Effects of Bisphosphonate Treatment on Circulating Lipid and Glucose Levels in Patients with Metabolic Bone Disorders

Bisphosphonates are the first-choice treatment of osteoporosis and Paget's disease of bone. Among the bisphosphonates, the non-amino-bisphosphonates, such as clodronic acid, are intracellular converted into toxic analogues of ATP and induce cellular apoptosis whereas the amino-bisphosphonates, such as zoledronic acid, inhibit the farnesyl-diphosphate-synthase, an enzyme of the mevalonate pathway. This pathway regulates cholesterol and glucose homeostasis and is a target for statins. In this retrospective cohort study, we evaluated the effects of an intravenous infusion of zoledronic acid (5 mg) or clodronic acid (1500 mg) on blood lipid (i.e. total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol and triglycerides) and glucose levels in patients with osteoporosis and Paget's disease of bone. All patients were evaluated before, 1 and 6 months after bisphosphonate treatment. Pagetic and osteoporotic patients treated with zoledronic acid showed a significant reduction in glucose and atherogenic lipids during follow-up whereas these phenomena were not observed after clodronic treatment. The effect on circulating lipid levels was similar in naïve and re-treated Pagetic patients. Zoledronic acid treatment was associated with a reduction in blood glucose and atherogenic lipids in patients with metabolic bone disorders. The extent of change was similar to that obtained with the regular assumption of a low-intensity statin. Further studies are warranted to better evaluate the clinical implications of these observations.