C Evans

University of Wales, Cardiff, Wales, United Kingdom

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Publications (16)88.51 Total impact

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    ABSTRACT: Renal osteodystrophy is an important complication in patients with end-stage renal disease on maintenance dialysis. The aim of this study was to compare the biochemical markers of bone formation (serum collagen type I C-terminal propeptide) and resorption (serum deoxypyridinoline - DPD - and pyridinoline - PYR) with the bone mineral density (BMD) at lumbar spine, femoral neck, and forearm in patients with end-stage renal disease on haemodialysis (HD) versus continuous ambulatory peritoneal dialysis (CAPD). Fifty-nine adult patients, 45 on CAPD (18 females, 27 males) and 14 on HD (2 females, 12 males), were studied. The mean age was 44 +/- SEM 1.6 and 54.4 +/- 4.8 years, respectively. No significant differences in serum calcium, phosphorus, creatinine, and parathyroid hormone were found between patients on HD and CAPD in predialysis samples. Serum urea was significantly lower (p = 0.02) in the CAPD group. Serum PYR (nmol/l) and DPD (nmol/l) were significantly higher in patients on HD as compared with those on CAPD: 105 +/- 23.3 versus 43.7 +/- 3.47 (p = 0.007) and 31.0 +/- 2.4 versus 24.4 +/- 1.4 (p = 0.027), respectively. The results were still significantly higher in the HD patients following correction for serum creatinine and body mass index. There was a close correlation between dialysate DPD and creatinine in both dialysis modalities (HD r = 0.9, CAPD r = 0.76). The clearance of DPD did not differ significantly between the CAPD membrane and the HD membrane (p = 0.22). Serum collagen type I C-terminal propeptide was not significantly different between the HD and CAPD patients. The results were unaffected following correction for age and gender. The BMD was measured in 38 (65%) of the patients (HD n = 8, CAPD n = 30) by dual-energy X-ray absorptiometry and expressed as 'Z' scores. This was reduced at all sites in the patients with end-stage renal disease. The BMD was significantly lower at the ultradistal forearm (mostly trabecular bone) in HD patients as compared with CAPD patients (n = 0.02). A similar trend was observed at the lumbar spine, although the results failed to reach significance. In the whole population (n = 38), linear regression analysis revealed a significant negative correlation between BMD at the ultradistal forearm and serum PYR (r = -0.35, p = 0.04) and DPD (r = -0.33, p = 0.049). Combined measurements of BMD and biochemical markers of bone resorption may have potential in the identification of patients at high risk of bone loss who may require further evaluation of bone remodeling by bone histomorphometry.
    Nephron 06/2002; 91(1):94-102. · 13.26 Impact Factor
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    ABSTRACT: Osteopenia is a recognised complication of diabetes mellitus which could be due to abnormal bone turnover or disturbances in the calcium/parathyroid hormone/vitamin D axis or both. Genetic factors also play an important part in determining bone mass although this has not been studied in diabetes. Recently a polymorphism of the collagen type 1 alpha 1 (COL1A1) gene has been shown to be associated with low bone mass in British women. To identify subjects with diabetes who may be at risk of developing osteoporosis and fractures, we analysed bone mineral density in relation to the biochemical markers of bone turnover, calcium homeostasis and the COL1A1 genotype in a group of premenopausal women with Type I (insulin-dependent) diabetes mellitus (n = 31), Type II (non-insulin dependent) diabetes mellitus (n = 21) and control subjects (n = 20). Bone mineral density was lower at the femoral neck in the subjects with Type I diabetes (p = 0.08) as were serum 25-hydroxyvitamin D compared with control subjects (p = 0.023) and this was negatively correlated with serum collagen type 1 C-terminal propeptide (r = -0.56, p < 0.001). Bone mineral density in Type II diabetes was not different from control subjects, after correction for body mass index. Bone resorption was, however, raised in the Type II diabetic subjects as reflected by the higher urinary deoxypyridinoline values (p = 0.016) and lower collagen type 1 C-terminal propeptide:deoxypyridinoline ratio (p = 0.04). In the whole group studied, subjects with the COL1A1 's' genotype had lower bone mineral density at the femoral neck (p = 0.01) which was partly attributable to a lower body mass index. Following multiple regression analysis body mass index and collagen type 1 C-terminal propeptide concentrations remained determinants of bone mass at all three sites, whereas genotype appeared to be a predictor of bone mass at the femoral neck only. We conclude that measurement of these variables could prove useful in firstly identifying those diabetic women at risk of osteoporosis and secondly guiding therapeutic intervention.
    Diabetologia 12/1998; 41(11):1314-20. · 6.49 Impact Factor
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    ABSTRACT: Summary Osteopenia is a recognised complication of diabetes mellitus which could be due to abnormal bone turnover or disturbances in the calcium/parathyroid hormone/vitamin D axis or both. Genetic factors also play an important part in determining bone mass although this has not been studied in diabetes. Recently a polymorphism of the collagen type 1 α 1 (COL1A1) gene has been shown to be associated with low bone mass in British women. To identify subjects with diabetes who may be at risk of developing osteoporosis and fractures, we analysed bone mineral density in relation to the biochemical markers of bone turnover, calcium homeostasis and the COL1A1 genotype in a group of premenopausal women with Type I (insulin-dependent) diabetes mellitus (n = 31), Type II (non-insulin dependent) diabetes mellitus (n = 21) and control subjects (n = 20). Bone mineral density was lower at the femoral neck in the subjects with Type I diabetes (p = 0.08) as were serum 25-hydroxyvitamin D compared with control subjects (p = 0.023) and this was negatively correlated with serum collagen type 1 C-terminal propeptide (r = –0.56, p < 0.001). Bone mineral density in Type II diabetes was not different from control subjects, after correction for body mass index. Bone resorption was, however, raised in the Type II diabetic subjects as reflected by the higher urinary deoxypyridinoline values (p = 0.016) and lower collagen type 1 C-terminal propeptide:deoxypyridinoline ratio (p = 0.04). In the whole group studied, subjects with the COL1A1 ’s' genotype had lower bone mineral density at the femoral neck (p = 0.01) which was partly attributable to a lower body mass index. Following multiple regression analysis body mass index and collagen type 1 C-terminal propeptide concentrations remained determinants of bone mass at all three sites, whereas genotype appeared to be a predictor of bone mass at the femoral neck only. We conclude that measurement of these variables could prove useful in firstly identifying those diabetic women at risk of osteoporosis and secondly guiding therapeutic intervention. [Diabetologia (1998) 41: 1314–1320]
    Diabetologia 01/1998; 41(11):1314-1320. · 6.49 Impact Factor
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    Annals of the Rheumatic Diseases 03/1994; 53(2):149. · 9.11 Impact Factor
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    ABSTRACT: 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.
    British Journal of Radiology 01/1994; 66(792):1134-7. · 1.22 Impact Factor
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    ABSTRACT: 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.
    Bone and Mineral 12/1993; 23(2):95-104.
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    ABSTRACT: 1. Serial measurements of total body calcium have been made by prompt gamma-neutron activation analysis in 13 patients with inflammatory bowel disease over a mean period of 23 months. Changes in spinal trabecular bone mineral density and radial shaft bone mineral content were also assessed by using quantitative computed tomography and single photon absorptiometry, respectively. 2. The mean annual decreases (95% confidence intervals) were: total body calcium, 7.8% (-12.0 to -3.7%; P less than 0.001); spinal trabecular bone mineral density, 2.5% (-5.0 to +0.1%; 0.05 less than P less than 0.1), radial bone mineral content, 2.1% (-3.4 to -0.8%; P less than 0.01). 3. No significant correlations were found between rates of change of the three variables. However, there were significant positive correlations between the baseline values for total body calcium and radial bone mineral content (r = 0.638, P less than 0.05), spinal bone mineral density and radial bone mineral content (r = 0.854, P less than 0.01), and total body calcium and spinal bone mineral density (r = 0.876, P less than 0.001). 4. These results demonstrate rapid decreases in total body calcium in patients with inflammatory bowel disease which, in conjunction with the significant decrease in radial shaft bone mineral content, indicate increased rates of cortical bone loss. Whilst values for bone mass at different skeletal sites showed positive correlations within individuals, no relationship was found between the rates of change in bone mass at these sites. 5. The rapid bone loss observed in some subjects emphasizes the importance of early detection of osteoporosis by bone densitometry and the need for effective prophylactic measures to be established in this group of patients.
    Clinical Science 05/1991; 80(4):319-24. · 4.86 Impact Factor
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    ABSTRACT: The rate of spinal trabecular bone loss during one year was measured in 54 patients with inflammatory bowel disease. The mean change in spinal bone mineral content was -5.1 mg/ml K2HPO4, representing 3% of the initial bone mineral content. The rate of bone loss showed a significant negative correlation with body mass index (r = -0.276, p less than 0.05) but no other significant correlations were found with other clinical or biochemical indices, including the total amount of prednisolone taken during the course of the study. Eleven patients had bone loss greater than 15 mg/ml/year; these included four non-steroid treated patients, two of whom had disease confined to the large bowel. The results indicate rapid rates of bone loss in some patients with inflammatory bowel disease over the course of one year. Although steroid therapy and malnutrition are likely to be contributory factors in some patients, other, as yet unidentified, risk factors also operate. The rapid bone loss observed in some patients emphasises the need for effective prophylactic regimes.
    Gut 11/1988; 29(10):1332-6. · 10.73 Impact Factor
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    ABSTRACT: Spinal trabecular bone mineral content was measured in the first, second, and third lumbar vertebrae by quantitative computed tomography in 88 patients with non-steroid treated rheumatoid arthritis. Results were compared with those obtained in 105 healthy control subjects. The mean bone mineral content in the patient group, 135.8 (SD 32.8) mg/ml K2HOP4, was significantly lower than that in the controls (151.9 (32.1) mg/ml, p less than 0.01). Division of patients and controls into three age groups showed that the reduction in bone mineral content was most marked in the youngest age group (21-40 years), the mean value in male patients being significantly lower than in controls (149.6 (51.3) v 171.7 (23.9) mg/ml K2HPO4, p less than 0.05); in female patients in this age group the corresponding values were 160 (26.1) v 178.4 (22.0) mg/ml, 0.05 less than p less than 0.1). No significant difference in mean values between patients and controls was found in the other age groups. Of the 88 patients, six (7%) had abnormally low values, defined as a bone mineral content greater than 2 SD below the normal mean. One vertebral crush fracture was found in one patient but not in any of the controls. No correlation was found between bone mineral content and body weight, duration of disease, or disability as assessed by the London and Steinbroker methods. These results demonstrate a lower spinal trabecular bone mineral content in non-steroid treated patients with rheumatoid arthritis than in age and sex matched controls, the difference being most marked in younger patients. The finding of abnormally low values in 7% of the patients indicates a slightly increased prevalence of spinal osteoporosis in these patients.
    Annals of the Rheumatic Diseases 09/1988; 47(8):660-4. · 9.11 Impact Factor
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    ABSTRACT: Bone mineral content in the lumbar vertebrae and in the shaft of the left radius has been measured in 129 normal British subjects using quantitative computed tomography and single-photon absorptiometry. Significant negative correlations between bone mineral content and age were found at both sites in males and females (p less than 0.001 in all cases). When expressed in g/cm the bone mineral content in the radial shaft showed significant positive correlations with body height and weight in both sexes, but after correction for bone size only a weak correlation with body height in males was found. Spinal trabecular bone mineral content showed no significant correlations with body height or weight in either sex. Comparison of the values obtained with normal data from centres in the USA revealed lower mean values for both radial and spinal bone mineral content in the British subjects. These differences emphasize the importance of using locally derived normal data for comparison with values obtained from patients.
    British Journal of Radiology 08/1988; 61(727):631-6. · 1.22 Impact Factor
  • Clinical Physics and Physiological Measurement 06/1988; 9(2):163-5.
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    ABSTRACT: Bone mineral content in spinal trabecular and peripheral cortical bone was measured in 75 unselected patients with small and/or large intestinal inflammatory bowel disease. Osteoporosis, defined as a bone mineral content greater than 2 SD below the age and sex matched normal mean value was present in 23 patients (30.6%). Three amenorrhoeic females aged 34, 38, and 42 years had severe clinical osteoporosis and a further three patients had one or more vertebral crush fractures. Eighteen of the 23 patients with osteoporosis had small intestinal disease with one or more resections and the mean lifetime steroid dose in those with osteoporosis was significantly higher than in those with normal bone mineral content. Bone mineral content in spinal trabecular bone showed significant negative correlations with lifetime steroid dose and serum alkaline phosphatase and a significant positive correlation with serum albumin. Peripheral cortical bone mineral content was positively correlated with body weight, height and body mass index. We conclude that the prevalence of osteoporosis is increased in patients with inflammatory bowel disease, severe clinical osteoporosis developing in some relatively young patients. The pathogenesis of this bone loss is probably multifactorial; steroid therapy is likely to be an important contributory factor.
    Gut 05/1987; 28(4):410-5. · 10.73 Impact Factor
  • Bone 01/1987; 8(1):48-49. · 3.82 Impact Factor
  • Bone 01/1987; 8(4):268-268. · 3.82 Impact Factor
  • Bone 01/1987; 8(1):50-50. · 3.82 Impact Factor
  • Bone 8(1):53. · 3.82 Impact Factor