Sleep characteristics and cardiometabolic disease risk factors in corporate executives

SUMMARY Hours spent in work and sleep comprise the majority of time in a typical day of working adults. As a result, the workplace is a key setting for public health action. Among working adults, 71% of deaths globally are related to non-communicable diseases (NCDs), most of which are attributed to cardiometabolic diseases (CMD). While there is clear evidence linking short sleep duration with CMD risk in the general population, similar data in a unique subset of the workforce, namely corporate executives, remains largely unexplored. The purpose of this thesis was to investigate the associations between sleep health and CMD risk in corporate executives. A systematic review and meta-analysis examined associations between self-reported sleep duration, all-cause mortality (ACM) and cardiovascular disease mortality (CVDM) in employed adults. Sleeping <6 h was associated with a 16% greater risk for ACM and a 26% greater risk for CVDM compared to 7-8 h of sleep, providing strong evidence that adequate sleep mitigates risk of ACM and CVDM (Chapter 2). Health risk assessment (HRA) data were utilised to investigate cross-sectional (Chapter 3) and longitudinal (Chapter 4) associations between self-reported sleep duration and CMD risk factors. Both studies confirmed that shorter sleep duration was associated with higher CMD risk. Longer work hours and work commute time, depression, anxiety and stress were all associated with shorter sleep duration; and the relationship between sleep duration and CMD risk was mediated by lower physical activity, longer work hours and elevated stress. To better understand the habitual sleep characteristics of corporate executives, sleep was measured objectively using actigraphy to describe and study the sleep-CMD risk relationship in Chapter 5. Corporate executives had an average actigraphy-derived sleep duration of below 7 h, 52% reported poor sleep quality and 26% displayed catch-up sleep on non-work days. Notably, shorter weekday total sleep time, lower sleep efficiency and being a catch-up sleeper were all associated with increased CMD risk. Given these findings, it was fundamental to consider workplace sleep health programmes. Chapter 6 qualitatively explored barriers and facilitators of employee participation in sleep health programmes and found that the most common themes that emerged were poor sleep health awareness; work culture; work-family balance and confidentiality. When asked to conceptualise an ideal sleep health programme, three key components were emphasised: identifying the need for such a programme in the workplace; incorporating sleep health screening into HRAs and raising awareness of the importance of sleep through sleep health education. In summary, the findings from this thesis collectively underpin the adverse cardiometabolic health consequences of shorter sleep duration among corporate executives in both the short and medium term. It further highlights the significance of protecting weekday sleep duration and reveals that occupational and psychological factors may contribute to, and mediate the observed sleep-cardiometabolic health relationship. A workplace sleep health programme designed to mitigate the adverse cardiometabolic health outcomes of suboptimal sleep should consider raising awareness around sleep health, addressing work culture and work-life balance to promote participation in such programmes.