In type-2 diabetics with abdominal obesity, hyperfiltration is a risk factor for accelerated GFR decline and nephropathy. In this academic, single-center, parallel-group, Prospective, Randomized, Open-label, Blinded Endpoint (PROBE) trial (ClinicalTRials.gov number: NCT01213212), consenting >18-year-old, type-2 diabetics with waist circumference >94 (males) or >80 (females) cm, serum creatinine <1.2 mg/dl, and normoalbuminuria were randomized (1:1) with permuted blocks to 6-month 25% CR or standard diet (SD). Primary outcome was measured GFR (iohexol plasma clearance). Analyses were by modified intention-to-treat. At 6 months GFR significantly decreased in 34 patients on CR and did not change appreciably in 36 on SD. Changes were significantly different between groups. GFR and body weight reduction were correlated. GFR reduction was larger in hyperfiltering (GFR >120 ml/min) than non-hyperfiltering patients, and associated with body mass index, waist circumference, blood pressure, heart rate, HbA1C, blood glucose, LDL/HDL cholesterol ratio, C-reactive protein, Angiotensin-II, and albuminuria reduction and with increased glucose disposal rate (measured by hyperinsulinemic euglycemic clamps). Protein and sodium intake and concomitant treatments were similar between groups. CR was tolerated well. In Type-2 diabetics with abdominal obesity, CR ameliorates glomerular hyperfiltration, insulin sensitivity and other cardiovascular risk factors, effects that might translate into long-term nephro- and cardio-protection.
- Received May 11, 2016.
- Accepted August 21, 2016.
- © 2016 by the American Diabetes Association.