Diabetics bear no extra heart burden after intense exercise

High-intensity exercise induces comparable cardiac responses in type 2 diabetes (T2D) patients vs healthy individuals, a recent study has found.

Researchers enrolled seven men with T2D (mean age 55.9 years) and seven age- and sex-matched healthy controls (mean age 56.1 years). Participants were made to undergo four sets of high-intensity aerobic exercises, each for 4-minute intervals at 90–95 percent of the maximal heart rate. Echocardiography was performed before and 30 minutes after the exercise protocol.

While peak oxygen uptake was significantly lower in diabetics (33.1 vs 44.0 mL min^–1 kg^–1; p<0.01), peak heart rate was comparable between the T2D and control arms (181 vs 175 beats min^–1, respectively). Similarly, blood biomarkers were largely comparable between groups.

In terms of cardiac response to exhaustive exercise, the researchers documented only one parameter that significantly differed between groups: end-diastolic intraventricular septum thickness, which grew by 1.5 mm in controls and decreased by 0.3 mm in T2D patients after exercise (p<0.05).

Of note, while the cardiac responses to exercise were statistically comparable between groups, there were still significant within-group changes. For example, early diastolic mitral annular velocity dropped to 1.4 and 0.8 cm/s in the control and diabetic arms, respectively, both representing significant changes from baseline (p<0.05). A similar effect was reported for mitral inflow peak early diastolic velocity.

“Th­e present study found no major differences in the cardiac response to acute exhaustive exercise between the patients with T2D and the healthy controls,” the researchers said, pointing out that cardiac function was acutely compromised to similar degrees in both groups.

“The comprehensive and blinded echocardiographic and electrophysiological analyses provided valuable information regarding the acute cardiac responses to high-intensity training in patients with T2D versus healthy controls and provided hypotheses for future research,” they added.