Does homocysteine contribute to bone disease in hyperparathyroidism?

Background Osteoporosis is a complication of hyperparathyroidism (HPT). Hyperhomocysteinemia (HHCy) is an independent risk factor for osteoporotic fractures. We hypothesize that HHCy correlates with bone disease in HPT. Methods A prospectively collected database of 250 patients treated for HPT was reviewed. Patients were categorized into 3 groups: group I, normal renal function; group 2, mild renal insufficiency; and group 3, secondary HPT with end-stage renal disease on dialysis. Serum homocysteine levels, markers of bone metabolism, and bone density studies were examined. Results The prevalence of HHCy in group 1 (208 patients) was 5%, in group 2 (23 patients), 82%, and in group 3 (19 patients), 78%. Mean (±SD) preoperative homocysteinemia (HCy) levels in groups 1, 2, and 3 were 9.3 ± 4.0, 20 ± 10.2, and 20.6 ± 12.3 μmol/L, respectively. Elevated serum markers of bone metabolism increased significantly with decreasing renal function. Conclusions Prevalence of HHCy is low in HPT patients with normal renal function. It is significantly greater in those with dialysis-independent and -dependent renal insufficiency. HHCy correlates with other serum markers of bone metabolism in HPT and may be useful for monitoring progression or improvement.