Elevated serum intact parathyroid hormone levels in elderly patients with hip fracture

What Is the Role of Vitamin D Supplementation in Acute Fracture Patients? A Systematic Review and Meta-Analysis of the Prevalence of Hypovitaminosis D and Supplementation Efficacy

OBJECTIVES

The objectives of this systematic review and meta-analyses are (1) to estimate the prevalence of hypovitaminosis D in fracture patients and (2) to summarize the available evidence on the efficacy of vitamin D supplementation in fracture patients.

DATA SOURCES

A comprehensive search of the MEDLINE, Embase, PubMed, and Cochrane Central Register of Controlled Trials databases was conducted. Conference abstracts from relevant meetings were also searched.

STUDY SELECTION

We included studies that investigate vitamin D insufficiency or examine the effect of vitamin D supplementation on 25-hydroxy-vitamin D (25(OH)D) serum levels in fracture patients.

DATA EXTRACTION

Two authors independently extracted data using a predesigned form.

DATA SYNTHESIS

We performed a pooled analysis to determine the prevalence of postfracture hypovitaminosis D and mean postfracture 25(OH)D levels. We present detailed summaries of each of the studies evaluating the impact of vitamin D supplementation.

RESULTS

The weighted pooled prevalence of hypovitaminosis D was 70.0% (95% confidence interval: 63.7%-76.0%, I = 97.7). The mean postfracture serum 25(OH)D was 19.5 ng/mL. The studies that evaluated the efficacy of vitamin D supplementation suggest that vitamin D supplementation safely increases serum 25(OH)D levels. Only 1 meeting abstract showed a trend toward reduced risk of nonunion after a single large loading dose of vitamin D.

CONCLUSIONS

This review found a high prevalence of hypovitaminosis D in fracture patients and that vitamin D supplementation at a range of doses safely increases 25(OH)D serum levels. To date, only 1 pilot study published as a meeting abstract has demonstrated a trend toward improved fracture healing with vitamin D supplementation.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

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.

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.

Association between vitamin D and bone mineral density in Iranian postmenopausal women

The role of vitamin-D in determining bone mineral density (BMD), especially in less severe vitamin D deficiency, is still unclear. To investigate the possible association between 25-hydroxyvitamin D [25(OH)D] and BMD, 245 healthy free-living postmenopausal women, aged between 40 and 80, were randomly selected from participants of a population-based study. BMD was measured at the lumbar spine and hip by dual X-ray absorptiometry (Lunar DPXMD 7164). Serum 25(OH)D, parathyroid hormone (PTH), calcium, phosphorus, total and bone alkaline phosphatases, and urine deoxypyridinoline were measured. PTH was logarithmically transformed (LnPTH). Linear regression models were developed to determine the association between serum 25(OH)D and BMD at different sites. Means of age and duration of menopause were 57.7 +/- 7 and 9.4 +/- 6.8 years, respectively. Mean 25(OH)D was 73.0 +/- 62.3 nmol/l; 5.3% (n = 13) had 25(OH)D < 25 nmol/l and 37.6% (n = 92) had 25(OH)D between 25 and 50 nmol/l. Eleven percent of the women (n = 27) were osteoporotic in femoral neck and 25.3% of them (n = 62) were osteoporotic in lumbar spine sites. 25(OH)D correlated inversely with LnPTH (r = -0.25, P < 0.01). In the multivariate analyses, no association was found between 25(OH)D and BMD at any of the skeletal sites after adjusting for age, duration of menopause, body mass index, calcium, and LnPTH. However, BMD was associated inversely with LnPTH only in femoral neck but not in the other sites. This study did not show any association between 25(OH)D and BMD in free-living Iranian postmenopausal women.

High prevalence of secondary hyperparathyroidism due to hypovitaminosis D in hospitalized elderly with and without hip fracture

OBJECTIVES

To determine and compare the prevalence of secondary hyperparathyroidism (HPTH) in a population of community-dwelling and institutionalized older adults hospitalized with and without hip fracture, and to evaluate factors correlated with secondary HPTH in this population.

METHODS

Circulating concentrations of serum intact PTH, 25-hydroxyvitamin D [25(OH)D] total serum calcium and albumin were measured in 160 subjects with an osteoporotic fracture of the proximal femur and in 160 matched controls hospitalized for a disease unrelated to bone status. Patients with secondary causes of bone loss and taking medications affecting bone metabolism were excluded. Age, sex, place of residence and the ability to perform basic activities of daily living (BADL) two weeks before hospital admission were recorded at baseline.

RESULTS

Patients were comparable with regard to the baseline demographic, biochemical and functional characteristics. The overall prevalence of secondary hyperparathyroidism was 51.2%, without significant differences between hip fractured patients and controls (50.6 vs 51.9%, p=0.911). In bivariate analysis only the age and functional status (BADL) demonstrated a significant relationship with secondary HPTH, while sex and place of residence were not significant. These results were also confirmed in multivariate analysis. Particularly, the risk of secondary HPTH increased with age and with the number of functions lost in BADL: patients fully dependent showed a 3 times as high risk (odd ratio 3.07, 95% confidence interval 1.73 to 5.46, p=0.000) compared to patients independent in BADL, and subject aged >88 yr had a twice as high risk of developing secondary HPTH compared to younger ones (odd ratio 2.28, 95% confidence interval 1.20 to 4.32, p=0.012).

CONCLUSION

These results show that secondary HPTH due to hypovitaminosis D is a frequent disorder in hospitalized elderly, strongly correlated with the functional status, irrespective of sex and place of residence.

Consumption of a high calcium mineral water lowers biochemical indices of bone remodeling in postmenopausal women with low calcium intake

Many postmenopausal women have a calcium intake far below the recommended amount and, in addition to attempting to improve their diet, need a calcium supplement. The aim of the study was to assess the effects of the consumption of a high calcium mineral water (HCaMW) on biochemical indices of bone remodeling in postmenopausal women with low Ca intake. A 6-month randomized double-blind placebo-controlled trial was designed to assess the effects of a daily consumption of 1 liter of a HCaMW (596 mg Ca/l) on serum parathyroid hormone (PTH) and biochemical markers of bone remodeling in postmenopausal women with a dietary Ca intake lower than 700 mg/day. The placebo group drank 1 liter of a mineral water with a low calcium content (10 mg/l). One hundred eighty healthy women were recruited (mean age: 70.1+/-4.0 years); 152 completed the 6-month trial. The changes from baseline of biochemical indices after 6 months consisted of a significant 14.1% decrease of serum PTH, osteocalcin (-8.6%), bone alkaline phosphatase (-11.5%), serum (-16.3%) and urine (-13.0%) type-1 collagen C-telopeptide in the HCaMW group compared to the placebo group, where all biochemical indices increased after 6 months. The additive effect of a small vitamin D supplement (400 iu/day) was also evaluated. In women receiving vitamin D in addition to HCaMW, the decrease in bone indices was not found to be greater than in women drinking only the HCaMW. A daily supplement of 596 mg of Ca through the consumption of 1 l of HCaMW was able to lower serum PTH and the indices of bone turnover in postmenopausal women with a low Ca intake. This could contribute to the repair of calcium deficiency and to the reduction of age-related bone loss in this population.

Seasonal variations in serum levels of 25-hydroxyvitamin D and parathyroid hormone but no detectable change in femoral neck bone density in an older population with regular outdoor exposure

OBJECTIVES

To investigate the influence of season and outdoor daylight exposure on serum levels of 25-hydroxyvitamin D (25OHD), intact parathyroid hormone (PTH), ionized calcium, and femoral neck bone mineral density (BMD).

DESIGN

A 12-month, longitudinal, prospective study on a consecutively selected sample of healthy independent older people.

SETTING

Men and women living in their own homes in the inner city of Stockholm (latitude 59.2 degrees N).

PARTICIPANTS

Sixty-four healthy men (n = 13) and women (n = 51), age 79 to 96 (mean age 83.7) were requested to spend at least 3 hours per week outdoors during April through September. Fifteen of these, who failed to comply with the required time outdoors, constituted a separate group. Subjects with serious diseases and subjects with medication that could interfere with vitamin D metabolism or bone mineralization were excluded from the study.

MEASUREMENTS

Daily dietary intakes of calcium and vitamin D were recorded on the basis of the subjects' recall. The participants kept a diary recording the time spent in sunlight and the area of skin exposed. Fasting blood samples were collected and analyzed on four occasions for 25OHD, intact PTH, and ionized calcium. BMD was determined at 6-month intervals in the femoral neck, using dual energy x-ray absorptiometry.

RESULTS

At study start in the spring, 6% of the subjects had 25OHD levels below 10 ng/ml and 78% had levels below 31 ng/ml. Forty-seven percent had intact PTH levels above the upper limit of the reference range (8-51 ng/L). Seasonal variations in the serum levels of 25OHD (P <.001), intact PTH (P <.001) and ionized calcium (P <.001) were observed only in the group with > or =3 hours of weekly outdoor daylight exposure. The 25OHD levels in autumn were positively correlated with the number of hours spent outdoors during the preceding summer (r = 0.63, P <.001). In the whole group and in the group with weekly outdoor exposure of > or =3 hours, there were no significant changes detectable in mean values of femoral neck BMD during the study year. Femoral neck BMD, expressed as Z-score, was significantly and positively correlated with serum 25OHD (r = 0.38, P =.003 after summer; r = 0.37, P =.003 after winter).

CONCLUSION

The seasonal changes in serum levels of 25OHD, PTH, and ionized calcium and the positive correlation between femoral neck BMD and 25OHD indicate that regular outdoor daylight exposure during the summer could enhance calcium homeostasis and possibly bone health, even among very old people living at northerly latitudes.

Spatial clustering of remodeling osteons in the femoral neck cortex: a cause of weakness in hip fracture?

Intracapsular femoral neck fractures are associated with decreased cortical width and increased proportions of Haversian canals with diameters greater than the normal mean plus 3 SD (i.e., >385 microm). Such canals might be formed if closely associated resorbing osteons merge; a cortical event analogous with the loss of cancellous connectivity. To test this, we investigated the pattern of osteon distribution in the aging femoral neck to determine if remodeling osteons were distributed in anatomical clusters. Femoral neck biopsies from female patients with intracapsular hip fractures (n = 13) were compared with age/gender-matched cadaveric controls (n = 13). Solochrome-stained sections were analyzed for Haversian canal location, canal diameter, and the presence of an osteoid surface. Clustering was investigated using statistical software with a cluster defined as two or more osteoid-bearing osteon centers within 0.75 mm of each other. Clusters occurred more frequently than would be expected by chance (p < 0.001). Fracture cases had more clusters per unit area (3.14 +/- 0.31 clusters/25 mm2 of cortical bone) than controls (1.89 +/- 0.22) (p = 0.002). In fracture cases, the antero-inferior, antero-superior, and infero-anterior regions had more clusters per 25 mm2 than comparable control regions (ant/inf: 4.12 +/- 0.79, 1.70 +/- 0.60,p = 0.025; ant/sup: 5.31 +/- 1.1, 1.80 +/- 0.59,p = 0.013; inf/ant: 3.15 +/- 0.49, 1.27 +/-0.29, p = 0.004). The mean number of clusters per 25 mm2 per region correlated with the mean porosity per region (adjusted r2 = 0.60;p = 0.014), and the total number of giant canals per region correlated with the total number of clusters per region (adjusted r2 = 0.58; p = 0.011). In conclusion, remodeling osteons are clustered or grouped anatomically, and fracture cases have more clusters than controls. Our data suggest that merging of adjacent, clustered osteons during resorption could lead to the rapid development of canals with excessive diameters and focal weakness. Clustering is greatest in those regions that we have previously shown to have the largest relative reductions in bone strength compared with controls and known to be maximally loaded during a sideways fall. This implicates the remodeling process underlying clustering of remodeling osteons in the aetiology of hip fracture.

Secondary hyperparathyroidism in patients from Western Australia with hip fracture: relationship to type of hip fracture, renal function, and vitamin D deficiency

OBJECTIVES

To determine the frequency of vitamin D deficiency and secondary hyperparathyroidism in Australian hip fracture patients living in the community.

PATIENTS

A total of 283 consecutive patients with hip fracture admitted over a 15-month period to a university teaching hospital in Western Australia. Included were residents of hostels for the elderly, and excluded were nursing home residents and those with malignant fractures.

METHOD

Data collected included biochemistry (25 hydroxyvitamin D, parathyroid hormone and creatinine levels), measurements of function and disability (Barthel Index, Frenchay Activity Index), sunshine exposure, and basic demographics.

RESULTS

Vitamin D deficiency occurred in 31.7% and secondary hyperparathyroidism occurred in 17.7% of cases. The major determinants of vitamin D deficiency were outdoor sunshine exposure, ambient daily sunshine, and disability (low Frenchay Activity Index or ADL difficulty). Secondary hyperparathyroidism was related to older age, renal dysfunction, and vitamin D deficiency. Secondary hyperparathyroidism was associated with an excess of trochanteric over subcapital hip fractures.

CONCLUSIONS

Secondary hyperparathyroidism appears to be a heterogeneous condition, caused in approximately equal proportions by vitamin D deficiency and renal dysfunction, that may confer increased cortical bone fragility and trochanteric fractures. Renal dysfunction in old age may be an important additional determinant of senile osteoporosis, which has implications for preventive therapy. Vitamin D deficiency occurs in disabled and, presumably, housebound older people despite near optimal climatic conditions.

Vitamin D and bone mineral density

Bone mineral density (BMD) at the lumbar spine and the neck of femur and serum concentrations of 25-hydroxyvitamin D (25OHD), intact parathyroid hormone (PTH), alkaline phosphatase, calcium, albumin, creatinine and phosphate were measured in a group of 166 postmenopausal women (30-79 years) attending a bone clinic for bone density measurements. Four subjects with suspected primary hyperparathyroidism were excluded from analysis. BMD at the lumbar spine was correlated with body mass index (BMI) (r = 0.278, p = 0.0003), age (r = -0.194, p = 0.0134) and serum 25OHD (r = 0.188, p = 0.0167). BMD at the neck of femur correlated with BMI (r = 0.391, p < 0.0001), age (r = -0.356, p < 0.0001), PTH (r = -0.156, p = 0.047) and serum 25OHD (r = 0.231, p = 0.0031). Stepwise multiple regression analysis showed that age, BMI and serum 25OHD contributed to the variation in BMD at lumbar spine. At the neck of femur, PTH was an additional contributor. We conclude that serum 25OHD makes a contribution to BMD a lumbar spine and neck of femur.

Osteoclast cytomorphometry in patients with femoral neck fracture

In patients with femoral neck fracture, nutritional deficiencies have been shown to be common. A low calcium diet and/or a reduced vitamin D intake have been suspected to cause secondary hyperparathyroidism responsible for increased bone turn over and bone loss. Parathyroid hormone (PTH) levels are increased in these patients, data which are in accordance with the pronounced changes observed on bone biopsies reflecting a true hyperparathyroidism. We have used a cytomorphometrical approach to characterize PTH-induced changes on the osteoclastic population. Osteoclasts were detected histochemically (by tartrate resistant acid phosphatase staining) on bone biopsies from 10 control subjects, 8 patients with primary hyperparathyroidism and 10 patients with a femoral neck fracture of osteoporotic origin. The maximum Feret's diameter of each osteoclast (Oc.Le) was determined with a semiautomatic image analyzer. In all groups, the frequency distribution of Oc.Le appeared positively skewed. In both hip fractured patients and primary hyperparathyroid patients, the mode of the distribution was higher (25-30 microns) than in controls (20-25 microns). When graphically converted on a probability graph, the osteoclastic populations appeared homogeneous and well described by a lognormal distribution in the three groups. However, osteoclasts appeared similarly enlarged in the groups of patients with primary hyperparathyroidism and with femoral neck fracture. PTH has been shown to increase both the recruitment of mononucleated precursors and their fusion into larger osteoclasts than controls. In the present study, a cytomorphometric method appeared able to identify the border line hyperparathyroidism in the hip fractured patients.

Appendicular cortical bone loss after age 65: sex-dependent event?

Distal radius photodensitometric and second metacarpal radiogrammetric measurements were obtained from computerized analyses of standard hand X-Ray films of 296 Caucasian subjects (189 women and 107 men). This sample included 134 subjects > or = 65 years old (75 women and 59 men). Distal radius bone density and metacarpal index showed a significant linear decrease with age in both sexes. Rates of bone loss, calculated from the regression curves, were -0.7% per year in women and -0.5% per year in men by distal radial photodensitometry, and -0.49% per year in women and -0.33% per year in men by metacarpal radiogrammetry. In the elderly subgroup, women > or = 65 years of age showed an even faster bone loss, with an annual decrease of -1.4% by distal radial photodensitometry. Conversely, men > or = 65 years of age had no significant bone loss, not even by metacarpal radiogrammetry. In conclusion, these data suggest that appendicular cortical bone loss occurs at a higher rate in elderly females than in the elderly males, both at the distal radial and at the metacarpal site.

Increased bone resorption and decreased bone formation in Chinese patients with hip fracture

Biochemical markers of bone formation (bone-specific alkaline phosphatase and osteocalcin) and bone resorption (hydroxyproline excretion and bone isoenzyme of acid phosphatase) were measured in 30 patients (15 M and 15 F) with hip fracture and 30 healthy subjects matched for age and sex. Bone isoenzyme of tartrate-resistant acid phosphatase (TRACP) was measured by a recently developed specific immunoassay. Serum osteocalcin concentration and bone-specific alkaline phosphatase activity were significantly lower and serum TRACP concentration and urinary hydroxyproline excretion were elevated in patients compared with healthy subjects. We suggest that there is reduced bone formation and increased bone resorption in patients with hip fracture.

Calciotropic hormones in elderly people with and without hip fracture

The effects of age on calciotropic hormones are not completely understood. The presence of secondary hyperparathyroidism has previously been demonstrated, particularly in patients with hip fracture. The role of a disturbance of vitamin D metabolism, especially a defect in 1 alpha-hydroxylation, is debated. The aim of this study was to compare serum parathyroid hormone (PTH), osteocalcin and vitamin D metabolites (25(OH)D and 1,25(OH)2D) in osteoporotic elderly patients with hip fracture (HF) and in elderly controls. We studied 57 HF patients aged 83.9 +/- 5.9 years (mean +/- SD) and 68 controls aged 82.5 +/- 5 years recruited during two periods: 1 January and 30 April 1988 and 1989. Patients with chronic renal failure (serum creatinine above 150 mumol/l), cancer, or other metabolic bone disease were excluded. Thirty healthy young adults were studied in 1989 only for measurement of 1,25(OH)2D. (1,25(OH)2D was measured by different laboratories in 1988 and 1989 for technical reasons.) We also measured serum PTH, osteocalcin, total calcium and ionized calcium. 1,25(OH)2D levels were not statistically different between HF patients and controls for the two years, nor between HF patients and young healthy adults in 1989. 25(OH)D was decreased in HF patients (p < 0.003), as was ionized calcium. Serum PTH levels were higher in HF patients than in controls (p < 0.01). A positive correlation has been found between PTH and age in HF patients (r = 0.29; p < 0.03) and in the whole group of HF patients and controls. There was a significant decrease in osteocalcin in HF patients versus elderly controls (p < 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)

Calcitriol. A review of its use in the treatment of postmenopausal osteoporosis and its potential in corticosteroid-induced osteoporosis

A synthetic form of calcitriol (1,25-dihydroxycholecalciferol; 1,25-dihydroxyvitamin D3), the most physiologically active metabolite of vitamin D, has shown efficacy in the treatment of postmenopausal osteoporosis and promise in corticosteroid-induced osteoporosis. Although results of small studies investigating calcitriol in the treatment of postmenopausal osteoporosis have been conflicting, a clinical trial in 622 women with postmenopausal osteoporosis demonstrated that patients with mild to moderate disease who received calcitriol (0.25 microgram twice daily) had a significant 3-fold lower rate of new vertebral fractures after 3 years of treatment, compared with patients receiving elemental calcium 1000 mg/day. In patients commencing long term treatment with prednisone or prednisolone, calcitriol 0.5 to 1.0 micrograms/day plus calcium 1000 mg/day, administered with or without intranasal calcitonin 400 IU/day, prevented steroid-induced bone loss. Overall, calcitriol is well tolerated. As shown in clinical studies, at recommended dosages hypercalcaemia is infrequent and mild, generally responding to reductions in calcium intake and/or calcitriol dosage. The narrow 'therapeutic window' of calcitriol requires that its use be adequately supervised, with periodic monitoring of serum calcium and creatinine levels. However, significant renal toxicity has not been seen in patients with osteoporosis treated with calcitriol in high dosages for several years in comparative and noncomparative trials. In conclusion, as with other drugs currently used in the management of patients with osteoporosis, questions remain to be answered regarding the efficacy of calcitriol relative to other agents, and its tolerability in such patients during the very long term. Nonetheless, at this stage, calcitriol should be considered a useful treatment option in patients with mild to moderate postmenopausal osteoporosis.

Secondary hyperparathyroidism, vitamin D deficiency and hip fracture: importance of sampling times after fracture

There is controversy about how often elevated parathyroid hormone (PTH) levels are found in hip fracture patients. The aim of this study was to determine whether changes in PTH levels after fracture and surgery could explain some of the variation in published data. Blood samples were obtained from 24 elderly patients with hip fracture before surgery, immediately after surgery and at 2 weeks and 3 months after fracture. PTH levels were elevated (> 5.5 pmol) in 33% initially and then fell significantly at 2 weeks in virtually all subjects (P < 0.001) and remained significantly lower after 3 months (n = 17). Although 25-hydroxyvitamin D levels were low (< 30 nmol) in 44% of the patients, the fall in PTH was not explained by alterations in vitamin D metabolites or other measured parameters. The cause of the variation in PTH levels is unknown but measurements immediately after fracture could overestimate the incidence of secondary hyperparathyroidism. Vitamin D deficiency is common in our hip fracture population and is not influenced by hospitalisation.

Elderly women in northern New England exhibit seasonal changes in bone mineral density and calciotropic hormones

A seasonal component to bone loss has been reported in some postmenopausal women. We hypothesized that elderly women in northern New England would be at high risk for bone loss during winter because of their age, diet and lack of sunlight. Eighteen elderly but healthy women (mean age 77 years) started a 2-year observational study in a remote area of northwestern Maine (Greenville: 45.5 degrees N latitude). Fifteen women completed the study. Bone mineral density of the spine (L-BMD) and hip (F-BMD) and biochemical markers of bone turnover were measured biannually. In vitro photo-conversion of provitamin D3 to previtamin D3 was determined in the winter and spring. Initial calcium and vitamin D intake averaged 700 +/- 72 mg/day and 6.2 +/- 1.2 micrograms/day, respectively. During the first year L-BMD dropped 4.2% (P = 0.002) while F-BMD dropped 2.4% (P = 0.09), primarily because of steep declines during the fall and winter (August to February: L-BMD: 3.6%, P = 0.001; F-BMD: 3.0%, P = 0.04). In that 6-month period, serum 25 hydroxyvitamin D (25(OH)D) fell 13 +/- 6% (P = 0.06) and PTH rose 27 +/- 11% (P = 0.01). Additionally, there was no detectable in vitro conversion of provitamin D to previtamin D over 8 h of one sunny winter day. In the summer, PTH and 25(OH)D reverted to basal levels and significant in vitro photoconversion of provitamin D to previtamin D was detected. In the 2nd year of the study, vitamin D consumption increased (+2.0 +/- 1.2 micrograms/day, P = 0.03 vs. baseline), L-BMD increased slightly (+1.8%, P = 0.05) and F-BMD did not change (+0.5%, P = NS). Again, changes in BMD and vitamin D were seasonal: L-BMD and F-BMD were constant during fall and winter but both sites showed increases during summer (L-BMD: +1.7%, P = 0.04, F-BMD: +1.6%, P = 0.25). In the second winter, serum 25(OH)D fell nearly 20% and PTH rose 17%. Increased dietary consumption of vitamin D was positively correlated with changes in F-BMD at 18 months (r = 0.61, P = 0.02) and resulted in slightly greater serum 25(OH)D concentrations during the second winter than the first. The difference in serum 25(OH)D between the first and second winter was the strongest predictor of lumbar bone accretion during the second year of the study (r = 0.59, P = 0.04). In this 24-month observational study, significant seasonal changes in BMD, 25(OH)D and PTH were reported.(ABSTRACT TRUNCATED AT 250 WORDS)

Can we stop bone loss and prevent hip fractures in the elderly?

The two main determinants of hip fractures are falls and bone loss leading to an intrinsic femoral fragility. Substantial femoral bone loss continues throughout old age, with a continuous and exponential increase in the risk of hip fracture; thus any reduction or arrest of this loss will induce an important reduction in the incidence of hip fracture. Preventive measures may be achieved during childhood by increasing peak bone mass with calcium and exercise, by using long-term estrogen replacement therapy after menopause, but also by using vitamin D and calcium supplements for late prevention in the elderly. Vitamin D insufficiency and a deficit in calcium intake are very common in the elderly living either in institutions or at home and the cumulative response to these deficits is a negative calcium balance which stimulates parathyroid hormone secretion. This senile secondary hyperparathyroidism is one of the determinants of femoral bone loss and can be reversed by calcium and vitamin D supplements. We have shown in a 3-year controlled prospective study that the daily use of supplements (1.2 g calcium and 800 IU vitamin D3) given in a large population of 3270 elderly ambulatory women living in nursing homes reduced the number of hip fractures by 23% (intention-to-treat analysis). In parallel, serum parathyroid hormone concentrations were reduced by 28% and low baseline serum 25-hydroxyvitamin D concentration returned to normal values. After 18 months of treatment the bone density of the total proximal femoral region had increased by 2.7% in the vitamin D3-calcium group and decreased by 4.6% in the placebo group (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Bone remodeling in hip fracture

Hip fracture incidence has shown strong upward secular trends in many societies with wide differences in age adjusted incidence between nations. Falls and reduced physical activity have emerged as the strongest risk factors in epidemiological studies, while clinical investigations have pointed to secondary hyperparathyroidism as an important candidate cause of the loss of femoral cortical bone in old age. Until recently there have been few studies performed directly on the region of interest in the proximal femur. Non-invasive methodology using 85Sr has now been developed by our group for measuring bone formation and (with concurrent serial DXA densitometry) resorption in the femoral neck. Bone turnover averaged about 8% annually in controls. A group of younger cases of femoral fracture showed similar indices of total and regional bone formation to a control group; but their resorption was higher. To further investigate this, a femoral neck bone biopsy technique has been developed which can be applied to fracture cases treated by arthroplasty. Preliminary studies have established that the anatomical asymmetry of the neck in cross-section is considerable and imposes restraints on the interpretation of smaller or incomplete femur biopsies. Prospects are quite good that, in the absence of tetracycline pre-labeling, mineralization can be studied by assessment of alkaline phosphatase-positive surfaces in cryostat sections. Moreover, such sections will permit study of other anatomically localized metabolic activities as well as antigen expression and osteocyte viability. Candidate mechanisms for the regional decline in bone quality as well as bone mass in subjects suffering hip fracture can now be investigated more effectively.

Serum intact parathyroid hormone levels in elderly Chinese females with hip fracture

Serum intact parathyroid hormone (PTH), 25 hydroxyvitamin D(25OHD), 1,25 dihydroxyvitamin D (1,25(OH)2D), albumin, and ionized calcium were measured in 61 Chinese female patients with hip fracture and 61 control subjects. Hip fracture patients had low albumin, ionized calcium, and 250HD levels. Serum PTH and 1,25(OH)2D values were not different between the two groups. We conclude that although 250HD level in hip fracture patients is low, there is no evidence of secondary hyperparathyroidism, suggesting that the low 250HD levels may be a secondary phenomenon in response to the fracture.

Renal insufficiency and secondary hyperparathyroidism in elderly patients

Glomerular filtration rate (GFR) is frequently reduced in elderly people. However, the effect of this on mineral metabolism in this population has received little attention. GFR, serum intact parathyroid hormone (PTH) and vitamin D metabolites were measured in 37 patients admitted to hospital for various reasons. In 20 patients with GFR greater than 50 mL/min, an elevated serum intact PTH concentration (greater than 5.4 pmol/L) was found in two, while in 17 patients with GFR less than 50 mL/min PTH was elevated in 13. One of this group was hypercalcaemic and presumed to have primary hyperparathyrodism. Adjusted calcium was normal in all other patients. Two patients had a low serum 25-hydroxyvitamin D concentration (less than 9 nmol/L) suggesting vitamin D insufficiency while a further five had a reduced 1,25-dihydroxyvitamin D concentration, four of these having a GFR less than 50 mL/min. We conclude that hyperparathyrodism is common in hospitalized elderly patients, particularly in those with mild to moderate renal insufficiency. This may contribute to bone mineral loss in such patients.

Hyperparathyroidism in proximal femur fractures biological and histomorphometric study in 21 patients over 75 years old

Proximal femur fractures in elderly people are more and more frequent. Falls and senile bone disorders are the risk factors of this fracture. In order to understand the mechanisms of these bone disorders, we studied 21 consecutive patients with this fracture using bone histomorphometry. Measurements of serum intact parathormone (PTH), 25-(OH)-vitamin D, 1,25-(OH) 2-vitamin D and osteocalcin have been performed in these 21 patients, included in a larger series. We excluded patients with renal failure (serum creatinine greater than 140 mumols/l), cancer, or previous metabolic bone disease. There were 19 female and 2 male patients, ranging from 75 to 96 years, (mean 84.9). We found a low frequency of cortical (2/21) and trabecular (3/21) osteoporosis. There was no case of clearcut osteomalacia. Following histomorphometric bone study, two patients showed a typical pattern of hyperparathyroidism, and in a third one, this condition seemed very likely. In these three patients who were among the oldest, and who had high levels of serum PTH, chronic renal failure and primary hyperparathyroidism could be excluded. High bone remodeling was frequent in our patients, as reflected by the enhancement of eroded surfaces (13 cases) and of osteoid thickness (7 cases). Intact PTH level was elevated in our series compared to normal values in adults (in accordance to the PTH elevation in the case control study in a larger series). These findings suggest a major role of a secondary hyperparathyroidism in senile bone disorders favoring proximal femur fractures. This hyperparathyroidism is probably secondary to mild calcium and vitamin D deficiency. It may lead to architectural bone changes favoring this fracture.(ABSTRACT TRUNCATED AT 250 WORDS)