Remission and progression of pre-existing micro- and macroalbuminuria over 15 years after bariatric surgery in Swedish Obese Subjects study

BACKGROUND: Bariatric surgery reduces incidence of albuminuria and end-stage renal disease in patients with obesity. Effects of bariatric surgery on long-term remission and progression of pre-existing obesity-related renal damage are mainly unexplored. Here we investigate the long-term effects of bariatric surgery compared with conventional obesity care on remission and progression of albuminuria. METHODS: 4047 patients were included in the Swedish Obese Subjects study. Inclusion criteria were age 37-60 years, BMI ≥ 34 kg/m(2) in men and BMI ≥ 38 kg/m(2) in women. Our analysis comprised 803 patients (19.8% of total population, 357 control, 446 surgery) with pre-existing albuminuria including 693 patients (312 control, 381 surgery) with microalbuminuria, and 110 patients (45 control, 65 surgery) with macroalbuminuria. Surgery patients were treated with banding, vertical banded gastroplasty, or gastric bypass. Control patients received conventional obesity care. RESULTS: Total urinary albumin excretion was 36.5% lower in all patients with albuminuria after 15 years, 44.5% lower in patients with microalbuminuria after 15 years, and 27.8% lower in patients with macroalbuminuria after 2 years following bariatric surgery compared with conventional care. In surgery patients with microalbuminuria, remission to normoalbuminuria was higher (OR, 5.9, 2.2, 3.2, p