Omland, Torbjørn

AbstractBackgroundCardiac troponin T (cTnT) and I (cTnI) concentrations provide strong prognostic information in anticoagulated patients with atrial fibrillation (AF). Whether the associations between cardiac troponin concentrations and mortality and morbidity differ by sex is not known.ObjectivesTo assess whether men and women have different concentrations and prognostic value of cTnT and cTnI measurements in anticoagulated patients with AF.MethodscTnT and cTnI concentrations were measured with high‐sensitivity (hs) assays in EDTA plasma samples obtained from the multicentre ARISTOTLE trial, which randomized patients with AF and at least one risk factor for stroke or systemic embolic event to warfarin or apixaban. Patients were stratified according to sex and the associations between hs‐troponin concentrations, and all‐cause death, cardiac death, myocardial infarction, stroke or systemic embolic event and major bleeding were assessed in multivariable regression models.ResultsWe found higher cardiac troponin concentrations in men (n = 9649) compared to women (n = 5331), both for hs‐cTnT (median 11.8 [Q1‐3 8.1–18.0] vs. 9.6 [6.7–14.3] ng L−1, P < 0.001) and hs‐cTnI (5.8 [3.4–10.8] vs. 4.9 [3.1–8.8] ng L−1, P < 0.001). Adjusting for baseline demographics, comorbidities and medications, men still had significantly higher hs‐troponin concentrations than women. C‐reactive protein and N‐terminal pro‐B‐type natriuretic peptide concentrations were higher in female patients. Both hs‐cTnT and hs‐cTnI concentrations were associated with all clinical outcomes similarly in men and women (p‐value for interaction >0.05 for all end‐points).ConclusionMen have higher hs‐troponin concentrations than women in AF. Regardless of sex, hs‐troponin concentrations remain similarly associated with adverse clinical outcomes in anticoagulated patients with AF.

Objective Obstructive sleep apnoea (OSA) and obesity are both associated with endothelial dysfunction, which precedes the development of atherosclerosis. As obesity is highly prevalent in OSA, we wanted to test the hypothesis that OSA is associated with endothelial dysfunction independently of obesity. Design Cross-sectional, population-based study. Setting Norwegian university hospital. Patients Seventy-one subjects (median age 44 years, 35% female) were recruited from a population-based study in Norway. Participants were categorised as obese (body mass index (BMI) ≥30 kg/m2), non-obese (BMI<30 kg/m2) with OSA (apnoea–hypopnoea index (AHI)≥10), or non-obese without OSA (AHI<5). Interventions None. Main outcome measures Endothelial function measured by brachial artery ultrasound and expressed as percentage of flow-mediated dilation (FMD%). Results When non-obese subjects without OSA were used as the reference (FMD% (mean±SD) 10.1±6.3), endothelial function was found to be impaired in subjects with OSA (FMD% 6.4±3.2) (p=0.003). FMD% did not differ between obese (6.0±3.4) and non-obese (6.7±3.1) OSA subjects (p=0.3). By univariate linear regression analysis, AHI, BMI, gender and baseline brachial artery diameter were significantly associated with FMD%. When these variables were entered into a multivariate model, only AHI was significantly associated with FMD%. Conclusions OSA is associated with endothelial dysfunction independently of obesity and conventional risk factors.