Prevalence and factors associated with atrial fibrillation in older patients with obstructive sleep apnea.

PURPOSE: This study sought to identify the prevalence and factors associated with atrial fibrillation (AF) in older patients with obstructive sleep apnea (OSA) in China.  METHODS: This was an explorative cross-sectional study. Between January 2015 and October 2017, we continuously recruited 1285 older patients with OSA who underwent overnight polysomnography from sleep centers of multiple hospitals. They were assessed using 12-lead ECG or 24-h dynamic ECG, and their baseline demographics, clinical characteristics, sleep parameters, and medical history were determined. Multivariate binary logistic regression analysis was used to investigate the factors related to AF in these older patients with OSA. RESULTS: The clinician classified 122 (9.5%) patients as having AF. The prevalence of AF significantly increased with age (P < 0.05) but did not significantly differ between the mild, moderate, and severe OSA groups. Additionally, the prevalence of paroxysmal AF was 7.2% among the overall study population, and it increased with OSA severity or advanced age (P < 0.05). Persistent AF was noted in 2.3% participants, and the prevalence also increased with age. The logistic regression analysis showed that age (OR = 1.054, 95%CI: 1.027-1.018, P < 0.001), history of drinking (OR = 1.752, 95%CI: 1.070-2.867, P < 0.05), chronic heart disease (OR = 1.778, 95%CI: 1.156-2.736, P < 0.01), diabetes mellitus (OR = 1.792, 95%CI: 1.183-2.713, P < 0.01), and reduced diastolic function (OR = 2.373, 95%CI = 1.298-4.337, P < 0.01) were relevant to AF among participants with OSA. CONCLUSION: The prevalence of AF is significantly common in older patients with OSA. Age, history of drinking, chronic heart disease, diabetes mellitus, and reduced diastolic function are independently related to AF in these patients.

Impact of obstructive sleep apnea complicated with type 2 diabetes on long-term cardiovascular risks and all-cause mortality in elderly patients.

BACKGROUND: The prognostic significance of obstructive sleep apnea (OSA) in elderly patients with type 2 diabetes is unclear. The aim of this study was to determine the risk of cardiovascular disease (CVD) and mortality in elderly patients with OSA complicated with type 2 diabetes compared to patients with OSA without type 2 diabetes. METHODS: From January 2015 to October 2017, 1113 eligible elderly patients with OSA, no history of cardiovascular, ≥60 years of age, and complete follow-up records were enrolled in this consecutive multicentre prospective cohort study. All patients had completed polysomnography (PSG) examinations. An apnoea-hypopnoea index of ≥5 events per hour recorded by polysomnography was defined as the diagnostic criterion for OSA. We collected baseline demographics, clinical characteristics, sleep parameters and follow-up outcomes. The primary aim of this study was to identify the risk of incident major adverse cardiovascular events (MACE). Secondary outcomes were all-cause mortality, components of MACE and a composite of all events. Kaplan-Meier survival analysis and Cox proportional hazards models were used to evaluate whether type 2 diabetes was associated with incident events. RESULTS: A total of 266 (23.9%) patients had OSA complicated with type 2 diabetes. MACE occurred in 97 patients during the median 42-month follow-up. Kaplan-Meier survival curves indicated a significant relationship between type 2 diabetes and MACE (log-rank P = 0.003). Multivariable Cox regression analysis showed that type 2 diabetes increased the risk of MACE (HR = 1.64, 95% CI:1.08-2.47, P = 0.019), hospitalisation for unstable angina (HR = 2.11, 95% CI:1.23-3.64, P = 0.007) and a composite of all events in elderly patients with OSA (HR = 1.70, 95% CI:1.17-2.49, P = 0.007). However, there were no significant differences in the incidence of cardiovascular death, all-cause mortality, MI and hospitalisation for heart failure between patients with and without diabetes (P > 0.05). The subgroup analysis demonstrated that females (AHR = 2.46, 95% CI:1.17-5.19, P = 0.018), ≥ 70 years (AHR = 1.95, 95% CI:1.08-3.52, P = 0.027), overweight and obese (AHR = 2.04, 95% CI:1.29-3.33, P = 0.002) with mild OSA (AHR = 2.42, 95% CI: 1.03-5.71, P = 0.044) were at a higher risk for MACE by diabetes. CONCLUSION: OSA and type 2 diabetes are interrelated and synergistic with MACE, hospitalisation for unstable angina and a composite of all events development. Overweight and obese females, ≥ 70 years with mild OSA combined with type 2 diabetes presented a significantly high MACE risk.

[Cardiac functional alterations and its risk factors in elderly patients with obstructive sleep apnea syndrome free of cardiovascular disease].

OBJECTIVE: To evaluate the changes of cardiac structure and function and their risk factors in elderly patients with obstructive sleep apnea syndrome (OSA) without cardiovascular complications. METHODS: Eighty-two elderly OSA patients without cardiovascular disease admitted between January, 2015 and October, 2016 were enrolled in this study. According to their apnea-hypopnea index (AHI, calculated as the average number of episodes of apnoea and hypopnoea per hour of sleep), the patients were divided into mild OSA group (AHI < 15) and moderate to severe OSA group (AHI ≥ 15). The demographic data and the general clinical data were recorded and fasting blood samples were collected from the patients on the next morning following polysomnographic monitoring for blood cell analysis and biochemical examination. Echocardiography was performed within one week after overnight polysomnography, and the cardiac structure, cardiac function and biochemical indexes were compared between the two groups. RESULTS: Compared with those with mild OSA group, the patients with moderate to severe OSA had significantly higher hematocrit (0.22±0.08 vs 0.17±0.04, P=0.032) and serum creatinine level (70.94± 27.88 vs 54.49±34.22 µmol/L, P=0.022). The left ventricular ejection fraction, interventricular septal thickness, left ventricular posterior wall thickness, left atrial diameter and left ventricular end-diastolic diameter were all similar between the two groups. With a similar early diastolic mitral flow velocity (E) between the two groups, the patients with moderate to severe OSA had a significantly higher late diastolic mitral flow velocity (A) (70.35±6.87 vs 64.09±8.31, P=0.0001) and a significantly lower E/A ratio (0.98±0.06 vs 1.08±0.05, P=0.0001) than the patients with mild OSA. Multiple linear regression showed that the E/A ratio was negatively correlated with AHI (ß =- 0.645, P=0.0001). CONCLUSIONS: Cardiac diastolic function impairment may occur in elderly patients with moderate or severe OSA who do not have hypertension or other cardiovascular diseases, and the severity of the impairment is positively correlated with AHI.

[Correlation between severity of obstructive sleep apnea syndrome and red cell distribution width in elderly patients].

OBJECTIVE: To investigate the correlation between the severity of obstructive sleep apnea syndrome (OSAS) and red cell distribution width (RDW) in elderly patients. METHODS: A cross-sectional study was conducted among 311 elderly patients diagnosed with OSAS in the snoring clinic between January, 2015 and October, 2016 and 120 healthy controls without OSAS from physical examination populations in the General Hospital of PLA. The subjects were divided into control group with apnea-hypopnea index (AHI) <5 (n=120), mild OSAS group (AHI of 5.0-14.9; n=90), moderate OSAS group (AHI of 15.0-29.9; n=113) and severe OSAS group (AHI ≥ 30; n=108). The clinical characteristics and the results of polysomnography, routine blood tests and biochemical tests of the subjects were collected. Multiple linear regression analysis was used to examine the correlation between OSAS severity and RDW. RESULTS: The levels of RDW and triglyceride were significantly higher in severe OSAS group than in the other groups (P < 0.01). The levels of fasting blood glucose and body mass index were significantly higher in severe and moderate OSAS groups than in mild OSAS group and control group (P < 0.05 or P < 0.01). Multiple linear regression analysis showed that AHI was positively correlated with body mass index (ß=0.111, P=0.032) and RDW (ß=0.106, P=0.029). The area under ROC curve of RDW for predicting the severity of OSAS was 0.687 (P=0.0001). CONCLUSIONS: The RDW increases as OSAS worsens and may serve as a potential marker for evaluating the severity of OSAS.