Sleep Duration & Quality Associated with Cardiovascular Disease

This week from Dr. Cerami and Utah Sports and Wellness

From: Journal of the American Heart Association, 2018

 

Quick Summary:

Cardiovascular disease (CVD) causes over 787 000 deaths in the United States. Whereas sleep duration is generally not considered a traditional risk factor for cardiovascular disease (CVD), growing evidence supports its association with cardiovascular risk (CVR) factors and disease, and quality of sleep appears to contribute to CVR. In this meta‐analysis of 74 studies representing over 3 million participants, the researchers found a J‐shaped relationship between sleep duration and mortality and incident cardiovascular disease. Duration of sleep >8 hours of sleep was associated with increased risk of mortality. No significant effect was identified for periods of sleep <7 hours. Similar patterns were observed for stroke and cardiovascular disease mortality.  Subjective poor sleep quality was associated with a significant increase in coronary heart disease, but not other outcomes. This study suggests that abnormal sleep is a marker of elevated cardiovascular risk.

Abstract:

We conducted a systematic review, meta‐analysis, and spline analysis of prospective cohort studies that evaluate the association between sleep duration and quality and cardiovascular outcomes. We searched MEDLINE and EMBASE for these studies and extracted data from identified studies. We utilized linear and nonlinear dose‐response meta‐analysis models and used DerSimonian–Laird random‐effects meta‐analysis models of risk ratios, with inverse variance weighting, and the I2 statistic to quantify heterogeneity. Seventy‐four studies including 3 340 684 participants with 242 240 deaths among 2 564 029 participants who reported death events were reviewed. Findings were broadly similar across both linear and nonlinear dose‐response models in 30 studies with >1 000 000 participants, and we report results from the linear model. Self‐reported duration of sleep >8 hours was associated with a moderate increased risk of all‐cause mortality, with risk ratio, 1.14 (1.05–1.25) for 9 hours, risk ratio, 1.30 (1.19–1.42) for 10 hours, and risk ratio, 1.47 (1.33–1.64) for 11 hours. No significant difference was identified for periods of self‐reported sleep <7 hours, whereas similar patterns were observed for stroke and cardiovascular disease mortality. Subjective poor sleep quality was associated with coronary heart disease (risk ratio, 1.44; 95% confidence interval, 1.09–1.90), but no difference in mortality and other outcomes. Divergence from the recommended 7 to 8 hours of sleep is associated with a higher risk of mortality and cardiovascular events. Longer duration of sleep may be more associated with adverse outcomes compared with shorter sleep duration.

These authors also note:

  • “Longer duration of sleep may be more associated with adverse outcomes compared with shorter sleep durations.”
  • “Self-reported duration of sleep >8 hours was associated with a moderate increased risk of all-cause mortality:”
    • 14% increased risk for 9 hours
    • 30% increased risk for 10 hours
    • 47% increased risk for 11 hours
  • Poor sleep quality (non-restorative sleep or waking up unrefreshed sleep) was also associated with coronary heart disease (increased risk by 47%).
  • Incremental decrease in hours of sleep (less than 7 hours) was associated with significant increase in mortality.
  • “Our results suggest that longer than the recommended duration of 7 to 8 hours of sleep may be associated with a moderate degree of harm.”
  • “Short sleep duration has been shown to increase levels of leptin and ghrelin, which leads to increased appetite, caloric intake, reduced energy
    expenditure, and facilitates the development of obesity and impaired glycemic control.”
  • “Low-grade inflammation occurs with reduced sleep, which may be associated with cardiovascular disease and cancer.”
  • Factors coupled with long sleep duration include depression, low socioeconomic status, unemployment, and low physical activity.
  • “Sleep duration above the recommended level of 7 to 8 hours was associated with a moderate degree of harm.”
  • “The greater the divergence from the recommended durations of sleep, the greater the association for cardiovascular harm and mortality.”
  • Clinical Perspective from Authors:
    •  In this meta-analysis of 74 studies representing over 3 million participants, we found a [bell curve/hormetic] relationship between sleep duration andmortality and incidence of cardiovascular disease.
      •  Duration of sleep >8 hours was associated with increased risk of mortality.
      •  Duration of sleep >8 hours was associated with increased risk for stroke and cardiovascular disease mortality.
  •  Subjective poor sleep quality (non-restorative sleep or waking up unrefreshed sleep) was associated with a significant increase in coronary heart disease.
2018-10-09T16:26:35+00:00October 9th, 2018|