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STUDY OBJECTIVES: Whether the association between sleep-disordered breathing (SDB) and cardiovascular disease is independent of comorbid risk factors for cardiovascular disease is controversial. The objective of this study was to elucidate whether the association between SDB severity and the surrogate markers of cardiovascular disease events differs in relation to the number of comorbidities. METHODS: This cross-sectional study included 7,731 participants. Severity of SDB was determined by the oxygen desaturation index adjusted by actigraph-measured objective sleep time. Participants were stratified according to SDB severity and the number of comorbidities (hypertension, diabetes, dyslipidemia, and obesity), and the associations between the maximum value of intima-media thickness of the common carotid artery (CCA-IMT-max), brachial-ankle pulse wave velocity, and cardio-ankle vascular index were evaluated. RESULTS: Among participants with no risk factors, CCA-IMT-max increased according to SDB severity (n = 1022, P < .0001). Even after matching the background, the median CCA-IMT-max value was 14% higher in moderate-severe SDB patients than those without SDB (n = 45 in each group, P = .020). The difference was not significant for brachial-ankle pulse wave velocity and cardio-ankle vascular index. On the other hand, a significant difference in CCA-IMT-max was not found in those with multiple comorbidities. Consistently, multiple regression analysis revealed an independent association between CCA-IMT-max and moderate-severe SDB for all study participants (β: 0.0222, 95% confidence interval: 0.0039–0.0405, P = .017), but the association was not significant for stratified participants with multiple comorbidities. CONCLUSIONS: SDB severity is associated with the CCA-IMT-max level, but the independent association becomes weaker for those with multiple comorbidities. CITATION: Nakatsuka Y, Murase K, Matsumoto T, et al. Markers of cardiovascular disease risk in sleep-disordered breathing with or without comorbidities: the Nagahama Study. J Clin Sleep Med. 2021;17(12):2467–2475.

Recently an association between blood glucose dysregulation and sleep disruption was suggested. The association between sleep disordered breathing, most of which is due to obstructive sleep apnea (OSA) in the general population, and diabetic severity, as well as the impact of antidiabetic treatment, remains unclear. This study aimed to investigate these associations as well as age and sex differences. This cross-sectional study evaluated 7,680 community participants as the main cohort (population-based cohort). OSA was assessed by the 3% oxygen desaturation index from pulse oximetry, which was corrected for sleep duration obtained by wrist actigraphy. For arguing the limitations for using pulse oximetry, 597 hospitalised patients, who were assessed by the apnea-hypopnea index from attended polysomnography, were also evaluated as the validation cohort (hospital-based cohort). Moderate-to-severe OSA was more prevalent as haemoglobin A1c (HbA1c) levels increased (5.6%/5.6%-6.5%/6.5%-7.5%/≥7.5%, respectively) in both cohorts (p 0.001), but only in those without antidiabetic treatment. The HbA1c level was an independent factor for moderate-to-severe OSA (population-based cohort, odds ratio [OR] 1.26, 95% confidence interval [CI] 1.10-1.45; hospital-based cohort, OR 1.69, 95% CI 1.22-2.33, per 1% increase). These associations were more prominent in the middle-aged (aged60 years) than in the elderly (aged ≥60 years) and in women than in men in both cohorts. The prevalence of moderate-to-severe OSA in patients with antidiabetic treatment in the hospital-based cohort was ≥75% regardless of HbA1c levels. In conclusion, an association between the prevalence of OSA and HbA1c level even within or over the normal range was found only in patients without antidiabetic treatment and was more prominent in the middle-aged and in women.

Social participation promotes and maintains the health of older adults. Working is a type of social participation; however, the effect of employment in old age on health outcomes has not been established. This study aimed to review the relationship between employment in old age (≥60 years) and all-cause mortality. For this systematic review, a computerized search was performed using PubMed, CINAHL and PsycINFO for prospective studies published through June 2020. The observational studies were extracted according to the study participants, indicators, follow-up period, statistical approach and main results. The quality of the studies was assessed using the Newcastle-Ottawa Scale. Of the 37 832 records identified, 14 studies were included in the systematic review based on the inclusion and exclusion criteria. Eight studies were derived from Asian countries (four from Japan, two from Taiwan and one from Thailand and South Korea), three were from the United States, two were from Israel and one was from Brazil. The baseline data of 13 studies were collected before 2000. Thirteen of the 14 studies reported any association between employment in later life and a lower risk of mortality. Four studies examined the sex-related differences in the effect of later-life employment on all-cause mortality, but the association was controversial. Overall, we revealed that working in old age would lower mortality risk. Although more findings based on recent data are required, this study indicates that working later in life is beneficial for promoting and maintaining health. Geriatr Gerontol Int 2022; 22: 705-714.

STUDY OBJECTIVES: Since subjective sleep duration (SSD) is considered to be longer than objective sleep duration (OSD), results of SSD minus OSD (SSD−OSD) might always be thought to be positive. Some recent reports showed different results, but exact results have not been obtained. The difference between SSD and OSD may change according to OSD. We investigated this difference and its association with sleep-disordered breathing (SDB) or nonrestorative sleep. METHODS: This cross-sectional study evaluated 6,908 community residents in Nagahama, Japan. SSD was determined by self-administered questionnaire. OSD was measured by wrist actigraphy and sleep diary. SDB was assessed according to the 3% oxygen desaturation index adjusted for OSD. RESULTS: Worthy of notice was that SSD was shorter than OSD for those with SSD longer than 6.98 hours in all participants, 7.36 hours in males, and 6.80 hours in females. However, SSD was longer than OSD (mean ± SD: 6.49 ± 1.07 vs 6.01 ± 0.96; P < .001) overall, as SSD is considered to be longer than OSD. In patients with SDB, the difference between SSD−OSD was greater when OSD was shorter. The difference also depended on SDB severity. The degree of positivity between OSD and SSD was a significant factor in nonrestorative sleep (odds ratio: 2.691; P < .001). CONCLUSIONS: When OSD was slightly less than 7 (6.98) hours, participants reported or perceived SSD > OSD. When OSD was > 6.98 hours, participants reported or perceived SSD < OSD. Patients with SDB reported longer SSD than OSD according to severity of SDB. Evaluating SSD, OSD, and their differences may be useful for managing sleep disturbances, including nonrestorative sleep. CITATION: Takahashi N, Matsumoto T, Nakatsuka Y, et al. Differences between subjective and objective sleep duration according to actual sleep duration and sleep-disordered breathing: the Nagahama Study. J Clin Sleep Med. 2022;18(3):851–859.

During the COVID-19 pandemic, informal caregivers’ mental health was more deteriorated than non-caregivers. The objective of this study was to examine the association between increased caregiver burden and severe psychological distress (SPD) during the pandemic. We used cross-sectional data from a nationwide internet survey conducted between August and September 2020 in Japan. Of 25,482 participants aged 15–79 years, 1,920 informal caregivers were analyzed (mean age, 52.3 ± 15.9 years; men, 48.8%). SPD was defined as the Kessler 6 Scale (K6) ≥ 13. The self-rated change in caregiver burden was measured with the single question item. A binary logistic regression analysis was used to examine the association between SPD and increased caregiver burden, adjusted for demographic, socioeconomic, health, and caregiving variables. To examine the differential association between increased caregiver burden and SPD, interaction terms were added and binary logistic regression was separately conducted in all variables. Of total caregivers, 56.7% reported the increased caregiver burden and 19.3% were SPD. Increased caregiver burden was significantly associated with SPD, with an adjusted odds ratio 1.90 (95% confidence interval 1.37–2.66). The association between increased caregiver burden and SPD was stronger among married caregivers, with disease treatment, and with their care-receiver’s care need level 1–2 (Japanese long term care service levels). This study demonstrated that increased caregiver burden was associated with SPD during the pandemic. Therefore, measures against mental health for the caregivers with increased caregiver burden need to be implemented immediately.

During the coronavirus disease 2019 (COVID-19) pandemic, informal caregivers' mental health deteriorated more than that of non-caregivers. We examined the association between increased caregiver burden during the pandemic and severe psychological distress (SPD).We used cross-sectional data from a nationwide internet survey conducted between August and September 2020 in Japan. Of 25,482 participants aged 15-79 years, 1,920 informal caregivers were included. SPD was defined as Kessler 6 Scale (K6) score ≥ 13. Self-rated change in caregiver burden was measured retrospectively with a single question item. Binary logistic regression analysis was used to examine the association between SPD and increased caregiver burden during the pandemic, adjusted for demographic, socioeconomic, health, and caregiving variables. To examine the differential association between increased caregiver burden and SPD, interaction terms were added and binary logistic regression was separately conducted for all variables.Participants' mean age was 52.3 years (standard deviation 15.9), 48.8% of participants were male, 56.7% reported increased caregiver burden, and 19.3% exhibited SPD. Increased caregiver burden was significantly associated with SPD (adjusted odds ratio: 1.90; 95% confidence interval: 1.37-2.66). The association between increased caregiver burden and SPD was stronger among caregivers who were married, those undergoing disease treatment, and those with a care-receiver with a care need level of 1-2.The results revealed that more than half of caregivers reported increased caregiver burden, and increased caregiver burden was associated with SPD during the pandemic. Measures supporting mental health for caregivers with increased caregiver burden should be implemented immediately.

In humans, most renal functions, including urine volume and electrolyte excretions, have a circadian rhythm. Light is a strong circadian entrainment factor and daytime-light exposure is known to affect the circadian rhythm of rectal temperature (RT). The effects of daytime-light exposure on the diurnal rhythm of urinary excretion have yet to be clarified. The aim of this study was to clarify whether and how daytime exposure to bright-light affects urinary excretions. Twenty-one healthy men (21–27 years old) participated in a 4-day study involving daytime (08:00–18:00 h) exposure to two light conditions, Dim (p = 0.017) and sodium (Na), chloride (Cl), and uric acid (UA) excretion and urine volumes were greater (all p

STUDY OBJECTIVES: It is well known that a family history of diabetes (FHD) is a definitive risk factor for type 2 diabetes. It has not been known whether sleep-disordered breathing (SDB) increases the prevalence of diabetes in those with an FHD. METHODS: We assessed SDB severity in 7,477 study participants by oximetry corrected by objective sleep duration determined by wrist actigraphy. Glycated hemoglobin ≥6.5% and/or current medication for diabetes indicated the presence of diabetes. In addition to the overall prevalence, the prevalence of recent-onset diabetes during the nearly 5 years before the SDB measurements were made was investigated. RESULTS: Of the 7,477 participants (mean age: 57.9; range: 34.2–80.7; SD: 12.1 years; 67.7% females), 1,569 had an FHD. The prevalence of diabetes in FHD participants with moderate-to-severe SDB (MS-SDB) was higher than in those without SDB (MS-SDB vs without SDB: all, 29.3% vs 3.3% [P < .001]; females, 32.6% vs 1.9% [P < .001]; males, 26.2% vs 11.7% [P = .037]). However, multivariate analysis showed that MS-SDB was significantly associated with a higher prevalence of diabetes only in FHD-positive females (odds ratio [95% confidence interval]: females, 7.43 [3.16–17.45]; males, 0.92 [0.37–2.31]). Among the FHD-positive participants, the prevalence of recent-onset diabetes was higher in those with MS-SDB than those without SDB, but only in females (MS-SDB vs without SDB: 21.4% vs 1.1%; P < 0.001). CONCLUSIONS: MS-SDB was associated with diabetes risk in females with an FHD, and future studies are needed on whether treatment of SDB in females with an FHD would prevent the onset of diabetes. CITATION: Minami T, Matsumoto T, Tabara Y, et al. Impact of sleep-disordered breathing on glucose metabolism among individuals with a family history of diabetes: the Nagahama study. J Clin Sleep Med. 2021;17(2):129–140.

Background: While self-reported subjective sleep duration (SSD) usually tends to exceed actual sleep duration (objective sleep duration, OSD), factors related to the differences between SSD and OSD are unknown. It was reported that sleep disordered breathing (SDB) altered the perception of sleep habits. Aims and Objectives: This study aimed to compare SSD with OSD and to examine whether SDB was related to the differences between SSD and OSD. Methods: This cross-sectional study evaluated 6908 community residents in Nagahama city, Japan. SSD was determined by a self-administered questionnaire while OSD was measured by wrist actigraphy and a sleep diary. SDB was assessed according to the 3% oxygen desaturation index modified for OSD obtained by actigraphy. Results: In groups of participants with SSD Conclusions: OSD tended to be longer than SSD in those who reported short SSD, while the opposite occurred in those reporting long SSD; however, this tendency was offset at 5.7 hours. OSD was shorter than SSD as the severity of SDB increased. These data will help to better assess patients’ complaints about sleep duration.