Blood pressure, pulse rate, and skin temperature during hot-water bathing in real-world settings among community-dwelling older adults: the HEIJO-KYO Study.

BACKGROUND: Home hot-tub bathing substantially increases drowning mortality rates among older adults in Japan. Previous laboratory studies on hemodynamic responses during hot-tub bathing have been inconsistent depending on the thermal conditions. Furthermore, real-world hemodynamic changes that occur during bathing remain poorly understood. This study investigated the association between individual thermal states and hemodynamic parameters during hot-tub bathing among community-dwelling older adults. METHODS: In this cross-sectional study conducted between January 2016 and April 2019, which involved 1,479 older adults (median [range] age, 68 [40-90] years), skin temperature on the abdominal surface was measured every minute. Ambulatory blood pressure and pulse rate were recorded at 15-min intervals for 24 h. Participants underwent simultaneous living room temperature measurements in their homes, and the time and methods of bathing were recorded. Associations between skin temperature and hemodynamic parameters during bathing and between the pre-bath living room temperature and in-bath maximum proximal skin temperature were evaluated using mixed-effects and linear regression models, respectively. RESULTS: A 1 °C increase in skin temperature was significantly associated with a 2.41 mmHg (95% confidence interval [CI]: 2.03-2.79) increase in systolic blood pressure and a 2.99 bpm (95% CI: 2.66-3.32) increase in pulse rate, after adjusting for potential confounders, including age, sex, body mass index, antihypertensive medication use, dyslipidemia, diabetes, and living room and outdoor temperatures. Significant interactions were not observed between sex and skin temperature in relation to systolic blood pressure and pulse rate (P = 0.088 and 0.490, respectively). One standard deviation lower living room temperature before bathing was significantly associated with a 0.41 °C (95% CI: 0.35-0.47) higher maximum skin temperature during bathing. CONCLUSIONS: Our findings suggest that pre-bath cold exposure may increase the skin temperature during hot-tub bathing, possibly resulting in excessive hemodynamic changes. This provides a framework for future interventions that utilize pre-bath thermal conditions and bathing environments to prevent bath-related deaths.

Daily light exposure profiles and the association with objective sleep quality in patients with Parkinson's disease: The PHASE study.

STUDY OBJECTIVES: Light information crucially influences the sleep initiation and continuity. The purpose of this study was to compare daily light exposure between patients with Parkinson's disease (PD) and non-PD older adults and evaluate the association of daily light exposure with objective sleep measures in patients with PD. METHODS: In this cross-sectional study of 189 outpatients with PD and 1101 community dwelling older adults (controls), daily light exposure was measured using wrist light meters during the daytime and light meters set in the bedrooms during the nighttime, and objective sleep quality was measured by wrist actigraphy. RESULTS: The median duration of exposure to ≥1000 lux light was significantly shorter in patients with PD than in controls. The median nighttime light intensity was higher in patients with PD than in controls. Among patients with PD, multivariable analysis suggested that the highest quartile of exposure to ≥1000 lux light during the daytime was linked to significantly higher sleep efficiency by 8.0% and shorter wake after sleep onset (WASO) by 36.9 min than the lowest quartile. During the nighttime, the highest quartile of mean light intensity had significantly lower sleep efficiency by 6.8%, longer WASO by 24.1 min, longer sleep onset latency, and higher fragmentation index, than the lowest quartile. Importantly, daytime and nighttime light levels were independently associated with objective sleep measures. CONCLUSION: The present study illustrated that greater daytime light exposure and lower nighttime light exposure are significantly associated with better objective sleep measures in patients with PD.

Effects of a violet-excitation light-emitting diode on melatonin secretion and sleepiness: preliminary findings from a randomized controlled trial.

STUDY OBJECTIVES: A new type of lighting using violet-excitation light-emitting diodes (LEDs) with an action spectrum centered at approximately 405 nm was developed. Although violet-excitation LEDs can reduce melatonin suppression compared with blue-excitation LEDs, no studies have compared the effects of violet-excitation LEDs with those of blue-excitation LEDs on melatonin suppression. This study was designed to compare the effects of violet-excitation LEDs with those of blue-excitation LEDs on melatonin suppression, psychomotor vigilance, and sleepiness. METHODS: Sixteen healthy Japanese males aged 20-39 years were exposed to violet- and blue-excitation LEDs for 3 hours in a crossover randomized manner. The primary outcome was changes in salivary melatonin levels compared with the baseline levels. The secondary outcomes were changes in psychomotor vigilance and the Karolinska Sleepiness Scale. Melatonin suppression was calculated from the difference in the area under the curves between the baseline and intervention. RESULTS: Of the 16 participants, 15 completed the measurements. The baseline characteristics did not differ significantly between the 2 groups. After adjusting for age, a difference of 16.28 pg/mL in mean melatonin suppression was observed between the violet- and blue-excitation LED groups (-2.15 pg/mL vs -18.43 pg/mL; P = .006). The overall melatonin suppression by violet-excitation LEDs was 48.6% smaller than that by blue-excitation LEDs. No significant differences in psychomotor vigilance and sleepiness were observed between the 2 groups. CONCLUSIONS: Melatonin suppression in healthy Japanese males exposed to violet-excitation LEDs was significantly smaller than that in those exposed to blue-excitation LEDs. Our preliminary findings indicate that violet-excitation LEDs may have the potential to reduce the magnitude of blue-excitation LED-induced melatonin suppression. CITATION: Mitsui K, Saeki K, Sun M, Yamagami Y, Tai Y, Obayashi K. Effects of a violet-excitation light-emitting diode on melatonin secretion and sleepiness: preliminary findings from a randomized controlled trial. J Clin Sleep Med. 2024;20(1):101-109.

Post-Illumination Pupil Response and Sleep Quality in Patients With Glaucoma: The LIGHT Study.

Purpose: This study aimed to investigate whether intrinsically photosensitive retinal ganglion cell function evaluated using post-illumination pupil response (PIPR) in patients with glaucoma is associated with sleep quality. Methods: This cross-sectional study measured the PIPR in 138 patients with glaucoma (mean age, 70.3 years) using pupil diameter after red and blue light exposure. The net PIPR change was classified into three groups according to tertiles (i.e., low, intermediate, and high groups), with lower net PIPR change indicating lower intrinsically photosensitive retinal ganglion cell (ipRGC) function. Subjective and objective sleep qualities were assessed using the Pittsburgh Sleep Quality Index (PSQI) questionnaire and actigraphy, respectively, with a total PSQI score of ≥6 indicating sleep disturbance. Results: The prevalence of subjective sleep disturbance significantly increased with decreasing tertile groups of net PIPR change (P = 0.036). Subgroup analysis obtained the same results in the severe glaucoma group (P = 0.004) but not in the non-severe glaucoma group. In the severe glaucoma group, multivariable logistic regression analysis adjusted for potential confounders showed a higher odds ratio for subjective sleep disturbance in the low-tertile group of net PIPR compared with the high-tertile group (odds ratio = 6.22; 95% confidence interval, 1.76-21.90; P = 0.004). Significant associations between PIPR and objective sleep quality (total sleep time, sleep efficiency, and wake after sleep onset) were found in the severe glaucoma group (P = 0.015, P = 0.013, and P = 0.015, respectively). Conclusions: The PIPR in patients with glaucoma was significantly associated with decreased sleep quality, independent of potential confounders.

Positive Association between Macular Pigment Optical Density and Glomerular Filtration Rate: A Cross-Sectional Study.

Although decreased macular pigment density is associated with the development of age-related macular degeneration (AMD), exactly how this decrease may contribute to the development of AMD is still not fully understood. In this study, we investigated the relationship between macular pigment optical density (MPOD) and estimated glomerular filtration rate (eGFR). MPOD was measured using MPS II (Electron Technology, Cambridge, UK) in 137 participants who showed no clinical signs of AMD at 3 months after cataract surgery, and simple and multiple linear regression analyses were performed to determine the associations with age, sex, abdominal circumference, diabetes, hypertension, smoking, intraocular lens color, visual acuity before and after surgery, and eGFR. The participants were divided into two groups based on the median MPOD (0.58): the high-pigment and low-pigment groups. The mean value of eGFR in the high-pigment group was significantly higher than that in the low-pigment group (64.2 vs. 58.1, p = 0.02). The simple linear regression analysis revealed a significant positive association between MPOD and eGFR (ß = 0.0034, 95% confidence interval [CI]: 0.0011-0.0056, p = 0.0038), and this association was independent of age, sex, abdominal circumference, diabetes, smoking, hypertension, best-corrected visual acuity (BCVA) before surgery, BCVA after surgery, and intraocular lens color (ß = 0.0033, 95% CI: 0.00090-0.0058, p = 0.0076). These results show a strong association of renal dysfunction with the decrease in MPOD.

Association between circadian skin temperature rhythms and actigraphic sleep measures in real-life settings.

STUDY OBJECTIVES: Skin temperature manipulation with little or no change in core body temperature affects sleep-wake states; however, the association of 24-hour skin temperature variation with sleep quality has not been investigated in a large-scale population. We examined the association between the circadian rhythm of distal skin temperature and sleep quality in real-life settings and aimed to provide additional evidence of the link between thermoregulation and sleep-wake states. METHODS: In this cross-sectional study of 2,187 community-dwelling adults, we measured distal skin temperature at the ventral forearm at 3-minute intervals for 7 consecutive days to calculate nonparametric indicators of a circadian skin temperature rhythm, including intradaily variability, interdaily stability, and relative amplitude. Participants underwent simultaneous 7-day wrist actigraphy to objectively measure sleep quality. The association between nonparametric circadian skin temperature rhythm indicators and 7-day sleep measures was evaluated using multivariable linear regression models. RESULTS: Lower intradaily variability and higher interdaily stability and relative amplitude of distal skin temperature were significantly associated with higher sleep efficiency, shorter wake after sleep onset, and longer total sleep time (all P < .001). After adjusting for demographic, clinical, and environmental factors, the coefficients for the linear trend of sleep efficiency were -1.20 (95% confidence interval: -1.53, -0.87), 1.08 (95% confidence interval: 0.80-1.36), and 1.47 (95% confidence interval: 1.04-1.89) per quartile increase in intradaily variability, interdaily stability, and relative amplitude, respectively (all P < .001). CONCLUSIONS: Distal skin temperature with lower fluctuations and higher regularity and rhythm amplitudes was associated with better sleep quality. Our results could be applied in chronobiological interventions to improve sleep quality. CITATION: Tai Y, Obayashi K, Yamagami Y, Saeki K. Association between circadian skin temperature rhythms and actigraphic sleep measures in real-life settings. J Clin Sleep Med. 2023;19(7):1281-1292.

Circadian variability of objective sleep measures predicts the relapse of a mood episode in bipolar disorder: findings from the APPLE cohort.

AIM: Sleep disturbance, a core feature of bipolar disorder, is closely associated with mood symptoms. We examined the association between actigraphy sleep parameters and mood episode relapses in patients with bipolar disorder. METHODS: This prospective cohort study analyzed 193 outpatients with bipolar disorder who participated in the Association between the Pathology of Bipolar Disorder and Light Exposure in Daily Life (APPLE) cohort study. The participants' sleep was objectively evaluated via actigraphy over seven consecutive days for the baseline assessment and then at the 2-year follow-up appointment for mood episode relapses. The actigraphy sleep parameters were presented using the mean and variability (standard deviation) of each sleep parameter for 7 days. RESULTS: Of the 193 participants, 110 (57%) experienced mood episodes during follow-up. The participants with higher variability in total sleep time had a significantly shorter mean estimated time to mood episode relapses than those with lower variability (12.5 vs. 16.8 months; P < 0.001). The Cox proportional hazards model, when adjusted for potential confounders, demonstrated that variability in total sleep time was significantly associated with an increase in the mood episode relapses (per hour; hazard ratio [HR], 1.407; 95% confidence interval (CI), 1.057-1.873), mainly in the depressive episodes (per hour; HR, 1.477; 95% CI, 1.088-2.006). CONCLUSIONS: Our findings suggest that consistency in sleep time might be useful, as an adjunct therapy, in preventing the recurrence or relapse of mood episodes in bipolar disorder.

Circadian blood pressure variability and asymmetric dimethylarginine in patients with glaucoma: cross-sectional study of The LIGHT cohort.

OBJECTIVE: Glaucoma is reportedly associated with asymmetric dimethylarginine (ADMA) and circadian blood pressure (BP) variability, including night-time SBP. We determined whether ADMA level is associated with night-time SBP in patients with glaucoma. METHODS: In this cross-sectional study, we measured the serum ADMA level and ambulatory BP of 163 patients with glaucoma and 705 participants without glaucoma. Based on the tertiles of serum ADMA level, the patients were divided into three groups: low, intermediate, and high-ADMA. Night-time SBP was determined based on ambulatory BP measured every 30 min for 48 h. The nondipper BP pattern was defined as having a night-time mean SBP decline of less than 10% relative to the mean daytime SBP. RESULTS: In the glaucoma group, the night-time SBP in the high-ADMA group was significantly higher than in the low-ADMA group (123.0 and 114.4 mmHg, respectively; P  = 0.003). Multivariable analysis adjusted for the potential confounders showed the night-time SBP, and the odds ratio for nondipper in the high-ADMA group were also significantly higher than in the low-ADMA group ( P  = 0.030 and P  = 0.021, respectively). Significant associations between continuous serum ADMA levels with night-time SBP and nondipper were also found ( P  = 0.002 and 0.006, respectively). In the control group, however, no significant associations were found between serum ADMA levels and night-time SBP and nondipper. A significant interaction effect of the serum ADMA levels and glaucoma on nondipper was found ( P  = 0.004). CONCLUSION: Serum ADMA level was significantly associated with the disturbance of circadian BP variability in patients with glaucoma.

Increased depressive symptoms in Parkinson's disease during the COVID-19 pandemic: Preliminary findings from longitudinal analysis of the PHASE study.

Introduction: The cumulative number of patients has increased through the four waves of the pandemic in Japan. Many people experienced mental stress due to the fear of infection, and restrictions of leaving the house and leisure activities. No longitudinal study has assessed the fluctuation of neuropsychiatric symptoms during the COVID-19 pandemic using the same scale. We examined changes in non-motor symptoms, and the scores of a Parkinson's Disease (PD)-specific questionnaire between the early and later periods during the COVID-19 pandemic. Methods: We conducted a questionnaire survey during the first wave (from February to April 2020) and the fourth wave of the COVID-19 pandemic (from March to April 2021). We compared the number of symptoms from the two periods. Results: Compared with the first wave, the Geriatric Depression Scale score was significantly higher in the fourth wave of the pandemic (median score of GDS: 4.00 vs. 5.50, p = 0.022). Consistently, the scores of symptoms on MDS-UPDRS part 1 in the fourth wave were significantly higher in hygiene (p = 0.033), handwriting (p = 0.033), performing hobbies and other activities (p = 0.035), and turning in bed (p = 0.046) than in the first wave. Conclusions: Our observation over a year between the early and later phases of the COVID-19 pandemic showed an increase in the severity of depression in patients with PD.

In Vivo Postoperative Motion of Fixed and Mobile Medial Pivot Knees Under Weight-Bearing Conditions after Cruciate-Sacrificing Total Knee Arthroplasty.

BACKGROUND: In vivo three-dimensional (3D) motion under weight-bearing conditions was analyzed postoperatively in medial pivot cruciate-substituting (CS) knee systems with fixed and mobile inserts. METHODS: Tibiofemoral knee kinematics during squatting were captured with X-ray fluoroscopy for 4 patients in each cohort. The 3D motion of implants was analyzed with KneeMotion motion analysis software (LEXI Corporation; Tokyo, Japan). In addition, anterior-posterior (AP) movement of the distal-most points and the angle of axial rotation of the femoral component on the tibial component were assessed in both cohorts. RESULTS: Mean AP movement of the femoral component on the tibial component was 3.8±0.5 mm on the medial side and 9.5±0.5 mm on the lateral side in the cohort with fixed prostheses and 5.9±2.1 mm on the medial side and 10.0±2.5 mm on the lateral side in the cohort with mobile prostheses. The mean angle of axial rotation of the femoral component on the tibial component was 14.4±1.1 degrees and 8.2±2.7 degrees of external rotation for fixed knees and mobile knees, respectively. CONCLUSIONS: Postoperative motion analysis confirmed that fixed and mobile CS implants, which have a similar design, guided medial pivot motion under weight-bearing conditions. However, motion differed between these implant types after mid-flexion: bicondylar rollback after medial pivot motion was noted in the mobile cohort.

Association between indoor noise level at night and objective/subjective sleep quality in the older population: a cross-sectional study of the HEIJO-KYO cohort.

STUDY OBJECTIVES: Noise exposure could be an important risk factor for low sleep quality; however, evidence on indoor noise in large-scale populations is limited. We evaluate the association between indoor noise at night and objective and subjective sleep quality in the older population. METHODS: In this cross-sectional study of 1076 participants (≥60 years), we measured indoor noise at night (A-weighted equivalent noise from bedtime to rising time [LAeq]) using a portable noise level meter set in bedrooms and sleep quality using actigraphy and a questionnaire for 2 nights. Using multivariable linear regression models, we examined the associations between indoor noise at night and objective and subjective sleep parameters independent of potential confounders such as age, body mass index, and sleep medication. RESULTS: Increased indoor noise at night by 1 dB of LAeq was significantly associated with lower objective sleep quality, such as lower sleep efficiency (regression coefficient [ß], -0.19%; 95% confidence interval [95% CI], -0.26 to -0.12; p < 0.001), longer log-transformed sleep onset latency (ß, 0.02 log min; 95% CI 0.01 to 0.03; p< 0.001) and wake after sleep onset (ß, 0.66 min; 95% CI 0.40 to 0.92; p < 0.001), and higher log-transformed fragmentation index (ß, 0.01; 95% CI 0.008 to 0.017; p < 0.001). These results remained consistent in the analysis using noise-event rate (≥45 dB) as an independent variable. CONCLUSION: This study revealed the quantitative association between indoor noise at night and objective and subjective sleep quality in the older population. Reducing noise and improving sleep quality may prevent fatal diseases.

Association Between Before-bedtime Passive Body Heating and Nocturia During the Cold Season Among Older Adults.

BACKGROUND: Cold exposure induces lower urinary tract symptoms, including nocturia. Cold-induced detrusor overactivity can be alleviated by increasing skin temperature in rats. However, no study has shown an association between passive heating via hot-water bathing and nocturia among humans. METHODS: We included 1,051 Japanese community-dwelling older adults (mean age: 71.7 years) in this cross-sectional study from 2010 to 2014. The number of nocturnal voids was recorded in a self-administered urination diary. Nocturia was defined as ≥2 nocturnal voids. We evaluated bathing conditions in the participants' houses. RESULTS: Hot-water bathing (n = 888) was associated with a lower prevalence of nocturia than no bathing (n = 163), independent of potential confounders, including age, sex, obesity, income, physical activity, diabetes, medication (diuretics, nondiuretic antihypertensives, and hypnotics), depressive symptoms, indoor/outdoor temperature, and day length (odds ratio [OR] 0.68; 95% confidence interval [CI], 0.48-0.97; P = 0.035). Compared with the quartile group with the longest bath-to-bed interval (range: 161-576 min), the second and third quartile groups (range: 61-100 and 101-160 min, respectively) were associated with a lower prevalence of nocturia, after adjusting for water temperature and bathing duration besides the same covariates (OR 0.60; 95% CI, 0.38-0.96; P = 0.031 and OR 0.59; 95% CI, 0.37-0.94; P = 0.025, respectively). CONCLUSION: Hot-water bathing, particularly with a bath-to-bed interval of 61-160 min, was significantly associated with a lower prevalence of nocturia among older adults.

Habitual light exposure and circadian activity rhythms in bipolar disorder: A cross-sectional analysis of the APPLE cohort.

BACKGROUND: Circadian activity rhythm disruption is a core feature in bipolar disorder. We investigated whether light exposure in daily life is associated with circadian activity rhythms in patients with bipolar disorder. METHODS: In a cross-sectional study, we enrolled 194 outpatients with bipolar disorder who were participants of the Association between Pathology of Bipolar Disorder and Light Exposure in Daily Life (APPLE) cohort study. The participants' physical activity and daytime illuminance were measured using an actigraph over 7 consecutive days. Nighttime illuminance in the bedroom was measured using a portable photometer. Circadian activity rhythm parameters were calculated using cosinor analysis and a nonparametric circadian rhythm analysis. RESULTS: The median daytime illuminance and nighttime illuminance were 224.5 lx (interquartile range, 154.5-307.5 lx) and 2.3 lx (0.3-9.4 lx), respectively. Multivariable linear regression analysis, adjusted for potential confounding factors, showed that higher daytime illuminance was significantly associated with higher amplitude and most active continuous 10-hour period, advanced acrophase, higher interdaily stability, and lower intradaily variability. Higher nighttime illuminance was significantly associated with lower relative amplitude, delayed onset of the least active continuous 5-hour period, and higher intradaily variability. LIMITATIONS: As this was a cross-sectional study, the results do not necessarily imply that light exposure alters circadian activity rhythms. CONCLUSIONS: Daytime light exposure was associated with a positive effect and nighttime light exposure with a negative effect on circadian activity rhythms in bipolar disorder.

Breakfast Skipping and Declines in Cognitive Score Among Community-Dwelling Older Adults: A Longitudinal Study of the HEIJO-KYO Cohort.

Previous studies outlined the correlation of adverse effects of breakfast skipping with cognitive function. However, the majority of these studies have focused on the short-term effects; to date, the long-term effect of breakfast skipping on cognitive function among older adults remains unclear. In this prospective cohort study of 712 older adults (mean age, 70.8 years), breakfast skipping was defined as skipping breakfast one or more times per week, and declines in cognitive score was defined as decreases in Mini-Mental State Examination (MMSE) score of two or more in the observed period. During follow-up (median, 31 months), 135 of 712 participants developed declines in cognitive score. Poisson regression models revealed that the incidence rate for declines in cognitive score was significantly higher in breakfast skipper (n = 29) than breakfast eaters (n = 683) [incidence rate ratio (IRR), 2.10; 95% CI, 1.28-3.44]. Additional propensity score adjustments related to breakfast skipping from baseline parameters (age, gender, smoking and drinking status, BMI, household income, educated level, depressive symptoms, hypertension, diabetes, sleep medication, physical activity, caloric intake, and baseline cognition) produced consistent results (IRR, 2.21; 95% CI, 1.33-3.68). Sensitivity analysis, when the cut-off value of decreases in MMSE score was changed to three points, suggested a significant and stronger association (IRR, 3.03; 95% CI, 1.72-5.35). Regarding daily intakes of food groups, breakfast skippers consumed a significantly lower amount of vegetables, fruits, and fish than breakfast eaters. In conclusion, our findings suggest that breakfast skipping is longitudinally associated with declines in cognitive score among older adults.

Associations between indoor light pollution and unhealthy outcomes in 2,947 adults: Cross-sectional analysis in the HEIJO-KYO cohort.

Nighttime use of artificial light is usual and essential in these modern times. Although light exposure at night (LAN) is reportedly a risk factor of several diseases, epidemiological studies on indoor LAN levels are still limited. Hence, the present study aimed to measure bedroom LAN levels by using light meters in a larger sample than in previous studies, and to evaluate the associations with comprehensive health outcomes. Out of 3012 participants, 2947 (mean age, 69.3 years; female, 60.6%) completed the bedroom LAN intensity measurement. The median bedroom LAN intensity was 1.0 lux (interquartile range, 0.2-4.0 lux). In a multivariable analysis adjusted for potential confounding factors, the highest quartile group of bedroom LAN intensity had significantly higher body weight, body mass index, abdominal circumference, and low-density lipoprotein cholesterol than the lowest quartile group. The group with a median LAN intensity ≥10 lux had significantly higher white blood cell counts and had significantly lower high-density lipoprotein cholesterol levels than the group with a median LAN intensity <10 lux. In addition, the groups with median LAN intensities ≥3 and ≥10 lux had significantly higher odds ratios for sleep disturbances and depressive symptoms than the group with <3 and <10 lux, respectively. Therefore, the present study provided real-world data on bedroom LAN levels as a marker for indoor light pollution in a large sample and suggested that higher bedroom LAN levels are significantly associated with parameters of obesity, dyslipidemia, systemic inflammation, sleep disturbances, and depressive symptoms.

Influence of depression on the association between colder indoor temperature and higher blood pressure.

OBJECTIVES: Cold exposure accounts for more than 7% of all-cause mortality worldwide, and cold-induced blood pressure (BP) elevation and consequent cardiovascular events are partially responsible. For prevention, it is important to identify risk factors for exaggerated temperature-sensitivity of BP but this is not fully understood. This study investigated whether depressive symptoms affect the relationship between indoor temperature and BP. METHODS: We conducted a cross-sectional analysis of 1076 community-based individuals who were at least 60 years of age. Depressive symptoms were assessed using the 15-item Geriatric Depression Scale at a cutoff point of 4/5. We performed ambulatory BP monitoring and indoor temperature measurement on two consecutive days during the cold season in Nara, Japan. RESULTS: When using daytime SBP as a dependent variable, multilevel linear regression analyses showed that lower daytime indoor temperature was significantly associated with higher daytime SBP in the depressive group (n = 216, ß = -0.804, P < 0.001) but not in the nondepressive group (n = 860, ß = -0.173, P = 0.120); moreover, a significant interaction between depression and daytime indoor temperature was observed (P = 0.014). These relationships were independent of potential confounders including age, gender, BMI, medications, and physical activity. Similar results were obtained for morning SBP, nocturnal SBP dipping, and morning BP surge. CONCLUSION: The results suggest that depressive participants are more likely to have cold-induced BP elevation than nondepressive participants. Further longitudinal studies are warranted to determine whether people with depressive symptoms are at a high risk for cold-related cardiovascular events.

Inverse Association of Skin Temperature With Ambulatory Blood Pressure and the Mediation of Skin Temperature in Blood Pressure Responses to Ambient Temperature.

BACKGROUND: The inverse association between ambient temperature and blood pressure (BP) has been investigated in the context of excess cardiovascular mortality in winter. However, the role of skin temperature (ST), which reflects our external and internal thermal environments, in BP regulation remains unclear. Therefore, we examined the association between ST and ambulatory BP and the mediation of ST in BP responses to ambient temperature in real-life settings. METHODS: We conducted a longitudinal analysis using repeated measurements of ambulatory BP and ST for 48 hours (30 711 daytime readings and 17 382 nighttime readings) among 584 older adults between October and March (2012-2014). Linear mixed-effect models were used to examine the association of distal (mean of wrist and ankle) and proximal (abdomen) ST with systolic BP. The mediation of ST in BP responses to ambient temperature was examined using path analysis. RESULTS: Distal and proximal STs were significantly associated with systolic BP during the daytime (regression coefficients: -4.27 mm Hg [95% CI, -4.58 to -3.96] and -2.74 mm Hg [95% CI, -3.14 to -2.56] per SD of ST, respectively), independent of potential confounders. The significant associations also existed during nighttime. The mediation effect of distal ST was 7.1 times higher than that of proximal ST during daytime, while those of distal and proximal STs during nighttime were almost identical. CONCLUSIONS: ST, especially in distal regions, was inversely associated with ambulatory BP. Our results have the potential for application to interventional studies targeting ST regulation to reduce excess cardiovascular deaths in winter.

[Sleep quality and mental well-being of mothers caring for children with disabilities and requiring oxygen therapy and night care at home].

Objectives　This study aimed to 1) determine what kind of care for children with disabilities is related to the mothers' sleep and mental well-being and 2) objectively measure the sleep state of mothers responsible for children with disabilities.Methods　A self-administered questionnaire was distributed to 180 mothers of children enrolled in the Special Needs Education School in prefecture A. Amongst these, nine who provided consent underwent objective sleep measurements using actigraphy. The questionnaire investigated the lifestyle and the type of care needed for children with disabilities and their influence on the mothers. Subjective sleep quality (Pittsburgh Sleep Quality Index) and mental well-being status (General Health Questionnaire) of the mothers were also evaluated. Logistic regression analysis was performed to analyze the background factors affecting sleep quality and mental health.Results　Of the 180 participants, 84 (46.7%) provided valid responses. Fifty-two (64.2%) and 34 (42.0%) individuals subjectively reported poor sleep quality and poor mental well-being, respectively. Mothers having responsibilities of oxygen therapy and night care reported significantly poor sleep quality and mental well-being. Moreover, objective sleep measurements showed that the changes in the child's physical condition, such as ventilator management, epileptic seizures, and fever, resulted in prolonged waking times and affected the sleep efficiency of the mother.Conclusion　Responsibilities toward providing oxygen therapy and night care for their children with disabilities influenced the sleep quality and mental well-being of the mothers. Thus, it is important to provide support to mothers caring such disabled children.

Association Between Postillumination Pupil Response and Glaucoma Severity: A Cross-Sectional Analysis of the LIGHT Study.

Purpose: This study determines whether the functional and structural severity of glaucoma is associated with intrinsically photosensitive retinal ganglion cell (ipRGC) function. Methods: This cross-sectional study assessed 148 eyes from 148 patients with glaucoma (mean age 70.5 years). The ipRGC function was assessed by postillumination pupil response (PIPR) using the pupil diameter after exposure to blue and red light. Main outcome measures were as follows: six-second PIPR amplitude, net PIPR, and net PIPR change. Functional and structural glaucoma severities were evaluated using visual field mean deviation (MD) and the circumpapillary retinal nerve fiber layer (RNFL) thickness, respectively. Results: Multivariable analysis adjusting for age, sex, body mass index, hypertension, diabetes, oral medication use, cataract surgery, axial length, and topical alpha2-adrenergic receptor agonist use showed that worsening in visual field MD was significantly associated with higher blue six-second PIPR amplitude (regression coefficient per -1 dB worsening, 0.25; 95% confidence intervals [CI], 0.14, 0.37; P < 0.001). The thinner RNFL thickness was significantly associated with higher blue six-second PIPR amplitude, lower Net PIPR change, and lower net PIPR (blue six-second PIPR amplitude: regression coefficient per 10-µm thinning, 1.29; 95% CI, 0.72, 1.87; P < 0.001; net PIPR change: regression coefficient, -0.70; 95% CI, -1.26, -0.14; P = 0.015; net PIPR: regression coefficient, -0.03; 95% CI, -0.05, -0.001; P = 0.044). No significant association was found between glaucoma severity and red six-second PIPR amplitude. Conclusions: Our findings revealed a significant association between functional and structural glaucoma severity and impaired ipRGC function independent of potential confounders.

Effect of nighttime bedroom light exposure on mood episode relapses in bipolar disorder.

OBJECTIVE: A previous cross-sectional study reported that nighttime light is associated with increased occurrence of manic symptoms in bipolar disorder; however, the longitudinal association between nighttime light and subsequent mood episode relapses remains unclear. We determined whether bedroom nighttime light was associated with mood episode relapses in patients with bipolar disorder. METHODS: This prospective cohort study included 172 outpatients with bipolar disorder who participated in an Association between the Pathology of Bipolar Disorder and Light Exposure in Daily Life (APPLE) cohort study. A portable photometer was used to measure illuminance in the bedroom from bedtime to rising time during 7 consecutive nights for baseline assessment. Then, the participants were assessed at a 2-year follow-up for mood episode relapses. RESULTS: Of the 172 participants, 157 (91%) completed the 2-year follow-up, and 39 (22%) experienced manic or hypomanic episodes (with or without mixed features), during that time. In the Cox proportional-hazards model, the hazard ratio (HR) for manic/hypomanic episode relapses was significantly higher when the average nighttime illuminance was ≥3 lux (n = 71) than when it was <3 lux (n = 101; HR, 2.54; 95% confidence interval (CI), 1.33-4.84). In the multivariable model adjusted for a propensity score in relation to nighttime light, the relationship remained significant (HR, 2.17; 95% CI, 1.04-4.52). The association between nighttime light and depressive episode relapses was not significantly different. CONCLUSIONS: Keeping the bedroom dark at night may prevent hypomanic and manic episodes.