Effects of reduced retroperitoneal adipose tissue and kidney volume on renal function and blood pressure following metabolic surgery in patients with severe obesity.

Background: Patients with severe obesity have glomerular hyperfiltration even without the overt renal dysfunction, but improvements are reported with metabolic surgery (MS). However, the mechanism underlying these effects of MS has not been investigated.

Objective: The aim of the present study was to determine whether MS for patients with severe obesity alters retroperitoneal adipose tissue (RAT) and kidney volume (KV), and whether these alterations lead to improvements in renal function and hypertension (HTN).

Setting: University hospital, Japan.

Methods: This single-center study included 80 patients with severe obesity who underwent laparoscopic sleeve gastrectomy (LSG). RAT, KV, body weight, and metabolic-related parameters were evaluated using computed tomography volumetry preoperatively and 1 year after LSG and correlations were analyzed.

Results: All patients were seen as per protocol. RAT (1149.5 vs 734.5 mL) and KV (right 218.5 vs 201 mL, left 220 vs 206.5 mL) were significantly decreased at 1 year after LSG. Significant reductions were observed in the personalized estimated glomerular filtration rate (103.5 vs 93.7 mL/min), standard estimated creatinine clearance (eCrCl) (157.2 vs 134.8 mL/min/1.73 m²), and personalized eCrCl (200.4 vs 153.4 mL/min/1.73 m²) (all P < .001). The degree of change in RAT was correlated with the degree of change in the personalized eCrCl (ρ = .219, P = .005). The rate of change in KV was correlated with the rate of change in the standard/personalized eCrCl (ρ = .232, P = .043, ρ = .232, P = .043).

Conclusion: LSG reduced body weight in patients with severe obesity and reduction of glomerular hyperfiltration and HTN correlating with RAT and KV reduction.