Lower 24-h urinary potassium excretion is negatively associated with excessive daytime sleepiness in the general...

Uncertainty remains about the association of potassium (K) intake and sleepiness. Therefore, we aimed to explore the relationship between K excretion using 24-h urine samples and excessive daytime sleepiness (EDS) in the general population.

In a cross-sectional study, we used multi-stage proportional random sampling to obtain a study sample aged ≥ 18 years from Emin, China between March and June 2019. We collected timed 24-h urine specimens and conducted EDS assessments using the Epworth Sleepiness Scale (ESS) questionnaire. Subjects were divided into two groups by the median of 24-h urinary potassium (24-h UK). EDS was defined as ESS score ≥ 10. Multi-variable linear regression was used to examine the association between the 24-h UK and the odds of prevalent EDS. We performed a sensitivity analysis by excluding subjects under anti-hypertensive treatment and those with sleep disordered breathing by the NoSAS scale.

A total of 470 participants with complete 24-h urine samples and ESS data (62% women, mean age 49.6 years, mean ESS score of 9.0 ± 5.2) were enrolled. The mean ESS score was significantly lower in the upper half of 24-h UK group than in the lower half (9.5 ± 5.3 vs 8.5 ± 5.1, P = 0.044), and accordingly, prevalent EDS was significantly greater in the lower half than in the higher half (49% vs 40%, P = 0.039). In further improving the propensity matching score, the results remained consistent with the overall results. In multiple linear regression, 24-h UK was negatively correlated with ESS score (β =  - 0.180 (- 0.276, - 0.085), < 0.001). Sensitivity analysis demonstrated augmented results in those without anti-hypertensive treatment.

Lower potassium intake, as suggested by lower UK excretion, may be implicated in the presence of EDS in the general population.