Plasma 25-hydroxycholecalciferol (25-H.C.C.) has been measured in 67 consective cases of fracture of the proximal femur. The values found in these patients were not different from values found in these patients were not different from those in control groups at the same time of the year. Plasma 25-H.C.C. was not correlated to plasma calcium or phosphorus, the Ca times P product, or the alkaline phosphatase. X-rays showed Looser zones in only 1 patient, in whom the lowest plasma 25-H.C.C. was found. Osteomalacia is not uncommon among elderly people in Denmark, but it is more likely to depend on a decline in the renal efficiency to convert 25-H.C.C. to 1,25-dihydroxycholecalciferol than a low dietary intake of vitamin D.
OBJECTIVES: To determine risk factors for low bone mass at menopause and risk factors for subsequent bone loss in the following period. DESIGN: A cross-sectional study and a 2-year prospective follow-up. SETTING: The catchment area of Sundby Hospital in Copenhagen. SUBJECTS: Four hundred and thirty-three women aged 45-58 years, with amenorrhea for 3-24 months, of whom 87 were followed for a 2-year period. MEASUREMENTS: Registration of life-style and anthropometric variables, reproductive history, and family history of fractures. Total body bone mineral content (BMC) was measured with dual energy X-ray absorptiometry. RESULTS: By means of multiple regression analysis height, body weight, and length of reproductive period were found to be positively related to whole body BMC (P
In 1990 we initiated a 20 year, partly randomised study (Danish Osteoporosis Prevention Study, DOPS) in order to (a) evaluate clinical, biochemical and osteodensitometric variables as predictors of low bone mass and future osteoporotic fractures, and (b) test the hypothesis, that hormone replacement therapy (HRT) initiated shortly after menopause reduces the risk of later osteoporotic fractures. This report describes study design and baseline characteristics of the DOPS-cohort.
The study design is pragmatic, attempting to mimic the normal clinical situation. Several HRT alternatives are available according to clinical need. It was considered futile, impractical and unethical to use placebo for 20 years. Instead the study focus on hard endpoints (fractures) confirmed by independent persons (peripheral fractures) or by methods which allow investigator blinding (spinal X-rays). Statistical evaluation will focus on intention to treat analyses evaluating the decision of HRT and it's feasibility. With a compliance of 60% we will have sufficient statistical power (88%) to detect a fracture reduction of 40% in the treatments group. Clinical risk factors, current daily intakes of macronutrients, vitamins and minerals, anthropometric variables, biochemical variables (including bone markers and 25-hydroxyvitamin D), regional bone mineral density (BMD) and total body composition were assessed in all participants at entry and at various follow up intervals.
2016 study participants were recruited by direct mailing to a random sample of 45-58 years old women. In the randomised arm 501 were allocated to HRT and 505 to no treatment. In the non-randomised arm 219 preferred HRT and 791 preferred no treatment. Post-randomisation analysis revealed a slight but significant difference in age (50.01 versus 50.44 years) but no difference in menopausal age, prevalence of hysterectomy, educational level, BMI, serum bone alkaline phosphatase, serum osteocalcin, urine hydroxyproline or serum 25-hydroxyvitamin D. In the non-randomised arm women preferring HRT were closer to menopause, had a higher prevalence of hysterectomy, were better educated, were leaner, and had lower bone turnover than the women, who refused HRT.
It is possible to include a sufficient number of perimenopausal women in a randomised 20 year study on the antifracture effect of HRT.
Soft body armour is designed to give protection against fragments and some low velocity bullets but is not designed to stop high velocity rifle bullets. Reports have claimed that soft body armour might disturb the stability of bullets that penetrate it, and that this might increase the size of the lesions. The reason for such an effect might be early yaw of the bullet, so we studied the behaviour of bullets which had passed through soft body armour. A 7.62 x 39 mm AK-47 rifle was fired from a permanent stand using full metal jacketed lead core bullets at a range of 30 m. Soft body armour composed for 14 and 28 layers of aramid fibres (Kevlar) was placed at 90 degrees and 60 degrees to the line of fire. Yaw was measured by the shadowgraph technique and a TERMA Doppler radar. A total of ten shots without body armour, and ten shots with each of the two types of body armour at the two angles were used. The results of the shadowgraph and Doppler radar measurements showed a proportional correlation between the two methods of determining the bullet yaw. The semiquantitative approach of the Doppler radar measurement was in agreement with the more concise measurement using the photographic technique. Velocity loss and loss of spin rate from penetrating 14 or 28 ply Kevlar was negligible. We observed induced instability after penetration of 14 and particularly 28 ply Kevlar, dependence of yaw with respect to the number of layers of Kevlar as well as to the angle of the body armour with respect to the line of fire.
Hormone replacement therapy dissociates fat mass and bone mass, and tends to reduce weight gain in early postmenopausal women: a randomized controlled 5-year clinical trial of the Danish Osteoporosis Prevention Study.
The aim of this study was to study the influence of hormone replacement therapy (HRT) on weight changes, body composition, and bone mass in early postmenopausal women in a partly randomized comprehensive cohort study design. A total of 2016 women ages 45-58 years from 3 months to 2 years past last menstrual bleeding were included. One thousand were randomly assigned to HRT or no HRT in an open trial, whereas the others were allocated according to their preferences. All were followed for 5 years for body weight, bone mass, and body composition measurements. Body weight increased less over the 5 years in women randomized to HRT (1.94 +/- 4.86 kg) than in women randomized to no HRT (2.57 +/- 4.63, p = 0.046). A similar pattern was seen in the group receiving HRT or not by their own choice. The smaller weight gain in women on HRT was almost entirely caused by a lesser gain in fat. The main determinant of the weight gain was a decline in physical fitness. Women opting for HRT had a significantly lower body weight at inclusion than the other participants, but the results in the self-selected part of the study followed the pattern found in the randomized part. The change in fat mass was the strongest predictor of bone changes in untreated women, whereas the change in lean body mass was the strongest predictor when HRT was given. Body weight increases after the menopause. The gain in weight is related to a decrease in working capacity. HRT is associated with a smaller increase in fat mass after menopause. Fat gain protects against bone loss in untreated women but not in HRT-treated women. The data suggest that women's attitudes to HRT are more positive if they have low body weight, but there is no evidence that the conclusions in this study are skewed by selection bias.
OBJECTIVE: To assess the influence of smoking on serum parathyroid hormone (PTH), serum vitamin D metabolites, serum ionized calcium, serum phosphate, and biochemical markers of bone turnover in a cohort of 510 healthy Danish perimenopausal women. DESIGN: A cross-sectional study. SETTING: Copenhagen, Denmark. SUBJECTS: Five-hundred-and-ten healthy women aged 45-58 y, included 3-24 months after last menstrual bleeding. None were using hormone replacement therapy. METHODS: The women were grouped according to their current smoking status. The two groups were compared with regard to serum levels of 25-hydroxyvitamin D (25OHD) and 1, 25-dihydroxyvitamin D (1,25-(OH)2D), intact PTH, ionized calcium and phosphate, osteocalcin, as well as urine pyridinolines. Bone mineral density (BMD) was measured with DEXA-scans. Multiple regression analyses were performed to detect the effect of potentially confounding lifestyle factors, such as calcium and vitamin D intakes, alcohol and coffee consumption, sunbathing, and physical exercise. RESULTS: Fifty percent were current smokers. Smokers had significantly reduced levels of serum 25OHD (P=0.02), 1,25(OH)2D (P=0.001), and PTH (P
A competitive protein-binding assay for 25-hydroxyvitamin D (25-OHD) based upon a specific binding protein in the cytosol from rachitic rat kidneys is described. A diethyl ether extraction followed by separation by freezing was used. The extracts were chromatographed on short silicic acid columns, which separated 25-hydroxycholecalciferol from cholecalciferol, 24,25-dihydroxycholecalciferol, and 1,25-dihydroxycholecalciferol. A small aliquot of the 25-OHD fraction was used in the assay and free and bound vitamin were separated by dextran coated charcoal. The lower detection limit was 0.8 ng/ml (2.0 nmol/l). The levels of 25-OHD were measured in 596 healthy subjects and a seasonal variation was demonstrated. This variation, however, was only found in those without regular vitamin D intake, whereas the level of 25-OHD remained constant throughout the year in subjects with regular vitamin D supplement. The levels of 25-OHD were lower in the elderly subjects compared to younger ones, but seasonal variation was observed in both groups. In the summer months there was a significant correlation between age and the 25-OHD level. The mean levels of 25-OHD in Denmark are within the range of means found in the United States and Sweden but are higher than those reported from England, Belgium and France. This indicates a relatively high vitamin D intake in the Danish population and a low risk of nutritional vitamin D deficiency.
To determine the relationships between serum vitamin D metabolites, bone mass, and dietary calcium and phosphorus in a cohort of 510 healthy Danish perimenopausal women.
A population-based cross-sectional study.
A total of 510 healthy women aged 45-58 years, with amenorrhoea for 3-24 months. None of the women was using hormone replacement therapy.
Measurements of total bone mineral content and regional bone mineral density were performed by dual-energy X-ray absorptiometry. Analyses of serum levels of 25-OHD and 1,25-(OH)2D, intact PTH, ionized calcium and phosphate, as well as biochemical markers of bone turnover in blood and urine. Assessment of calcium and phosphorus intake using dietary records.
A consistent inverse relationship between serum 1,25-(OH)2D and bone mineral content/ density was found in whole-body mineral content (P = 0.001), spine (P = 0.005) and femoral neck (P
The serum 25-hyroxyvitamin D (25-OHD) concentrations of healthy young hospital laboratory workers in Britain and Denmark were compared in relation to assay variation and vitamin D intake. Serum samples from subjects in London and Copenhagen were assayed in both countries. The Danish assay gave higher values than the British assay with a correlation r = 0.88 and a linear regression of British values on Danish values of y = 0.60x + 3.35. Factors which might account for this difference were differences in the extraction procedure and in the range of values covered by the standards used in the two countries. However, the mean serum 25-OHD concentrations of the Danish group were significantly higher than those of the British group when all the samples were assayed in both countries. The mean total daily vitamin D uptake of the Danish group was significantly higher than that of the British group but this difference was almost entirely due to the regular intake of vitamin D tablets by sixteen of the twenty-five Danish subjects. Only one British subject took supplements. The vitamin D content of the food eaten was similar in the two groups. No correlation was found between dietary, as opposed to supplementary, vitamin D intake and serum 25-OHD levels presumably because the exposure of these subjects to ultra-violet light was adequate to compensate for minor differences in intake.