Bone and stone in ankylosing spondylitis: osteoporosis and urolithiasis.

Ankylosing spondylitis (AS) has well-defined renal complications, but urolithiasis has not been studied in detail. We aimed to evaluate the relation between AS and urolithiasis presence and the effect of this coexistence on the bone mineral status of patients. By dual-energy x-ray absorptiometry measurements at the femoral neck and lumbar vertebrae, we assessed the influence of urolithiasis, disease activity, and duration on bone mineral density (BMD) at different sites. Fifty-three AS patients and 25 control subjects were enrolled in the study. Mean age was 39.49+/-13.01 years for the AS group and 43.80+/-10.69 years for the control group, with no statistically significant difference. Patients were accepted as having active disease if two of the following were present: (1) symptomatic peripheral arthritis, (2) erythrocyte sedimentation rate greater than 30 mm/h, (3) C-reactive protein greater than 5 mg/L, and (4) dorsal-lumbar morning stiffness more than 60 min. The ratios of urinary stone presence were 11.32 and 12% for AS and control groups, respectively. We observed that a statistically significant difference in femur neck BMD between AS patients with or without urolithiasis was apparent. The lumbar BMD values were also lower in the urolithiasis subgroup but could not reach the statistical significance. There were no significant BMD alterations in the control group due to stone presence. Comparison of active-inactive disease groups revealed significantly low T scores in either the femur neck or L2-4 regions of patients with higher activity indices, but this difference was more prominent in the femur neck. In the early AS group (23 patients), 18 patients (78.26%) had L2-4 T scores lower than -1 SD, and in the advanced AS population, 19 of 30 patients (63.33%) had either osteopenia or osteoporosis (OP). We conclude that severe disease and concomitant urolithiasis might increase bone loss and fracture risk especially at the femur neck.

Effect of stanford pouch and ileal conduit urinary diversions on bone mineral density and metabolism.

After urinary-intestinal diversions metabolic complications may occur in long term follow up. We aimed to evaluate bone metabolism changes in urinary diverted patients. Nineteen patients with urinary diversions (11 Stanford pouch and 8 ileal conduit) performed with diagnosis of locally invasive bladder cancer and 19 age-sex matched healthy subjects were enrolled in the study. Bone mineral density (BMD), arterial blood pH, bicarbonate and base excess as well as bone mineralisation parameters at urine and serum were evaluated for all groups. For statistical evaluation, nonparametric comparisons between groups were used. Comparison of ileal conduit and control groups displayed higher alkaline phosphatase and parathormone levels in the patient group though the difference was not significant. The mean BMD values of ileal conduit group were osteopenic, revealing a significant difference with the control group. Statistically significant differences between alkaline phosphatase, parathormone levels of Stanford pouch and control groups were apparent whereas BMD values were not significantly different. When the two patient groups were compared with each other, no difference in BMD or bone metabolism parameter values could be observed. Patients with urinary diversions are under risk of bone demineralisation and must be followed by BMDs, arterial blood analysis and bone mineral metabolism parameters.

Bone mineral density and urolithiasis interaction in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a systemic inflammatory disease with extraarticular manifestations involving many organs. Both urinary stone formation and bone mineral density (BMD) can be affected by calcium (Ca) metabolism changes in RA. We aimed, in our study, to investigate the incidence of urolithiasis in adult RA patients and to identify the BMD characteristics of stone-forming RA patients. Seventy-nine RA patients and 35 control subjects participated in our study. None had a known renal disease, except for urolithiasis. Complete blood count (CBC), erythrocyte sedimentation rate (ESR), rheumatoid factor (RF), and C-reactive protein (CRP) were recorded. Twenty-four-hour urinalysis, as well as plain X-ray, ultrasound imaging, and BMD measurements with dual-energy X-ray absorptiometry (DEXA) were performed. T scores more than 1 SD below the mean value were accepted as low BMD. There was no statistically significant difference between urinary stone incidence in RA patients and controls. There was a significant difference between BMD values in RA patients with and without urinary stone disease. The low T scores of stone-forming RA patients may be explained by the additive effect of two coexisting diseases, both shown to be related to low bone mass. From another point of view, both BMD loss and urolithiasis can be consequences of altered Ca metabolism in RA. So we suggest that RA patients with urolithiasis should be evaluated for BMD, and that RA patients with low BMD be evaluated for urolithiasis.