Short-term aerobic exercise reduces nitroglycerin-induced orthostatic intolerance in older adults with type 2 diabetes

Abstract

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 μg of sublingual nitroglycerin, each subject was placed in a 70° 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 (χ(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.

FIGURE 1

With respect to the TTT Kaplan–Meier curves, there was a significant difference in the survival curves posttraining in the AT group as compared with the NA group (χ²_MC = 7.271, P = 0.007). The y-axis represents the proportion of subjects in each group tolerating upright tilt, whereas the x-axis shows the duration of upright tilting. The tilt table test was halted if the subject demonstrated presyncopal symptoms (lightheaded-ness or ‘dizziness’) in association with at least a 30-mm Hg drop in blood pressure compared with baseline or developed outright syncope.