Steroids and Bone Density in Patients With Functioning Kidney Allografts

Abstract

Introduction Osteopenia and osteoporosis after renal transplantation have been associated with factors related to the cause of end-stage renal disease, as well as to clinical events and therapeutic factors in the posttransplant period. We studied the prevalence of low bone density (LBD) according to WHO criteria. Methods A cross-sectional study was performed in a cohort of 106 patients (54 men and 52 women) with functioning renal allografts, who underwent bone densitometry (DEXA) of the lumbar spine and femoral neck. Patients were grouped according to DEXA into those with normal bone density (NBD) or LBD. We studied clinical, analytical, and therapeutic variables. Results Thirtysix patients (34%) had NBD and 70 patients (66%) LBD. Weight was the only parameter showing a significant difference ( P = .034), namely, among NBD it was 80.44 ± 15.13 versus LBD 73.94 ± 14.54 kg, respectively. Creatinine clearance (CCr) tended to be lower among patients with LBD 59.62 ± 22.73 versus 69.59 ± 28.15 mL/min in patients with NBD ( P = .052). PTHi levels were higher in patients with LBD (149.39 ± 110.75) than those with NBD (110.94 ± 82.61) ( P = .069). In the multivariate analysis the important determinants were weight Exp(ß) = 0.967 [CI = 0.939 to 0.996] ( P = .036); CCr Exp(ß) = 0.982 [CI = 0.965 to 1.000] ( P = .055); and PTHi levels Exp(ß) = 1.003 [CI = 0.932 to 0.994] ( P = .059). Conclusions Osteopenia and osteoporosis are frequent among kidney transplant patients (66%), with a similar distribution between the lumbar spine and femoral neck. Excess weight and possibly better renal function may be protective factors. The cumulative steroid dose showed a significant effect on bone density. As expected, secondary hyperparathyroidism in patients with renal impairment seemed to be a risk factor for LBD.