The influence of intermittent hypoxia, obesity and diabetes on male genitourinary anatomy and voiding physiology
We used male BTBR mice carrying the Lepob mutation, which are subject to severe and progressive obesity and diabetes beginning at 6 weeks of age, to examine the influence of one specific manifestation of sleep apnea, intermittent hypoxia, on male urinary voiding physiology and genitourinary anatomy. A custom device was used to deliver continuous normoxia (NX, control) or intermittent hypoxia (IH) to wild type and Lepob/ob (mutant) mice for 2 weeks. Intermittent hypoxia was delivered during the 12-hour inactive (lighted) period in the form of 90 sec of 6% O2 followed by 90 sec of room air. Continuous room air was delivered during the 12-hour active (dark) period. We then evaluated genitourinary anatomy and physiology. As expected for the type 2 diabetes phenotype, mutant mice consume more food and water, weighed more, and voided more frequently and in larger urine volumes. They also have larger bladder volumes but smaller prostates, seminal vesicles, and urethras than wild type mice. IH decreases food consumption and increases bladder relative weight independent of genotype and increases urine glucose concentration in mutant mice. When evaluated based on genotype (NX+IH), the incidence of pathogenic bacteriuria is greater in mutant than wild type mice, and among mice exposed to IH, bacteriuria incidence is greater in mutant than wild type mice. We conclude that IH exposure and type 2 diabetes can act independently and together to modify male mouse urinary function.