Association of nightmares with cardio-cerebrovascular disease, hypertension and hyperlipidemia in older adults: A population-based cross-sectional study.

OBJECTIVE: This cross-sectional study investigated the relationship of nightmares with cardio-cerebrovascular disease (CVD), hypertension and hyperlipidemia which are major preceding diseases of CVD in older adults. METHODS: Participants (n = 2824; mean age 63.6 ± 6.6 years, females 49.3%) completed the Disturbing Dream and Nightmare Severity Index (DDNSI), which was used to divide the sample into either the Nightmare or Non-Nightmare group (cut-off score ≥ 10). Demographic information, history of CVD (cerebrovascular disease, myocardial infarction, congestive heart failure, coronary artery disease, and arrhythmia), hypertension, hyperlipidemia, and self-report questionnaires about stress (Perceived Stress Scale), depression (Beck Depression Inventory), sleep quality (Pittsburgh Sleep Quality Index), and insomnia symptoms were also collected. RESULTS: Among the sample, 379 participants (13.4%) reported experiencing nightmares more than once a year, and 73 participants (2.6%) were classified as having nightmare disorder based on DDNSI scores (≥10). 11.3% of participants (n = 319) reported having more than one CVD. Approximately half of the participants reported a history of hypertension (52.1%, n = 1471) and hyperlipidemia (47.7%, n = 1346). Logistic regression analysis indicated the Nightmare group was 2.04 times at higher risk for hyperlipidemia (OR = 2.04, 95% CI 1.22-3.40, p = .006) after controlling for covariates compared to the Non-Nightmare group. Although non-significant, there was a trend toward a higher risk of hypertension in the Nightmare group (OR = 1.67, 95% CI 0.99-2.84, p = .056). CONCLUSIONS: Results of this study indicate frequent nightmares in older adults may be associated with hyperlipidemia, which are risk factors for CVD. Further studies are needed to explore nightmares' directionality and health consequences in an aging population.

Effects of paternal involvement in nighttime childcare on child and maternal sleep: exploring the roles of relationship satisfaction and maternal competence about child sleep.

STUDY OBJECTIVES: Supportive coparenting between couples has been shown to have positive effects on the dyadic relationship, child development, and parental and child sleep. This study aimed to investigate the association between paternal involvement in nighttime childcare and child and maternal sleep, while exploring relationship satisfaction and maternal competence about child sleep as mediators. METHODS: The sample consisted of 290 mothers (mean age ± standard deviation = 34.8 ± 4.1) with children (50.7% male) aged 6-36 (mean ± standard deviation = 22.7 ± 8.6) months. Participants reported their paternal involvement in nighttime childcare and completed the following questionnaires: Brief Infant Sleep Questionnaire-Revised, Dyadic Adjustment Scale-4 items, and the Insomnia Severity Index. Path analysis was conducted to examine the impact of paternal involvement on child and maternal sleep through relationship satisfaction and maternal competence. RESULTS: Among the sample, 74.8% responded that paternal participation in nighttime childcare was less than 25%. Path analysis showed that paternal involvement had a significant direct effect on maternal insomnia (ß = -.15, P < .05) but not on child sleep. Direct pathways from paternal involvement to relationship satisfaction (ß = .17), from relationship satisfaction to maternal competence (ß = .19), from maternal competence to child's sleep (ß = -.57), and from child sleep to maternal insomnia (ß = .48) were significant (P < .01). Relationship satisfaction mediated the associations between paternal involvement and child (ß = -.08, P < .05) and maternal (ß = -.04, P < .05) sleep. CONCLUSIONS: Paternal nighttime childcare involvement was low in South Korea. The results highlight the importance of considering paternal supportive participation and relationship satisfaction in future research on child and maternal sleep. CITATION: Song J, Jang E, Astbury L, Bei B, Suh S. Effects of paternal involvement in nighttime childcare on child and maternal sleep: exploring the roles of relationship satisfaction and maternal competence about child sleep. J Clin Sleep Med. 2024;20(8):1241-1250.

Fatigued but not sleepy? An empirical investigation of the differentiation between fatigue and sleepiness in sleep disorder patients in a cross-sectional study.

OBJECTIVE: Sleepiness and fatigue are common complaints among individuals with sleep disorders. The two concepts are often used interchangeably, causing difficulty with differential diagnosis and treatment decisions. The current study investigated sleep disorder patients to determine which factors best differentiated sleepiness from fatigue. METHODS: The study used a subset of participants from a multi-site study (n = 606), using a cross-sectional study design. We selected 60 variables associated with either sleepiness or fatigue, including demographic, mental health, and lifestyle factors, medical history, sleep questionnaires, rest-activity rhythms (actigraphy), polysomnographic (PSG) variables, and sleep diaries. Fatigue was measured with the Fatigue Severity Scale and sleepiness was measured with the Epworth Sleepiness Scale. A Random Forest machine learning approach was utilized for analysis. RESULTS: Participants' average age was 47.5 years (SD 14.0), 54.6% female, and the most common sleep disorder diagnosis was obstructive sleep apnea (67.4%). Sleepiness and fatigue were moderately correlated (r = 0.334). The model for fatigue (explained variance 49.5%) indicated depression was the strongest predictor (relative explained variance 42.7%), followed by insomnia severity (12.3%). The model for sleepiness (explained variance 17.9%), indicated insomnia symptoms was the strongest predictor (relative explained variance 17.6%). A post hoc receiver operating characteristic analysis indicated depression could be used to discriminate fatigue (AUC = 0.856) but not sleepiness (AUC = 0.643). CONCLUSIONS: The moderate correlation between fatigue and sleepiness supports previous literature that the two concepts are overlapping yet distinct. Importantly, depression played a more prominent role in characterizing fatigue than sleepiness, suggesting depression could be used to differentiate the two concepts.