Emotional Vulnerability to Short Sleep Predicts Increases in Chronic Health Conditions Across 8 Years.

backgroundSleep is a robust determinant of next-day emotions, but people vary in the extent that their emotions fluctuate on days following short sleep duration. These individual differences in day-to-day sleep and emotion dynamics may have long-term health implications. PURPOSE: To evaluate emotional vulnerability to short sleep (within-person associations between sleep duration and next-day emotions) as a risk factor for future chronic conditions.

methodsAdults aged 33-84 (N = 1,426; 57% female) in the Midlife in the United States Study reported sleep duration and emotions by telephone for eight consecutive days. Chronic conditions were assessed via checklist at baseline and at a median follow-up of eight years (range: 5-10 years). Short sleep was examined in three ways: person-centered continuous variable, ≤6 hr, and <7 hr; long sleep was defined as ≥9 hr.

resultsMultilevel structural equation models revealed that people with greater negative emotions following nights of sleep ≤6 hr (vs. their negative emotions after longer sleep) had increased chronic conditions at follow-up, compared to people who were less emotionally vulnerable to short sleep (Est. = 1.04, SE = .51, p < .028). Smaller declines in positive emotions following ≤6 hr of sleep were marginally predictive of lower risk for chronic conditions (Est. = -.77, SE = .44, p = .054). Emotional vulnerability to <7, ≥9, and continuous sleep hours were not associated with subsequent chronic conditions.

conclusionsEmotional vulnerability to short sleep is a unique risk factor for the development of chronic conditions, independent of mean-level sleep duration and emotions.