SAT-637 Impact of Weight Loss Through Non-Surgical Approaches on Kidney Stone Risk

Abstract K. Feghali: None. N. Maalouf: None. X. Li: None. Introduction: Obesity and weight gain are independent risk factors for the development of kidney stones. The impact of weight loss through non-surgical modalities on nephrolithiasis is not well-understood. We hypothesize that weight reduction through recently approved pharmacotherapies, such as GLP-1 receptor agonists (GLP-1 RA) and dual GLP-1 and GIP receptor agonists (GIP RA), may prevent stone formation. Methods: We conducted a retrospective analysis of electronic health records to investigate the impact of weight loss on kidney stone risk at an academic medical center’s multidisciplinary weight management program. We included patients with kidney stones, age ≥ 18 years who have had at least 2 encounters ≥ 6 months apart from September 2015 through June 2023 and who have had at least two 24 h urine collections for assessment of stone risk ≥ 6 months apart. We abstracted data on demographic information, prior medical and surgical history, patient weight, and medication use. Patients with prior bariatric surgery were excluded from our analysis. Two treatment approaches were predefined for this analysis (1) GLP-1-RA or dual GLP-1 and GIP RA-based weight loss pharmacotherapy alone (GLP group) and (2) nonpharmacologic weight-management interventions that included dietary, activity, and behavioral counseling (conservative group). The primary outcome was the change in the risk of stone disease assessed by urine supersaturation levels of calcium oxalate (CaOx) before and after weight loss among the two treatment approaches. Results: We included 23 patients in the GLP group and 14 patients in the conservative group. The cohort was predominantly white (73%) and female (65%) with an average age of 61 years. The majority of stones were CaOx in composition. The baseline BMI was 35 kg/m2. The average follow-up duration was 1.6 years. Average weight loss was 4.7±5.3 kg in the GLP group and 2.8±2.6 kg in the conservative group. There was no statistical difference in urine supersaturation levels of calcium oxalate (6.5±3.8 to 6.9±4.1 in GLP vs 5±2 to 4.7±4.1 in conservative; p=0.27), urine calcium (258±150 to 218±128 mg/day in GLP vs 258±143 to 201±101 mg/day in conservative; p=0.91) and urine oxalate (33±16 to 30±9 mg/day in GLP vs 37±13 to 29±9 in conservative; p=0.16), before and after weight loss among the two groups. Conclusion: Our urine results indicate that the newly approved pharmacotherapies for weight loss, such as GLP-1RA and dual GLP-RA and GIP RA, do not increase the risk of kidney stone formation, unlike what happens with bariatric surgery. Additional larger prospective studies are needed to further assess the impact of these drugs on kidney stones. Saturday, June 1, 2024