The effect of exercise on cardiac function in patients with type 2 diabetes and diastolic dysfunction

Abstract

Background: Type 2 diabetes mellitus (T2DM) is associated with diastolic dysfunction (DD), which could ultimately lead to heart failure. Purpose: To compare the effect of high-intensity exercise (HIE) and moderate-intensity exercise (MIE) in accordance to present recommendations in patients with T2DM (duration <10 years) and DD. Methods: 47 subjects (mean age 56,6 years, 31 male) with DD defined as early diastolic tissue velocity (E') < 8 m/s were included and randomized to HIE (4x4minutes) at 90-95% of HRmax 3 times/week (n=24) or MIE for 210 minutes/week (n=23), both for 12 weeks. Subjects were examined with echocardiography including tissue Doppler, VO2peak-test and biochemical measurements pre- and post exercise. Results: There were no difference between groups at baseline and 38 completed the intervention (MIE n=17 and HIE n=21). HIE significantly improved DD; E' by 21%, early mitral filling velocity (E) by 16% and shortened isovolumic relaxation time (IVRT) by 11% (Table). Systolic tissue Doppler velocity (S') increased with 15% and stroke volume with 11%, waist circumference (WC) reduced with 2 cm, VO2peak increased with 4.1 ml/kg/min, HbA1c reduced with 6% (Table). The MIE group reduced WC with 2,1 cm and reduced insulin resistance (IR) with 8% (Table). There were no changes in resting heart rate or blood pressure (BP) after intervention. View this table: Baseline- and post exercise results Conclusions: In patients with T2DM with duration <10years, HIE improved DD and decreased HbA1c, in contrast to present recommendations of MIE. This could have future implications on today's exercise recommendations.