Uroflowmetry and Altitude Hypoxia: A Report from Healthy Italian Trekkers and Nepali Porters During Himalayan Expedition

Hypoxia alters micturition, which influences bladder function by involving different neurological and humoral systems. In this study we assessed the mid-term effects of altitude hypoxia on uroflowmetry in healthy male lowlander native Nepali porters and Italian trekkers, four each, who coattended a Himalayan expedition. All the participants completed a 19-day trek along a demanding route with ascent and descent at the Kanchenjunga Mountain. They underwent micturition and urodynamic analysis twice, at low altitude of 665 m a.s.l. and high altitude of 4,750 m a.s.l. Statistical comparisons considered the altitude effects (low vs. high) and ethnicity (Italian vs. Nepali). Food consumption was recorded, and water and energy intake were calculated. We found trends of borderline significance in the mean urinary flow rate (Qmean) (p ¼ 0.058; effect size η2 p ¼ 0.478) and in Qmax to the advantage of the Nepali. There was no evidence of differences when comparing time to Qmax and urine volume at Qmax and Qmean for altitude or altitude ethnicity. In addition, there was a lonely female participant, who, analyzed as a case report, showed increased Qmean at high altitude. Older age mitigated while energy intake potentiated the ethnic differences noted in uroflowmetry. We conclude that altitude hypoxia rather inappreciably affects micturition in healthy men. However, a trend for possible ethnic differences raises worthy of note perspectives on adaptive ability of micturition. Also, dietary intake and age should be considered as confounding elements when evaluating micturition.