GLUCOSE-TOLERANCE AND INSULIN ACTION IN HEALTHY CENTENARIANS

Advancing age has been found to be associated with a decline in insuli n action. Nevertheless, no study has been conducted in healthy centena rians. Our study investigates glucose tolerance and insulin action in centenarians. Fifty-two subjects were enrolled. The subjects were divi ded in three groups as follows: 1) adults (<50 yr; n = 20); 2) aged su bjects (>75 yr; n = 22); and 3) centenarians (>100 yr; n = 14). Body c omposition was studied by bioimpedance analysis. In all subjects, an o ral glucose tolerance test and euglycemic glucose clamp were performed . Centenarians have a lower fat-free mass (FFM) than aged subjects and adults, whereas fasting plasma glucose, triglycerides, free fatty aci ds, urea, and creatinine were not different in the groups studied. Cen tenarians had a 2-h plasma glucose concentration (6.0 +/- 0.2 mmol/l) that was lower than that in aged subjects (6.6 +/- 0.5 mmol/l, P < 0.0 5) but not different from adults [6.4 +/- 0.4 mmol/l, P = not signific ant (NS)]. During the clamp, plasma glucose and insulin concentrations were similar in the three groups. In these conditions, centenarians h ad a whole body glucose disposal (34.1 +/- 0.6 mu mol . kg FFM(-1) min (-1)) that was greater than that in aged subjects (23.3 +/- 0.5 mu mol . kg FFM(-1) min(-1) P < 0.01) but not different from adults (34.6 +/ - 0.5 mu mol/kg x min, P = NS). In conclusion, our study demonstrates that centenarians compared with aged subjects had a preserved glucose tolerance and insulin action.