Abstract 18133: Severity of Obstructive Sleep Apnea is Independently Associated with Cardiac Troponin I Concentrations

Abstract

Objectives: Chronic, low-level cardiac troponin (cTn) elevation is associated with left ventricular (LV) dysfunction and hypertrophy. Obstructive sleep apnea (OSA) is associated with increased risk of several cardiovascular disorders, including LV hypertrophy and heart failure. Accordingly, in a community-based study we tested the hypothesis that severity of OSA, as measured by the apnea-hypopnea index (AHI), is associated with increasing concentrations of cTnI and cTnT.

Methods: In fasting morning venous samples from 531 persons (54% men, mean age 48 years) included in the Akershus Sleep Apnea Project, cTnI was analyzed with a prototype high-sensitivity (hs) assay (Abbott, limit of detection (LoD) 1.2 ng/L). cTnT was analyzed with a commercially available hs-assay (LoD 3.0 ng/l). AHI was assessed by in-hospital polysomnography.

Results: hs-cTnI and hs-cTnT were detectable in 330 (62%) and 229 (44%) participants, respectively. Severity of OSA was associated with detectable cTnI and cTnT-levels (p for trend =0.001) (Figure 1). In multivariate linear regression analyses that adjusted for age, gender, creatinine levels, prior coronary artery disease (CAD), use of antihypertensives, current smoking, diabetes mellitus, systolic blood pressure (SBP), body mass index (BMI), and total/ high-density lipoprotein cholesterol ratio, higher AHI was independently associated with increasing hs-cTnI levels (standardized beta=0.13, p=0.004). Age, prior CAD, SBP and creatinine levels were other determinants of increasing hs-cTnI levels. In contrast, AHI was not independently associated with hs-cTnT levels. In participants with hs-cTnT levels below the LoD (n=292), an independent association between higher AHI and increasing hs-cTnI levels (p=0.005) was observed.

Conclusion: The severity of OSA is independently associated with circulating cTnI, but not cTnT concentrations.