Physical activity effects on bladder dysfunction in an obese and insulin-resistant murine model
André Matos de Oliveira1, Fernando Mello Froes Fonseca1, Sabrina Thalita Reis1
1Laboratory of Medical Research - LIM 55, Urology, University of Sao Paulo Medical School, Sao Paulo, Brazil.
Objective:
To investigate the role of physical activity in functional and molecular bladder alterations in an obese and insulin-resistant murine model.
Methods:
Wistar rats were randomized into 1. physical activity and standard diet; 2. physical activity and high-fat diet; 3. no physical activity and standard diet; and 4. no physical activity and high-fat diet. Groups 1 and 2 were subjected to a 10-week swimming protocol. Urodynamic study (UDS) was performed, and the expression of genes in the bladder tissue related to the insulin pathway (IRS1/IRS2/PI3K/AKT/eNOS) was assessed using quantitative real-time polymerase chain reaction.
Results:
Groups 1 and 2 presented lower body weight gains than groups 3 (213.89 ± 13.77 vs 261.63 ± 34.20 grams (g), p = 0.04) and 4 (209.84 ± 27.40 vs 257.57 ± 32.95 g, p = 0.04), respectively. Group 4 had higher insulin level (6.05 ± 1.79 vs 4.14 ± 1.14 ng/ml, p = 0.038) and higher homeostasis model assessment of insulin resistance (HOMA-IR) index (1.95 ± 0.73 vs 1.09 ± 0.37, p = 0.006) than group 1. On UDS, group 4 had greater number of micturition (13.6 ± 4.21 vs 6.0 ± 1.82, p = 0.04), higher postvoid pressure (8.06 ± 2.24 vs 5.08 ± 1.23, p = 0.04), lower capacity (0.29 ± 0.18 vs 0.91 ± 0.41 ml, p = 0.008), and lower bladder compliance (0.027 ± 0.014 vs 0.091 ± 0.034 ml/mmHg, p = 0.016) versus group 1. High-fat diet was related to an underexpression throughout insulin signaling pathway, and physical activity was related to an overexpression of the pathway.
Conclusions:
The insulin signaling pathway may be involved in the pathogenesis of bladder dysfunction related to a high-fat diet. Physical activity may help to prevent bladder disfunction induced by a high-fat diet through the insulin pathway.
