Exercise training improves hemodynamic recovery to isometric exercise in obese men with type 2 diabetes but not in obese women

Abstract

Objectives: Women with type 2 diabetes (T2D) show greater rates of mortality due to ischemic heart disease than men with T2D. We aimed to examine cardiovascular and autonomic function responses to isometric handgrip (IHG) exercise between men and women with T2D, before and after an exercise training program.

Materials/methods: Hemodynamic responses were measured in 22 men and women with T2D during and following a 3-min IHG test, and before and after 16 wks of aerobic exercise training.

Results: Women had a smaller decrease in mean arterial pressure (MAP) and systolic blood pressure (BP) during recovery from IHG (ΔMAP(REC)) than men pre- and post-training (P<0.05). Men showed a greater reduction in diastolic BP during recovery from IHG (P<0.05), and exercise training improved this response in men but not in women (men, pre-training: -13.9±1.8, post-training: -20.5±5.3 mmHg vs. women, pre-training: -10.7±1.7, post-training: -4.1±4.9 mmHg; P<0.05). Men had a greater reduction in sympathetic modulation of vasomotor tone (P<0.05), as estimated by blood pressure variability, following IHG. This response was accentuated after training, while this training effect was not seen in women. Post-training ΔMAP(REC) was correlated with recovery of low frequency component of the BP spectrum (ΔLF(SBPrec), r=0.52, P<0.05).

Conclusions: Differences in BP recovery immediately following IHG may be attributed to gender differences in cardiovascular autonomic modulation. An improvement in these responses occurs following aerobic exercise training in obese men, but not in obese women with T2D which reflects a better adaptive autonomic response to exercise training.

Figure 1

A. Mean arterial pressure (MAP) at rest, during isometric handgrip exercise and recovery both before and after 16 weeks of aerobic training (n=10 men, n=12 women). B. The absolute change in MAP from handgrip to recovery (ΔMAP_REC). (*P<0.05 gender difference; †P<0.05 gender by training interaction), mean ± SE.

Figure 2

The effect of IHG exercise on low frequency power of systolic blood pressure spectrum (lnLF_SBP) before and after 16 weeks of aerobic training. B. The absolute change in lnLF_SBP from handgrip and recovery. (†P<0.05 training by gender interaction; **P<0.01 main effect of training, ‡P<0.05 main effect of gender), mean ± SE.