Short-term Aerobic Exercise Reduces Nitroglycerin-induced Orthostatic Intolerance in Older Adults With Type 2 Diabetes

Aims/Hypothesis: Older adults are at a high risk for syncope due to orthostatic intolerance (OI), and this risk increases with comorbid type 2 diabetes and vasoactive medications. Despite many benefits, previous investigations have shown worsening OI with aerobic training. We examined whether aerobic exercise reduced OI in older adults with type 2 diabetes who were given a short-acting vasoactive agent (nitroglycerin). Methods: Forty older adults (25 males and 15 females, mean age 71.4 +/- 0.7 years, ranging in age from 65 to 83 years) with type 2 diabetes were recruited. Subjects were randomized to each of 2 groups: an aerobic group (3 months of vigorous aerobic exercise) and a nonaerobic (no aerobic exercise) group. Exercise sessions were supervised by a certified exercise trainer 3 times per week. After being given 400 mu g of sublingual nitroglycerin, each subject was placed in a 70 degrees head-up tilt for 30 minutes. Results: When the 2 groups were compared using a Cox proportional hazards model, tilt table tolerance was significantly better in the aerobic group as compared to in the nonaerobic group (chi(2)(MC) = 7.271, P = 0.007). Conclusions: Our findings indicate that a relatively short aerobic exercise intervention can improve postnitroglycerin orthostatic tolerance in older adults with type 2 diabetes.