Increased lactate release per fat cell in normoglycemic first-degree relatives of individuals with type 2 diabetes

The aim of this study was to examine subcutaneous lactate production in the relatives of individuals with type 2 diabetes. Therefore, we recruited sev en healthy first-degree relatives of type 2 diabetic patients and seven pai rwise, matched, healthy control subjects without any heredity for diabetes. All subjects were studied with a euglycemic insulin clamp at similar to 60 0 pmol/l, abdominal subcutaneous microdialysis, and Xe-133 clearance. Furth ermore, a subcutaneous needle biopsy was performed to determine fat cell si ze. In the fasting state, interstitial lactate was 40% higher in relatives than in control subjects (P = 0.043), but net lactate production was simila r in both groups. However, during the insulin clamp, interstitial lactate ( 2.50 +/- 0.29 vs. 1.98 +/- 0.26 mmol/l, P = 0.018), interstitial-arterial l actate concentration difference (1.08 +/- 0.30 vs. 0.53 +/- 0.24 mmol/l, P = 0.028), and net lactate release. Ver fat cell (10.9 +/- 3.7 vs. 2.8 +/- 1 .3 fmol . cell(-1) . min(-1), P = 0.018) were increased in the relatives. W e conclude that first-degree relatives of type 2 diabetic patients may have an enhanced net lactate release per fat cell in abdominal subcutaneous tis sue. This could suggest a pathological regulation in adipose tissue that is of importance for the metabolic defects known in type 2 diabetic relatives .