Endocrine Abstracts

Background: Renal dysfunction is known to be more prevalent amongst patients with obesity. Metabolic and bariatric surgery is associated with positive renal effects through intricate pathways. We aimed to determine the short-term impact of laparoscopic sleeve gastrectomy (LSG) on renal function and to identify parameters associated with its variation.

Materials and methods: We performed a retrospective study on 268 patients (115 males and 153 females) evaluated before and six months after LSG. Clinical and anthropometrical data were collected, as well as an extensive biological panel and body composition assessment using whole-body dual-energy X-ray absorptiometry (DXA). CKD-Epi (2021) formula was used to estimate glomerular filtration rate (eGFR) both pre- and postoperatively.

Results: Mean baseline BMI was 44.25 kg/m² (± 6.17 kg/m²) and mean 6 months excess weight loss percentage (EWL) was 70.04% (±17,38%). Diabetes mellitus (DM) and hypertension had a prevalence of 18.3 and 50% respectively. Mean eGFR (ml/min/1.73 m²) was 87,68 (15.92), with a cumulative prevalence of mild and moderate renal dysfunction of 55.2%. The prevalence of renal hyperfiltration was surprisingly low (0.7%). Six months postoperatively, mean eGFR increased to 93.23 (P<0.001) and the prevalence of renal dysfunction decreased to 40.7%. Interestingly, this improvement correlated with EWL (rho=-0.307, P=0.001), total lean mass (rho=-0.257, P=0.012) and appendicular skeletal muscle mass index (ASMI; rho=-0.264, P=0.01) variations in males, as opposed to total visceral adipose tissue (VAT) mass (rho=-0.235, P=0.01) and LDL cholesterol (rho=-0.187, P=0.02) variations in females. Of these, EWL, VAT mass and LDL cholesterol variations were independent predictors in a model adjusted for the remission of either hypertension or DM.

Discussion and conclusions: Our results are in line with previous findings on the positive impact of LSG on renal function. Hyperfiltration is thought to be associated with early stages of obesity-related glomerulopathy and its low prevalence suggests delayed presentation in our cohort. The identified differences might point to gender-specific drivers of kidney dysfunction associated with obesity and its resolution. Specifically, visceral adiposity seems to play a more prominent role in females. If confirmed by further studies, this could aid in the optimization of medical treatment.