Comparison of rates and risk factors for development of osteoporosis and fractures after radical or partial nephrectomy.

Objective: To examine incidence of and risk factors for development of osteoporosis and fractures in patients who underwent radical nephrectomy (RN) and partial nephrectomy (NSS), as osteoporosis is an important cause of morbidity in chronic kidney disease.

Methods: This was a retrospective review of 905 patients (mean age 57.5 years, mean follow-up 6.4 years) who underwent RN or NSS for renal tumors at 2 institutions from July 1987 to June 2007. Demographics, renal function, metabolic parameters, and history of preoperative and postoperative osteoporosis and fractures were recorded. Data were analyzed within subgroups based on treatment (RN vs NSS). Multivariate analysis was conducted to elucidate risk factors for developing osteoporosis following surgery.

Results: A total of 610 patients underwent RN and 295 underwent NSS. Tumor size (cm) was significantly larger for RN (RN 7.0 vs NSS 3.7, P<.0001). No significant differences were noted with respect to demographic factors and preoperative osteoporosis (RN 8.7% vs NSS 9.5%, P=.785) and fractures (RN 1.7% vs NSS 0.7%, P=.382). Postoperatively, significantly less osteoporosis (NSS 12.5% vs RN 22.6%, P<.001) and fewer fractures (NSS 4.4% vs RN 9.8%, P=.007) developed in the NSS cohort. MVA demonstrated female (OR 1.85, P=.001), Caucasian (OR 2.33, P<.0001), preoperative eGFR<60 mL/min/1.73 m2, (OR=3.02, P<.0001), preoperative metabolic acidosis (OR=4.22, P=.0006), and RN (OR 2.59, P<.0001) were risk factors for developing osteoporosis.

Conclusions: Patients undergoing RN had a significantly higher incidence of osteoporosis and fractures compared with a well-matched cohort of patients who underwent NSS. In addition to RN, female gender, Caucasian background, preoperative eGFR<60, and preoperative metabolic acidosis were associated with developing osteoporosis.