ODP595 Case Series Of Idiopathic Hypercalciuria And Secondary Osteoporosis

BACKGROUND: Secondary causes for low bone density may be present in 30% of women and up to 50% of men with low bone density and osteoporosis. Idiopathic hypercalciuria is associated with lower bone density and higher bone turnover, and an increased risk of fractures. Thiazide diuretics have been used often for treatment for idiopathic hypercalciuriaCase Series: We present a case series of 9 patients who presented for low or declining bone density. They underwent workup for secondary causes of osteoporosis and were noted to have idiopathic hypercalciuria with high bone turnover on initial evaluation. They were started on thiazide diuretics or amiloride and the dose titrated up daily based on their blood pressure tolerance. They were monitored for hypokalemia and hyponatremia. Several of these patients exhibited a > 30% decrease in bone resorption, as measured by urine N-telopeptide on a second fasting specimen. Follow-up bone density at 1 year and 3-year after starting diuretic therapy showed stability or significant increase in bone density. Some of these patients were able to maintain bone density in the osteopenic range on follow up for > 6 years. CONCLUSION: Some patients with idiopathic hypercalciuria may have a more robust response to thiazide diuretics compared to others even in the absence of anti-resorptive therapy. Significant reduction of > 30% in bone resorption markers may identify patients who are more likely to have a robust response in the bone density after starting thiazide medications. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.