Prospective associations among objectively and subjectively assessed sleep and the metabolic syndrome

Abstract

Objective: Subjective sleep disturbances have been associated with greater risk for concurrent and incident metabolic syndrome (MetS). Previous studies have not examined prospective associations among polysomnography-assessed sleep and the MetS, despite knowledge that self-reported sleep is subject to reporting bias, and that subjectively and objectively assessed sleep are weakly correlated.

Method: In the current study, objectively-assessed (polysomnography) and subjectively-assessed (Pittsburgh Sleep Quality Index, PSQI) sleep was measured in 145 adults at two timepoints, separated by 12-30 years. A continuous measure of the MetS was assessed at the second time point. Statistical analyses were adjusted for age, sex, lifetime history of major depressive disorder, follow-up time, and apnea-hypopnea index.

Results: Polysomnography-assessed sleep duration, latency, efficiency, and slow wave sleep were not significantly prospectively associated with the MetS (ps ≥ 0.16). Self-reported longer sleep latency was prospectively associated with higher MetS scores in unadjusted (β = 0.29, p = 0.002) and adjusted models (β = 0.25, p = 0.009). Longer sleep latency was associated with higher fasting glucose levels (β = 0.47, p < 0.001).

Conclusion: Our study provides evidence that subjective and objective measures of sleep may differ in their ability to prospectively predict MetS.

Keywords: Cardiometabolic health; Glucose; Metabolic syndrome; Pittsburgh sleep quality index; Polysomnography; Sleep.