Sleep Disordered Breathing as a Risk of Cardiac Events in Subjects With Diabetes Mellitus and Normal Exercise Echocardiographic Findings

Study Questions:

In patients with type 2 diabetes mellitus (T2DM) without evidence of subclinical coronary artery disease (CAD) at baseline, how often does sleep disordered breathing (SDB) contribute to developing heart failure (HF), coronary artery disease (CAD), or atrial fibrillation (AF)?

Methods:

This was a longitudinal observational, single-center study of adult patients with T2DM without known CAD, who were referred for stress echocardiography. Patients were excluded if residing outside of Ohio or if they had any history of heart disease, AF, HF, CAD, moderate or severe valvular disease, cancer, advanced liver or renal disease, positive stress test, ejection fraction <50%, or a diagnosis of CAD, HF, or AF within 30 days of the echocardiogram. SDB was confirmed by a comprehensive sleep evaluation and/or polysomnography before echocardiography. Treatment of SDB was assessed for all patients, and adherence to treatment was measured by self-report.

Results:

Stress echocardiography was performed on 1,371 adult patients with T2DM between 2004 and 2007. After exclusions, 834 patients (ages 56 ± 11 years, 369 women) with a normal exercise echocardiogram were followed for up to 8 years. SDB was diagnosed in 188 patients (21%) at baseline; 116 (62%) were untreated. During a median follow-up of 4.9 years (interquartile range 3.9-6.1), 22 congestive HF, 72 CAD, and 40 AF incident events were observed. Limiting SDB to only those patients diagnosed using polysomnography (n = 132), SDB was associated with incident CAD (hazard ratio [HR], 1.9; 95% confidence interval [CI], 1.1-3.3; p = 0.03; adjusted HR, 2.2; 95% CI, 1.2-3.9; p = 0.01) and HF (HR, 2.7; 95% CI, 1.1-7.0; p = 0.03; adjusted HR, 3.5; 95% CI, 1.4-9.0; p < 0.01). Female gender, age, elevated blood pressure, and left ventricular mass were additional correlates of CAD in those with asymptomatic T2DM.

Conclusions:

Association of SDB with incident CAD, AF, and HF in patients with T2DM justifies increased screening for SDB in patients with T2DM, realizing that SDB is a potentially modifiable risk factor.

Perspective:

Only 38% of the study population with SBD was compliant with continuous positive airway pressure (CPAP). Because of the lack of objective data on the use of CPAP, no outcome analyses were performed to compare patients with SDB who were treated versus untreated. Apnea-hypopnea index severity and associations between SDB severity and incident CAD, HF, or AF would provide additional clinical value in future studies.

Clinical Topics: Heart Failure and Cardiomyopathies, Atherosclerotic Disease (CAD/PAD), Acute Heart Failure, Sleep Apnea

Keywords: Coronary Artery Disease, Neoplasms, Diabetes Mellitus, Type 2, Coronary Disease, Blood Pressure, Heart Diseases, Ketoprofen, Ohio, Cardiology, Heart Failure, Continuous Positive Airway Pressure, Cardiovascular Diseases, Sleep Apnea, Obstructive, Diabetes Mellitus, Exercise Test


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