Impact of sleep insufficiency on cardiovascular mortality in United States: a nationwide county-level analysis 2016–2019
Authors: Abohashem S , Sayed A , Aldosoky W , Elsaiey A , Dar T , Abbasi T 
Published: October 2022

Abstract

Background
Sleep plays an integrated role in health maintenance including cardiovascular (CV) health. Sleep Insufficiency (SI) is a common modifiable risk condition that is strongly linked to major adverse CV events and mortality. However, data on the overall impact and related disparities of SI on CV mortality (CVM), at nationwide level and within different patient groups, are scarce and uncertain.

Purpose
Herein, we aim to study the independent relationship between county level SI and CVM in overall population and within various age, sex, and race/ethnic subgroups.

Methods
Using the Behavioral risk Factors Surveillance System (BRFSS), SI county levels were assessed as the percentage of adults who report fewer than the recommended level of optimal sleep duration (&lt;7 hours). Age-adjusted CVM rates (ACVM) between 2016 to 2019, were obtained using wide-ranging online data for epidemiologic research tool of Centers for Disease and Prevention (CDC). BRFSS, CDC diabetes interactive atlas, census population estimates, environmental public network, and county health rankings databases, were utilized to acquire county data of demographics, CV risk, socio-environmental, and health care access factors. Poisson multivariate generalized linear mixed models were employed to assess incidence rate ratios (IRR). To evaluate the absolute impact of SI on ACVM, additional yearly deaths per 100,000 individuals (AYD) were calculated.

Results
Among 3143 US counties, 2853 counties who had data on SI and ACVM, were analyzed. Of 321,625,744 residents (50.8% women, 12.4% non-Hispanic blacks, 15% aged ≥65) lived at 2853 US counties in 2016, total 3,408,047 (1.1%) CV deaths occurred between 2016–2019. In fully adjusted analysis*, SI significantly associated with overall ACVM (IRR: 1.021; 95% CI: 1.013 to 1.029), that translated to 4.6 AYD. In additional subgroup analysis, SI significantly associated with higher ACVM among middle aged adults [45 to 64] (IRR: 1.024; 95% CI: 1.010 to 1.038), elderly [≥65] (IRR: 1.022; 95% CI: 1.014 to 1.030), males (IRR: 1.019; 95% CI: 1.010 to 1.028), females (IRR: 1.023; 95% CI: 1.013 to 1.033), and in non-Hispanic whites (IRR: 1.024; 95% CI: 1.016 to 1.033). Notably, this association remained significant in the (≥65) aged subgroup of males, and females, as well as in both age subgroups of the non-Hispanic whites, (Figure).

Conclusion
County level SI is robustly related to high ACVM, and that relationship is most apparent amongst both age and sex subgroups as well as non-Hispanic whites. Moreover, this association is significantly independent of potential confounders that have a plausible association with CVM, such as demographics, socioeconomic, environmental, health care access, and cardiovascular risk factors. Therefore, tailored population-level strategies to promote healthy sleep pattern and reduce the prevalence of SI, are imperative for preventing CVM, especially in the most impacted communities and patient subgroups.

Funding Acknowledgement
Type of funding sources: None.