Association between global sleep quality and coronary microvascular function in male physicians with occupational burnout

OBJECTIVE Occupational burnout has been associated with an increased risk of coronary heart disease, although the mechanisms involved are elusive. We investigated whether poor global sleep quality is associated with impaired coronary microvascular function in male physicians, a professional group at increased risk for burnout. METHODS Study participants were 30 male physicians with clinical burnout and 30 controls without burnout defined by the Maslach Burnout Inventory. Global sleep quality was measured with the Pittsburgh Sleep Quality Index (PSQI). Endothelium-dependent (cold pressor test) and endothelium-independent (adenosine challenge) coronary microvascular function were quantified with myocardial perfusion positron emission tomography. In multivariable analyses, the interaction between burnout and the PSQI global score was regressed on measures of coronary microvascular function, adjusting for age, body mass index, physical activity, alcohol consumption, and main effects of burnout and PSQI score. RESULTS The prevalence of poor sleepers (PSQI score > 5) was 40% in the burnout group and 10% in the control group. Adjusting for covariates, burnout-by-global PSQI score interactions were observed for myocardial blood flow (MBF) at rest (r partial = -.30, p = .025), endothelium-dependent coronary flow reserve (r partial = -.26, p = .062), MBF response (r partial = -.30, p = .028), and hyperemic MBF (r partial = -.34, p = -.012). The global PSQI score was inversely associated with these MBF measures in the burnout group relative to the control group. No significant interactions emerged for endothelium-independent MBF. CONCLUSIONS In male physicians with occupational burnout, poor global sleep quality was associated with reduced endothelium-dependent coronary microvascular function, suggesting a mechanism by which burnout may affect cardiovascular health.