Background: Limited evidence for association of weight gain with sleep-disordered breathing (SDB) has been produced for Asian populations whose body mass index (BMI) levels are lower than in western countries.
Objective: The aim of this study was to examine weight change since 20 years of age and risk of SDB among Japanese.
Design: Retrospective cohort study.
Subjects: This study includes a large sample of 5320 male Japanese truck drivers aged 30-69 years.
Measurements: The respiratory disturbance index (RDI) was selected as an indicator of SDB, and it was estimated with a one-night sleep test using an airflow monitor, and the Epworth Sleepiness Scale (ESS) was used to estimate excessive daytime sleepiness.
Results: Respiratory disturbance and sleepiness were more prevalent among men with BMI of 25.0-29.9 and > or =30.0 kg/m(2) than among those with BMI of 18.5-24.9; multivariable odds ratios (ORs) were 1.8(1.5-2.0), P<0.001 and 4.4(3.5-5.5), P<0.001 for RDI > or =10, and 1.2(0.9-1.4), P=0.18 and 1.5(1.1-2.1), P=0.02 for ESS > or =11, respectively. Compared with men showing BMI changes within +/-1.0, the respective multivariable ORs for those with BMI changes of 3.0-4.9 and > or =5.0 were 1.4(1.2-1.6), P<0.001 and 2.4(2.0-2.9), P<0.001 for RDI > or =10, and 1.2(0.9-1.6), P=0.22 and 2.0(1.5-2.6), P<0.001 for ESS > or =11. The corresponding ORs for weight gain of > or =10.0 kg compared with weight change less than +/-5.0 kg were 2.0(1.7-2.4), P<0.001 for RDI > or =10 and 1.5(1.2-2.0), P=0.002 for ESS > or =11. Similar trends were observed for RDI > or =20.
Conclusion: Our results suggest that an increase in BMI of > or =5 kg/m(2) or weight gain of > or =10 kg is a risk factor for SDB and excessive daytime sleepiness among Japanese truck drivers.