Bisphosphonate therapy improves BMD and lowers the fracture risk in general population. The large randomized trials excluded those with known renal failure.Post hocstudies on the subjects with an estimated eGFR lower than 60 have shown that the fracture reduction was similar to subjects with a normal eGFR.This study was done to evaluate efficacy and safety of bisphosphonates in subjects with various degrees of renal function impairment.