Physical activity effects on bladder dysfunction in an obese and insulin-resistant murine model.

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.