Sleep duration and risk of stroke and coronary heart disease: a 9-year community-based prospective study of 0.5 million Chinese adults
Authors: Chen Yiping , Kartsonaki Christiana , Clarke Robert , Guo Yu , Du Huaidong , Yu Canqing , Yang Ling , Pei Pei , Stevens Rebecca , Burgess Sushila , Hua Yujie , Chen Junshi , Lv Jun , Li Liming , Chen Zhengming ,   on behalf of the China Kadoorie Biobank Collaborative Group, Chen Junshi , Chen Zhengming , Clarke Robert , Collins Rory , Guo Yu , Li Liming , Lv Jun , Peto Richard , Walters Robin , Avery Daniel , Boxall Ruth , Bennett Derrick , Chang Yumei , Chen Yiping , Chen Zhengming , Clarke Robert , Du Huaidong , Gilbert Simon , Hacker Alex , Hill Mike , Holmes Michael , Iona Andri , Kartsonaki Christiana , Kerosi Rene , Lancaster Garry , Lewington Sarah , Lin Kuang , McDonnell John , Millwood Iona , Nie Qunhua , Radhakrishnan Jayakrishnan , Ryder Paul , Sansome Sam , Schmidt Dan , Sherliker Paul , Sohoni Rajani , Stevens Becky , Turnbull Iain , Walters Robin , Wang Jenny , Wang Lin , Wright Neil , Yang Ling , Yang Xiaoming , Guo Yu , Han Xiao , Hou Can , Lv Jun , Pei Pei , Liu Chao , Yu Canqing , Xia Qingmei , Pang Zengchang , Gao Ruqin , Li Shanpeng , Wang Shaojie , Liu Yongmei , Du Ranran , Zang Yajing , Cheng Liang , Tian Xiaocao , Zhang Hua , Zhai Yaoming , Ning Feng , Sun Xiaohui , Li Feifei , Lv Silu , Wang Junzheng , Hou Wei , Zou Mingyuan , Jiang Ge , Zhou Xue , Yang Liqiu , He Hui , Yu Bo , Li Yanjie , Xu Qinai , Kang Quan , Guo Ziyan , Wang Dan , Hu Ximin , Chen Jinyan , Fu Yan , Fu Zhenwang , Wang Xiaohuan , Weng Min , Guo Zhendong , Wu Shukuan , Li Yilei , Li Huimei , Fu Zhifang , Wu Ming , Zhou Yonglin , Zhou Jinyi , Tao Ran , Yang Jie , Su Jian , Liu Fang , Zhang Jun , Hu Yihe , Lu Yan , Ma Liangcai , Tang Aiyu , Zhang Shuo , Jin Jianrong , Liu Jingchao , Tang Zhenzhu , Chen Naying , Huang Ying , Li Mingqiang , Meng Jinhuai , Pan Rong , Jiang Qilian , Lan Jian , Liu Yun , Wei Liuping , Zhou Liyuan , Wang Ningyu Chen Ping , Meng Fanwen , Qin Yulu , Wang Sisi , Wu Xianping , Zhang Ningmei , Chen Xiaofang , Zhou Weiwei , Luo Guojin , Li Jianguo , Chen Xiaofang , Zhong Xunfu , Liu Jiaqiu , Sun Qiang , Ge Pengfei , Ren Xiaolan , Dong Caixia , Zhang Hui , Mao Enke , Wang Xiaoping , Wang Tao , zhang Xi , Zhang Ding , Zhou Gang , Feng Shixian , Chang Liang , Fan Lei , Gao Yulian , He Tianyou , Sun Huarong , He Pan , Hu Chen , Zhang Xukui , Wu Huifang , Yu Min , Hu Ruying , Wang Hao , Qian Yijian , Wang Chunmei , Xie Kaixu , Chen Lingli , Zhang Yidan , Pan Dongxia , Gu Qijun , Huang Yuelong , Chen Biyun , Yin Li , Liu Huilin , Fu Zhongxi , Xu Qiaohua , Xu Xin , Zhang Hao , Long Huajun , Li Xianzhi , Zhang Libo , Qiu Zhe 
Published: September 2023

Abstract

Background
There is uncertainty about the optimum sleep duration for risk of different subtypes of stroke and ischaemic heart disease.

Methods
The present analyses involved 409,156 adults in the China Kadoorie Biobank study without a prior history of coronary heart disease or stroke or insomnia symptoms. The mean age of study participants was 52 years and 59% were women. Self-reported sleep duration including daytime napping was recorded using a questionnaire. The adjusted hazard ratios (HRs) for disease outcomes associated with sleep duration were estimated by Cox proportional hazards after adjustment for confounding factors.

Results
The overall mean (SD) sleep duration was 7.4 (1.4) hours. The associations of sleep duration with CVD types were U-shaped, with individuals reporting 7–8 h of sleep having the lowest risks. Compared with those who typically slept 7–8 h, individuals with very short sleep duration (≤ 5 h) had adjusted HRs of 1.10 (95% CI 1.04–1.16), 1.07 (1.01–1.13), 1.19 (1.06–1.33) and 1.23 (1.10–1.37) for total stroke, ischaemic stroke (IS), Intracerebral haemorrhage (ICH) and major coronary events (MCE), respectively. Likewise, individuals with very long sleep duration (≥ 10 h) had HRs of 1.12 (1.07–1.17), 1.08 (1.03–1.14), 1.23 (1.12–1.35) and 1.22 (1.10–1.34) for the same diseases, respectively, with little differences by sex and age. The patterns were similar for all-cause mortality.

Conclusions
While abnormal sleep duration (≤ 6 h or ≥ 9 h) was associated with higher risks of CVD, the risks were more extreme for those reporting ≤ 5 or ≥ 10 h, respectively and such individuals should be prioritised for more intensive treatment for CVD prevention.