Associations of snoring frequency with blood pressure among the lean Japanese population: the Toon Health Study

To date, there are few studies in Asian populations on the association between snoring (a major clinical symptom of sleep apnea) and hypertension. This study aims to examine whether snoring frequency is associated with blood pressure and hypertension in the general Japanese population, after adjustment for major confounding factors. A cross-sectional study of 2021 middle-aged Japanese men and women enrolled in the Toon Health Study between 2009−2012 was conducted. Snoring frequency was assessed using a self-reported questionnaire, and was classified into four categories: never, ≤2 times/week, ≥3 times/week, and unknown. Multivariable regression coefficients for each snoring category were calculated for systolic and diastolic blood pressure, and their odds ratios (ORs) and 95% confidence intervals (95% CIs) for hypertension were calculated after adjusting for major confounding factors. The same analyses were also conducted after stratification by several major confounding factors. Multivariable-adjusted means of systolic and diastolic blood pressure among individuals who snored ≥3 times/week were 4.57 mmHg and 2.58 mmHg higher, respectively, than in individuals who never snored (p < 0.05). The multivariable-adjusted OR (95% CI) for hypertension in the group that snored ≥3 times/week was 1.79 (1.29–2.48), compared with the group that never snored. We also found a significant positive association between snoring frequency and hypertension not only in normal and overweight individuals, but also in lean individuals (body mass index ≤22.8 kg/m²). Higher snoring frequency was associated with higher blood pressure and hypertension among both lean and non-lean Japanese.