MODERATE EXERCISE MITIGATES PULMONARY DAMAGE IN TYPE 1 DIABETIC RATS

Diabetes mellitus (DM), a hyperglycemic endocrine-metabolic disorder, can lead to significant alterations in the lung. Moderate exercise improves cardiometabolic fitness, reducing systemic inflammation and oxidative stress, which are crucial in counteracting the detrimental effects of DM on lung tissue. We aimed to evaluate whether the streptozotocin-induced type 1 diabetic (DM1) model can generate lung functional and histological impairments and whether moderate exercise can prevent these changes. This study was approved by the Ethics Committee on Animal Use (CEUA-UECE/31032.011205/2024-52). Wistar rats were assigned to groups: control (C, n = 7), exercise (C+EXE, n = 7), diabetic (D, n = 5), and diabetic with exercise (D+EXE, n = 8). The DM1 model was triggered by streptozotocin (65 mg/kg b.w., i.p.). Rats (C+EXE and D+EXE groups) were trained by running on a motorized treadmill, 5 days a week for 8 weeks. Blood glucose, body weight, exercise capacity, lung mechanics, and the bronchoconstriction index (IBC) were analysed. One-way ANOVA followed by Holm-Sidak test was used. The significance level was 5%. After 8 weeks of exercise, the post-pandrial glycemia of D (455 ± 28.68 mg/dL) and D+EXE (495 ± 26.89 mg/dL) rats was higher than C (104 ± 9.58 mg/dL) and C+EXE (106 ± 10.56 mg/dL). The exercise capacity of the C+EXE (1.200 ± 0.10 km/h) and D+EXE (1.325 ± 0.09 km/h) groups improved compared to C (0.742 ± 0.07 km/h) and D (0.440 ± 0.04 km/h) rats. At 1 Hz, D rats exhibited significantly higher tissue viscance (0.930 ± 0.01 N.s/m²), elastance (65.271 ± 0.97 10⁴ N/m²), and hysteresis (0.152 ± 0.003) than C (0.457 ± 0.02, 46.814 ± 1.74, 0.090 ± 0.006), C+EXE (0.497 ± 0.03, 44.244 ± 6.73, 0.098 ± 0.008), and D+EXE (0.784 ± 0.06, 51.897 ± 4.49, 0.119 ± 0.010) rats, respectively. The BCI in D group (2.747 ± 0.07) was significantly higher than in C (2.345 ± 0.06), C+EXE (2.276 ± 0.06), and D+EXE (2.351 ± 0.06). Diabetes-induced pneumopathy was evidenced by the deterioration of pulmonary mechanics and morphology in the diabetic rats. Moreover, moderate exercise completely prevented all diabetes-induced respiratory alterations.