Sleep duration is associated with increased risk for cardiovascular outcomes: a pilot study in a sample of community dwelling adults in Ghana.

Background: Associations between sleep duration and cardiovascular disease (CVD) risk factors have been demonstrated in past studies. However, previous studies have not investigated these relationships using objective sleep measures in sub-Saharan Africa. Our objective was to investigate the association between sleep duration and cardiovascular risk factors in a sample of community-dwelling Ghanaian adults.

Methods: We used wrist actigraphy along with a seven-day sleep diary to measure sleep duration, wake after sleep onset, sleep latency, and sleep quality. Participants were randomly selected from among those participating in the RODAM study in rural and urban Ghana. Outcome measurements included 10-year risk of CVD events, prevalent CVD, and metabolic syndrome. Additional participant characteristics were assessed using a structured questionnaire. Linear and logistic regression analyses were used to assess the relationships between sleep measures and CVD risk.

Results: A total of 263 participants from rural and urban Ghana participated. Total sleep time was positively associated with a 10-year CVD risk; this association remained after adjusting for age, sex, urban vs rural location, socio-economic status, physical activity, and sleep disturbance (β = 0.990, p = 0.015). Short sleep, defined as sleeping less than seven hours per night on average, was negatively associated with a 10-year CVD risk, and this relationship remained in the fully adjusted model (β = -2.100, p = 0.011). Sleep duration was not associated with prevalence of CVD or metabolic syndrome.

Conclusion: Using actigraphy to measure sleep duration among a population of community-dwelling adults in sub-Saharan Africa is feasible. We found a positive association between sleep and CVD risk. No association was found between sleep duration and prevalent CVD or metabolic syndrome. The implications and new directions relating to these findings are stated.