vitamin D in osteoporosis is still low and further work needs to be done to increase awareness among physicians, patients, and women at risk; and (6) in order that calcium and vitamin D continues to be manufactured to Good Manufacturing Practice standards and physicians and other health care professionals continue to provide guidance for the optimal use of these agents, they should continue to be classified as medicinal products.

Vitamin D status and bone turnover in women with acute hip fracture

Hypovitaminosis D is common in elderly women. Few data are available on vitamin D status and bone turnover in women with acute hip fracture. The aims of this study were to determine whether elderly Italian women with an acute hip fracture also had low vitamin D levels and an increase of bone turnover compared with elderly women with osteoporosis but without fractures. Seventy-four women with acute osteoporotic hip fracture and 73 women with postmenopausal osteoporosis were studied. All women were self-sufficient and had adequate sunlight exposure. To exclude the effect of trauma on serum 25-hydroxycolecalciferol levels and bone markers (bone alkaline phosphatase and C-terminal telopeptides of Type I collagen as indices of bone formation and bone resorption), blood samples were drawn within 24 hours of the fracture. Current data indicated that in our patients the prevalence of hypovitaminosis D is common although to a lesser extent than in women who are housebound. Women with acute hip fractures had a higher prevalence of vitamin deficiency defined as serum 25-hydroxycolecalciferol lower than 12 ng/mL, compared with women with osteoporosis. Moreover, the presence of fracture did not influence the rate of bone formation, whereas the increase in bone resorption could be attributed to an older age of women with acute hip fracture because of similar values of parathyroid hormone levels in the two groups.

Insulin-like growth factor I is a determinant of hip bone mineral density in men less than 60 years of age: MINOS study

Several studies show that in elderly men bone mineral density (BMD) is not correlated with the insulin-like growth factor (IGF-I) level, but data are scanty in young men. Results of studies correlating insulin-like growth factor binding protein 3 (IGFBP-3) and BMD in men are discordant. As different hypotheses can explain the discordant results, we evaluated the correlation of BMD with serum IGF-I, IGFBP-3, and IGF-I/IGFBP-3 index in a large cohort of 721 men aged 19-85 years taking into account age, body weight, 17beta-estradiol, free testosterone, and parathyroid hormone. Serum IGF-I and IGFBP-3 decreased with age (r = -0.44 and r = -0.36, P = 0.0001). After adjustment for confounding variables, IGF-I correlated weakly positively with BMD and with bone mineral apparent density (BMAD) of hip as well as with cortical thickness of femoral neck, both of which are determined mainly by bone resorption, but not with bone size determined by periosteal apposition. IGF-I correlated weakly positively with BMD at the whole body and at the third lumbar vertebra IGFBP-3 and IGF-I/IGFBP-3 index did not correlate with densitometric parameters. In men aged 19-60 years, IGF-I correlated with BMD and BMAD of total hip and with cortical thickness of femoral neck positively and more strongly than in the entire cohort but not with the size of proximal femur. BMD of total hip was 6% higher in men in the highest quartile of IGF-I than in men in the lowest quartile. IGF-I, IGFBP-3, and IGF-I/IGFBP-3 index did not correlate with densitometric parameters of other sites. In the men aged more than 60 years, neither IGF-I nor IGFBP-3 nor IGF-I/IGFBP-3 index correlated with BMD, BMAD, or bone size. In men aged 19-60 years, the most significant hormonal determinants of BMD and BMAD of the hip and of the cortical thickness of femoral neck were 17beta-estradiol and IGF-I (P < 0.05-0.0001). In men aged more than 60 years, the most significant determinants of hip BMD were 17beta-estradiol and PTH. In conclusion, IGF-I seems to contribute to the inhibition of bone resorption and to maintaining bone mass of the proximal femur during the phase of slow bone loss in men aged less than 60 years. IGFBP-3 and IGF-I/IGFBP-3 index were not correlated with BMD or bone size.

Dietary calcium, sodium, phosphorus, and protein and bone metabolism in elderly Japanese women:

OBJECTIVES

Associations between dietary factors and bone metabolism in Asians have not been thoroughly investigated. The purpose of this study was to determine the effect of dietary intake of calcium (Ca), phosphorus (P), sodium (Na), and protein on bone metabolism in elderly Japanese women by the duplicate portion sampling method.

METHODS

The subjects were 43 healthy female volunteers (mean age, 68.3 y; standard deviation, 6.8). Dietary nutrients were directly determined by using a 24-h duplicate meal portion. Serum osteocalcin and bone alkaline phosphatase and urinary deoxypyridinoline (DPD) and type I collagen cross-linked N-telopeptides (NTX-I) were measured as markers of bone turnover. Hormones related to bone metabolism, including serum 25-hydroxyvitamin D(3), 1,25-dihydroxyvitamin D(3), and intact parathyroid hormone also were determined. Urinary parameters were corrected for urinary creatinine concentration.

RESULTS

The mean (standard deviation) daily dietary intakes of Ca, P, Na, and protein were 660 (195) mg, 996 (208) mg, 4080 (1142) mg, and 63.9 (15.5) g, respectively. Dietary Ca was negatively correlated with urinary DPD (r = -0.417, P = 0.005) and NTX-I (r = -0.324, P = 0.034), and dietary P was negatively correlated with urinary DPD (r = -0.307, P = 0.045). Multiple regression analysis showed that only dietary Ca was associated with urinary DPD and NTX-I. Dietary Ca intake was significantly associated with bone resorption markers, but no other dietary factors were associated with any of the biochemical markers.

CONCLUSION

The major factor having an adverse effect on the bone health of the elderly Japanese women is low Ca intake and not other dietary minerals or protein.

Role of vitamin D and parathyroid hormone in the regulation of bone turnover and bone mass in men: the MINOS study

We investigated the role of vitamin D and of parathyroid hormone (PTH) in the regulation of bone mineral density (BMD), tone dimensions and seasonal variation of bone turnover in 881 men aged 19-85 years. Bone mineral content (BMC) and BMD of the lumbar spine, hip and whole body were measured with HOLOGIC 1000W and those of distal forearm with an OSTEOMETER DTX 100 device. Bone formation was evaluated using osteocalcin, bone alkaline phosphatase and N-terminal extension propeptide of type I collagen (PINP). Bone resorption was evaluated by 24-hour excretion of deoxypyridinoline and of C-terminal telopeptide of collagen type I. In young men (< 55 yrs) PTH level decreased with age (r = -0.18, P < 0.005) whereas 25-hydroxyvitamin D (25OHD) concentration was stable. In older men (> 55 years) 25OHD decreased whereas PTH increased with age (r = -0.27 and r = 0.21, P = 0.0001). In young men, 25OHD level varied with season but not PTH, biochemical markers of bone turnover nor BMD. In young men, 25OHD, but not PTH, was a significant determinant of BMC, cortical thickness and of biomechanical properties of the femoral neck. Biochemical bone markers and BMD were not correlated with PTH nor with 25OHD. In elderly men, winter levels of 25OHD were lowest whereas those of PTH, bone resorption markers and PINP were highest. After adjustment for age, body weight and season, biochemical markers of bone turnover were correlated with PTH. In elderly men, 25OHD and PTH were significant determinants of BMC, cortical thickness and of biomechanical parameters of the femoral neck. Men with vertebral deformities had lower concentrations of 25OHD, higher PTH levels and slightly elevated urinary excretion of biochemical markers of bone resorption compared with men without vertebral deformities. In conclusion, in young men, 25OHD discloses a seasonal variability in contrast to PTH and biochemical bone markers. In this group, 25OHD is a significant determinant of BMC and BMD but not of bone size. In elderly men, seasonal variation of 25OHD and PTH concentrations result in seasonal variation of bone resorption. In this group, both 25OHD and PTH are determinants of BMC and cortical thickness of the femoral neck and, consequently, of its mechanical parameters.

Correlates of bone mineral density in elderly women living in nursing homes for the disabled in Japan

BACKGROUND AND AIMS

Characteristics of bone aging in the institutionalized elderly are not well known. The aim of this study was to determine the factors correlated with the forearm bone mineral density (BMD) in elderly women with disability.

METHODS

Of 175 female residents living in nursing homes for the disabled in Niigata, Japan, 119 agreed to participate and underwent medical examinations in 1999; 107 (age range, 66-100) met our inclusion criteria. We measured forearm BMD by dual-energy X-ray absorptiometry (DXA), and the serum concentrations of 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, intact parathyroid hormone, albumin, total protein, and creatinine. Body weight, score of activities of daily living, and history of femoral neck fractures were also recorded.

RESULTS

Forearm BMD decreased with age, and the regression equation was BMD=0.9035exp (-0.0179Age) (R2=0.170, p<0.0001). Multiple linear regression analysis revealed that only age (R2=0.178, p<0.0001), and serum creatinine (R2=0.153, p<0.0001) and albumin (R2=0.051, p=0.005) concentrations were independently associated with log-BMD. Twenty-five of the 107 subjects had a history of femoral neck fracture, and only serum albumin concentration (p=0.031) was shown to be associated with fracture history.

CONCLUSIONS

Forearm BMD was associated with age, serum creatinine and albumin, which may be useful parameters for assessing the bone health of elderly women with disability.

Osteoporosis in men: pathophysiology, evaluation, and therapy

Osteoporosis is a serious health problem for men. An advance in our understanding of the pathophysiology and treatment of this disorder has resulted in the possibility of a gender-specific approach to screening, diagnosis, and treatment. Here we review the data on osteoporosis in men, discuss controversies regarding whom to screen, whom to treat, and how to treat. Recent treatment data as they relate to men are reviewed, and a clinical treatment algorithm is presented.

Determinants of bone mineral density in older men and women: body composition as mediator

This study aimed to assess the relative importance of several determinants of bone mineral density (BMD) and to examine to what extent these potential determinants influence total hip BMD through body composition. The study population consisted of 522 participants (264 women and 258 men) of the Longitudinal Aging Study Amsterdam (LASA), aged 65 years and over, and living in Amsterdam and its vicinity. BMD of the total hip was measured using dual-energy X-ray absorptiometry (DXA). Potential determinants of BMD were age, weight change since age 25 years, lifestyle factors, chronic diseases, medication use, and hormonal factors. Potential mediators between the possible determinants and BMD were two measures of body composition: fat mass (FM) and appendicular muscle mass (AMM). Multiple regression analyses including all potential determinants in one model without body composition identified age, weight change, walking activity, and sex hormone-binding globulin (SHBG) as independent determinants for total hip BMD in women. In men, current smoking, participation in sports, and parathyroid hormone (PTH) concentration were independently associated with total hip BMD. When total hip BMD was regressed on the potential determinants and each measure of body composition, it appeared that FM, and to a lesser extent, muscle mass (MM), were independently related to BMD. In women, adjustment for FM reduced the strength of the associations of weight change, walking activity, and SHBG with total hip BMD. Adjustments for MM did not influence the associations between the determinants and BMD. In men, neither FM nor MM appeared to play a mediating role between the determinants and BMD. It can be concluded that (1) FM and MM are strong independent determinants of total hip BMD and that (2) FM possibly plays a mediating role in the association of weight change, walking activity, and SHBG with total hip BMD in women.

Protein intake and bone disorders in the elderly

Malnutrition, most notably protein deficiency, contributes to the occurrence of osteoporotic fractures not only by decreasing bone mass but also by altering muscle function. Furthermore, malnutrition is associated with increased morbidity in patients with osteoporotic fractures. The somatomedin system (IGF-1) may be directly involved in the pathogenesis of osteoporotic hip fractures and their complications in elderly patients. A low IGF-1 level is a risk factor for hip fracture. In subjects with appropriate intakes of vitamin D and calcium, giving protein supplements to correct an inadequate spontaneous protein intake increases circulating IGF-1 levels, improves clinical outcomes after hip fracture, and prevents bone mineral density loss at the proximal femur. Supplemental protein also significantly reduces the length of inpatient rehabilitation care. These data emphasize the importance of adequate nutrient intake in the prevention and treatment of osteoporotic fractures.

Vitamin D deficiency and secondary hyperparathyroidism in the elderly: consequences for bone loss and fractures and therapeutic implications

Vitamin D deficiency is common in the elderly, especially in the housebound and in geriatric patients. The establishment of strict diagnostic criteria is hampered by differences in assay methods for 25-hydroxyvitamin D. The synthesis of vitamin D3 in the skin under influence of UV light decreases with aging due to insufficient sunlight exposure, and a decreased functional capacity of the skin. The diet contains a minor part of the vitamin D requirement. Vitamin D deficiency in the elderly is less common in the United States than elsewhere due to the fortification of milk and use of supplements. Deficiency in vitamin D causes secondary hyperparathyroidism, high bone turnover, bone loss, mineralization defects, and hip and other fractures. Less certain consequences include myopathy and falls. A diet low in calcium may cause an increased turnover of vitamin D metabolites and thereby aggravate vitamin D deficiency. Prevention is feasible by UV light exposure, food fortification, and supplements. Vitamin D3 supplementation causes a decrease of the serum PTH concentration, a decrease of bone turnover, and an increase of bone mineral density. Vitamin D3 and calcium may decrease the incidence of hip and other peripheral fractures in nursing home residents. Vitamin D3 is recommended in housebound elderly, and it may be cost-effective in hip fracture prevention in selected risk groups.

Hyperparathyroidism is augmented by ovariectomy in Nagase analbuminemic rats

The role of albumin in bone metabolism was studied in Nagase analbuminemic (NA) rats. Serum calcium (Ca), inorganic phosphate (Pi) and magnesium (Mg) concentrations did not differ between female NA and control Sprague-Dawley (SD) rats at the time of ovariectomy (ovx), although serum ionized Ca was significantly lower in NA rats than in SD rats. Serum parathyroid hormone (PTH) and osteocalcin (OC) concentrations and urinary Ca excretion were significantly greater in NA rats than in SD rats, suggesting hyperparathyroidism and the resultant enhanced bone turnover in NA rats. Paradoxically, ovx increased serum PTH and OC in NA rats but not in SD rats. Ovx-induced exacerbation of hyperparathyroidism was confirmed by significantly greater conversion of 25-hydroxyvitamin D to 1, 25-dihydroxyvitamin D in ovx NA rats even after normalization to vitamin D-binding protein. Bone mineral density (BMD) in proximal tibia increased similarly in a time-dependent manner in sham-operated NA and SD rats. However, ovx ablated the time-dependent increase of BMD in SD rats and significantly decreased BMD in NA rats by 2 wk after ovx, resulting in a significantly lower BMD in ovx NA rats than in ovx SD rats. In summary, NA rats, which are analbuminemic with compensatory increases in lipid and protein synthesis, developed hyperparathyroidism, possibly due to an increase in serum Pi and a reduction of ionized Ca, and ovx induced a greater BMD reduction in NA rats than in SD rats, probably by exacerbating hyperparathyroidism.

[Malnutrition and osteoporosis]

Undernutrition, particularly protein undernutrition, contributes to the occurrence of osteoporotic fracture, by lowering bone mass and altering muscle strength. Furthermore, the rate of medical complications after fracture can also be increased by nutritional deficiency. The IGF-I system appears to be directly involved in the pathogenetic mechanisms leading to osteoporotic hip fracture in elderly and to its complications. In the presence of adequate calcium and vitamin D supplies, protein supplements increasing the intakes from low to normal, raises IGF-I levels, improves the clinical outcome after hip fracture, and attenuates the decrease in proximal femur bone mineral density in the year following the fracture. This nutritional approach is associated with a significant reduction of the stay in rehabilitation hospital. This underlines the importance of nutritional supports in preventing and healing osteoporotic fractures.

Relationships between bone mineral density, serum vitamin D metabolites and calcium:phosphorus intake in healthy perimenopausal women

OBJECTIVES

To determine the relationships between serum vitamin D metabolites, bone mass, and dietary calcium and phosphorus in a cohort of 510 healthy Danish perimenopausal women.

DESIGN

A population-based cross-sectional study.

SUBJECTS

A total of 510 healthy women aged 45-58 years, with amenorrhoea for 3-24 months. None of the women was using hormone replacement therapy.

MEASUREMENTS

Measurements of total bone mineral content and regional bone mineral density were performed by dual-energy X-ray absorptiometry. Analyses of serum levels of 25-OHD and 1,25-(OH)2D, intact PTH, ionized calcium and phosphate, as well as biochemical markers of bone turnover in blood and urine. Assessment of calcium and phosphorus intake using dietary records.

RESULTS

A consistent inverse relationship between serum 1,25-(OH)2D and bone mineral content/ density was found in whole-body mineral content (P = 0.001), spine (P = 0.005) and femoral neck (P<0.05). There was a positive relationship between levels of 1,25-(OH)2D and biochemical bone markers, indicating that high levels of 1,25-(OH)2D are accompanied by increased bone turnover. The dietary calcium:phosphorus ratio was inversely related to serum 1,25-(OH)2D (P = 0.04) and positively related to bone mineral density (P<0.0005). No relationships could be detected between levels of PTH, serum ionized calcium and phosphate, and serum vitamin D metabolites.

CONCLUSION

Within normal physiological range, elevated levels of 1,25-(OH)2D were associated with decreased bone mineral density and content, reduced calcium:phosphorus ratio in the diet and increased bone turnover.

Insulin-like growth factor-I and bone mineral density

To assess the relationship between insulin-like growth factor-I (IGF-I) and bone mineral density (BMD) 201 healthy postmenopausal women (age 41-68 years) within 10 years of menopause were studied. In all subjects, BMD at the lumbar spine and left hip were measured using dual-energy X-ray absorptiometry and blood samples were obtained. In all subjects, serum IGF-I and parathyroid hormone (PTH) were measured. In a subgroup of these subjects serum concentrations of IGF-binding protein-3 (IGFBP-3), osteocalcin (OC), bone-specific alkaline phosphatase (BALP), tartrate-resistant acid phosphatase (TRAP), and carboxyterminal propeptide of type I procollagen (PICP) were also measured. Serum IGF-I correlated significantly with age (r = -0.159, p = 0.0241), serum OC (r = 0.226, p = 0.0131), BALP (r = 0.259, p < 0.0001), and TRAP (r = 0.261, p < 0.0015), but not with PICP, PTH, or BMD at any site. Although there was a strong correlation between IGF-I and IGFBP-3 (r = 0.559, p < 0.0001), there was no correlation between IGFBP-3 and any of the markers of bone turnover (OC, BALP, TRAP, or PICP) nor with PTH or BMD at any site. We conclude that IGF-I and markers of bone turnover are related, but there is no relationship between IGF-I and BMD.

Pathophysiology of osteoporosis

As with many chronic diseases that express themselves late in life, osteoporosis is distinctly multifactorial, both in etiology and pathophysiology. Osteoporotic fractures occur because of a combination of injury and intrinsic bony fragility. Injury comes most often from a combination of falls, falling to the side, poor postural reflexes that fail to protect bony parts from impact, and reduced soft-tissue padding over bony prominences. The bony fragility itself is a composite of geometry, low mass density, severance of microarchitectural connections in trabecular structures, and altered bone material quality. The latter is primarily the result of accumulated fatigue damage, but reduced collagen cross-links and other intrinsic material defects may play a role as well. Reduced bone mass, in turn, is the result of varying combinations of gonadal hormone deficiency, inadequate intakes of calcium and vitamin D, decreased physical activity, comorbidity, and the effects of drugs used to treat various unrelated medical conditions. Finally, the often poor outcome from hip fracture in the elderly is partly due to associated protein-calorie malnutrition. An adequate preventive program for osteoporotic fracture must address as many of these factors as possible and be as multifaceted as the disease is multifactorial.