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Biomedical subjects

J E Compston

Publications and source records attributed to J E Compston.

At least 109 records · Page 6Linked to original sources
PubMed1993

Sex hormones and bone mineral density in elderly men.

The aim of this study was to determine the relationships between sex hormones and bone mineral density (BMD) in older men. Community-dwelling men (n = 134, mean age (SD) 69.5 (3.1) years) were recruited from two general practices in Cambridge, UK. Plasma total testosterone and sex hormone binding globulin (SHBG) were assayed and a free androgen index (FAI) was derived as the ratio of total testosterone to SHBG (x 100). Spine and hip BMD were measured by dual energy x-ray absorptiometry using the Hologic QDR-1000. After adjusting for age and body mass index (BMI), the FAI correlated with femoral neck (r = 0.20, P = 0 0.03), intertrochanteric, trochanteric and Ward's Triangle BMD (r = 0.22, P = 0.01). Analysis of variance, with adjustment for age and BMI, showed a progressive upward trend of hip BMD with increasing quartiles of FAI. The findings suggest that free testosterone plays a role in determining bone mineral density in older men.

Absorptiometry, Photon↗
PubMed1993

A four-year longitudinal study of bone loss in patients with inflammatory bowel disease.

Serial measurements of spinal trabecular and radial cortical bone density were made over 4 years in 70 patients with inflammatory bowel disease. Mean rates of bone loss for the cohort differed little from rates reported in normal populations; however, some patients showed increased rates of loss, including patients whose bone density at entry to the study was already well below normal. There was a significant correlation between the amount of corticosteroid prescribed and spinal trabecular bone loss in males, but no significant correlation with other clinical parameters. Increased rates of bone loss emphasise the need for bone densitometry and prophylactic measures in patients with inflammatory bowel disease.

Adult↗
PubMed1993

Comparison between the lengths of individual osteoid seams and resorption cavities in human iliac crest cancellous bone.

The current concept of bone remodelling is based on the belief that bone resorption and formation are coupled both in time and space; this implies that the surface extent of bone eroded in a bone remodelling unit would approximate to the surface extent of the osteoid seam formed subsequently. The greater total surface extent of osteoid as opposed to erosion is generally attributed to the longer life-span of bone formation, but no comparison of the length of eroded surface and osteoid seam within individual bone remodelling units has been reported. In this study we have compared the length of individual osteoid seams, resorption cavities and bone structural units in iliac crest trabecular bone obtained from normal subjects and from patients with renal osteodystrophy. Values for osteoid seam and bone packet length were significantly greater than resorption cavity length in both the normal and patient groups (P < 0.001), the ratio of osteoid seam and eroded length being similar in the two groups (1:0.44 and 1:0.40, respectively). These results indicate that the discrepancy between total osteoid and eroded surface extent cannot be wholly explained on the basis of a longer formation life-span. Possible additional explanations include underestimation of eroded surface by light microscopic techniques, initiation of bone formation within a cavity before the completion of resorption, the presence of arrested resorption cavities, non-random distribution of resorption cavities on the trabecular surface and bone formation on quiescent bone surfaces.

Adult↗
PubMed1993

Relationships between parathyroid hormone, 25-hydroxyvitamin D, and bone mineral density in elderly men.

This study aimed to determine the relationships between parathyroid hormone, vitamin D status and bone mineral density (BMD) in healthy older men. Subjects [n = 133, mean age (SD) 69.5 (3.1), range 65-76 years] were recruited from two general practices in Cambridge. Blood samples were drawn for measurement of intact parathyroid hormone (1-84, hPTH) and total 25-hydroxyvitamin D. Bone mineral density at the hip and spine was measured by dual-energy X-ray absorptiometry (DEXA). After adjusting for age and body mass index (BMI), PTH was negatively correlated with trochanteric (r = -0.24, p = 0.007), intertrochanteric (r = -0.29, p = 0.001), and Ward's Triangle BMD (r = -0.15, p = 0.087). By analysis of variance, controlling for age and BMI, PTH showed a relatively consistent downward trend with increasing tertiles of bone mineral density, especially at the hip. These results suggest a role of parathyroid hormone in determining hip bone mineral density in a community-based sample of healthy elderly men.

Aged↗
PubMed1993

Lack of relationship between hip and spine bone mineral density and oral contraceptive use.

The aim of this study was to examine the relationships between oral contraceptive use and bone mineral density at the hip and spine. Community based women aged 41-76 years (n = 841) were recruited from four general practices in Cambridge. Each subject completed a health questionnaire. Spine (L2-L4, n = 841) and hip (n = 833) bone mineral density were measured by dual energy X-ray absorptiometry using the Hologic QDR-1000. After adjustment for age, there was no significant difference in regional bone mineral density between ever and never users of oral contraceptives. Similar results were obtained after stratifying for potential confounding factors including menopausal status, parity, smoking, hormone replacement therapy use, and body mass index. There was no relationship between duration of oral contraceptive use and bone mineral density. These results suggest that there is no relationship between oral contraceptive use and bone mineral density at the hip and spine in middle-aged women.

Adult↗
PubMed1993

Hormone replacement therapy prevents bone loss in patients with inflammatory bowel disease.

Patients with inflammatory bowel disease have an increased prevalence of osteoporosis, and suffer high rates of spinal bone loss. Hormone replacement therapy (HRT) is effective in the treatment and prevention of osteoporosis but has not been studied in patients with inflammatory bowel disease. A two year prospective study of HRT in inflammatory bowel disease was performed in 47 postmenopausal women aged 44 to 67 years with ulcerative colitis (25) or Crohn's disease (22). Patients had radial and spinal bone density measured annually by single photon absorptiometry and quantitative computed tomography respectively. The mean (95% confidence intervals) annual change in radial bone density was +1.42%/yr (+0.58 to +2.26; P < 0.005) and for spinal bone +2.60%/yr (+1.06 to +4.15; p < 0.005). There was no significant correlation between rates of change of bone density at the two sites, or between the rates of change and the initial bone density either in the radius or spine. Twelve patients were given prednisolone during the study, and their rates of change for spinal bone density were lower, but values were not statistically significantly different from those who did not receive corticosteroids. Changes in bone density for patients with ulcerative colitis and Crohn's disease were not significantly different. The change in bone density did not correlate with the patients' age or number of years after the menopause. It is concluded that HRT is effective in prevention of bone loss in postmenopausal women with inflammatory bowel disease.

Adult↗
PubMed1993

Bone loss in normal British women; a 5 year follow-up.

To assess the rates of loss, forearm and spinal bone mineral were remeasured in 16 out of 18 peri- and post-menopausal women aged 45 to 60 years who had taken part in a previously reported cross-sectional study. The mean interval between measurements was 4.8 years (range 4.2-5.3 years). The mean (95% confidence interval (CI)) annual change in radial bone mineral density was -0.78%/year (-1.73 to +0.18%; not significant) and in spinal bone mineral -2.41%/year (-3.55 to 1.27%; p < 0.001). There was considerable variation in the rate of change in radius and spine, and between individuals. There was no significant correlation between rates of bone loss at either site, or between rates of loss and the initial bone density at either the radius or spine. There was no significant correlation between the rates of change and the age or number of years post-menopause of the women. There was no significant change in the Z score for the forearm (mean -0.20; 95% CI -0.65 to +0.25) or for the spine (mean -0.04; 95% CI -0.30 to +0.22). There have been no previous longitudinal studies of the changes of bone density in normal British women. These results show considerable variation between individuals, and rates of change at one site cannot be predicted from measurements at another site. Untreated, some normal individuals have high rates of loss that cannot be predicted from baseline values, age or number of years post-menopause.

Absorptiometry, Photon↗
PubMed1992

Characteristics of trabecular bone resorption cavities in patients with chronic renal failure.

Using a computerised technique, resorption cavity characteristics in iliac crest trabecular bone were assessed in 30 patients with chronic renal failure and compared with data obtained from healthy subjects. The mean and maximum cavity depth were significantly greater in the patient group (P less than 0.0001); in addition, cavity area, the percentage of bone being remodelled, the number of cavities per mm trabecular surface and the percentage eroded surface were all significantly greater than in controls (P less than 0.0001). However, the surface length of individual cavities in the patient group did not differ significantly from that of controls. In the patient group, serum intact parathyroid hormone concentrations showed a significant positive correlation with mean resorption cavity depth (r = 0.451, P less than 0.05). Our results demonstrate that the increase in bone resorption associated with hyperparathyroidism secondary to chronic renal failure is due to an increase both in the number and depth of cavities, although the surface extent of individual cavities is normal. These findings indicate that factors determining the length of trabecular surface eroded and the depth of individual resorption cavities are controlled by different mechanisms.

Adult↗
PubMed1992

Combined inter-observer and inter-method variation in bone histomorphometry.

Manual methods for the measurement of bone biopsies have largely been superseded by semi-automatic computerised techniques. Histomorphometrists often use control data obtained by other observers using different methods, thus combining inter-observer and inter-method variation. We have examined the combined effect of inter-method and inter-observer variation on measurements of bone area, osteoid perimeter, and osteoid width in iliac crest biopsies from healthy subjects, one observer using the manual grid system and the other using a semi-automated technique. Inter-observer and inter-method variation were independently determined, and the proportion of each expressed as a percentage of combined error. Our results indicate that the combination of inter-method and inter-observer variation causes significant differences in the values obtained for osteoid perimeter, whereas inter-method variation is mainly responsible for differences in osteoid width values; differences in bone area are largely due to inherent sampling variation. These variations indicate that caution is required when comparison is made with control data from other sources, especially if different techniques are employed.

Analysis of Variance↗
PubMed1992

Effect of diet-induced weight loss on total body bone mass.

1. Total body areal bone mineral density was measured by dual-energy X-ray absorptiometry in eight women before and 10 weeks after a very-low-calorie diet [405 kcal (1701 kJ)/day]. 2. The mean weight loss of 15.6 kg was accompanied by a statistically significant reduction in total body bone mineral density from 1.205 +/- 0.056 to 1.175 +/- 0.058 g/cm2 (mean +/- SD, P less than 0.005). 3. After cessation of the diet, weight gradually increased and by 10 months was similar to baseline values. Total body bone mineral density also increased after stopping the diet and mean values obtained 10 months after the diet did not differ significantly from initial values. Throughout the study total body bone mineral density values in all subjects were well within the range reported for normal subjects. 4. These data indicate that diet-induced weight loss is associated with rapid bone loss, subsequent weight gain being accompanied by increases in bone mass. Further studies are required to establish the clinical significance of these findings and, in particular, the skeletal distribution of bone loss.

Adult↗
PubMed1992

HRT and osteoporosis.

Osteoporosis is characterised by low bone mass, leading to an increased risk of fragility fracture, particularly in the femoral neck, vertebrae and radius. These fractures constitute a major public health problem in the Western world; the estimated annual cost to the health services of hip fracture alone is over 500 million pounds in the United Kingdom. Using population-based data from the USA, Cummings et al. have estimated that the lifetime risks of hip, vertebral and Colles' fractures in a 50 year old, white, postmenopausal woman are 16%, 32% and 15% respectively. Of these, vertebral fractures probably cause the most significant morbidity, since they occur at a younger age than hip fractures and may result in pain, deformity and disability for many years until death intervenes from other causes. Hip fractures occur most commonly in the eight and ninth decades of life and have a mortality at six months of around 15%, increased dependency occurring in the majority of survivors. Colles' fractures, although not usually associated with long-term morbidity, nevertheless cause considerable inconvenience and require hospital treatment.

Aged↗
PubMed1992

Body composition and bone mass in post-menopausal women.

OBJECTIVE: We aimed to assess total body composition and to study the interrelationships between fat and lean tissue mass with total and regional bone mass in healthy British post-menopausal women. DESIGN AND PATIENTS: Total body composition and regional bone mass were measured in 97 healthy post-menopausal women recruited from the general community. The mean age was 57.9 years, range 49-65. MEASUREMENTS: Total body composition (fat, lean tissue and bone mineral) and regional bone density in the lumbar spine and femur were measured by dual energy X-ray absorptiometry on a Lunar DPX. RESULTS: Significant negative correlations with age were found for total body bone mineral density (r = -0.200, P = 0.049), and lumbar spine bone mineral density (r = -0.28, P = 0.006); the calculated rate of bone loss from these two sites was 0.33 and 0.7% per annum respectively. Fat tissue mass showed a positive correlation with age (r = 0.22, P = 0.03). High correlations were observed between total body and regional bone mineral density (r = 0.755-0.829, P < 0.001). After adjustment for age and lean mass, statistically significant correlations were seen between fat tissue mass and all bone mass measurements (P < 0.01-0.001), the strongest correlations being found for total body bone mineral content and density (r = 0.477 and 0.488 respectively). Lean tissue mass showed a strong correlation with total body bone mineral content (r = 0.580, P < 0.001), after adjustment for age and fat mass; it was less strongly correlated with other bone mass measurements than fat mass, showing only weak correlations with total body, trochanteric and lumbar spine bone mineral density (r = 0.228-0.246, P < 0.05). Age-adjusted body weight showed stronger correlations with total and regional bone mass than did either body mass index or height. CONCLUSIONS: Both fat and lean tissue mass are related to total and regional bone mass in post-menopausal women, the relationship being strongest for fat mass. Body weight shows stronger correlations with bone mass than either height or body mass index. In view of the direction and magnitude of changes in fat, lean tissue and bone mineral after the menopause, adiposity and muscularity are more likely to be determinants of peak bone mass than of the rate of post-menopausal bone loss.

Absorptiometry, Photon↗
PubMed1992

Differential involvement of the dorsal and lumbar spine in osteoporosis.

The presence of normal bone density values in the lumbar spine is often assumed to exclude osteoporosis. Eleven cases are reported in which normal lumbar spine bone density and radiology were associated with one or more dorsal spine fractures; the diagnosis was postmenopausal osteoporosis in eight patients and corticosteroid induced osteoporosis in three. These findings suggest that spinal osteoporosis may sometimes be a focal disorder and emphasise the need for dorsal spine radiology in addition to bone densitometry in patients with strong risk factors for osteoporosis or with clinical evidence of the dorsal spine being affected.

Absorptiometry, Photon↗
PubMed1992

Endogenous sex hormones and bone mineral density among community-based postmenopausal women.

In order to describe the relationships between endogenous sex hormones and bone mineral density in healthy postmenopausal women, we carried out a cross-sectional study of 90 community-based women, all at least one year since their last menstrual period (mean 9.6 +/- 4.9 years, range 1-22) and with a serum oestradiol level less than 100 pmol/l. None was currently using hormone replacement therapy. Serum oestradiol, testosterone, sex hormone binding globulin, dehydroepiandrosterone sulphate, and androstenedione were measured using standard techniques. Free oestradiol and testosterone indices were derived as the ratio of total hormone to sex hormone binding globulin, respectively. Total body, spine and hip bone mineral density (g/cm2) were measured by dual energy X-ray absorptiometry. Significant positive correlations were found between the free oestradiol and testosterone indices and bone mineral density at all sites. These relationships remained significant for the free oestradiol index after adjustment for age and body mass index. By stepwise multiple regression analysis, the free oestradiol index was an independent predictor of total body, spine and hip bone mineral density, accounting for 4-17% of the variance. These findings suggest an independent positive relationship between endogenous free oestradiol and total body, spine and hip bone mass even in the late postmenopause.

Aged↗