Background: There is a high incidence of acute cardiovascular events in obese subjects.
Objective and hypotheses: We hypothesised that exercise tolerance is different in metabolically healthy (MHO) and metabolically unhealthy (MUO) obese adolescents.
Method: 45 obese adolescents aged 1017 (23 males and 22 females) were examined with an anthropometry, fasting blood glucose, insulin and lipids. IDF criteria were used for grouping for MHO and MUO. Multistage cycle protocol was offered to each participant with further analysis of cardiovascular parameters: resting heart rate (HRr), maximal heart rate (HRm), resting and maximal systolic and diastolic blood pressure (SBPr, SBPm, DBPr, DBPm respectively). Maximal predicted heart rate (MPHR) was calculated by Tanaka formula and HRm in patient was compared with MPHR as a percent of it (%MPHR). Standard statistical methods were used for the data analysis.
Results: The chosen population was homogenous by gender, age, body composition, fasting glucose and insulin levels (P>0.05 for all), resting cardiovascular parameters HRr (P=0.467), SBP (P=0.370) and DBP (P=0.477). There was statistical difference in between groups by the fasting lipids (P for TC=0.003; TG<0.001; HDL=<0.001; FFA=0.002). There was predominantly chronotropic response in MHO with an increasing HRm till 152.714+18.611 vs 137.2+23.917 bpm (P=0.041) and predominantly inotropic response in MUO with an increasing SBPm till 171.222+18.123 vs 149.171+21.467 mmHg (P=0.007). Observed HRm was lower than expected (Chi-Square=767.8897; P=0.0000001). Statistic difference in groups by % MPHR (82.847+12.49 in MHO vs 71.167+10.144 in MUO (P=0.019). Multiple linear regression model was created to predict % MPHR at the top of exercising in obese children (MR=0.695; F (6.34)=5.53; P=0.004). The model includes Lean BMI (b=−0.72; P<0.001), ISI-FFA (b=−0.3; P=0.02), Cholesterol (b=0.52; P=0.001), HDL (b=0.36; P=0.009).
Conclusion: There is an adequate chronotropic reactivity and moderate SBP increasing in MHO. MUO are under the risk of exercise induced chronotropic incompetence, which associated with acute cardiovascular events in studies.
01 Oct 2015 - 03 Oct 2015