OBJECTIVES: Although previous epidemiological studies have investigated the relationship between sleep duration and various cardiovascular events, the results have been inconsistent. Accordingly, we conducted a follow-up survey to investigate the relationship between sleep duration and cardiovascular events among male workers, accounting for occupational factors that might confound the true relationship. METHODS: A total of 2282 male employees aged 35-54 years based in a factory in Japan were followed for 14 years. The risk of cardiovascular events was compared among 4 groups stratified based on sleep duration at baseline (<6, 6-6.9, 7-7.9, and ≥8 hours). Cardiovascular events included stroke, coronary events and sudden cardiac death. The hazard ratios for events were calculated using a Cox proportional hazards model, with the 7-7.9-hour group serving as a reference. The model was adjusted for potential confounders including traditional cardiovascular risk factors and working characteristics. RESULTS: During 14 years of follow-up, 64 cardiovascular events were recorded including 30 strokes, 27 coronary events and 7 sudden cardiac deaths. After adjustment for possible confounders, the hazard ratios for cardiovascular and coronary events in the <6-hour group were 3.49 [95% confidence interval (95% CI) 1.30-9.40] and 4.95 (95% CI 1.31-18.73), respectively. There was no significant increment in the risk of stroke for any sleep duration groups. CONCLUSION: Short sleep duration (<6 hours) was a significant risk factor for coronary events in a Japanese male working population.
OBJECTIVES: Although previous epidemiological studies have investigated the relationship between sleep duration and various cardiovascular events, the results have been inconsistent. Accordingly, we conducted a follow-up survey to investigate the relationship between sleep duration and cardiovascular events among male workers, accounting for occupational factors that might confound the true relationship. METHODS: A total of 2282 male employees aged 35-54 years based in a factory in Japan were followed for 14 years. The risk of cardiovascular events was compared among 4 groups stratified based on sleep duration at baseline (<6, 6-6.9, 7-7.9, and ≥8 hours). Cardiovascular events included stroke, coronary events and sudden cardiac death. The hazard ratios for events were calculated using a Cox proportional hazards model, with the 7-7.9-hour group serving as a reference. The model was adjusted for potential confounders including traditional cardiovascular risk factors and working characteristics. RESULTS: During 14 years of follow-up, 64 cardiovascular events were recorded including 30 strokes, 27 coronary events and 7 sudden cardiac deaths. After adjustment for possible confounders, the hazard ratios for cardiovascular and coronary events in the <6-hour group were 3.49 [95% confidence interval (95% CI) 1.30-9.40] and 4.95 (95% CI 1.31-18.73), respectively. There was no significant increment in the risk of stroke for any sleep duration groups. CONCLUSION: Short sleep duration (<6 hours) was a significant risk factor for coronary events in a Japanese male working population.
Authors: Nathaniel F Watson; M Safwan Badr; Gregory Belenky; Donald L Bliwise; Orfeu M Buxton; Daniel Buysse; David F Dinges; James Gangwisch; Michael A Grandner; Clete Kushida; Raman K Malhotra; Jennifer L Martin; Sanjay R Patel; Stuart F Quan; Esra Tasali Journal: J Clin Sleep Med Date: 2015-08-15 Impact factor: 4.062
Authors: Nathaniel F Watson; M Safwan Badr; Gregory Belenky; Donald L Bliwise; Orfeu M Buxton; Daniel Buysse; David F Dinges; James Gangwisch; Michael A Grandner; Clete Kushida; Raman K Malhotra; Jennifer L Martin; Sanjay R Patel; Stuart F Quan; Esra Tasali Journal: Sleep Date: 2015-08-01 Impact factor: 5.849
Authors: Michael A Grandner; Natasha J Williams; Kristen L Knutson; Dorothy Roberts; Girardin Jean-Louis Journal: Sleep Med Date: 2015-02-28 Impact factor: 3.492
Authors: Yue Leng; Francesco P Cappuccio; Nick W J Wainwright; Paul G Surtees; Robert Luben; Carol Brayne; Kay-Tee Khaw Journal: Neurology Date: 2015-02-25 Impact factor: 9.910