Rest/Activity Rhythms and Cardiovascular Disease in Older Men

Abstract

Prior studies have suggested an increased risk of cardiovascular disease (CVD)-related mortality in older adults with disturbed circadian rest/activity rhythms (RARs). The objective goal of this study was to examine the association between disrupted RARs and risk of CVD events in older men. A total of 2968 men aged 67 yrs and older wore wrist actigraphs for 115 ± 18 consecutive hours. RAR parameters were computed from wrist actigraphy data and expressed as quartiles (Q). CVD events consisted of a composite outcome of coronary heart disease (CHD), stroke, and peripheral vascular disease (PVD) events. Secondary analyses examined associations between RARs and individual components of the composite outcome (CHD, stroke, and PVD). There were 490 CVD events over an average of 4.0 ± 1.2 yrs. Overall, reduced amplitude (HR = 1.31, 95% confidence interval [CI] 1.01–1.71 for Q2 vs. Q4) and greater minimum (HR = 1.33, 95% CI 1.01–1.73 for Q4 vs. Q1) were associated with an increased risk of CVD events in multivariable-adjusted models. In secondary analyses, there was an independent association between reduced amplitude (HR = 1.36, 95% CI 1.00–1.86) and greater minimum activity counts (HR = 1.39, 95% CI 1.02–1.91) with increased risk of CHD events. Reduced F value (HR = 2.88, 95% CI 1.41–5.87 for Q1 vs. Q4 and HR = 2.71, 95% CI 1.34–5.48 for Q2 vs. Q4) and later occurring acrophase of the RAR (HR = 1.65, 95% CI 1.04–2.63 for Q4 vs. Q2–3) were associated with an increased risk of PVD events. Results were similar in men without a history of CVD events. The findings revealed that among older men, measures of decreased circadian activity rhythm robustness (reduced amplitude and greater minimum activity) were associated with an increased risk of CVD events, primarily through increased risk of CHD or stroke events, whereas measures of reduced circadian activity rhythmicity were not associated with risk of CVD events overall, but were associated with an increased risk of PVD events. These results should be confirmed in other populations. (Author correspondence: E-mail: [email protected])

Keywords:

• Rest/activity rhythm
• Cardiovascular disease
• Circadian rhythms
• Elderly
• Sleep

ACKNOWLEDGMENTS

The National Heart, Lung and Blood Institute (NHLBI) provides funding for the MrOS Sleep ancillary study “Outcomes of Sleep Disorders in Older Men” under the following grant numbers: R01 HL071194, R01 HL070848, R01 HL070847, R01 HL070842, R01 HL070841, R01 HL070837, R01 HL070838, R01 HL070839, and NIA AG08415. This work was also supported with resources and the use of facilities at the Minneapolis VA Medical Center. The views expressed herein do not necessarily represent the views of the Department of Veterans Affairs or the United States Government. Sponsor's Role: The funding institutes had no role in the design, methods, subject recruitment, data collections, analysis, and preparation of paper, or in the decision to submit the manuscript for publication.

We thank the study staff at each site and all the men who participated in MrOS Sleep.

Declaration of Interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.