Impact of combined training with different exercise intensities on inflammatory and lipid markers in type 2 diabetes : a secondary analysis from a 1-year randomized controlled trial

Abstract

Background: Exercise is a well-accepted strategy to improve lipid and infammatory profle in individuals with type 2 diabetes (T2DM). However, the exercise intensity having the most benefts on lipids and infammatory markers in patients with T2DM remains unclear. We aimed to analyse the impact of a 1-year combined high-intensity interval training (HIIT) with resistance training (RT), and a moderate continuous training (MCT) with RT on infammatory and lipid profle in individuals with T2DM. Methods: Individuals with T2DM (n=80, aged 59 years) performed a 1-year randomized controlled trial and were randomized into three groups (control, n=27; HIIT with RT, n=25; MCT with RT, n=28). Exercise sessions were super‑ vised with a frequency of 3 days per week. Infammatory and lipid profles were measured at baseline and at 1-year follow-up. Changes in infammatory and lipid markers were assessed using generalized estimating equations. Results: After adjusting for sex, age and baseline moderate-to-vigorous physical activity (MVPA), we observed a time-by-group interaction for Interleukin-6 (IL-6) in both the MCT with RT (β=−0.70, p=0.034) and HIIT with RT (β=−0.62, p=0.049) groups, whereas, only the HIIT with RT group improved total cholesterol (β=−0.03, p=0.045) and LDL-C (β=−0.03, p=0.034), when compared to control. No efect was observed for C-reactive protein (CRP), cortisol, tumour necrosis factor-α (TNF-α), soluble form of the haptoglobin-hemoglobin receptor CD163 (sCD163), triglycerides and HDL-C in both groups (p>0.05). Conclusions: Favorable adaptations on IL-6 were observed in both the HIIT and MCT combined with RT groups fol‑ lowing a long-term 1-year exercise intervention in individuals with T2DM. However, only the HIIT with RT prevented further derangement of total cholesterol and LDL-C, when compared to the control group. Therefore, in order to encourage exercise participation and improve infammatory profle, either exercise protocols may be prescribed, however, HIIT with RT may have further benefts on the lipid profle.