Regular aerobic exercise protects against impaired fasting plasma glucose-associated vascular endothelial dysfunction with aging

In the present study, we tested the hypothesis that age-associated vascular endothelial dysfunction is exacerbated by IFG (impaired fasting plasma glucose) and that regular aerobic exercise prevents this effect. Data were analysed from a cohort of 131 non-smoking men and women without overt clinical disease. Compared with young adult controls (age = 24 +/- 1 years, n = 29; values are means +/- S.E.M.), brachial artery FMD (flow-mediated dilation), a measure of conduit artery EDD (endothelium-dependent dilation), was 33% lower [7.93 +/- 0.33 against 5.27 +/- 0.37%Delta (% change), P < 0.05] in MA/O (middle-aged/older) adults with NFG (normal fasting plasma glucose) (<= 99 mg/dl, 62 +/- 1 years, n = 35). In MA/O adults with IFG (100-125 mg/dl, 64 +/- 1 years, n = 28), FMD was 30% lower (3.37 +/- 0.35%Delta) than in their peers with NFG and 58% lower than young controls (P < 0.05). Brachial artery FMD was greater (6.38 +/- 0.35%Delta) in MA/O adults with NFG who regularly performed aerobic exercise (>45 min/day for >= 5 days/week, 62 +/- 1 years, n = 23) compared with their non-exercising peers and only slightly less than young controls (P < 0.05). Most importantly, FMD was completely preserved in MA/O adults with IFG who regularly performed aerobic exercise (6.99 +/- 0.69%Delta, 65 +/- 1 years, n = 16). In the pooled sample, fasting plasma glucose was inversely related to FMD (r = -0.42, P < 0.01) and was the strongest independent predictor of FMD (R-2=0.32). Group differences in FMD were not affected by other subject characteristics or brachial artery properties, including brachial artery dilation to sublingual NTG (nitroglycerine, i.e. endothelium-independent dilation). IFG exacerbates age-associated vascular endothelial dysfunction and this adverse effect is completely prevented in MA/O adults who regularly perform aerobic exercise.