Exercise Training Normalizes Left Ventricular Diastolic Dysfunction in Type 2 Diabetes

Abstract

Left ventricular diastolic dysfunction (LVDD) is common in type 2 diabetes (T2DM) and often progresses to heart failure. PURPOSE: To examine exercise training effects on LV diastolic function. METHODS: Persons, aged 40-65 years old, with uncomplicated T2DM without clinical heart disease or impaired systolic function were randomized to supervised aerobic and resistance training 3 times per week for 6 months or to a control group that were advised to increase physical activity. Forty-one exercisers (27 M; 13 F) and 54 controls (33 M; 21 F) completed the study. LV diastolic grade was evaluated by the echocardiographic parameters of E/A, E/Em, and left atrial (LA) area. Diastolic rating was normal if the grade was 0 or impaired if the grade was 1 to 3 (mild to severe). Maximal oxygen uptake was determined on a treadmill; strength was expressed as the sum of 1-repetition maximum on 7 weight exercises; body fat was determined by dual-energy x-ray absorptiometry. RESULTS: At baseline, there were no group differences for age, 57.1 ± 5.8 years; maximal oxygen uptake, 22.2 ± 5.1 ml/kg/min; strength, 927.5 ± 258.5 lbs; body fat, 35.4 ± 7.4 %; E/A, 0.96 ± 0.21; or E/Em, 9.21 ± 2.3. LA area was higher in controls versus exercisers, 17.3 ± 2.67 vs. 15.7 ± 3.0 cm2. At baseline, both groups had similar diastolic grade distribution: 64% had normal diastolic function (grade 0) and 36% were impaired (15%, grade 1; 21% grade 2). After training, fitness increased and body fat decreased in exercisers vs. controls, (all p's < 0.01). Seventy-nine % of exercisers had normal LV diastolic function and 21% were impaired (3%, grade 1; 15%, grade 2; 3%, grade 3) whereas 51% of controls were normal and 49% were impaired (19%, grade 1, 30% grade 2), (p < 0.01). Compared to baseline, diastolic rating improved in 21% and worsened in 8% of exercisers, whereas in controls 15% improved and 28% worsened (p = 0.04). The improvement in diastolic grade in exercisers was accounted for by an increase in E/A to 1.06 ± 0,21 vs. 0.95 ± 0.21 for controls, (p < 0.02). E/Em or LA area did not change in either group. CONCLUSION: Exercise training increased fitness and decreased fatness. The novel finding was that among persons with T2DM, exercisers had more reversal and controls had more progression of LVDD. Supported by NIH Grant RO1DK062368 and UL1 RR 025005.