Myocardial Function Improves Over The Year After Two 16-week HIIT Rounds In Metabolic Syndrome Patients.

Metabolic syndrome (MS) is associated with the development of myocardial dysfunction. Among people with MS, global longitudinal strain (GLS) allows the identification of subclinical changes in myocardial function as observed after High-intensity interval training (HIIT). However, It is unknown, whether separate HIIT rounds can have a cumulative effect and attenuate the deterioration that GLS undergoes over time. PURPOSE: To follow the changes in GLS and its association with other parameters of cardiometabolic health in middle-aged adults with MS after 2 rounds of 16-week HIIT separated by a year. METHODS: Eighty-eight middle-aged adults (62 ± 7 yo) with MS were randomly allocated in one of two groups: i). HIIT: Two rounds of 16-week HIIT (stationary bike, 43 minutes/session, 3 times/week) plus regular medical treatment or ii) CONTROL: Medical treatment. Systolic and diastolic function from an echocardiogram, cardiorespiratory fitness, and MS components were assessed at baseline, at the end of the first round of 16-week HIIT, and after the second round of 16-week HIIT (68 weeks after baseline). Mixed-model ANOVA analyzed variables, while pairwise comparisons were conducted with Bonferroni adjustment. RESULTS: Sixty-five participants completed the study. Main variables at baseline, and after each of the two HIIT rounds (16 and 68 weeks) are displayed in the table. GLS only improved after the second HIIT round. GLS changes correlated only with changes in left ventricle ejection fraction (LVEF; -0.388; p = 0.001), E wave velocity (-0.302; p = 0.014, E/A waves velocity ratio (-0.280; p = 0.024), and left ventricular mass index (LVMI; -0.367; p = 0.003). CONCLUSIONS: Among middle-aged adults with MS, HIIT provides a cumulative improvement of myocardial function, that is associated with changes in mitral inflow filling and is independent of the improvement in cardiorespiratory fitness, and body weight/composition. - * Different from CONTROL at the same time point. † Different from Baseline Baseline 16 weeks 68 weeks time P group*time P CONTROL HIIT CONTROL HIIT CONTROL HIIT GLS % -17.6 ± 1.9 -17.1 ± 1.9 -17.5 ± 2.5 -17.8 ± 2.1 -17.2 ± 2.4 -18.3 ± 1.6*† 0.144 0.004 LVEF % 61.2 ± 2.6 61.0 ± 5.1 61.4 ± 4.0 61.3 ± 4.9 60.1 ± 5.1 63.1 ± 4.6*† 0.595 0.002 E Wave velocity m/seg 0.65 ± 0.11 0.70 ± 0.16 0.70 ± 0.14 0.72 ± 0.16 0.72 ± 0.13 0.80 ± 0.13 <0.001 0.202 E/A velocity ratio m/seg 0.96 ± 0.27 0.93 ± 0.26 1.04 ± 0.33 0.88 ± 0.22 * 0.90 ± 0.19 0.96 ± 0.16 0.500 <0.001 e' wave velocity m/seg 0.089 ± 0.028 0.085 ± 0.024 0.084 ± 0.019 0.086 ± 0.024 0.083 ± 0.016 0.092 ± 0.015 0.468 0.053 E/e' waves ratio 8.1 ± 2.9 8.5 ± 2.3 8.6 ± 2.6 8.7 ± 2.2 8.8 ± 2.3 8.7 ± 1.4 0.172 0.593 LVMI g/m2 68.3 ± 19.4 72.8 ± 13.8 67.8 ±17.0 70.5 ± 14.1 84.7 ± 21.6 † 65.3 ± 15.3 *† 0.001 <0.001 Body weight kg 90.5 ± 15.5 92.0 ± 13.1 90.1 ± 15.1 90.7 ± 13.2 91.3 ± 15.4 89.7 ± 12.6 † 0.057 <0.001 VO2max L/min 2.20 ± 0.61 2.45 ± 0.60 2.23 ± 0.60 2.74 ± 0.63*† 2.13 ± 0.61 2.76 ± 0.76*† 0.014 <0.001 MS z-score -0.22 ± 0.70 -0.11 ± 0.53 -0.09 ± 0.65 -0.01 ± 0.56 0.02 ±0.55 -0.21 ± 0.51 † 0.087 0.002 Supported by: Spanish Ministry of Science, Innovation, and Universities (Project PID2020-116159RB-I00)