Inspiratory Muscle Training on Glucose Control in Diabetes: A Randomized Clinical Trial
in International Journal of Sport Nutrition and Exercise MetabolismThis study evaluated the effects of inspiratory muscle training (IMT) in glucose control and respiratory muscle function in patients with diabetes. It was a randomized clinical trial conducted at the Physiopathology Laboratory of the Hospital de Clínicas de Porto Alegre. Patients with Type 2 diabetes were randomly assigned to IMT or placebo-IMT (P-IMT), performed at 30% and 2% of maximal inspiratory pressure, respectively, every day for 12 weeks. The main outcome measures were HbA1c, glycemia, and respiratory muscle function. Thirty patients were included: 73.3% women, 59.6 ± 10.7 years old, HbA1c 8.7 ± 0.9% (71.6 ± 9.8 mmol/mol), and glycemia 181.8 ± 57.8 mg/dl (10.5 ± 3.2 mmol/L). At the end of the training, HbA1c was 8.2 ±0.3% (66.1 ± 3.3 mmol/mol) and 8.7 ± 0.3% (71.6 ± 3.3 mmol/mol) for the IMT and P-IMT groups, respectively (p = .8). Fasting glycemia decreased in both groups with no difference after training although it was lower in IMT at 8 weeks: 170.0 ± 11.4 mg/dl(9.4 ± 0.6 mmol/L) and 184.4 ± 15.0 mg/dl (10.2 ± 0.8 mmol/L) for IMT and P-IMT, respectively (p < .05). Respiratory endurance time improved in the IMT group (baseline = 325.9 ± 51.1 s and 305.0 ± 37.8 s; after 12 weeks = 441.1 ± 61.7 s and 250.7 ± 39.0 s for the IMT and P-IMT groups, respectively; p < .05). Considering that glucose control did not improve, IMT should not be used as an alternative to other types of exercise in diabetes. Higher exercise intensities or longer training periods might produce better results. The clinical trials identifier is NCT 03191435.
Pinto and Schaan are with the Cardiology Program, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. Pinto, Bock, Schein, Portes, Monteiro, and Schaan are with the Exercise Pathophysiology Research Laboratory, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil. Bock is with the Faculdades Integradas de Taquara, Taquara, Rio Grande do Sul, Brazil. Bock and Schaan are with the National Institute of Science and Technology for Health Technology Assessment (IATS)—CNPq/Brazil, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil. Schaan is also with the Department of Internal Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
© 2021 Human Kinetics