Inspiratory Muscle Strength Training to Improve Cardiometabolic Health in Patients with Type 2 Diabetes Mellitus

Abstract

Type 2 diabetes mellitus (T2DM) is a complex, chronic metabolic disease that is associated with a high prevalence of comorbid conditions. Traditional lifestyle interventions (e.g., diet and exercise) can counter some adverse effects of T2DM; however, participation in these activities is low. High-resistance inspiratory muscle strength training (IMST) is a time-effcient and simple breathing exercise that significantly reduces blood pressure (BP) and improves vascular endothelial function in several nondiabetic populations. Herein, we performed a blinded, randomized, sham-controlled trial to investigate the effects of a 6-week IMST regimen (30 breaths/day, 6 days/week) on glycemic control and insulin sensitivity in adults with T2DM. Currently, we have eight participants (aged 35-71 years, 5 females and 3 males) who have completed either low-resistance sham training (15% maximal inspiratory mouth pressure, n=5) or high-resistance IMST (75% maximal inspiratory mouth pressure, n=3). Our data suggests that fasting plasma glucose and fasting serum insulin did not significantly change by IMST or sham training. Utilizing a homeostatic model assessment of insulin sensitivity to evaluate insulin action, our results indicate no change by either IMST or sham training. IMST revealed a trend towards a reduction in systolic BP (pre: 133.0 ± 4.8 vs. post: 128.8 ± 4.9) and diastolic BP (pre: 84.8 ± 2.7 vs. post: 81.7 ± 3.6). These findings align with prior research indicating improved resting BP, further corroborating previous studies. We performed an exploratory analysis to examine the potential impact of IMST on lipid levels. Interestingly, IMST resulted in a trend towards a reduction in cholesterol (pre: 259.3 ± 29.4 vs. post: 230.3 ± 3.7) and LDL (pre: 153.3 ± 19.7 vs. post: 127.7 ± 8.7). Analysis of the endothelial function data is forthcoming until we have enough individuals to complete those analyses. In conclusion, our results to date are preliminary; however, we expect to see continued improvements in resting BP and cholesterol/LDL with IMST. Moreover, with a higher number of individuals in the study (our goal is to have 12 in each group), we anticipate seeing changes in glycemia or insulin action. Lastly, IMST stands out as a distinctive and time-effective exercise method, addressing adherence challenges while demonstrating enhancements in cardiometabolic health. This could be particularly advantageous for T2DM patients with an increased cardiovascular disease risk. University of Arizona College of Medicine SPARK Grant. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.