Sleep-related breathing disorder in a Japanese occupational population and its association with hypertension-stratified analysis by obesity status.

Sleep-related breathing disorder (SRBD) causes hypertension, and obesity has been highly associated with SRBD, which has become a serious health problem in young and middle-aged Japanese males. However, the relation between SRBD and hypertension considering the effects of obesity remains unknown. In this cross-sectional study, we examined the relationship between SRBD and hypertension, with consideration for the effects of obesity, in Japanese occupational population. Using 3% oxygen desaturation index (3%ODI) obtained by simplified polysomnography (PSG), participants were classified into low (0 ≤ 3%ODI < 5), medium (5 ≤ 3%ODI < 15), and high (15 ≤ 3%ODI) 3%ODI groups. We excluded employees who had not undergone medical examination with simplified PSG in the same year from 2012 to 2018. Logistic regression analysis was performed to calculate odds ratios for having hypertension according to 3%ODI levels. In total, 2532 employees were included. Among them, 25% and 4% were categorized into the medium and high 3%ODI groups, respectively. The odds ratio for hypertension increased significantly with higher 3%ODI levels after adjustment for age, sex, alcohol drinking status and smoking status (p for trend < 0.0001). However, further adjustment for obesity status (body mass index ≥ 25 kg/m2) attenuated the associations. When we performed the stratified analysis by obesity status, the odds ratio for hypertension increased significantly with higher 3%ODI only for non-obese individuals, with significant interaction (p for interaction = 0.014). Higher 3%ODI was significantly associated with higher prevalence of hypertension especially in non-obese participants, suggesting the importance of vigilance for the presence of SRBD even in non-obese individuals. We investigated the association between SRBD and hypertension considering the effects of obesity, which would suggest the need to keep in mind the presence of SRBD even in non-obese individuals.

Relationship between casual serum triglyceride levels and the development of hypertension in Japanese.

OBJECTIVE: The purpose of the present study was to investigate the effects of serum triglyceride levels on the risk of new-onset hypertension in Japanese. METHODS: Five thousand nine hundred and thirty-three Japanese workers without hypertension at baseline, who participated in medical check-ups from 2006 to 2018, were followed retrospectively. The participants were divided into quartiles of casual serum triglyceride levels and were followed from the first to last visit of the study period. The outcome was development of hypertension. Risk estimates were computed using Cox's proportional hazards model. RESULTS: During the follow-up period (average: 6.7 years), 946 individuals developed hypertension. The crude incidence rates of hypertension (per 1000 person-years) increased with rising serum triglyceride levels: 10.1 for quartile 1 (<0.76 mmol/l), 19.6 for quartile 2 (0.76-1.17 mmol/l), 26.0 for quartile 3 (1.18-1.84 mmol/l), and 36.5 for quartile 4 (>1.84 mmol/l) (P < 0.0001 for trend). These associations remained significant even after adjustment for other risk factors: the multivariable-adjusted hazard ratio was 1.29 (1.01-1.66) for the second quartile, 1.27 (0.99-1.63) for the third quartile, and 1.39 (1.09-1.77) for the highest quartile compared with the lowest. There were comparable effects of serum triglyceride levels for incidence of hypertension between subgroups defined by sex, obesity, and diabetes (all P > 0.1 for interaction), whereas stronger associations were observed for participants under 40 years of age than for those aged 40 or above (P = 0.002 for interaction). CONCLUSION: Serum triglyceride levels were significantly associated with development of hypertension in a Japanese worksite population.