Long-term kidney and systemic effects of calorie restriction in overweight or obese type 2 diabetic patients (C.Re.S.O. 2 randomized controlled trial)

AIMS: In type 2 diabetic patients with obesity, hyperfiltration is a risk factor for accelerated glomerular filtration rate (GFR) decline and is ameliorated by calorie restriction (CR). We assessed whether CR-induced amelioration of hyperfiltration could translate into slower long-term GFR decline in this population. Primary outcome was 6-month measured GFR. Analyses were by modified intention-to-treat. RESULTS: At 6 months GFR decreased by 5.16 ± 10.03 mL/min (P = 0.001) with CR, and by 0.98 ± 9.71 mL/min (P = 0.497) with SD. Between-group difference was significant (P = 0.044). GFR decline from 6 to 24 months was significant with SD (P < 0.01), but not with CR (P = 0.075). Between-group difference, however, was not significant (P = 0.414). Body weight, BMI, waist circumference, systolic blood pressure, HbA1c, blood glucose, serum triglycerides decreased and ApoA-I concentration increased with CR. No changes were observed with SD. Between-group differences were significant. CR was tolerated well. CONCLUSIONS: In obese type 2 diabetic patients, CR ameliorated glomerular hyperfiltration and several cardiovascular risk factors, and blunted long-term GFR decline. TRIAL REGISTRATION: NCT01930136.