Left ventricular remodeling and systolic function changes in patients with obstructive sleep apnea: a comprehensive contrast-enhanced cardiac magnetic resonance study.

Background: A comprehensive assessment of left ventricular (LV) remodeling and systolic function using contrast-enhanced cardiac magnetic resonance (CMR) imaging in patients with obstructive sleep apnea (OSA) has not yet been reported. This retrospective case-control study aimed to explore and assess the myocardial structure, function, and tissue characteristic changes of LV remodeling in patients with OSA using the CMR method. Methods: Fifty-one selected participants 32 OSA and 19 non-OSA underwent overnight polysomnography and CMR examination using T1 mapping and feature tracking techniques. Twenty age- and sex-matched healthy controls were also enrolled for comparison between the groups. Results: Patients were grouped by apnea-hypopnea index (AHI): AHI <5 events/h as non-OSA group (n=19, 40.7±8.0 years), 5-30 events/h as mild-moderate OSA (n=13, 47.8±9.4 years), and >30 events/h as severe OSA (n=19, 39.0±10.0 years). The OSA group had a higher LV mass index (LVMI) to height2.7 than the non-OSA and healthy control groups (21.0±3.8 vs. 16.4±3.1 and 16.3±3.2 mL/m2.7, P<0.001). Compared with healthy controls, OSA patients had lower global circumferential strain values, although the LV ejection fraction was preserved. Late gadolinium enhancement was not detected in all participants, whereas the extracellular volume fraction was lower in patients with OSA than in the non-OSA and healthy control groups (24.4%±1.9% vs. 26.2%±2.5%, P=0.006 and 24.4%±1.9% vs. 26.5%±2.3%, P=0.004, respectively). The indexed cellular volume (iCV) of the myocardium was significantly higher in subjects with mild-to-moderate and severe OSA than in those without OSA (14.2±2.3 and 15.8±3.1 vs. 11.6±2.4 mL/m2.7, P<0.05). On multivariate linear regression analysis of patients with two different models, OSA severity remained significantly associated with increased LVMI (ß=0.348, P=0.004 and ß=0.233, P=0.048, respectively) and iCV (ß=0.337, P=0.004 and ß=0.231, P=0.047, respectively) after adjusting for clinical risk factors. Conclusions: LVMI is elevated in OSA with a normal LV ejection fraction, mainly with cellular hypertrophy. Cellular hypertrophy without focal fibrosis in OSA may be our main finding.

Cardiac imageology changes in patients with mild obstructive sleep apnea without cardiovascular disease.

PURPOSE: This study aims to assess changes in cardiac imageology of patients with mild obstructive sleep apnea (OSA) without cardiovascular disease. METHODS: All enrolled participants underwent polysomnography (PSG). Some participants underwent transthoracic echocardiography, speckle tracking echocardiography, and cardiac-enhanced magnetic resonance imaging (MRI) if they were willing. They were divided into three groups according to PSG results: non-OSA, mild OSA, and moderate-to-severe OSA. Imageology parameters were compared, and the relationship between OSA severity and imageology indices was analyzed by correlation analysis and multiple linear regression. RESULTS: Of the 352 enrolled participants, 274 participants with OSA had an apnea-hypopnea index (AHI) of ≥ 5 (86 mild OSA and 188 moderate-to-severe OSA cases), and 78 participants with non-OSA had an AHI of < 5. Transthoracic echocardiography showed that E/A and E'/A' values were lower in the mild OSA group than in the non-OSA group (1.12 ± 0.37 vs 1.27 ± 0.45 and 0.83 ± 0.33 vs 0.99 ± 0.42, respectively, p < 0.05). The aorta and ascending aorta widths were smaller in the mild OSA group than in the moderate-and-severe OSA groups (27.36 ± 2.87 mm vs 28.87 ± 2.95 mm and 30.27 ± 3.79 mm vs 31.63 ± 3.74 mm, respectively, p < 0.05). A regression analysis showed that cardiac function changes in patients with OSA may be related to age, obesity, and OSA severity. CONCLUSION: Patients with mild OSA without cardiovascular disease displayed changes in cardiac structure and function on transthoracic echocardiography.

Risk factors for obstructive sleep apnea-related hypertension in police officers in Southern China.

BACKGROUND: Obstructive sleep apnea (OSA) is an independent risk factor for hypertension. OSA-related hypertension is common and treatment of OSA can reduce blood pressure (BP). However, few studies have been conducted on this type of hypertension in the Chinese occupational population. METHODS: We conducted a field investigation of a team of police officers who underwent an annual health check-up in 2017 in the city of Guangzhou, in southern China. Participants were screened with the Berlin Questionnaire and those at high risk for OSA performed a home sleep apnea test (HSAT). BP over 140/90 mmHg or taking antihypertensive drugs is considered hypertension. RESULTS: Of the 1,036 individuals (799 males and 237 females) included in our study, the mean age was 40.7±9.1 years (range, 22-63 years), 228 (22.0%) were at high risk for OSA, and 103 (9.9%) were diagnosed with OSA. Of the 103 diagnosed with OSA, none had ever been diagnosed with and treated for OSA, and 49 (47.6%) were also diagnosed with hypertension; of these 49, 15 (30.6%) had not been diagnosed with hypertension before, and 27 (55.1%) had never been treated for hypertension. Age [odds ratio (OR) =5.81, 95% confidence interval (CI): 1.78-18.98, P<0.01] and severity of OSA (OR =5.07, 95% CI: 1.72-14.89, P<0.01) were associated with increased risk of OSA-related hypertension. After mood (depression and anxiety) status adjustment, age (adjusted OR =5.81, 95% CI: 1.80-18.80, P<0.01) and severity of OSA (adjusted OR =4.56, 95% CI: 1.49-13.93, P<0.01) were still risk factors for OSA-related hypertension. CONCLUSIONS: Among the policemen of southern China, a higher prevalence was detected not only of OSA but also of OSA-related hypertension which was associated with higher OSA severity and age.