Associations between Sleep Duration, Sleep Quality, and Cognitive Performance among Older Adults from Six Middle Income Countries: Results from the Study on Global AGEing and Adult Health (SAGE)

Theresa E. Gildner, University of Oregon
Melissa A. Liebert, University of Oregon
Somnath Chatterji, World Health Organization (WHO)

Previous studies have documented associations between sleep duration, sleep quality, and cognitive function in older individuals, yet the association between these variables in non-Western populations is poorly understood. Here we present results from the World Health Organization’s Study on global AGEing and adult health (SAGE), a longitudinal study of older adults (>50 years old) in six countries (China, Ghana, India, Russian Federation, South Africa, and Mexico). Sleep duration and quality over the previous two nights was self-reported, and five cognitive tests were used to create a summary cognition variable. Linear regressions were used to assess the contribution of sleep duration and quality on cognitive test performance variation, controlling for education. Intermediate sleep duration and high sleep quality were significantly associated with higher cognitive scores (p < .001). This study documented a relationship between sleep patterns and cognitive scores, which is important given the growing rates of dementia and aging populations.