The pathogenesis and treatment of hip fractures

Osteoporosis and metabolic syndrome according to socio-economic status, contribution of PTH, vitamin D and body weight: The Canarian Osteoporosis Poverty Study (COPS)

BACKGROUND

Poverty is associated with a great number of diseases, but the prevalence of vitamin D deficiency, secondary hyperparathyroidism and the potential association of osteoporosis, osteoporotic fractures and metabolic syndrome in this situation are less well known.

OBJECTIVE

To evaluate the associations between poverty, bone density, fragility fractures and metabolic syndrome in a population of southern European postmenopausal women. Also, to assess the potential role of vitamin D and parathyroid hormone (PTH) levels in these associations.

METHOD

Cross-sectional study was carried out in 1 250 postmenopausal Caucasian Spanish women. The socio-economic status of the participants was determined after a personal interview, according to the criteria of the Spanish Institute of Statistics. Participants were divided into two socio-economic levels: low (poverty) and medium or high socioeconomic level. The study protocol included a health questionnaire, a complete physical examination, lateral radiograph of the dorsal and lumbar spine and measurement of bone mineral density (BMD) at the lumbar spine (L2-L4) and proximal femur. Fasting blood was obtained to measure 25-hydroxy-vitamin D (25-OHD), intact PTH and selected biochemical variables.

RESULTS

Low socio-economic status was associated with 25-OHD insufficiency, higher values of PTH, higher body weight and body mass index (BMI), lower values of BMD at the lumbar spine and a higher prevalence of fragility fractures, both vertebral and nonvertebral. Poverty was also associated with higher prevalence of metabolic syndrome, but this association was driven mainly by the higher BMI and not by poverty itself. Both vitamin D insufficiency and elevated PTH were consistently related to poverty and osteoporotic fractures.

CONCLUSIONS

Poor postmenopausal women in southern Europe have a high prevalence of metabolic syndrome and osteoporotic fractures. Poverty was associated with higher BMI and metabolic syndrome on the one hand and, on the other, with 25OHD insufficiency, higher PTH levels and osteoporosis. 25OHD insufficiency and/or secondary hyperparathyroidism do not have a significant influence on the presence of metabolic syndrome in this population.

Role of physical activity in the prevention of falls and their consequences in the elderly

This work aims to provide an inventory of the risk factors and consequences of falling in the elderly, namely fractures, and to identify strategies to prevent falls and minimise their effects. Falls in elderly people are a major cause of injuries, leading to a general fear of falling, poorer quality of life and even death. The increase in life expectancy brought by developments in the medical and health sciences has not always brought enhanced quality of life. More elderly people live with reduced functional capacities resulting in a higher prevalence of falls and associated problems for themselves and for society. Risk factors for falling, commonly resulting from normal aging processes, have already been identified through multiple studies. Exercise may play an important role in fall prevention and their consequences. Although, effective strategies are usually multi-disciplinary and focus simultaneously on several risk factors. However, only large-scale prevention programmes can have significant effective social impact. To minimise occurrence and consequences of falls, policies to systematically implement prevention programmes should be established.

Sacral insufficiency fractures: current concepts of management

BACKGROUND

Sacral insufficiency fractures (SIFs) are often overlooked in elderly patients presenting with low back and pelvic pain following no or minimal trauma.

OBJECTIVE

The aim of this review is to raise awareness and outline the clinical presentation, methods of diagnosis and treatment of SIFs.

DISCUSSION

Insufficiency fractures represent a special category of stress fractures that occur in bones with reduced mineral content and elastic resistance. SIFs, a well-defined subgroup of the latter group, are not uncommon, but lack of clinical suspicion results in many being undiagnosed. SIFs are set to become an important clinical entity of both social and economic significance as the Western population ages. Subtle clinical presentations and signs coupled with radiographic findings that can mimic other unrelated or overlapping conditions, such as sacroiliac joint infection, spinal stenosis and metastatic bone disease, often make SIF diagnosis a challenge. The aim of this review is to increase awareness among clinicians, highlighting SIFs as an important differential diagnosis to be considered when patients present with low back and pelvic pain and subsequently allow prompt management. The paper provides an overview of epidemiology, anatomical considerations, relevant pathophysiology and risk factors, presenting symptoms and signs, investigations and imaging techniques, differential diagnoses and current treatment methods available for the management of SIFs.

Bioavailability of vitamin D2 from irradiated mushrooms: an in vivo study

Vitamin D2 from irradiated edible mushrooms might present a possible dietary source of this vitamin, subject to its bioavailability. Having previously optimized a method for the conversion of ergosterol in mushrooms to vitamin D2, this paper examines the vitamin D-enriched mushrooms (Lentinula edodes) for their bioavailability of the vitamin, using an animal model. Thirty male Wistar rats were fed for 1 week with a diet deficient in vitamin D. After this 1-week period, six rats were randomly selected and killed for analysis of initial bone mineral density, and serum level of 25-hydroxyvitamin D. A group of twelve rats of the test animals received 1 mug of vitamin D2 from irradiated mushrooms for a period of 4 weeks until being killed. The remaining twelve rats were fed un-irradiated mushrooms at the same level to act as controls. At the end of a 4-week period, the mean serum 25-hydroxyvitamin D level of the experimental group was 129.42 (sd 22.00) nmol/l whereas it was only 6.06 (sd 1.09) nmol/l in the control group. Femur bone mineral density of the experimental group of animals was significantly higher (P<0.01) than the control group. In addition, serum Ca concentrations among groups were shown to be significantly higher (P<0.01). It may be concluded from the results that vitamin D2 from UV-irradiated mushrooms is well absorbed and metabolized in this model animal system. Significant increase in femur bone mineralization (P<0.01) was shown in the presence of vitamin D2 from irradiated mushrooms compared with the controls.

Calcium and vitamin D3 supplements in calcium and vitamin D3 sufficient early postmenopausal healthy women

OBJECTIVE

To study the calcium homeostasis in healthy, calcium and vitamin D replete early postmenopausal women during oral supplementation with calcium and vitamin D3.

DESIGN

A prospective, placebo-controlled, randomised, double-single-blind, 3-week study.

SETTING

Outpatient clinic at Copenhagen University Hospital, Denmark.

SUBJECTS

In all, 17 started, one was excluded. Totally, 16 healthy women, 45-61 y of age (mean 57.3 y) who were at least 4 y after menopause (mean 6.7 y) completed.

INTERVENTIONS

All underwent three consecutive 7-day study periods. Each began with 4 days of normal diet followed by 3 days treatment of either C: one tablet of 1.250 mg calcium carbonate (ie 500 mg Ca2+ per tablet) twice daily (breakfast and dinner), or CD3: as in C but plus 400 IU vitamin D3 b.i.d., or P (only) placebo tablets b.i.d.

RESULTS

At baseline plasma 25-hydroxycholecalciferol was normal (66+/-22 nmol/l) and the calcium intake without supplements 850 mg/day. In group C, the 24-h urinary calcium increased by 35% (6.9+/-2.0 mmol), vs the placebo group P (5.1+/-1.6 mmol) (P < 0.05). Addition of 800 IU vitamin D3 daily (CD3) did not increase calcium excretion further (6.6+/-2.1 mmol) but decreased plasma 1,25-(OH)2-vitamin D3 by 21% (P < 0.05).

CONCLUSIONS

In this carefully controlled study calcium plus vitamin D3 supplements only had minor influences of uncertain significance on the calcium balance in healthy, calcium and vitamin D sufficient early postmenopausal women.

The heterogeneity of bone disease in cirrhosis: a multivariate analysis

This study aimed to assess the clinical, biochemical and hormonal factors contributing to low bone density in a large ambulatory group of patients with cirrhosis of diverse aetiology. Bone density of the lumbar spine, neck of femur, total hip, total body, as well as total body fat, was measured by dual X-ray (DEXA) absorptiometry in 81 men and 32 women (average age 50.3 years). Morning blood and urine samples were taken for hormonal and biochemical analysis. Viral hepatitis was the most common cause of cirrhosis (54%) and the severity of cirrhosis ranged from Child-Pugh A5-C14. Osteoporosis was most common in the lumbar spine but was present at any site in 31% of women and 22% of men, with osteopenia present in another 40% of both genders. Urinary deoxypyridinoline, a marker of bone resorption, was elevated in 56% of patients and was associated with increasing severity of cirrhosis and a higher prevalence of osteoporosis, particularly of the lumbar spine. Hip-bone density was primarily affected by low 25-hydroxyvitamin D levels and was associated with secondary hyperparathyroidism in one third of these patients. Additional important predictors for low bone density at all sites were age in women and testosterone in men. These findings indicate that, although the pathophysiology of osteoporosis in chronic liver disease is heterogeneous, high bone turnover may be the underlying pathophysiological mechanism in a significant subgroup of cirrhotic patients and may reflect metabolic effects of hypogonadism or secondary hyperparathyroidism on bone.

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.

Hypovitaminosis D in a sunny country: relation to lifestyle and bone markers

Hypovitaminosis D is associated with poor dietary intake and inadequate sunshine exposure. It is common worldwide, particularly in European elderly people. Information about vitamin D status in young adult populations from the Middle East is scarce. Furthermore, the relationship between hypovitaminosis D and some lifestyle factors such as style of clothing and dwelling location is not well defined. We assessed vitamin D intake and measured serum calcium, phosphorus, albumin, alkaline phosphatase, 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH), osteocalcin, and urinary-free deoxypyridinoline (DPD) in 316 Lebanese volunteers (99 men and 217 women) aged 30-50 years; 156 were recruited from rural areas and 160 from urban areas. Fifty-one women from each area were veiled. The average daily vitamin D intake was 100.3 +/- 67.9 IU and was found to be higher in men compared with women, in urban subjects compared with rural ones and in nonveiled women compared with veiled ones. The mean level of 25(OH)D was 9.71 +/- 7.07 ng/ml. Hypovitaminosis D [25(OH)D < 12 ng/ml] affected 72.8% of our population. It was more common in women than in men (83.9% vs. 48.5%). Severe hypovitaminosis D [25(OH)D < 5 ng/ml] was observed in 30.7% of our subjects and was more prevalent in women (41.5%), particularly in the veiled ones (61.8%). 25(OH)D levels were the lowest in veiled women, and in women living in rural areas. Rural men had the highest 25(OH)D levels despite their very low vitamin D intake. In a multivariate model, inadequate vitamin D intake, urban dwelling, veil wearing, and high parity in women were independent predictors of hypovitaminosis D. 25(OH)D was related inversely to PTH and free DPD whereas osteocalcin achieved only a weak positive correlation with 25(OH)D. In the absence of information regarding time spent outdoors, our results show that hypovitaminosis D is common among young Lebanese people and is related mostly to low vitamin D intake. This should emphasize the need for more vitamin D in our population.

Age-related changes in insulin-like growth factor I and II in human femoral cortical bone: lack of correlation with bone mass

The concentration of insulin-like growth factor-I (IGF-I) in human cortical bone declines with age, but the relevance of this decline for cortical bone turnover and bone mass is unknown. In the present study, we simultaneously assessed the concentration of IGF-I and -II in cortical bone matrix and histomorphometric parameters of bone mass and bone turnover in 125 samples from the proximal human femur shaft. Bone width decreased by 27% and porosity increased by 100% in female cortical bone between the fourth and the ninth decade. Similar, but weaker, changes tended to occur in male cortical bone. The concentrations of both IGF species were correlated with the percentage of osteons undergoing bone remodeling. However, despite age-related decreases in both IGF species in men and in IGF-I in women, neither of the IGFs accounted for age-related or age-independent variability in cortical porosity or bone width. In conclusion, these data suggest that the local concentrations of IGF-I and -II are related to cortical bone turnover. In contrast, our study provides no evidence for a major role of bone matrix IGF-I and -II as determinants of cortical bone mass in elderly individuals. Whether other components of the IGF system may be stronger determinants of cortical bone loss remains to be determined.

Role of polypeptides in the treatment and diagnosis of osteoporosis

Osteoporosis is a common disorder characterized by reduced bone mineral density, deterioration of the microarchitecture of bone tissue and increased risk of fracture. The aim of treatment of osteoporosis is to maintain and, ideally, to restore bone strength safely. In recent years the role of polypeptide growth factors in bone metabolism has begun to appear. It has been proposed that alterations in the expression or production of growth factor can modulate the proliferation and activity of bone forming cells. In this direction, the role of structurally diverse peptides for the management and diagnosis of osteoporosis has attracted the attention of many investigators. This paper reviews numerous findings concerning the use of polypeptides, hormones, and growth factors, for the management of osteoporosis. Many of the compounds mentioned here are experimental prototypes of new therapeutic classes. Though it is unlikely that some of the compounds may ever be used clinically, development of safe and efficacious agents in each class will define the future course of therapy for osteoporosis.

Sex steroids, bone turnover and bone mineral density in pre-, peri-, and postmenopausal women

To examine 1) the relationships between endogenous androgens and bone mineral density (BMD), 2) the relationships between sex-hormone binding globulin (SHBG) and BMD, and 3) the associations of endogenous androgens and SHBG with biochemical markers of bone turnover, a cross-sectional study was carried out in 88 healthy pre-, peri-, and postmenopausal women aged 35 to 74. Measurements of BMD(s) at the ultradistal radius and ulna, and the distal radius (using DEXA), estrogens, androgens, deoxypyridinoline (D-Pyr) and intact bone gla protein (I-BGP) were performed. In the multivariate regression models testosterone (T) was positively correlated with BMD at the ultradistal radius and ulna in perimenopausal women, and was positively correlated with BMD at the ultradistal radius and ulna, and the distal radius in postmenopausal women. T was positively associated with I-BGP in premenopausal women (r = 0.65, p < 0.01), and negatively associated with D-Pyr in pre- (r = -0.53, p < 0.05) and postmenopausal women (r = -0.49, p < 0.001). On the other hand, SHBG was negatively correlated with BMD at die ultradistal radius and ulna, and die distal radius in pre- and postmenopausal women in the models. SHBG was positively related to D-Pyr in pre(r = 0.57, p < 0.05) and postmenopausal women (r = 0.41, p < 0.01), and negatively related to I-BGP in postmenopausal women (r = -0.38, p < 0.01). These findings suggest that endogenous androgens may exert positive influences on BMD, and that SHBG may have negative effects on BMD.

Ultraviolet irradiation corrects vitamin D deficiency and suppresses secondary hyperparathyroidism in the elderly

The objective of this study was to compare the effect of ultraviolet radiation (UV) and oral vitamin D3 on the vitamin D status and parathyroid hormone (PTH) concentration in elderly nursing home patients. The design of the study was a randomized clinical trial. The setting was a psychogeriatric nursing home. Subjects included 45 female psychogeriatric patients with a mean age of 85 years. Exclusion criteria were going outdoors more than once a week and the presence of actinic or cancer skin lesions. Intervention was random allocation of UV-B irradiation at half the minimal erythemal dose of the lower back, three times per week during 12 weeks (UV-B), or oral vitamin D3 400 IU/day during 12 weeks (VIT-D), or no treatment (CONTR). Main outcome measures were change in fasting serum levels of vitamin D metabolites at 0, 2, 4, 8, and 12 weeks in the treatment groups, compared with the control group. PTH(1-84) was measured at 0 and 12 weeks. Baseline serum 25-hydroxyvitamin D (25(OH)D) was lower than 30 nmol/l in 95% of the participants. It increased to a median value of around 60 nmol/l after 12 weeks both in the UV-B and VIT-D groups, whereas there was no change in the CONTR group. Serum 1,25-dihydroxyvitamin D increased significantly in the UV-B group. Serum calcium increased significantly in both treatment groups. Serum PTH decreased more than 30% in both treatment groups (p < 0.001), whereas there was no significant change in the control group. Irradiation with UV-B in the very elderly for a few minutes per day leads to adequate improvement of the vitamin D status. It is as effective as oral vitamin D3 in increasing serum 25(OH)D and suppressing secondary hyperparathyroidism.

Physiological plasma levels of androgens reduce bone loss in the ovariectomized rat

The effect of androstenedione (ADIONE) slow-release pellets on cancellous bone volume (BV/TV) at the tibial metaphysis was investigated in ovariectomized (OVX) rats at various times from 21 to 180 days. Plasma levels of ADIONE and testosterone (T) in OVX rats were significantly reduced at 21 days and were restored close to levels in the sham rats with the 1.5-mg ADIONE pellet. OVX animals with and without ADIONE pellets resulted in close to a 50% reduction in BV/TV, by day 21. By day 180, OVX rats had only approximately 5% BV/TV, whereas that in ADIONE-treated OVX rats was significantly greater at approximately 12%. The reduced BV/TV was associated with increased bone resorption and formation. In a separate 90-day experiment, we found that the antiandrogen, Casodex, abrogated the ADIONE-induced skeletal-protective effect in OVX rats, whereas the antiaromatase, Arimidex, had no effect. This provides evidence that ADIONE protects against the development of osteopenia in the estrogen-deficient rat and mediates its effect through androgens and not estrogens.

Regional variation in vertebral bone density and trabecular architecture are influenced by osteoarthritic change and osteoporosis

STUDY DESIGN

The effects of age-related osteoarthritic disease and bone loss on cortical and trabecular bone density in the human spine were analyzed. Changes were quantified by a new method of computed quantitative radiography. Using this method, the relative losses of bone mineral from specific areas and the specific redistribution of bone within vertebrae as a function of age-related bone loss and osteoarthritic change were determined.

OBJECTIVES

To quantify the effects of age-related bone loss and osteoarthritic disease on cortical and trabecular density in the human spine by the use of a new method of computed quantitative radiography.

SUMMARY OF BACKGROUND DATA

To the authors' knowledge, osteoarthritic and age-related changes resulting in the relative loss of bone mineral from specific areas within vertebrae have never been quantitatively studied.

METHODS

Seventy-four vertebrae were obtained from 23 normal, human subjects at autopsy. Vertebral bodies were measured by dual-energy x-ray absorption, and then sectioned for analysis by computerized quantitative radiography. Attention was focused on overall bone density, regional cancellous bone density, and cortical bone density (anterior cortex, superior, and inferior endplates) for both mid-sagittal and para-sagittal sections. One hundred forty sections were so analyzed.

RESULTS

Quantitative radiography demonstrated previously undescribed, well defined patterns of cortical and trabecular architecture and bone density within vertebral bodies that were uniform among vertebrae, but strongly influenced by osteoarthritic change and bone loss. These changes were neither detected nor documented by dual-energy x-ray absorption.

CONCLUSIONS

Understanding the patterns of bone lose, and knowing how osteoarthritic change affects normal bone loss yields insight into the pathophysiology of the aging process and osteoarthritic disorders. Knowledge of the variations in density and microanatomy within vertebrae may improve techniques of internal fixation and designs of spinal implants, and may help to clarify the pathogenesis of clinical problems such as fractures.

Epidemiology and predictors of fractures associated with osteoporosis

Approximately 40 in 100 women will experience one or more fractures after the age of 50 years. At 50 years for women the lifetime risk is 17.5% for hip fracture, 16% for vertebral fracture, and 16% for Colles' fracture; for men, the respective lifetime risks are 6%, 5%, and 2.5%. The incidence of hip fractures has increased in recent years in most but not all European countries, partly as a result of the aging of the population. However, the age-adjusted incidence has also increased in several countries. The age-adjusted incidence of hip fractures varies greatly between European countries; in women incidence varies from about 50 per 10,000 women in Malta and Poland to 500 per 10,000 in Sweden. In addition, the sex ratio (female:male) varies from 1.6 in Poland to 4.2 in Iceland. A proportion of this large variation may be the result of underreporting of cases, although most European countries now have an adequate hospital registration. The prevalence of vertebral deformities also shows geographic variation. In the multinational European Vertebral Osteoporosis Study, a population-based study, the prevalence of vertebral deformities was similar among men and women at ages 65-69 years (12-13%); at younger ages the prevalence was higher in men than women, whereas the reverse was true at older ages. Incidence data on vertebral fractures are scarce because a large proportion of vertebral fractures are not clinically diagnosed. Prospective epidemiologic studies indicate that bone mineral density (BMD) is the single best predictor of fractures in perimenopausal women. Historic risk factors do not predict bone mass (or fractures) with sufficient precision to be useful in assessment of fracture risk or BMD. However, the presence of one vertebral fracture doubles the risk of future vertebral fracture as assessed by a BMD measurement. At advanced ages, other risk factors may be more important, such as the risk of falling, and combinations of risk factors for falls and low BMD may predict hip fractures. Risk factor assessment is currently of less value for the prediction of other fractures, such as vertebral or Colles' fracture. Determining the causes of the large geographic differences in hip fracture incidence and the large differences in sex ratios for hip fractures in European countries could lead to identification of hitherto unknown risk factors and provide clues for prevention of fractures. Many risk factors cannot be prevented or modified; however, these risk factors (for example, family history, past fracture, and visual loss) can identify risk groups amenable to drug treatment or to preventive measures such as protective hip pads or environmental changes. Assessment of risk factors and definition of risk profiles are important steps toward the prevention of fractures in the elderly.

The effect of vitamin D supplementation on the bone mineral density of the femoral neck is associated with vitamin D receptor genotype

Recent studies suggest that variations of the vitamin D receptor (VDR) gene are related to bone mineral density (BMD). In this study, we examined the effect of vitamin D3 supplementation on BMD at the femoral neck in relation to VDR genotype. We analyzed 81 women, age 70 years and over, who participated in a placebo-controlled clinical trial on the effect of vitamin D3 supplementation (400 IU daily for at least 2 years) on BMD and fracture incidence. VDR genotype was based on the presence (b) or absence (B) of the BsmI restriction site. Mean BMD of the right and left femoral neck was measured at baseline and after 1 and 2 years. Dietary calcium, body mass index, and years since menopause were assessed at baseline while biochemical markers were measured at baseline and after 1 year. There was no difference among the BB, Bb, and bb genotype for baseline measurements of BMD at the femoral neck (mean and SD, g/cm2: 0.70 (0.10), 0.71 (0.12), and 0.69 (0.10), respectively), nor for any of the biochemical indices. The mean increase of BMD in the vitamin D group relative to the placebo group, expressed as percentage of baseline BMD, was significantly higher (p = 0.03) in the BB (delta BMD: 4.4%, p = 0.04) and Bb genotype (delta BMD: 4.2%, p = 0.007) compared with the bb genotype (delta BMD: -0.3%, p = 0.61). No significant changes were found for any of the other measured parameters. The VDR genotype-dependent effect of vitamin D supplementation in these elderly subjects suggest a functional involvement of VDR gene variants in determining BMD.

Ageing and calcium metabolism

Ageing alters the metabolism of calcium and vitamin D in a number of ways. Intake of calcium and vitamin D, exposure to sunlight, cutaneous production of vitamin D3, renal production of 1,25-dihydroxyvitamin D (1,25(OH)2D3), intestinal absorption of calcium and the ability to adapt to a low calcium diet may all be reduced in elderly subjects. As a consequence, secondary hyperparathyroidism often occurs with ageing and can contribute to accelerated bone loss. In fact, alterations in calcium and vitamin D metabolism may be widespread in the ageing population and play a central role in the pathogenesis of senile (age-related) osteoporosis. From a preventive point of view, recent intervention studies have indicated the need to optimize calcium intake and to maintain serum 25(OH)D3 levels within the normal range in elderly people.

Lack of in vitro evidence for storage of 1,25-dihydroxycholecalciferol (1,25(OH)2D3) and 1,25(OH)2D3 binding protein in skeletal matrix

A few studies have reported on the measurement of 1, 25-dihydroxycholecalciferol (1,25(OH)2D3) in bone, using chloroform/methanol extraction and radioreceptor assay. As the significance of bone 1,25(OH)2D3 content was not defined in any of these reports, the objective of the current investigation was to determine whether 1,25(OH)2D3 may be stored in skeletal matrix. Bone powder samples from the iliac crest were extracted in ethylacetate/cyclohexane and 1,25(OH)2D3 isolated from the extract by means of Sephadex LH-20 and high pressure liquid chromatographic separation and subsequently measured by radioimmunoassay (RIA). Within the detection range of the RIA, no 1,25(OH)2D3 could be measured, suggesting that 1,25(OH)2D3 is not stored in skeletal matrix. Vitamin D bone concentrations previously measured may therefore have reflected plasma contamination. Consistent with this hypothesis, only traces of skeletal 1,25(OH)2D3 binding protein were measured when compared with serum values. Although 1,25(OH)2D3 may act as a potential local determinant of bone remodeling, there is no evidence supporting a delayed paracrine function by matrix-derived 1, 25(OH)2D3.

Relationship between baseline insulin-like growth factor-I (IGF-I) and femoral bone density in women aged over 70 years: potential implications for the prevention of age-related bone loss

OBJECTIVE

To test the hypothesis that the decline in femoral bone mass associated with healthy aging is partially accounted for by deficiency of the growth hormone-insulin-like growth factor-I (IGF-I) axis.

DESIGN

Cross-sectional study.

STUDY PARTICIPANTS

A sample of 245 community-dwelling healthy women aged 70 and older. Exclusion criteria were diseases or medications known to affect the musculoskeletal system or the somatotrophic axis.

MEASUREMENTS

Serum levels of IGF-I, calcitriol, and osteocalcin were determined by radioimmunoassay; serum calcidiol was measured by competitive binding assay, and serum parathyroid hormone (PTH) was assessed immunochemically. Urinary pyridinium crosslinks were measured by fluorescent detection after high-pressure liquid chromatography. Isometric and isokinetic quadriceps strength was evaluated using an isokinetic dynamometer. Bone density (BMD) was assessed by dual-energy X-ray absorptiometry at the proximal femur. Multiple regression was used to adjust for potential confounders.

RESULTS

At the proximal femur, BMD declined by 0.59-0.84% per year. In addition to body mass index and muscle strength, serum IGF-I was found to be an independent predictor of BMD at all femoral sites.

CONCLUSION

The data support the hypothesis that circulating IGF-I not only reflects the integrated growth hormone secretion but also has a direct role in the endocrine regulation of bone remodeling. The present findings support the need for further studies to assess the potential of IGF-I in attenuating age-related femoral bone loss.

Markers of bone resorption predict hip fracture in elderly women: the EPIDOS Prospective Study

Increased bone turnover has been suggested as a potential risk factor for osteoporotic fractures. We investigated this hypothesis in a prospective cohort study performed on 7598 healthy women more than 75 years of age. One hundred and twenty-six women (mean years 82.5) who sustained a hip fracture during a mean 22-month follow-up were age-matched with three controls who did not fracture. Baseline samples were collected prior to fracture for the measurement of two markers of bone formation and three urinary markers of bone resorption: type I collagen cross-linked N- (NTX) or C-telopeptide (CTX) and free deoxypyridinoline (free D-Pyr). Elderly women had increased bone formation and resorption compared with healthy premenopausal women. Urinary excretion of CTX and free D-Pyr, but not other markers, was higher in patients with hip fracture than in age-matched controls (p = 0.02 and 0.005, respectively). CTX and free D-Pyr excretion above the upper limit of the premenopausal range was associated with an increased hip fracture risk with an odds ratio (95% confidence interval) of 2.2 (1.3-3.6) and 1.9 (1.1-3.2), respectively, while markers of formation were not. Increased bone resorption predicted hip fracture independently of bone mass, i.e., after adjustment for femoral neck bone mineral density (BMD) and independently of mobility status assessed by the gait speed. Women with both a femoral BMD value of 2.5 SD or more below the mean of young adults and either high CTX or high free D-Pyr levels were at greater risk of hip fracture, with an odds ratio of 4.8 and 4.1, respectively, than those with only low BMD or high bone resorption. Elderly women are characterized by increased bone turnover, and some markers of bone resorption predict the subsequent risk of hip fracture independently of hip BMD. Combining the measurement of BMD and bone resorption may be useful to improve the assessment of the risk of hip fracture in elderly women.

Prevention of hip fractures: drug therapy

Drug therapy to prevent hip fractures may be considered for postmenopausal women with low bone mass and elderly people with risk factors for hip fracture. As most hip fractures occur 25 years or more after menopause, drug therapy may have to be prescribed for many years to be effective. A preventative drug should be effective, safe, and without side effects. Estrogen therapy decreases bone loss and hip fracture incident, but the effect wears off when treatment is stopped. The positive effect of estrogens on cardiovascular disease should be balanced against the increased risk of breast cancer with long-term use. The newer bisphosphonates are potent inhibitors of bone resorption and decrease bone loss substantially. Again, the effect may wear off after the drug is stopped. The bisphosphonates appear to be safe, but long-term data are lacking. Calcium and/or vitamin D may prevent bone loss in late postmenopausal women and elderly people. The combination was shown to prevent hip fractures and other peripheral fractures in elderly nursing home residents. No single drug will be used more than 10-15 years. Therefore, a public health strategy should be developed with a logical sequence of drug and nondrug interventions for the successful prevention of hip fractures.

The effects of a community exercise program on fracture risk factors in older women

One hundred and seventy-nine women aged 60-85 years (mean age 71.6 years, SD 5.3 years) were randomly recruited from the community to participate in a 12-month randomized controlled trial to determine whether a program of twice-weekly structured exercise has beneficial effects on three factors associated with osteoporotic fractures: quadriceps strength, postural sway and bone density. At initial testing, there were no significant differences in the strength, sway and bone density measures (assessed at the hip and lumbar spine) between the exerciser and control groups. The exercise classes included strengthening, coordination and balance exercises, and approximately 35 min of each class comprised weight-bearing exercise. The mean number of classes attended for the 68 exercisers who completed the program was 59.8 of the 82 classes (72.9%). At the completion of the trial, the intervention group showed significant improvements in quadriceps strength and sway but not bone mineral density when compared with the control group. Indices of fracture risk, indicated by (i) the sum of standard score results and (ii) the sum of quartile grades of the femoral neck bone density, sway and strength measures, decreased significantly in the exercisers at the end of the trial compared with the controls. In conclusion, the program of general aerobic exercise may have reduced overall fracture risk, even though it did not significantly increase bone density. Further long-term studies are required that include acceptable weight-loaded exercises to determine optimal programs for reducing fracture risk factors by improving bone density as well as strength and balance.

Age-related bone loss and senile osteoporosis: evidence for both secondary hyperparathyroidism and skeletal growth factor deficiency in the elderly

Aging is characterized by a decrease in bone volume, implying that net bone resorption exceeds net bone formation. This age-related bone loss can be regarded as the main determinant of hip fracture risk in the elderly. In the concept of senile osteoporosis, a key role has been attributed to vitamin D deficiency. Lack of vitamin D activity may affect femoral strength through impaired mineralization as well as through a hyperparathyroidism-mediated increase in bone resorption. In addition to vitamin D-related mechanisms, recent evidence has indicated a decline in the skeletal content of anabolic growth factors--such as insulin-like growth factor-I (IGF-I)--in femoral (cortical) bone, suggesting that skeletal growth factor deficiency may contribute to the age-related bone loss in the proximal femur as well. It is tempting to speculate that skeletal IGF-I loss might, at least partially, be accounted for by growth hormone deficiency. However, critical evidence does not yet support the concept that the decreased activity of the growth hormone-IGF-I-axis alters bone remodeling, and the extent to which serum concentrations of growth factors are reflective of skeletal activity remains to be clarified.

Vitamin D status and sex hormone binding globulin: determinants of bone turnover and bone mineral density in elderly women

To examine the relation of the vitamin D status and the remaining estrogen activity with bone turnover and bone mineral density (BMD) in elderly women, BMD was measured at both hips using dual-energy X-ray absorptiometry and at the distal radius using single photon absorptiometry, in 330 healthy women aged 70 and over. Vitamin D metabolites, sex hormone binding globulin (SHBG), PTH(1-84), osteocalcin, alkaline phosphatase, and hydroxyproline and calcium excretion in 2 h fasting urine were measured. Multiple linear regression was used to adjust for potential confounders. In 65% of the women, serum 25(OH)D was below 30 nmol/l. Only values below a threshold for 25(OH)D were negatively related to serum PTH(1-84) (p = 0.02, threshold at 25 nmol/l) and to osteocalcin levels (p = 0.04, threshold at 30 nmol/l). BMD of the femoral neck and trochanter was positively related to serum 25(OH)D (left neck p = 0.001) with thresholds at 30 nmol/l whereas the distal radius was not (p = 0.32). Serum PTH was negatively related to BMD at all measurement sites (all p < 0.001). Serum SHBG, an inverse measure of estrogen activity, was positively related to osteocalcin levels (p = 0.004) and the urinary hydroxyproline/creatinine ratio (p = 0.002) and negatively related to the BMD of the trochanter (left trochanter p = 0.02) and the distal radius (p = 0.001). We conclude that in elderly women, serum 25(OH)D levels below 30 nmol/l are associated with secondary hyperparathyroidism and increased bone turnover. SHBG is positively related to bone turnover.(ABSTRACT TRUNCATED AT 250 WORDS)

Hip fracture incidence in the canton of Vaud, Switzerland, 1986-1991

The objective of this study was to estimate the incidence of hip fracture in the canton of Vaud, Switzerland (total population 584,000), for the period 1986-1991 using routine hospital discharge data collected by the Cantonal Service of Statistical Research and Information (SCRIS). For the survey period, the estimated average annual crude incidence rate of hip fractures was 167 per 100,000 persons aged 20 or older (241 for women and 84 for men). For the population aged 50 years or older, the crude incidence rate was 388 per 100,000 persons (546 for women and 185 for men). The average annual age-specific rates rose exponentially by successive 5-year age groups. The median age of patients at the time of the fracture was 82 years in women and 74 years in men. There was no significant difference between the total number of cervical and trochanteric fractures. Between the ages of 20 and 84 years, the cumulative risk for a woman to be admitted to hospital with a hip fracture was twice that of a man (15.8% vs 7.8%). From 1986 to 1991, the age- and sex-adjusted incidence, like the ratio of cervical to trochanteric fractures, did not show any significant trend, although it was consistent with an increase in men (p = 0.09). However, the annual number of fractures rose from 644 to 776, particularly among very aged men. The mean length of stay in the acute care hospital fell from 38 days in 1986 to 25 days in 1991.(ABSTRACT TRUNCATED AT 250 WORDS)

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)

Age-related hip fractures in men: clinical spectrum and short-term outcomes

Clinical spectrum, treatment and short-term outcomes were assessed among the 131 Rochester, Minnesota, men who contracted an initial hip fracture due to moderate trauma during 1978-89. Three-fourths of falls leading to hip fracture occurred indoors with little seasonality, and 91% of fractures were in men 65 years of age or older. The ratio of cervical to intertrochanteric femur fractures was 1.4:1, and there was a tendency toward more neurological conditions among the patients with cervical fractures. Hemiarthroplasty and total hip replacement were mostly performed for cervical fractures, while internal fixation was preferred for intertrochanteric fractures. In-hospital mortality was 11.5%, and the 30-day case fatality rate was 16.0%. Age and postoperative deterioration of mental status significantly increased the risk of early death, the latter even after adjustment in a multivariate model, while comorbidity had a suggestive but not statistically significant influence on mortality. More than half the men were discharged to nursing homes, and 79% of the patients who survived at 1 year resided in nursing homes or intermediate care facilities or were attended by home care. Only 41% of survivors recovered their prefracture level of functioning and nearly 60% of patients limped and required a cane or walker. After implementation of the prospective payment system in 1984, the length of hospital stay was reduced, but there was no change in early mortality rates, in the duration of physical therapy following fracture or in attendance at nursing homes. The results of this population-based study demonstrate the strong impact of hip fractures on short-term outcomes in men.

Assessment of fracture risk and its application to screening for postmenopausal osteoporosis: synopsis of a WHO report. WHO Study Group

The criteria required for an effective screening strategy for osteoporosis are largely met in Caucasian women. The disease is common and readily diagnosed by the measurement of bone mineral with single- or dual-energy absorptiometry. Such measurements have high specificity but lower sensitivity, so that the value of the technique is greater for those identified as being at higher risk. Against this background there is little evidence that osteoporosis can usefully be tackled by a public health policy to influence risk factors such as smoking, exercise and nutrition. This suggests that it is appropriate to consider targetting of treatment with agents affecting bone metabolism to susceptible individuals. Since the main benefits of the use of hormone replacement therapy (HRT) are probably on cardiovascular morbidity, the major role for selective screening is to direct non-HRT interventions. An appropriate time to consider screening and intervention is at the menopause, but screening at later ages is also worthy of consideration. Since the cost of screening is low and that of bone-active drugs is high, the selective use of screening techniques will improve the cost-benefit ratio of intervention.

Loss of bone in the proximal part of the femur following unstable fractures of the leg

We evaluated the subsequent loss of bone from the proximal part of the ipsilateral and contralateral femora and from the lumbar spine of seven men and nine women who had a fracture of the tibia. The average age was sixty years. All of the fractures were unstable, and the involved leg bore no weight for an average of eight weeks. The bone mineral density was measured with dual-energy x-ray absorptiometry of the lumbar spine and of the femoral neck and the trochanteric region of both hips immediately after the fracture, after the period of immobilization, and at approximately three, six, and twelve months after the fracture. During the period of immobilization, the bone mineral density of the trochanteric region decreased an average of 9 +/- 7 per cent on the side of the fracture, compared with the value immediately after the fracture, but there was no change on the contralateral side (p < 0.01). At twelve months, the average decrease in the trochanteric area was 15 +/- 10 per cent on the side of the fracture, compared with the value immediately after the fracture, but again there had been no change on the uninjured side (p < 0.01). The bone mineral density of the femoral neck on the side of the fracture had decreased 6 +/- 6 per cent at twelve months, compared with a decrease of 2 +/- 4 per cent on the uninjured side (p < 0.05). The bone mineral density of the lumbar spine decreased only during the period of unloading of the fractured leg (1 +/- 2 per cent, p = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

The incidence of hip fractures in independent and institutionalized elderly people

The incidence density of hip fractures in the population of Amsterdam, aged 70 years and over, was studied according to the type of residence. In 1989, 655 patients were admitted to nine hospitals within Amsterdam for a hip fracture. Postal codes were used to classify the residence of the population and the hip fracture cases as independent, home for the elderly or nursing home. Stepwise logistic regression was used for data analysis. The risk of hip fracture increased with age and was 1.7 times higher for women than for men. In the age group 70-74 years the relative risk (RR) was 7.6 for those in homes for the elderly and 5.8 for those in nursing homes, when compared with the independent elderly. This RR was approximately 1 for those in homes for the elderly aged 85 years and over. However, in nursing homes the RR was still 2.8 in the age group 95+. We concluded that, despite protective measures against falls, the institutionalized elderly are at greater risk of hip fracture than the independent elderly of the same age and sex. This higher risk is especially apparent in the 'younger' age groups.

Impairment of bone turnover in elderly women with hip fracture

Hip fracture is one of the most severe consequences of osteoporosis affecting aged women. However, abnormalities of bone turnover responsible for bone loss in this condition have not been clearly defined. To further evaluate the bone metabolic status of women sustaining hip fracture, we have prospectively measured serum osteocalcin as a marker of bone formation and urinary excretion of pyridinoline (Pyr) and deoxypyridinoline (D-pyr) cross-links as markers of bone collagen degradation in 174 independently living women (80 +/- 8 years) within a few hours after a hip fracture. Comparison was made with 77 age-matched controls (80 +/- 5 years) and 17 premenopausal women (39 +/- 3 years). In addition 15 of the patients were followed with daily measurements during the first postoperative week. At the time of admission osteocalcin was 20% lower in the fractured women compared to the elderly controls (7.6 +/- 3.8 vs. 9.5 +/- 4.5 ng/ml, P = 0.001). Pyr and D-pyr were 36% and 40% higher, respectively (P = 0.0001), than in elderly controls and 85% and 76% higher than in premenopausal controls (P = 0.0001). Serum osteocalcin did not correlate with the cortisol level measured at the same time (r = 0.03, ns), nor with serum albumin and creatinine. Serum osteocalcin remained unchanged within 18 hours after fracture, whereafter it progressively decreased until the third postoperative day. No correlation was noted between the excretion of pyridinoline cross-links and the time elapsed from fracture.(ABSTRACT TRUNCATED AT 250 WORDS)

Seasonal variation in the incidence of hip fractures in Emilia-Romagna and Parma

Though some reports suggest the existence of seasonal changes in hip fracture incidence, with a peak in winter months, other investigations have failed to confirm this finding. In this study we present data on the month-to-month variability of hip fractures in Emilia-Romagna, a region of Northern Italy with a population of approximately four million inhabitants, and in Parma, a province of Emilia-Romagna (population of approximately 400,000). Data on cervical and trochanteric fractures were obtained from two sources: a) records of all operative procedures in the five orthopaedic centres serving the area of the Parma province; and b) a computerised database of all hospital discharges from public and private hospitals of Emilia-Romagna. In both cases, the analysis gave similar results, with no evidence of a consistent seasonal pattern in hip fracture rates.