Background and Objectives To evaluate the prevalence of REM sleep behavior disorder (RBD) and its possible prodromal conditions, isolated dream enactment behavior (DEB) and isolated REM without atonia (RWA), in a general population sample, and the factors associated with diagnosis and symptom frequency. Methods From a population-based prospective cohort in Korea, 1,075 participants (age 60.1 ± 7.0 years; range 50–80 years; men 53.7%) completed the RBD screening questionnaire (RBDSQ), a structured telephone interview for the presence and characteristics of repeated DEB, and home polysomnography (PSG). RWA was measured on submentalis EMG, including 30-second epoch-based tonic and phasic activity as well as 3-second mini-epoch–based phasic and any EMG activities. Based on the presence of repeated DEB and any EMG activity of ≥22.3%, we categorized the participants into no RBD, isolated RWA, isolated DEB, and RBD groups. Results RBD was diagnosed in 20 participants, isolated RWA in 133 participants, and isolated DEB in 48 participants. Sex and DEB frequency-adjusted prevalence of RBD was 1.4% (95% CI 1.0%–1.8%), isolated RWA was 12.5% (95% CI 11.3%–13.6%), and isolated DEB was 3.4% (95% CI 2.7%–4.1%). Total RBDSQ score was higher in the RBD and isolated DEB groups than in the isolated RWA and no RBD group (median 5 [interquartile range (IQR) 4–6] for RBD, median 4 [IQR 3–6] for isolated DEB, median 2 [IQR 1–3] for isolated RWA, and median 2 [IQR 1–4] for no RBD groups, p < 0.001). RBDSQ score of ≥5 had good specificity but poor positive predictive value (PPV) for RBD (specificity 84.1% and PPV 7.7%) and its prodromal conditions (specificity 85.2% and PPV 29.1%). Among the RWA parameters, any EMG activity showed the best association with the RBD and its possible prodromes (area under the curve, 0.917). Three-second mini-epoch–based EMG activity and phasic EMG activity were correlated with the frequency of DEB (standardized Jonckheere-Terpstra statistic [std. J-T static] for trend = 0.488, p < 0.001, and std. J-T static = 3.265, p = 0.001, respectively). Discussion This study provides prevalence estimates of RBD and its possible prodromal conditions based on a structured telephone interview and RWA measurement on PSG from the general population.

Background: Apart from nondippers’ impact on cardiovascular events, the prevalence of isolated nocturnal hypertension (INH) and its consequences on both the heart and brain were not clearly investigated in the general population. Methods and Results: The participants underwent ambulatory blood pressure monitoring evaluations for arterial stiffness, echocardiography, and brain magnetic resonance imaging. They were grouped into normotension, INH, and overt diurnal hypertension, based on ambulatory blood pressure monitoring and history of antihypertensive treatment. White matter hyperintensity, arterial stiffness, and echocardiographic parameters were compared. Of the 1734 participants, there were 475 (27.4%) subjects with normotension, 314 with INH (18.1%), and 945 with overt diurnal hypertension (54.5%). Prevalence of INH was not different between sex or age. Of INH, 71.3% (n=224) was caused by elevated diastolic blood pressure. After multivariable adjustment, INH showed higher pulse wave velocity ( P <0.001) and central systolic blood pressure ( P <0.001), left ventricular mass index ( P =0.026), and worse left ventricular diastolic function (early diastolic mitral annular velocity) ( P <0.001) than normotension. Mean white matter hyperintensity scores of INH were not different from normotension ( P =0.321), but the odds for white matter hyperintensity presence were higher in INH than normotension (odds ratio, 1.504 [95% CI, 1.097–2.062]; P =0.011). Conclusions: INH was common in the general population and associated with increased arterial stiffness, left ventricular hypertrophy, and diastolic dysfunction. White matter hyperintensity was more likely to be present in the INH group than in the normotension group. The use of ambulatory blood pressure monitoring should be encouraged to identify masked INH and prevent the occurrence of cardiovascular events.

Background: Obstructive sleep apnoea (OSA) is associated with increased risk of type 2 diabetes. However, results from large population-based prospective cohort studies are rare. The main aim of the present study was to investigate the relative risk of 8-year incident type 2 diabetes in relation to OSA severity in a prospective cohort study of middle-aged and older adults.Methods: A total of 2918 participants (mean age 59 years) of the Korean Genome and Epidemiology Study (KoGES), who underwent home-based overnight polysomnography at baseline examination between 2011 and 2014, were followed up 4-yearly between 2015–2018 and 2019–2021. A total of 1697 participants were present in both follow-ups. After excluding participants who had diabetes at baseline (n=481), a total of 1216 participants were eligible for the analyses.Results: OSA at baseline was categorised by apnoea–hypopnoea index levels as non-OSA (0–4.9 events·h⁻¹), mild OSA (5.0–14.9 events·h⁻¹) and moderate–severe OSA (≥15.0 events·h⁻¹). Incident type 2 diabetes was identified at each follow-up. Compared with non-OSA, participants with moderate–severe OSA had 1.5 times higher risk of developing type 2 diabetes at the end of the 8-year follow-up after adjusting for potential covariates (relative risk 1.50, 95% CI 1.02–2.21). In the same analytical models for 4-year relative risk of incident type 2 diabetes, none of the OSA groups were at significantly higher risk compared with the non-OSA group.Conclusion: Moderate–severe OSA, a modifiable risk factor, poses a higher risk of incident type 2 diabetes compared with non-OSA over an 8-year period in general middle-aged and older adults.

Obstructive sleep apnoea (OSA) is a common form of sleep disordered breathing. Untreated OSA might accelerate atherosclerosis, potentially increasing the cardiovascular disease burden in patients. The present study aimed to evaluate the association between objectively measured OSA severity and the presence of subclinical systemic atherosclerosis using noninvasive measurements, including tomographic quantification of the calcium burden.A total of 2157 participants of the Korean Genome and Epidemiology Study, who were free of structural heart disease and underwent both in-home polysomnography and chest computed tomography, were cross-sectionally analysed. Participants were divided into three groups based on the severity of OSA: no OSA (apnoea–hypopnoea index (AHI) <5 events·h⁻¹, n=1096), mild OSA (AHI 5– <15 events·h⁻¹, n=700) and moderate-to-severe OSA (AHI ≥15 events·h⁻¹, n=361). Calcium deposits in the thoracic aorta and coronary arteries were measured by the Agatston score.Participants with moderate-to-severe OSA were 1.6 times (95% CI 1.18–2.15 times; p=0.002) more likely to have ascending thoracic aorta calcification (≥100 units) than those without OSA, after adjustment for cardiovascular risk factors. In addition, the association between moderate-to-severe OSA and ascending thoracic aorta calcification of subjects with higher epicardial fat volume was slightly stronger than that in patients without OSA and in the lowest epicardial fat volume tertile (OR 2.11, 95% CI 1.30–3.43).Severity of OSA in the general population was independently associated with subclinical systemic atherosclerosis. These findings highlight the potential importance of severe OSA, especially in subjects with higher epicardial fat, as a possible predictive factor for systemic atherosclerosis and cardiovascular disease.

This study analyzed the associations between mobile phone call frequency and duration with non-specific symptoms. This study was conducted with a population group including 532 non-patient adults established by the Korean Genome and Epidemiology Study. The pattern of phone call using a mobile phone was investigated through face-to-face interview. Structured methods applied to quantitatively assess health effects are Headache Impact Test-6 (HIT-6), Psychosocial Well-being Index-Short Form, Beck Depression Inventory, Korean-Instrumental Activities of Daily Living, Perceived Stress Scale (PSS), Pittsburgh Sleep Quality Index, and 12-item Short Form Health Survey where a higher score represents a higher greater health effect. The average daily phone call frequency showed a significant correlation with the PSS score in female subjects. Increases in the average duration of one phone call were significantly correlated with increases in the severity of headaches in both sexes. The mean (standard deviation) HIT-6 score in the subgroup of subjects whose average duration of one phone call was five minutes or longer was 45.98 (8.15), as compared with 42.48 (7.20) in those whose average duration of one phone call was <5 minutes. The severity of headaches was divided into three levels according to the HIT-6 score (little or no impact/moderate impact/substantial or severe impact), and a logistic regression analysis was performed to investigate the association between an increased phone call duration and the headache severity. When the average duration of one phone call was five minutes or longer, the odds ratio (ORs) and the 95% confidence intervals (CIs) for the moderate impact group were 2.22 and 1.18 to 4.19, respectively. The OR and 95% CI for the substantial or severe impact group were 4.44 and 2.11 to 8.90, respectively. Mobile phone call duration was not significantly associated with stress, sleep, cognitive function, or depression, but was associated with the severity of headaches.