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.

In vivo tissue characterization using quantitative computed tomography: a review.

Over the past 15 years many attempts have been made to make use of the quantitative information contained within computed tomography (CT) scanner images. A survey of the various approaches to quantitative computed tomography (QCT) is reported. The technical limitations of QCT are discussed. It is concluded that the measurement of bone mineral content is currently the only clinically well-established QCT technique.

The relationship between spinal trabecular bone mineral content and iliac crest trabecular bone volume.

The relationship between spinal trabecular bone mineral density and iliac crest trabecular bone volume has been studied in 84 patients, 23 with primary osteoporosis, 19 with osteoporosis secondary to inflammatory bowel disease, and 42 with nonsteroid-treated rheumatoid arthritis. Spinal trabecular bone mineral density was measured in the first three lumbar vertebrae by quantitative computed tomography, and iliac crest trabecular bone volume was assessed histomorphometrically in sections from trans-iliac biopsies using computerized techniques. In all 84 patients, there was a significant positive correlation between the two measurements (r = 0.60, P less than 0.001). However, when the three patient groups were analyzed separately, a significant correlation was found in the group with secondary osteoporosis (r = 0.65, P less than 0.01) but not in the patients with primary osteoporosis (r = 0.07) or rheumatoid arthritis (r = 0.19). These results indicate that the relationship between spinal trabecular bone mineral density and iliac crest trabecular bone volume differs according to the underlying disease process, these differences possibly reflecting variations in skeletal patterns of bone loss in different types of osteoporosis.

Increased rate of spinal trabecular bone loss in patients with inflammatory bowel disease.

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.

A theoretical analysis of the accuracy of single-energy CT bone-mineral measurements.

A relationship has been derived between the in vivo concentration of calcium hydroxyapatite and the in vitro concentration of K2HPO4 solution in a single-energy quantitative computed tomography (QCT) bone-mineral determination. Under certain simplifying assumptions this relationship is linear. The gradient term has been calculated as a function of scanner effective energy using the measured variation of solvent water density with K2HPO4 concentration; it ranges from 1.17 at 60 keV to 1.21 at 80 keV. The intercept term has been calculated as a function of effective energy, patient age and trabecular bone volume (TBV) by modelling the constituents of whole trabecular bone and using published normal composition data. It varies from about 15 to 25 mg cm-3 at an effective energy of 70 keV and within a TBV range of 5 to 20%. This intercept term may be used as an additive correction which improves the accuracy of single-energy QCT results without significant loss of precision. However, the method is limited by the uncertainties of tissue composition in an individual patient.

Spinal trabecular bone mineral content in patients with non-steroid treated rheumatoid arthritis.

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.

Bone mineral content in normal UK subjects.

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.

Osteoporosis in patients with inflammatory bowel disease.

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.

Gastric emptying after surgery for the dumping syndrome.

The dumping syndrome following gastric surgery for peptic ulcer disease can cause severe morbidity. In this study the benefit of interposition of an antiperistaltic jejunal loop to reverse peristalsis and delay gastric emptying was assessed in four patients with severe symptoms by performing gastric emptying studies pre-operatively, and at 6 months and 24 months following surgery. Gastric emptying was delayed at 6 months but by 2 years had returned to pre-operative values. Patients' symptoms were improved at 6 months and remained so despite the deterioration in gastric emptying. This surgical procedure is of some value to patients with severe symptoms due to the dumping syndrome.