The present study aimed to determine the association between poor sleep quality and cognitive capacity of the middle-aged and elderly urban population in India.

A total of 7505 adults ≥ 50 years old were enrolled.

Cross-sectional associations between OSA symptoms (by Berlin Questionnaire), poor sleep quality (by Pittsburgh Sleep Quality Index), and cognitive function were studied.

Using a standard neuropsychological battery for cognitive function, a G-factor was derived as the first rotated principal component assessing information processing, memory, and executive function domains.

The associations of exposures with cognitive measures were modeled using linear regression, adjusted for metabolic risk factors, lifestyle factors, and psychosocial problems, followed by stratified analysis by decadal age group.

The findings suggested that both symptoms of OSA and poor sleep quality have a direct adverse impact on cognition in an Indian setting.