Prevalence of low trauma fractures in long-term kidney transplant patients with preserved renal function

ABSTRACT

We evaluated the prevalence of low bone mineral density (BMD) and osteoporotic fractures in kidney transplantation (KT) patients and determined risk factors associated with osteoporotic fractures. The study was conducted on 191 patients (94 men and 97 women) with first KT for 3 years or more presenting stable and preserved renal function (serum creatinine levels lower than 2.5 mg/dl). KT patients were on immunosuppressive therapy and the cumulative doses of these drugs were also evaluated. BMD was determined by dual-energy X-ray absorptiometry at multiple sites (spine, femur and total body). Quantitative ultrasound of the calcaneus (broadband ultrasound attenuation, speed of sound, and stiffness index, SI) was also performed. Twenty-four percent (46) of all patients had either vertebral (29/46) or appendicular (17/46) fractures. We found osteoporosis and osteopenia in 8.5-13.4 and 30.9-35.1 percent of KT patients, respectively. Women had more fractures than men. In women, prevalent fractures were associated with diabetes mellitus [OR = 11.5, 95 percent CI (2.4-55.7)], time since menopause [OR = 3.7, 95 percent CI (1.2-11.9)], femoral neck BMD [OR = 1.99, 95 percent CI (1.4-2.8)], cumulative dose of steroids [OR = 1.1, 95 percent CI (1.02-1.12)] and low SI [OR = 1.1, 95 percent CI (1.0-1.2)]. In men, fractures were associated with lower lumbar spine BMD [OR = 1.75, 95 percent CI (1.1-2.7)], lower SI [OR = 1.1, 95 percent CI (1.03-1.13)], duration of dialysis [OR = 1.3, 95 percent CI (1.13-2.7)], and lower body mass index [OR = 1.24, 95 percent CI (1.1-1.4). Our results demonstrate high prevalence of low BMD and osteoporotic fractures in patients receiving a successful kidney transplant and indicate the need for specific intervention to prevent osteoporosis in this population.