Osteoporosis and osteomalacia

Clinical and laboratory safety of one year's use of a combination calcium + vitamin D tablet in ambulatory elderly women with vitamin D insufficiency: results of a multicenter, randomized, double-blind, placebo-controlled study

OBJECTIVE

This article presents the results of an evaluation of the clinical and laboratory safety of a 1-year course of treatment with a combination calcium and vitamin D tablet in ambulatory women aged >65 years with vitamin D insufficiency.

METHODS

In a multicenter, randomized, double-blind, placebo-controlled study conducted in France, women with a 25-hydroxyvitamin D level < or =12 ng/mL were randomized to receive either a combination tablet containing calcium carbonate 500 mg and vitamin D3 400 IU taken twice daily or a matching placebo tablet for 1 year. A complete clinical examination was performed at baseline and at 3, 6, 9, and 12 months of treatment; blood and urine samples were collected for laboratory analyses at the same time points. Safety was monitored based on adverse events recorded during the treatment period and on the results of laboratory tests, including measurement of creatinine and uric acid levels.

RESULTS

The study included 192 women (mean [SD] age, 74.6 [6.9] years; mean weight, 64.0 [12.5] kg), 95 in the calcium + vitamin D group and 97 in the placebo group. Fifty women (21/95 [22.1%] calcium + vitamin D, 29/96 [30.2%] placebo) were prematurely withdrawn from the study for various reasons, with no difference in withdrawals between groups. Treatment-related adverse events were reported in 21 (22.1%) and 23 (24.0%) women in the respective treatment groups. These events consisted mainly of metabolic disorders (9 [9.5%] and 10 [10.4%], respectively), particularly hypercalcemia (6 [6.3%] and 8 [8.3%]) and gastrointestinal disorders (9 [9.5%] and 8 [8.3%]). No major complications directly related to calcium and vitamin D supplementation occurred during the course of treatment. Although renal function was not altered, the group who received calcium + vitamin D had significantly elevated concentrations of serum uric acid compared with those who received placebo (52.3% vs 37.2%; P = 0.046) but not urinary uric acid.

CONCLUSIONS

In these ambulatory elderly women with vitamin D deficiency, supplementation with calcium + vitamin D appeared to be well tolerated over 1 year of treatment. No significant effects on creatinine clearance were observed. However, the proportion of women with elevated serum uric acid concentrations was significantly greater in those who received calcium + vitamin D compared with those who received placebo.

Herbal extract prevents bone loss in ovariectomized rats

This research aims to test a new drug candidate based on a traditional medicinal herb, F1, an herbal extract obtained from Astragalus membranaceus and its main ingredient, 1-monolinolein that may have fewer side effects and less uterine hypertrophy. In vitro experiments, human osteoblast-like cell lines, MG-63 and Saos-2, were analyzed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and an alkaline phosphatase (ALP) assays. Mouse osteoclasts were induced through a calcium-deficient diet and inhibition effects were measured. In vivo experiments were done using ovariectomized (OVX) rats for 9 weeks. At necropsy, uterus weights were measured, trabecular bone area (TBA) of tibia and lumbar vertebra were measured bone histomorphology. In results, cell proliferation and ALP activity in Saos-2 by ether F1 or 1-monolinolein did not increased significantly compared to the control. The F1 inhibited osteoclast development (IC25 = 3.37 x 10(-5) mg/mL) less than 17beta-estradiol. The OVX rats administered F1 (2 mg/kg/day and 10 mg/kg/day) showed an increase in TBA of the tibia significantly (136.3 +/- 4.2% and 138.5 +/- 10.3% of control). In conclusions, the herbal extract, F1 inhibited tibia and lumbar bone loss and did not cause uterine hypertrophy. However, 1-monolinolein, the main ingredient of the herbal extract, did not inhibit bone loss.

[Case report: celiac disease]

INTRODUCTION

Celiac disease (nontropical sprue, gluten-sensitive enteropathy, chronic intestinal malabsorption disorder) is caused by gluten intolerance. This hereditary disorder is caused by sensitivity to gliadin. Because the body's own immune system causes the damage, celiac disease is considered to be an autoimmune disorder. However, it is also classified as a disease of malabsorption because nutrients are not absorbed. When people with celiac disease eat foods containing gluten, their immune system responds by damaging the small intestine. Specifically, tiny finger-like protrusions, called villi, on the lining of the small intestine are lost. The diagnosis is suspected on the basis of symptoms and signs, enhanced by laboratory and x-ray studies, and confirmed by biopsy revealing flat mucosa and subsequent clinical and histologic improvement on a gluten-free diet. Gluten must be excluded from diet. Supplementary vitamins, minerals and hematinics may be given depending on deficiency.

CASE REPORT

This is a case report of a 23-year old female patient with a mineralization defect (osteomalacia) and secondary osteoporosis caused by long-time unrecognized celiac disease. The patient had many symptoms: short stature, steatorrhea, anemia, weight loss and chronic bone pain. Laboratory and x-ray studies and jejunal biopsy revealed a chronic intestinal malabsorption disorder caused by gluten intolerance. Gluten-free diet and supplementary vitamins, minerals and hematinics were included with apparent clinical remission.

DISCUSSION AND CONCLUSION

Some people with celiac disease may not have symptoms. The undamaged part of their small intestine is able to absorb enough nutrients to prevent symptoms. However, people without symptoms are still at risk for complications of celiac disease. Biopsy of the small intestine is the best way to diagnose celiac disease. Decreased bone density (osteoporosis and osteomalacia) is a serious problem for celiacs. If calcium is not absorbed, due to small intestinal damage caused by untreated celiac disease, bones are not as dense. The only treatment for celiac disease is gluten-free diet, that is, avoiding all foods that contain gluten. For most people, this diet stops symptoms, heals the existing intestinal damage, and prevents further damage.

Genetics of osteoporosis

Osteoporosis is a common multifactorial disorder of reduced bone mass. The disorder in its most common form is generalized, affecting the elderly, both sexes, and all racial groups. Multiple environmental factors are involved in the pathogenesis. Genes also play a major role as reflected by heritability of many components of bone strength. Quantitative phenotypes in bone strength in the normal population do not conform to a monogenetic mode of inheritance. The common form of osteoporosis is generally considered to be a polygenic disorder arising from the interaction of common polymorphic alleles at quantitative trait loci, with multiple environmental factors. Finding the susceptibility genes underlying osteoporosis requires identifying specific alleles that coinherit with key heritable phenotypes in bone strength. Because of the close correspondence among mammalian genomes, identification of the genes underlying bone strength in mammals such as the mouse is likely to be of major assistance in human studies. Identification of susceptibility genes for osteoporosis is one of several important approaches toward the long-term goal of understanding the molecular biology of the normal variation in bone strength and how it may be modified to prevent osteoporosis. As with all genetic studies in humans, these scientific advances will need to be made in an environment of legal and ethical safeguards that are acceptable to the general public.

Femur bone mineral density, age and fracture type in 300 hip-fractured women

BACKGROUND AND AIMS

Several studies showed that cervical and trochanteric hip fractures were associated with different levels of bone mineral density (BMD). Our aim was to investigate the association between femur BMD and hip fracture type at different ages.

METHODS

We studied 300 postmenopausal women affected by their first hip fracture. 17 women could not undergo BMD measurement and were excluded. The fractures of the remaining 283 women were classified as either cervical (N=129) or trochanteric (N=154). The BMD of the unfractured femur was assessed by DXA.

RESULTS

The women with trochanteric fracture had significantly lower BMD than those with cervical fracture at four sites: total proximal femur (p<0.001), trochanter (p<0.001), intertrochanteric area (p<0.01), and Ward's triangle (p<0.05). Logistic multiple regression showed that the association between hip fracture type and BMD was independent of age, weight, height, time between fracture occurrence and DXA assessment, number of concomitant diseases and number of drugs administered when BMD was evaluated at total proximal femur (p<0.001), trochanter (p<0.001), and intertrochanteric area (p<0.01). Age stratification showed that BMD was actually lower in the group with trochanteric fracture in the women aged 69 years and younger, and in those aged 80 years and older, but not in the intermediate age group (70-79 years).

CONCLUSIONS

Data confirm previous reports showing that the two types of hip fractures are associated with different levels of BMD. Moreover, we show that the role played by BMD as a determinant of the hip fracture type varies with age.

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.

Estimation of in vivo bone mineral density (BMD) and shape characterization for diagnosing osteoporosis by ultrasonic inspection

A new method for estimating in vivo bone mineral density (BMD) and characterizing the shape of cancellous bone has been proposed using the results of ultrasonic inspection for the diagnosis of osteoporosis. The method is based on two-dimensional bone area fraction S (percent bone area between bone and bone marrow) calculated from the difference in the speed of ultrasonic wave propagation through cancellous bone. It was shown that the two-dimensional area fraction of a heel bone gives a good relationship to the BMD by DXA (dual energy x-ray absorptiometry) testing of human heel bone (calcaneus) and spine (vertebrae lumbar), as expressed by the relation, BMD (g/cm2) = 0.0167S for heel bone (r = 0.83), and BMD (g/cm2) = 0.0254S + 0.123 for the spine (r = 0.77). Shape characterization is based on the image simulation procedure employing eight random variables from a computer and the statistical results of fractal analysis for numerous cancellous bone patterns. We also demonstrate the validity of the shape characterization using autopsy specimens as a diagnostic tool for osteoporosis.

Are the etiologies of cervical and trochanteric hip fractures different?

Review of results published in the past few years indicates that there are several differences between women sustaining trochanteric fractures of cervical hip fractures. In most series women with trochanteric fractures are older, shorter, and lighter than those with cervical fractures. The bone mineral density was found to be lower in trochanteric fractures, but although in the majority of the studies the diminution was statistically significant at the level of the trochanter and spine--with predominant trabecular bone--the decrease was not uniformly significant at the level of the femoral neck or total skeleton. Previous vertebral fractures were twice as common in patients with trochanteric fractures. Ultrasound exploration of the calcaneus disclosed that the values were significantly lower in women with trochanteric fractures and this finding was independent of the diminution of the bone mineral density. On the other hand, fall biomechanics have not been found to be different in the two types of hip fractures. In summary, women with trochanteric fractures have a more severe and generalized bone loss, especially of the trabecular component. Cervical fractures seem to be more related to pelvic structure-failure of the outer diameter of the femoral neck to expand with age and increased acetabular bone width-added to a focal bone loss. The two main types of fractures should be treated separately in epidemiological or clinical studies to increase the knowledge and the possibilities of preventing hip fractures.

Biochemical Studies in the Evaluation and Management of Osteoporosis: Current Status and Future Prospects

OBJECTIVE

To examine the current status of biochemical markers of bone remodeling and to offer a perspective on their future clinical applications.

METHODS

We provide a comprehensive overview of the bone remodeling cycle, the hormonal control of bone remodeling, the specific biochemical markers of bone resorption and bone formation, and their current clinical applications.

RESULTS

Bone remodeling occurs in discrete packets, known as bone modeling units, on the surfaces of the skeleton. Osteoclasts are responsible for bone resorption, and osteoblasts are responsible for bone formation. Bone resorption and formation are normally coupled, and an imbalance in these processes can lead to metabolic bone diseases such as osteoporosis. Investigators have attempted to measure various biochemical markers of bone resorption (such as urine calcium and hydroxyproline) and formation (such as bone-specific alkaline phosphatase and osteocalcin) as a reflection of response to therapy. Although several markers of bone resorption and formation can be assayed, an ideal marker has yet to be discovered or proved.

CONCLUSION

Until a precise, inexpensive assay is developed, currently available biochemical markers, used in conjunction with measurements of bone density, are considered the most reasonable tools for classifying and directing the management of osteoporosis.

Osteoporosis

Two complementary notions need to be considered in the definition of osteoporosis: a reduction in bone mineral density and the occurrence of fracture. Bone mineral density is an established determinant of the risk of future fracture, but current interventions are most usefully targeted before bone density has fallen to the levels at which fractures usually occur. Bone density may now be measured accurately and precisely, and the sensitivity and specificity of this technology for fracture risk prediction are high. It therefore seems reasonable to classify osteoporosis in terms of both a reduction in bone density and the occurrence of fracture. On this basis, a four point scale has recently been proposed by the World Health Organization: 1) normal, 2) low bone mass, 3) osteoporosis and 4) established osteoporosis. While it is likely that this diagnostic classification will change as experience of osteoporosis increases, it is important to have widely adopted guidelines of this type which act as a framework for further research.

Does vitamin D3 have negative effects on serum levels of lipids? A follow-up study with a sequential combination of estradiol valerate and cyproterone acetate and/or vitamin D3

The effects of four different treatment schedules on serum lipid concentrations were studied for 1 year in 402 postmenopausal women in the Kuopio Osteoporosis Study. The women were randomized to four treatment groups: A, Sequential combination of estradiol valerate and cyproterone acetate (Climen); B, Vitamin D3, 300 IU/day; C, Climen+Vitamin D3, D, placebo. In group A, serum concentrations of total cholesterol (Chol) decreased by 4.8% in 6 months and by 6.2% in 12 months (P < 0.001), but in group C the decrease was only 2.9% in 6 months (P < 0.05) and 3.4% in 12 months (P < 0.01). The decline of total-Chol in group A was accounted for by the 6.8% to 7.5% decrease in LDL-Chol levels (P < 0.001). The decrease of LDL-Chol in group C was statistically non-significant. Use of vitamin D3 (group B), increased serum Chol by 2.7% (6 months), P < 0.05 and by 2.1% (12 months) and the increases were the result of the 6.0% to 6.2% increase in LDL-Chol levels in 6 and 12 months, respectively (P < 0.001). Serum concentrations of HDL-Chol and TG remained relatively stable in all groups. No correlations were found between LDL-Chol, 25-OH-D3 and 1,25(OH)2-D3 levels in group B. Our results confirm the beneficial effect of estradiol valerate and cyproterone acetate on the lipid profile. In contrast, vitamin D3 had a negative influence on this profile by increasing serum concentrations of LDL-Chol.(ABSTRACT TRUNCATED AT 250 WORDS)

Low bioavailable testosterone levels predict future height loss in postmenopausal women

The objective of this study was to examine the relation of endogenous sex hormones to subsequent height loss in postmenopausal women, in whom height loss is usually a surrogate for osteoporotic vertebral fractures. This was a prospective, community-based study. The site chosen was Rancho Bernardo, an upper middle class community in Southern California. A total of 170 postmenopausal women participated, aged 55-80 years. None of them were taking exogenous estrogen between 1972 and 1974. Plasma was obtained for sex hormone and sex hormone-binding globulin (SHBG) assays. Estradiol/SHBG and testosterone/SHBG ratios were used to estimate biologically available hormone levels; bioavailable (non-SHBG-bound) testosterone was measured directly in 60 women. Height loss was based on height measurements taken 16 years apart. Height loss was strongly correlated with age (p = 0.001). These women lost an average 0.22 cm/year in height. Neither estrone nor estradiol levels were significantly and independently related to height loss. Both estimated bioavailable testosterone (testosterone/SHBG ratio) and measured bioavailable testosterone levels predicted future height loss (p = 0.02 and 0.08, respectively) independent of age, obesity, cigarette smoking, alcohol intake, and use of thiazides and estrogen. We conclude that bioavailable testosterone is an independent predictor of height loss in elderly postmenopausal women. The reduced height loss is compatible with a direct effect of testosterone on bone mineral density or bone remodeling.

Effects of increasing doses of 1 alpha-hydroxyvitamin D2 on calcium homeostasis in postmenopausal osteopenic women

This study is the first reported administration of 1 alpha-hydroxyvitamin D2 (1 alpha-OHD2) to human subjects. A total of 15 postmenopausal osteopenic women were given increasing oral doses of 1 alpha-OHD2, beginning with a low dose of 0.5 microgram/day. In 15 subjects, the doses were raised at weekly intervals to 1.0, 2.0, 4.0, and 5.0 micrograms/day, and in 5 of these subjects, the dose was further increased to 8.0 or 10.0 micrograms/day. Mean urine calcium +/- SEM showed a dose-related increase from 134 +/- 17 mg/24 h on 0.5 microgram/day to 198 +/- 21 mg/24 h on 4.0 micrograms/day (p < 0.05) and to 241 +/- 35 mg/24 h on 5.0 micrograms/day (p < 0.05). No subjects had hypercalciuria (> 350 mg/24 h, the upper limit of the laboratory normal range) at doses less than 5.0 micrograms/day; 5 subjects had hypercalciuria at or above 5.0 micrograms/day (3 at 5.0 micrograms/day, 1 at 8.0 micrograms/day, and 1 at 10.0 micrograms/day). Mean serum calcium increased slightly on the 4.0 micrograms dose only (p < 0.05) but remained well within the normal range. Mean creatinine clearance and BUN, used as measures of renal function, showed no significant changes. Routine blood and urine assays also showed no significant changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Hormonal alterations and osteoporotic syndromes

Hormonal control of skeletal growth, modeling, and remodeling is characterized by a complex interaction between the calciotropic hormones (25-hydroxycholecalciferol, 1,25-dihydroxycholecalciferol, parathyroid hormone, and calcitonin), growth, and thyroid hormones in addition to the estrogenic and androgenic gonadal hormones. Although both growth and thyroid hormones are essential skeletal growth and modeling and also can produce detrimental skeletal effects in adults when circulating in excess concentrations, these hormones assume a minor role in the day-to-day bone remodeling of the mature skeleton. Following the attainment of the peak bone mass, bone mineral content begins to decline in the fourth and fifth decades of life, accelerating in females in the first 5-7 years after the menopause as a result of estrogen deficiency. Associated with this age-dependent loss in skeletal mass are decreases in calcitonin reserve primarily in the 5-7 years following the menopause, decreases in circulating 25-hydroxycholecalciferol, intestinal resistance to 1,25-dihydroxycholecalciferol, and a gradual progressive rise in blood parathyroid hormone. These changes in calciotropic hormone profiles, together with poor nutritional habits, anticonvulsant, glucocorticoid, and thyroid medications, diseases such as type I diabetes, immobilization, or decreased physical activity all serve to weaken the aging skeleton. The result is a gradual and subtle change in skeletal anatomy, which progresses to alterations in vertebral structure, such as kyphosis, scoliosis, and pseudospondylolisthesis, and a variety of sciatic and nerve entrapment syndromes. Vertebral, forearm, and hip fractures and edentulism ultimately comprise the syndrome of age-related bone loss, resulting in lifestyle disabilities, extensive morbidity, analgesic drug abuse, hospitalization, and escalating annual health care expenditures.

Osteoporosis in men

Bone is lost with advancing age in men as in women, leading to an increased incidence of osteoporotic fractures of the fore-arm, vertebral body and femoral neck. By the ninth decade of life, 4% of men will have sustained a fore-arm fracture, 7% a vertebral fracture and 5% a femoral neck fracture. The absolute number of osteoporotic fractures is rising in men, because of the ageing population and an increase in the age-specific incidence of fractures. Even if the age-specific incidence of fractures stabilizes, demographic trends suggest that a further increase in the number of men with osteoporotic fractures is inevitable. Peak bone mass in men is influenced by race, hereditary, hormonal factors, physical activity and calcium intake during childhood and adolescence. Bone loss in men starts at about the age of 35 years and is regulated by genetic, endocrine, mechanical and nutritional factors. Secondary causes of osteoporosis may be detected in about 55% of men with vertebral crush fractures. The major causes are steroid therapy, hypogonadism, skeletal metastases, multiple myeloma, gastric surgery and anticonvulsant treatment. Hypogonadism is found in up to 20% of men with vertebral crush fractures, although the clinical features of testosterone deficiency may not always be present. Hypogonadal osteoporosis is associated with increased bone resorption and decreased mineralization, which is reversed by treatment with testosterone, leading to an increase in bone density. There is little published information on the treatment of primary osteoporosis in men. Although calcitonin, bisphosphonates and testosterone may be effective in the management of osteoporosis in men, confirmation is required in formal clinical trials.

A review of postgastrectomy bone disease

Postgastrectomy bone disease was a term devised to describe the metabolic disorders of bone which may follow a gastrectomy operation. Although the use of this operation has declined drastically in recent years, this metabolic bone disorder is still with us and may escape and confuse the unwary. These disorders may take the form of osteomalacia, osteoporosis in excess of normal ageing, or a combination of both. For screening purposes, regular estimations of plasma alkaline phosphatase levels identify patients who may be developing osteomalacia which can then be treated with calcium and vitamin D supplements. Numerically, osteoporosis in excess of ageing is a bigger problem and its prevention and treatment is at present unsatisfactory. Screening procedures for osteoporosis are reviewed, including the more recent methods of bone mineral density assessment. Osteopenia or demineralization occurs in both osteomalacia and osteoporosis therefore osteomalacia must be excluded before attributing any loss to osteoporosis. The present situation with regards to the prevention and treatment of osteoporosis is also reviewed.

Fracture thresholds in osteoporosis: implications for hormone replacement treatment

The bone mineral densities of the lumbar spine and femoral neck were determined by dual energy chi ray absorptiometry in 110 women aged 40-82 years (average 65 years) with spinal osteoporosis who had had at least one atraumatic vertebral compression fracture and in 1026 normal women aged 40-79 years (average 52 years). The women with osteoporosis showed a significant decrease in bone mineral density (BMD) at the lumbar spine and femoral neck compared with age matched normal women (sixth decade of life -26% spine, -23% femoral neck; seventh decade -26% spine, -16% femoral neck). The fracture threshold, defined as the 90th centile of spinal BMD for women with osteoporosis, was 0.81 g/cm2 at the lumbar spine and 0.656 g/cm2 at the femoral neck. Five per cent of normal women aged 40-49 years, 20% aged 50-59 years, and 45% aged 60-69 years had a BMD below this threshold. To maintain the bones of women above the fracture threshold until the age of 70 years about 50% of postmenopausal women need hormone replacement therapy. However, if the BMD is to be kept above the fracture threshold for a women's lifetime, e.g. until the age of 80-90 years, then most women will need treatment, though for various lengths of time depending on their initial BMD. Measurements of BMD in postmenopausal women currently help in identifying the risk of osteoporotic fractures but in the lifetime assessment of risk in a single subject they may have a more important role in deciding the duration of hormone replacement therapy.

Screening for antibodies against gliadin in patients with osteoporosis

Intestinal disease might contribute to osteopenia. Measurements of IgA antibodies to gliadin have been established as an accepted screening procedure for detection of coeliac disease. When we applied these measurements to 92 patients with verified osteoporosis, 11 subjects (12%) were found to have elevated levels. This is markedly higher than the incidence in healthy subjects (3%). However, the patients with raised levels of IgA antibodies displayed no clinical symptoms and no laboratory evidence of calcium malabsorption. Thus their values for serum calcium, phosphate, parathyroid hormone (PTH), alkaline phosphatase and osteocalcin, as well as the fasting urinary excretion of hydroxyproline and calcium, were similar to those found in other patients with osteoporosis. Intestinal biopsy verified coeliac disease in three patients and was normal in another three. This gives an incidence of verified coeliac disease in this patient group that is approximately tenfold higher than that in the healthy population. Subclinical coeliac disease appears to be unusually over-represented among patients with idiopathic osteoporosis, and screening for gliadin antibodies might therefore be a valuable addition to the routine assessment of the osteopenic patient. The mechanisms underlying the relationship are not clear, but calcium malabsorption is not evident.

Postgastrectomy osteoporosis

Osteoporosis is a recognized complication following partial gastrectomy and is more common than osteomalacia. Recent improvements in the measurement of bone mineral status (dual energy X-ray absorptiometry, DEXA) have assisted in measuring osteoporosis. Sixteen men who had undergone gastrectomy more than 30 years previously were examined. This study reports the effect of calcium supplementation in six patients in whom osteomalacia had been excluded and who showed abnormally low bone mineral densities on DEXA scanning. Calcium supplementation for 6 months (microcrystalline hydroxyapatite, Ossopan 8-32 g per day) produced no significant advantage for the treatment group at any site measured.

Hormonal replacement therapy and the skeletal system

The two most important risk factors for maintaining skeletal health are the bone mass obtained at skeletal maturity (peak bone mass) and the subsequent bone loss. Those women with a low peak bone mass and a rapid bone loss are thus at increased risk of developing osteoporosis in the future, and should be identified. This may be accomplished by determination of the bone mass combined with an estimate of the rate of the postmenopausal bone loss. The bone mass can be accurately assessed in the forearm by single photon absorptiometry. The postmenopausal bone loss can be estimated by three or four biochemical markers of bone turnover. The women at highest risk of developing osteoporosis should be offered preventive therapy, e.g., hormonal replacement therapy (HRT). HRT arrests the bone loss not only in early, but also in elderly postmenopausal women. The effect lasts as long as the therapy is continued. Several epidemiological studies have demonstrated that HRT decreases the number of osteoporotic fractures.

The necessity and safety of calcium and vitamin D in the elderly

The necessity and safety of an oral calcium (Ca) and vitamin D regimen was evaluated in a population of 66 independently living and 73 institutionalized elderly women over an 11-week winter period. The members of both groups were randomly assigned into trial and control groups. Serum Ca, creatinine, and calcidiol levels were measured before and after the trial. The regimen consisted of 1.558 g of Ca and 45 micrograms (equal to 1,800 IU) of vitamin D administered daily in addition to the normal diet. The controls received no treatment. A majority of the elderly subjects living independently had ensured their Ca, and a quarter of them also their vitamin D intake on their own initiative. The mean serum calcidiol concentration before the trial was 24.1 nmol/L in the institutionalized and 38.5 nmol/L in the elderly subjects living independently (P less than .001). After the trial, serum calcidiol was 10.4 nmol/L in the institutionalized control subjects and had decreased (P less than .001) in both control groups, but increased (P less than .001) in both treatment groups. The safety indicators, serum Ca, creatinine, and calcidiol, did not indicate any group or individual side effect.

High fat-sucrose diet effects on femoral neck geometry and biomechanics

Diets high in fat and sucrose may affect calcium metabolism, by decreasing calcium absorption in the gastrointestinal tract and decreasing calcium reabsorption in distal renal tubules, but information about the effects of high fat-sucrose diet on immature-bone material and structural properties is lacking. The present study examined the effects of a high fat-sucrose diet on the geometrical and biomechanical properties of the femoral neck in rapidly-growing rats. Sprague-Dawley female rats were assigned randomly to a high fat-sucrose diet group or a control-diet group for 10 weeks. Cantilever-bending tests to failure were conducted, and geometrical and material properties were calculated from fracture-surface cross-sections and were correlated with mechanical data. Geometrically, the high fat-sucrose diet decreased the relative size of the femoral neck cortical shell and increased the trabecular core. The femoral necks of rats fed the high fat-sucrose diet had signiflcanctly lower structural rigidity, load at proportional limit, maximum load, energy at proportional limit, total energy, normal stress at proportional limit and maximum normal stress than the controls.

Role of calcitriol in prevention of osteoporosis: Part I

Prevention of postmenopausal osteoporosis is an alternative to the currently problematic goal of reversing the trabecular plate thinning and perforation that constitute the major pathologic defects in patients with established osteoporosis. 1,25(OH)2D3 (calcitriol) has been suggested as a drug that may decrease bone resorption sufficiently to preserve trabecular structure in perimenopausal women. In the present study, we compared the effects of calcitriol and an investigational analog, 1,25,26-(OH)3delta22-D3 (Ro-23-8525), to those of an inert vehicle in maintaining the bone mass of oophorectomized adult beagles. In these studies, we used dual-energy radiography to serially quantitate the bone density of control and treated animals. Treatment for 1 year with either agent resulted in no evidence of hypercalcemia or decreased renal function. Moreover, calcitriol and Ro-23-8525 effectively abolished the loss of bone mass observed in untreated oophorectomized controls. Indeed, treated animals displayed variations in bone density similar to that observed in sham-operated untreated animals. These data suggest that calcitriol and Ro-23-8525 may be potentially effective agents for prophylaxis of postmenopausal osteoporosis.

Bone mineral density after adjuvant chemotherapy for premenopausal breast cancer

Lumbar bone mineral density (BMD) determination by dual photon absorptiometry was used to study the influence of adjuvant chemotherapy for premenopausal breast cancer on the risk of premature osteoporosis. Six cycles of combination chemotherapy caused ovarian failure in 31 of 44 (71%) women, amenorrhoea mostly already beginning during treatment. In contrast, only seven of 44 (16%) women, who were pair-matched for age and year of breast cancer surgery and had not been treated with chemotherapy, were post-menopausal at the time of measurement. The mean interval after breast surgery was 3.5 years. The significantly decreased BMD in the treated group (1.17 compared to 1.29 g cm-2) could only be explained by the high incidence of menopause in these women, which on average occurred 10 years prematurely. Extrapolation of these findings suggests that adjuvant chemotherapy may precipitate osteoporotic fractures by some 10 years in a considerable proportion of women cured of premenopausal breast cancer.

[comparison of the effects on phosphocalcic metabolism and bone of 3 protocols of vitamin D administration in the elderly]

According to recent studies, vitamin D deficiency may contribute to the osteoporosis observed in elderly subjects, with reduced intestinal calcium absorption and secondary hyperparathyroidism. Vitamin D deficiency is often present in elderly people, due to inadequate diet and confinement at home. The administration of either oral vitamin D in doses of 4,000 IU per day, or six-monthly intramuscular injections of ergocalciferol 600,000 IU, combined with a daily intake of at least 1 g of calcium brings back to normal both 25 OH D concentrations and parathyroid hormone levels. When pursued for one year, these treatments also maintain the formation of cortical bone, as shown by the metacarpal index. As for the concentration of 25 OH D, it seems that 60 to 75 nmol/l are necessary to restore calcium homeostasis. The dietary habits of elderly people are such that a supplement of medicinal calcium is required. Finally, we regard the parenteral form of ergocalciferol as being preferable to the oral form at that age for better compliance with treatment.

Bone biopsies and serum vitamin-D levels in patients with hip fracture

To assess the correlation between osteoid and vitamin D in patients with a proximal femoral fracture, bone biopsies of the fracture site and the iliac crest were studied; and vitamin-D levels were measured in fasting blood taken on the day of admission. No osteomalacia was found at either site in any of the 95 patients investigated. In 65/95 patients, levels of 25-hydroxy-vitamin D (25-OHD) and 24,25-dihydroxy-vitamin D (24, 25-OH2D) were within the normal range, whereas 30/95 patients were deficient. Because there was no correlation between the amount of osteoid and vitamin-D metabolites in our patients, we concluded that osteomalacia was not a contributory factor in the pathogenesis of the hip fracture.

Discriminative ability of total body bone-mineral measured by dual photon absorptiometry

We investigated the discriminative ability of total body bone-mineral expressed as the total body bone-density (TBBD) measured by dual photon absorptiometry (DPA) in 79 healthy premenopausal women, 27 healthy postmenopausal women, and 120 female osteoporotic fracture patients presenting with either Colles' fracture, vertebral fracture or femoral neck-fracture. TBBD was compared to the bone-mineral density of the lumbar spine (BMDspine) also measured by DPA, and to the bone-mineral content of the forearms (BMCforearm) measured by single photon absorptiometry (SPA). TBBD, BMDspine and BMCforearm showed that all the fracture patient groups had significantly reduced bone-mass. Using receiver operating characteristic (ROC) analysis, we found that TBBD had a tendency towards better discriminative ability than BMDspine or BMCforearm with regard to the discrimination between healthy premenopausal women and the three types of osteoporotic fractures (not significant in spinal fracture patients). BMCforearm had an intermediate position, whereas BMDspine had the smallest discriminative ability. TBBD also discriminated better between healthy postmenopausal women and hip-fracture patients than BMDspine or BMCforearm, whereas there was no significant difference between the three methods regarding the discrimination between the healthy postmenopausal women and the Colles' and spinal fracture patients. We conclude that the TBBD measurement by DPA has a discriminative potential which is better than the local spine or forearm measurements.

Spinal osteoporosis in men

In 94 men with crush fracture, 40 were found to have primary osteoporosis. Cross-sectional measurements of a number of variables related to bone in these 40 patients were compared to the values in various groups of healthy men aged 20-96. In healthy men, metacarpal and femoral cortical area/total area, bone volume, osteoid surfaces, seam and trabecular width, plasma dihydroepiandrosterone and estrone, and radiocalcium absorption fell with age, whereas eroded surfaces, trabecular number, urine hydroxyproline and calcium/creatinine ratios, plasma alkaline phosphatase, estradiol, androstenedione, cortisol and testosterone remained constant with age. As compared with healthy men, men with primary osteoporosis had reduced femoral cortical area/total area (P less than 0.05), and Singh grade (P less than 0.001) and in seven there was a history of forearm or femoral fracture. On iliac crest biopsy, bone volume (P less than 0.001) and trabecular number (P less than 0.01) were decreased. Plasma alkaline phosphatase (P less than 0.02) was increased but urine hydroxyproline and calcium excretion were not significantly raised. Calcium balance was negative due to failure of absorption to match urinary calcium loss and radiocalcium absorption (P less than 0.01) and plasma 1,25-dihydroxyvitamin D (P less than 0.05) were reduced.

Rates of bone loss in normal women: evidence of accelerated trabecular bone loss after the menopause

We have followed the changes in bone mass over 2 years in 42 premenopausal, seven perimenopausal and 76 postmenopausal women. The latter had passed a natural menopause between 6 months and 7 years previously. Bone mass was measured every 3 months at the proximal and distal forearm sites by single photon absorptiometry, and every 6 and 12 months in the lumbar spine and whole body by dual photon absorptiometry. The relative content of trabecular bone is approximately 15, 50, 60 and 20% at these four sites. Before the menopause there was a significantly low rate of bone loss from the two forearm sites and the whole body, whereas the spinal loss was insignificant. The rate of loss was five- to ten-fold higher at all sites after the menopause (P less than 0.001). With increasing menopausal duration the rate of loss declined at the two forearm sites and whole body (P less than 0.01). The distal forearm loss was larger than the proximal, both before and after the menopause (P less than 0.01). From the forearm results we thus conclude that a slightly larger loss of trabecular than cortical bone takes place both before and immediately after the menopause. The loss of both types of bone is, however, much larger after the menopause and this rapid bone loss seems to take place throughout the skeleton.

Nutritional requirements of the aged

The age of the population continues to increase. At the turn of the century, 4% (about 3.1 million people) were 65 years of age or older. Today the percentage has increased to 12%, or 27.4 million people, and the prediction for the 21st century may increase to 17 to 20%. It should be noted that the number of individuals 85 years of age and older, as well as those over the age of 100, is increasing rapidly. The nutritional problems of the elderly are related to physiological decline, to low economic status and limited food consumption, and to a multitude of disease processes and the therapeutic regimens prescribed to cure or treat those illnesses. Examined as a group, the elderly at first appear to be less uniform in their health status than younger members of the population. However, only 10% of the elderly population contributes to the disproportionate (30%) expenditure of health care services. A majority of the elderly are normal, healthy individuals. Yet, with each decade of life the percentage of the elderly population needing additional care increases. The national nutritional surveys (National Food Consumption Survey and the National Health and Nutrition Examination Surveys, I and II) used entirely different methodologies, but reported very similar findings. The mean intake of this population was actually quite good, revealing low intakes of calcium and iron in the elderly female population. However, the standard deviation of the intake data strongly suggests a major portion of the population is at nutritional risk. For more than 30% of the population, nutrient intakes below two thirds of the recommended dietary allowances (RDA) occurred for calories, calcium, and vitamin A, while for more than 20% of the population, iron and vitamin C were at risk. Although the data evaluating the effects of age on the nutritional requirements of the elderly are limited, careful interpretation of the existing assessment and intervention efforts can provide some basic guidelines. Generalities about calorie intake must be avoided, and emphasis must be placed on calorie needs. Enhanced activity should be encouraged. Protein intake for the majority of elderly exceeds the RDA, but with increased age a greater amount of high quality protein is needed to maintain nitrogen balance. The group at greatest risk is the poor elderly who may not be able to afford enough high quality protein. Increased consumption of complex carbohydrates serves several functions including decreased caloric density and enhanced nutrient intake. Decreasing total dietary fat decreases caloric intake and indirectly decreases dietary cholesterol.(ABSTRACT TRUNCATED AT 400 WORDS)

Alteration in osteoblast activity and nutritional vitamin-D deficiency in non-hypercalcemic malignancy

The biochemical parameters of bone mineral metabolism in patients with nonhypercalcemic malignancy have not been extensively investigated. Therefore, a group of 29 such patients with different types of malignancy was studied. Ten patients received corticosteroids. In the entire group, serum ionized calcium (Ca2+), bone gla protein (BGP), 25-hydroxyvitamin D (25OHD), and 1,25-dihydroxyvitamin D (1,25(OH)2D) were all lower than in age-matched controls, and carboxy-terminal parathyroid hormone (CPTH) was higher. Although both corticosteroid- and noncorticosteroid-treated patients had decreased BGP values, the corticosteroid-treated patients had lower BGP levels than those not on steroids (4.24 +/- 0.70 SE vs. 11.50 +/- 2.20 ng/ml; P less than 0.005). Patients on corticosteroids had lower 1,25(OH)2D values than controls (18.81 +/- 2.71 vs. 27.83 +/- 1.17 pg/ml; P less than 0.01), whereas those not on corticosteroids had normal 1,25(OH)2D values. These results suggest that patients with nonhypercalcemic malignancy have nutritional vitamin-D deficiency and secondary hyperparathyroidism with perhaps corticosteroid-induced suppression of serum 1,25(OH)2D and BGP. The decreased levels of serum BGP in the nonsteroid-treated patients suggest, in addition, a defect in osteoblast function.

Pharmacology and pharmacokinetics of estrogens

The primary source of estrogen, ovarian 17 beta-estradiol, is normally converted to estrone and estriol, both of which are metabolized to their sulfate and glucuronide forms, as well as oxidated to nonestrogens. In postmenopausal women, the primary sources of estrogen are nonovarian, including the production of androstenedione from the adrenal cortex and its metabolism to estrone by the liver, adipose tissue, skeletal muscle, kidney, brain, and hair follicles. Estrogen circulates bound to sex hormone-binding globulin and albumin. The sulfate form may be a storage form of this hormone and is freely converted back to estrone and estriol. The glucuronide and sulfate forms have limited cell penetration; they are excreted mainly in the kidney, with little tubular reabsorption. Several theories have been advanced to explain the effects of estrogens on the basis of their receptors. A consideration of pharmacologic and pharmacokinetic characteristics reveals specific advantages and disadvantages of the preparations currently available for estrogen replacement therapy. Oral agents have the disadvantage of being subject to a considerable first-pass hepatic effect, resulting in their conversion to estriol, oxidation to nonestrogens, and conjugation to sulfate and glucuronide salts. These preparations can also be associated with poor patient compliance, as can injectable, topical, or suppository preparations. On the other hand, transdermal patches are not subject to a first-pass hepatic effect, provide relatively uniform serum levels, and may help alleviate the problem of noncompliance.

Cyproterone acetate, an alternative gestagen in postmenopausal oestrogen/gestagen therapy

Seventy-six healthy, early postmenopausal women (aged 45-54 years) were allocated to 2 years of treatment with a cyclic combination of 2 mg oestradiol valerate (21 d) and 1 mg cyproterone acetate (11 d) or placebo. Sixty-five women (86%) completed the study. In the placebo group the bone mineral content in the forearms (measured by single photon absorptiometry) and the bone mineral content in the lumbar spine and total skeleton (measured by dual photon absorptiometry) decreased significantly and at the same magnitude (P less than 0.001), whereas all bone mass measurements remained unchanged in the hormone-treated group. In the hormone-treated group there was a significant decrease in biochemical estimates of bone turnover (serum alkaline phosphatase, serum phosphate, fasting urinary calcium and hydroxyproline), whereas these values were unchanged in the placebo treated group. We conclude that treatment with a cyclic combination of 2 mg oestradiol valerate and 1 mg cyproterone acetate is effective as prophylaxis of postmenopausal bone loss.

Does calcium supplementation prevent postmenopausal bone loss? A double-blind, controlled clinical study

During a two-year study, we examined the effect of calcium supplementation on postmenopausal bone loss in 43 women in the early postmenopausal period who were assigned to one of three treatment groups: percutaneous 17 beta-estradiol (combined with progesterone during the second year), oral calcium (2000 mg daily), and placebo. All participants were examined every three months. Bone mineral content in the forearm (measured by single-photon absorptiometry) and in the entire body and spine (measured by dual-photon absorptiometry) remained constant in the estrogen-treated group but decreased significantly in the groups receiving calcium and placebo. In the calcium-treated group, we observed a tendency toward a slowed loss of compact bone (in the proximal forearm and total skeleton) as compared with the placebo group, while the rate of loss of trabecular bone (the distal forearm and spine) was the same as in the placebo group. Our preliminary data suggest that calcium supplementation in the dosage we used is not as effective as estrogen therapy for the prevention of early postmenopausal bone loss. Calcium supplementation may have had a minor effect on the loss of cortical bone, but it had no effect on the trabecular bone.

Longitudinal microradioscopic comparisons on endosteal and juxtaendosteal bone loss in premenopausal and postmenopausal women, and in those with end-stage renal disease

Endosteal bone resorption is the principal mechanism of bone loss in involutional osteoporosis and in renal osteodystrophy. In the cortical bone it is often accompanied by juxtaendostal bone resorption. Using fine-detail radiographs and x6 magnified viewing, longitudinal radiographic observations and measurements were made on these two forms of bone resorption in the metacarpals II, III, and IV in three groups of women: (1) premenopausal, (2) postmenopausal, and (3) patients with end-stage renal disease. Bone loss was found to be negligible in the premenopausal women, but in postmenopausal and renal patients both endosteal and juxtaendosteal bone resorption were frequently demonstrable. It is suggested that when a base-line fine-detail hand radiograph is obtained at the time of the menopause, follow-up radiographs may permit detection of relatively early endosteal and juxtaendosteal bone loss by comparing the respective areas in metacarpals with those of the original radiograph. Since the methodology does not require expensive equipment, has a low intraobserver error and is simple to perform, it may deserve to be further evaluated in studies aimed at developing a simple and inexpensive approach as a screening method for early detection of postmenopausal osteoporosis.