Prediction of osteoporotic fragility re-fracture with lumbar spine DXA-based derived bone strain index: a multicenter validation study.

A new qualitative index of bone strength, based on finite element analysis and named bone strain index, has been recently developed from lumbar DXA scan. This study shows that BSI predicts subsequent re-fracture in osteoporotic patients affected by fragility fractures. INTRODUCTION: Dual-energy X-ray absorptiometry (DXA) can provide quantitative (bone mineral density, BMD) and qualitative (trabecular bone score, TBS) indexes of bone status, able to predict fragility fractures in most osteoporotic patients. A new qualitative index of bone strength, based on finite element analysis and named bone strain index (BSI), has been recently developed from lumbar DXA scan. This study presents the validation results of BSI prediction for re-fracture in osteoporotic patients with fragility fractures. METHODS: In three academic hospitals, 234 consecutive fractured patients with primary osteoporosis (209 females) performed a spine X-ray for the calculation of spine deformity index (SDI) and DXA densitometry for BMD, TBS and BSI at the basal time and in the follow-up at each clinical check. A subsequent fracture was considered as one unity increase of SDI. RESULTS: For each unit increase of the investigated indexes, the univariate hazard ratio of re-fracture, 95% CI, p value and proportionality test p value are for age 1.040, 1.017-1.064, 0.0007 and 0.2529, respectively, and for BSI 1.372, 1.038-1.813, 0.0261 and 0.5179, respectively. BSI remained in the final multivariate model as a statistically significant independent predictor of a subsequent re-fracture (1.332, 1.013-1.752 and 0.0399) together with age (1.039, 1.016-1.064 and 0.0009); for this multivariate model proportionality test, p value is 0.4604. CONCLUSIONS: BSI appears to be a valid DXA index of prediction of re-fracture, and it can be used for a more refined risk assessment of osteoporotic patients.

Bone strain index reproducibility and soft tissue thickness influence: a dual x-ray photon absorptiometry phantom study.

BACKGROUND: Bone strain index (BSI) is a tool measuring bone strain, derived from dual x-ray photon absorptiometry. It is able to characterise an aspect of bone quality that, joined to the quantity and quality parameters of bone mineral density (BMD) and trabecular bone score (TBS), permits an accurate definition of fracture risk. As no data are available about BSI precision, our aim was to assess its in vitro reproducibility. METHODS: A Hologic spine phantom was used to perform BSI scans with three different scan modes: fast array (FA), array (A), and high definition (HD). Different soft tissue thicknesses (1, 3, 6 cm) of fresh pork rind layers as a surrogate of abdominal fat were interposed. For each scan mode, the phantom was consecutively scanned 25 times without repositioning. RESULTS: In all scan modes (FA, A, HD) and at every fat thickness, BSI reproducibility was lower than that of BMD. The highest reproducibility was found using HD-mode with 1 cm of pork rind and the lowest one using HD-mode with 6 cm of pork rind. Increasing fat thickness, BSI reproducibility tended to decrease. BSI least significant change appeared to be about three times that of BMD in all modalities and fat thicknesses. Without pork rind superimposition and with 1-cm fat layer, BSI reproducibility was highest with HD-mode; with 3 or 6 cm fat thickness, it was higher with A-mode. CONCLUSIONS: BSI reproducibility was worse than that of BMD, but it is less sensitive to fat thickness increase, similarly to TBS.

Long-term intermittent treatment with low-dose 5-aminosalicylic enemas is efficacious for remission maintenance in ulcerative colitis.

BACKGROUND: The standard remission maintenance treatment for ulcerative colitis (UC) is 5-amino-salicylic acid (5-ASA), given orally and topically and in different doses, with various frequencies and duration of administration. Both the efficacy of long-term intermittent therapy with low-dose 5-ASA enemas in preventing UC relapses and its economic implications were evaluated. METHODS: In accordance with a prospective case control study, 42 adult UC outpatients (29 M and 13 F) were treated with 5-ASA tablets (1.6 g/day) and 5-ASA enemas (2 g/50 mL) twice weekly, and 42 concurrent UC outpatients, matched for sex, age, extension and duration of disease, received only the oral therapy; the median treatment period was 6 years. RESULTS: There was a significant reduction in the number (42%: P = 0.034) and incidence of relapses (43%: P = 0.022) in the patients receiving combined oral + topical 5-ASA, who also had a significantly higher cumulative probability of not experiencing a first relapse (P = 0.001). There were no dropouts or side effects. Local therapy increased drug costs, but decreased the costs of relapses by 48% and completely precluded hospitalization costs. CONCLUSIONS: The scheduled oral + topical 5-ASA treatment, at the lowest cumulative topical dosage tested over the longest known observation period, is efficacious in improving clinical outcome and decreasing overall costs in UC patients.

Bone mineral density and body composition in ulcerative colitis: a six-year follow-up.

Reduced bone mineral density (BMD) has been reported in ulcerative colitis (UC), but there are no data concerning body composition (fat and lean mass) in such patients. We used whole body dual-energy X-ray absorptiometry (Hologic QDR 1000 W) at baseline and after 6 years of follow-up to study bone density, and fat and lean mass in 43 outpatients with mild UC (21 men, mean age 36 years, range 21-57 years, and 22 women, mean age 35 years, range 23-45 years at baseline; disease extent: 2 proctitis, 18 proctosigmoiditis, 8 left colitis, 5 substantial colitis, 10 pancolitis; mean disease duration 8 years, range 2-18 years; no hospitalization; few relapses during the follow-up) and 111 healthy volunteers matched by sex, age and body mass index. There were 5 drop-outs. We observed no significant difference in BMD, or fat and lean mass between the male patients and controls at baseline or after 6 years. The total lean mass (Z-score = -3.2, p = 0.001) and trunk lean mass (Z-score = -2.01, p = 0.03) of the female patients were lower than those of the controls at baseline, whereas their limb lean mass was higher at both the beginning and the end of the study (Z-score = 2.14, p = 0.03; Z-score = 2.8, p = 0.004, respectively). At baseline there was a significant negative correlation between lifetime steroid intake (enteral and parenteral) and lumbar spine BMD, obtained as whole body subregion (r = -0.53, p = 0.0006). After 6 years there was a significant negative correlation in women between whole body and lumbar spine BMD and both steroid intake (r = -0.53, p = 0.01; and r = -0.62, p = 0.003) and the number of relapses (r = -0.49, p = 0.02; and r = -0.44, p = 0.05). Mild UC thus does not represent a risk factor for osteopenia per se. The differences in lean mass between the female patients and controls do not seem to be clinically relevant.

Bone mineral density and body composition in patients with ulcerative colitis.

OBJECTIVE: Reduced bone mineral density (BMD) has been reported in ulcerative colitis (UC) patients, but body composition (fat and lean mass) has never been concomitantly studied. We sought to investigate BMD and body composition in a group of UC outpatients with the following characteristics: age 18-60 yr (men) and 18-45 yr (women); no intestinal resection; no immunosuppressive treatment; and regular menstruation. METHODS: Whole body and subregional BMD and body composition in 43 UC patients (21 men, 22 women; male mean age, 36.5 [21-57] yr; female mean age, 35.3 [23-45] yr) and 121 healthy volunteers were studied by means of dual X-ray photon absorptiometry. RESULTS: There were no differences in total and subregional BMD, or fat and lean mass between the patients and controls, except that the total and trunk lean mass of the UC women was lower than that in the normal controls. No correlation was found between lifetime steroid intake and BMD. CONCLUSIONS: UC outpatients do not differ from normal subjects in terms of BMD and fat mass. Mild and moderate UC does not represent a risk factor for osteopenia.