[show abstract][hide abstract] ABSTRACT: Epidemiologic data have demonstrated associations of sleep-onset insomnia with a variety of diseases, including depression, dementia, diabetes and cardiovascular diseases. Sleep initiation is controlled by the suprachiasmatic nucleus of the hypothalamus and endogenous melatonin, both of which are influenced by environmental light. Exposure to evening light is hypothesized to cause circadian phase delay and melatonin suppression before bedtime, resulting in circadian misalignment and sleep-onset insomnia; however, whether exposure to evening light disturbs sleep initiation in home settings remains unclear. In this longitudinal analysis of 192 elderly individuals (mean age: 69.9 years), we measured evening light exposure and sleep-onset latency for 4 days using a wrist actigraph incorporating a light meter and an accelerometer. Mixed-effect linear regression analysis for repeated measurements was used to evaluate the effect of evening light exposure on subsequent sleep-onset latency. The median intensity of evening light exposure and the median sleep-onset latency were 27.3 lux (interquartile range, 17.9-43.4) and 17 min (interquartile range, 7-33), respectively. Univariate models showed significant associations between sleep-onset latency and age, gender, daytime physical activity, in-bed time, day length and average intensity of evening and nighttime light exposures. In a multivariate model, log-transformed average intensity of evening light exposure was significantly associated with log-transformed sleep-onset latency independent of the former potential confounding factors (regression coefficient, 0.133; 95% CI, 0.020-0.247; p = 0.021). Day length and nighttime light exposure were also significantly associated with log-transformed sleep-onset latency (p = 0.001 and p < 0.001, respectively). In conclusion, exposure to evening light in home setting prolongs subsequent sleep-onset latency in the elderly.
Chronobiology International 10/2013; · 4.35 Impact Factor
[show abstract][hide abstract] ABSTRACT: Recent advances in understanding the fundamental links between chronobiology and depressive disorders have enabled exploring novel risk factors for depression in the field of biological rhythms. Increased exposure to light at night (LAN) is common in modern life, and LAN exposure is associated with circadian misalignment. However, whether LAN exposure in home settings is associated with depression remains unclear.
We measured the intensities of nighttime bedroom light and ambulatory daytime light along with overnight urinary melatonin excretion (UME) in 516 elderly individuals (mean age, 72.8). Depressive symptoms were assessed using the Geriatric Depression Scale.
The median nighttime light intensity was 0.8lx (interquartile range, 0.2-3.3). The depressed group (n=101) revealed significantly higher prevalence of LAN exposure (average intensity, ≥5lx) compared with that of the nondepressed group (n=415) using a multivariate logistic regression model adjusted for daytime light exposure, insomnia, hypertension, sleep duration, and physical activity [adjusted odds ratio (OR): 1.89; 95% confidence interval (CI), 1.10-3.25; P=0.02]. Consistently, another parameter of LAN exposure (duration of intensity ≥10lx, ≥30min) was significantly more prevalent in the depressed than in the nondepressed group (adjusted OR: 1.71; 95% CI, 1.01-2.89; P=0.046). In contrast, UME was not significantly associated with depressive symptoms.
These results suggested that LAN exposure in home settings is significantly associated with depressive symptoms in the general elderly population. The risk of depression may be reduced by keeping nighttime bedroom dark.
Journal of affective disorders 07/2013; · 3.76 Impact Factor
[show abstract][hide abstract] ABSTRACT: Although oral melatonin administration may enhance a nocturnal blood pressure fall, it remains unclear whether endogenous melatonin, which is present at considerably lower levels than pharmacological melatonin, is associated with the non-dipper pattern. The present cross-sectional study aimed to determine the association between urinary melatonin excretion, an index of endogenous melatonin, and the non-dipper pattern. We measured the following variables in 141 elderly hypertensives: overnight urinary melatonin excretion, ambulatory blood pressure and actigraphic physical activity. We defined a non-dipper pattern as a <10% fall in sleep systolic blood pressure compared with awake systolic blood pressure. When participants were divided into two groups (high and low melatonin groups) by the cutoff value for identifying the top tertile, the characteristics, except for age, did not significantly differ between the two groups. Crude logistic regression analysis showed significant associations of the non-dipper pattern with age, diabetes, higher urinary melatonin excretion (high vs. low) and daytime activity. In a multivariate analysis after adjustment for age, diabetes and daytime activity, the odds ratio for the non-dipper pattern in the high melatonin group was significantly lower than that in the low melatonin group (odds ratio: 0.39, 95% confidence interval (CI): 0.17-0.91, P=0.03). Moreover, the mean percentage systolic blood pressure nocturnal fall, adjusted for the former covariates, was significantly higher in the high melatonin group than the low melatonin group (difference 3.5%, 95% CI: 0.0-7.0%, P=0.048). Among elderly hypertensive individuals, nocturnal urinary melatonin excretion is significantly and inversely associated with the non-dipper pattern.Hypertension Research advance online publication, 11 April 2013; doi:10.1038/hr.2013.20.
Hypertension Research 04/2013; · 2.79 Impact Factor
[show abstract][hide abstract] ABSTRACT: OBJECTIVE: Metabolic syndrome contains many risks for medical diseases such as cardiovascular disease and diabetes, which might precipitate depressive symptoms in the older people. However, the association between depressive symptoms and metabolic syndrome in Japanese community-dwelling older people is unclear. This study was performed to answer this important question. METHODS: Cross-sectional analyses were performed on 3796 community-dwelling independent older people (≥65 years, 1911 men and 1885 women) from the 2007-2008 baseline examination of the Fujiwara-kyo study, a prospective cohort study on successful aging. Depressive symptoms were assessed using the 15-item short form of the Geriatric Depression Scale and metabolic syndrome was defined according to the 2005 International Diabetes Federation. Covariates were social supports, negative life events, health behavior, education, cognitive function, anthropometric status, and others. Multiple logistic regression analyses were performed to determine the relationships between depressive symptoms and these variables. RESULTS: The prevalence of depressive symptoms (Geriatric Depression Scale-15 ≥6) and metabolic syndrome were 14.8% and 16.6%, respectively. Significant protective factors against depressive symptoms were higher education, more opportunity for drinking of alcohol, better social supports, and more walking daily. Metabolic syndrome was statistically associated with depressive symptoms (adjusted odds ratio = 1.32, 95% confidence interval = 1.03-1.68). Other risk factors significantly associated with depressive symptoms were sleep disturbance, visual or hearing impairment, and negative life events. CONCLUSIONS: The present study showed an association between metabolic syndrome and depressive symptoms in ambulatory Japanese older people, as in western countries.
International Journal of Geriatric Psychiatry 03/2013; · 2.98 Impact Factor
[show abstract][hide abstract] ABSTRACT: BACKGROUND: Previous studies have proposed that higher blood pressure (BP) in winter is an important cause of increased mortality from cardiovascular disease during the winter. Some observational and physiological studies have shown that cold exposure increases BP, but evidence from a randomised controlled study assessing the effectiveness of intensive room heating for lowering BP was lacking. OBJECTIVES: The present study aimed to determine whether intensive room heating in winter decreases ambulatory BP as compared with weak room heating resulting in a 10°C lower target room temperature when sufficient clothing and bedclothes are available. METHODS: We conducted a parallel group, assessor blinded, simple randomised controlled study with 1:1 allocation among 146 healthy participants in Japan from November 2009 to March 2010. Ambulatory BP was measured while the participants stayed in single experimental rooms from 21:00 to 8:00. During the session, participants could adjust the amount of clothing and bedclothes as required. Compared with the weak room heating group (mean temperature±SD: 13.9±3.3°C), systolic morning BP (mean BP 2 h after getting out of bed) of the intensive room heating group (24.2±1.7°C) was significantly lower by 5.8 mm Hg (95% CI 2.4 to 9.3). Sleep-trough morning BP surges (morning BP minus lowest night-time BP) in the intensive room heating group were significantly suppressed to about two thirds of the values in the weak room heating group (14.3 vs 21.9 mm Hg; p<0.01). CONCLUSIONS: Intensive room heating decreased morning BP and the morning BP surge in winter.
Journal of epidemiology and community health 02/2013; · 3.04 Impact Factor
[show abstract][hide abstract] ABSTRACT: Objectives: To investigate factors associated with activities of daily living in independently living elderly persons in a community. Subjects and Methods: The potential subjects were 4,472 individuals aged 65 years and older who voluntarily participated in a large cohort study, the Fujiwara-kyo study. We used self-administered questionnaires consisting of an activities of daily living (ADL) questionnaire with the Physical Fitness Test established by the Ministry of Education, Culture, Sports, Science and Technology (12 ADL items) to determine the index of higher-level physical independence, demographics, Geriatric Depression Scale, and so on. Mini-mental state examination, measurement of physical fitness, and blood tests were also carried out. A lower ADL level was defined as having a total score of the 12 ADL items (range, 12-36 points) that was below the first quartile of a total score for all the subjects. Factors associated with a low ADL level were examined by multiple logistic regression. Results: A total of 4,198 remained as subjects for analysis. The male, female and 5-year-old groups showed significant differences in the median score of 12 ADL items between any two groups. The highest odds ratio among factors associated with lower ADL level by multiple logistic regression with mutually adjusted independent variables was 4.49 (95%CI: 2.82-7.17) in the groups of "very sharp pain" or "strong pain" during the last month. Low physical ability, self-awareness of limb weakness, a BMI of over 25, low physical activity, cerebrovascular disorder, depression, low cognitive function, unable "to see normally", unable "to hear someone", "muscle, bone and joint pain" were independently associated with lower ADL level. Conclusion: Multiple factors are associated with lower ADL level assessed on the basis of the 12 ADL items.
Nippon Eiseigaku Zasshi (Japanese Journal of Hygiene) 01/2013; 68(1):22-32.
[show abstract][hide abstract] ABSTRACT: Context:Obesity and exposure to light at night (LAN) have increased globally. Although LAN suppresses melatonin secretion and disturbs body mass regulation in experimental settings, its associations with melatonin secretion, obesity, and other metabolic consequences in uncontrolled home settings remain unclear.Objective:The aim of this study was to determine the association of exposure to LAN in an uncontrolled home setting with melatonin secretion, obesity, dyslipidemia, and diabetes.Design and Participants:A cross-sectional study was performed in 528 elderly individuals (mean age, 72.8 yr).Measures:The intensity of LAN in the bedroom was measured at 1-min intervals during two consecutive nights, along with overnight urinary melatonin excretion and metabolic parameters.Results:Compared with the Dim group (average <3 lux; n = 383), the LAN group (average ≥3 lux; n = 145) showed significantly higher body weight (adjusted mean, 58.8 vs. 56.6 kg; P = 0.01), body mass index (23.3 vs. 22.7 kg/m(2); P = 0.04), waist circumference (84.9 vs. 82.8 cm; P = 0.01), triglyceride levels (119.7 vs. 99.5 mg/dl; P < 0.01), and low-density lipoprotein cholesterol levels (128.6 vs. 122.2 mg/dl; P = 0.04), and showed significantly lower high-density lipoprotein cholesterol levels (57.4 vs. 61.3 mg/dl; P = 0.02). These associations were independent of numerous potential confounders, including urinary melatonin excretion. Furthermore, LAN exposure is associated with higher odds ratios (ORs) for obesity (body mass index: OR, 1.89; P = 0.02; abdominal: OR, 1.62; P = 0.04) and dyslipidemia (OR, 1.72; P = 0.02) independent of demographic and socioeconomic parameters. In contrast, urinary melatonin excretion and glucose parameters did not show significant differences between the two groups.Conclusions:Exposure to LAN in an uncontrolled home setting is associated with impaired obese and lipid parameters independent of nocturnal urinary melatonin excretion in elderly individuals. Moreover, LAN exposure is associated with higher ORs for obesity and dyslipidemia independent of demographic and socioeconomic parameters.
The Journal of clinical endocrinology and metabolism 11/2012; · 6.50 Impact Factor
[show abstract][hide abstract] ABSTRACT: Context:Melatonin is involved in a variety of diseases, including cancer, insomnia, depression, dementia, hypertension, and diabetes; its secretion is influenced by environmental light. Although daylight exposure increases nocturnal melatonin secretion in a controlled laboratory setting, whether it increases nocturnal melatonin secretion in an uncontrolled daily life setting remains unclear.Objective:We aimed to determine the association between daylight exposure in an uncontrolled daily life setting and urinary 6-sulfatoxymelatonin excretion.Design and Participants:A cross-sectional study was conducted in 192 elderly individuals (mean age, 69.9 yr).Measures:We measured ambulatory daylight exposure using a wrist light meter in two 48-h sessions; furthermore, we measured overnight urinary 6-sulfatoxymelatonin excretion, an index of melatonin secretion, on the second night of each session.Results:The median duration of daylight exposure of at least 1000 lux was 72 min (interquartile range, 37-124). Univariate linear regression analysis showed marginal to significant associations between log-transformed urinary 6-sulfatoxymelatonin excretion and age, current smoking status, benzodiazepine use, day length, log-transformed duration of daylight exposure of at least 1000 lux, and daytime physical activity. In a multivariate model, log-transformed duration of daylight exposure of at least 1000 lux was significantly associated with log-transformed urinary 6-sulfatoxymelatonin excretion (regression coefficient, 0.101; 95% confidence interval, 0.003-0.199; P = 0.043). Furthermore, an increase in the duration of daylight exposure of at least 1000 lux from 37 to 124 min (25th to 75th percentiles) was associated with a 13.0% increase in urinary 6-sulfatoxymelatonin excretion (6.8 to 7.7 μg).Conclusions:Daylight exposure in an uncontrolled daily life setting is positively associated with urinary 6-sulfatoxymelatonin excretion in the elderly.
The Journal of clinical endocrinology and metabolism 09/2012; · 6.50 Impact Factor
[show abstract][hide abstract] ABSTRACT: PURPOSE: Little is known about the usefulness of the Hearing Handicap Inventory for the Elderly-Screening (HHIE-S) and a single question (SQ) in assessing hearing impairment (HI) and the impact of HI on quality of life (QOL). The objective of this study was to examine the reliability, validity, and associations with QOL measures (i.e., subjective well-being, depressive symptoms, subjective loneliness, and physical functioning) of the HHIE-S and the SQ in the elderly community. METHODS: A self-report questionnaire including HHIE-S, SQ, Philadelphia Geriatric Center Morale Scale, Geriatric Depression Scale, UCLA Loneliness Scale, and the Tokyo Metropolitan Institute of Gerontology Index of Competence was administered to community elderly (781 males and 950 females). Among them, 97 males and 100 females also responded voluntarily to a request for test-retest and auditory tests. The criterion validity was tested by using pure-tone averages. RESULTS: Regarding the reliability of HHIE-S, Cronbach's alpha coefficient was 0.91, Spearman-Brown coefficient was 0.90, and intra-class correlation coefficient was 0.85. Regarding the test-retest reliability of SQ, kappa coefficient was 0.65. HHIE-S had significantly lower sensitivity in identifying >25-dB HI, but significantly higher specificity for the detection of >40-dB HI than SQ. HHIE-S had stronger associations with QOL measures than did SQ. CONCLUSIONS: HHIE-S had high reliability, while SQ had insufficient reliability. HHIE-S was more specific in detecting HI and more sensitive in assessing the impact of HI on QOL than SQ. HHIE-S is a more effective instrument for assessing HI and QOL research than SQ in the elderly community.
Quality of Life Research 07/2012; · 2.41 Impact Factor
[show abstract][hide abstract] ABSTRACT: To investigate the relationship between swallowing problems and the number of remaining teeth in healthy elderly people.
Three thousand six hundred sixty-three male and female volunteers aged 65 and older who were living independently were analyzed.
Swallowing problems were defined operationally using a questionnaire and the 30-mL water swallow test. Data were collected on the number of remaining teeth, maximum bite force, occlusal status, presence or absence of oral dryness, and medical history.
The prevalence of swallowing problems was 15.1% (n = 554) in this population. A positive correlation was observed between the number of remaining teeth and maximum bite force. The number of remaining teeth was categorized according to tertiles. Multiple logistic regression analysis revealed that the adjusted odds ratios for 0 to 13 or 14 to 24 remaining teeth to 25 to 32 remaining teeth for swallowing problems were 2.04 (95% confidence interval (CI) = 1.60-2.60) and 1.31 (95% CI = 1.02-1.70), respectively. Significant increases in these odds ratios were found in a trend test (P < .001).
Tooth loss is associated with swallowing problems. Having fewer teeth inhibits masticatory ability, which disturbs the execution of smooth swallowing. Preventive measures against tooth loss at a younger age may be effective at reducing the risk of laryngeal penetration and aspiration at an older age.
Journal of the American Geriatrics Society 04/2012; 60(5):849-53. · 3.98 Impact Factor
[show abstract][hide abstract] ABSTRACT: The International Physical Activity Questionnaire (IPAQ) is a self-reported questionnaire for assessing physical activity and has been tested in 12 countries among adults aged 18 to 65 years. The present study evaluated the reliability and validity of the IPAQ among adults aged 65 years and older.
The study included 164 men and 161 women selected from participants of the Fujiwara-kyo Study, a prospective cohort of elderly Japanese adults. To examine test-retest reliability, the participants were asked to complete the IPAQ twice, 2 weeks apart. The criterion validity of the IPAQ was tested by using an accelerometer.
Based on intraclass correlation coefficients, the reliability of the total IPAQ was 0.65 and 0.57 for men and women, respectively, aged 65 to 74 years and 0.50 and 0.56 for those aged 75 to 89 years. The Spearman correlation coefficients between total IPAQ score and total physical activity measured by accelerometer (TPA-AC) were 0.42 and 0.49 for men and women, respectively, aged 65 to 74 and 0.53 and 0.49 for those aged 75 to 89. Weighted kappa coefficients between total IPAQ score and TPA-AC were 0.49 and 0.39 for men and women, respectively, aged 65 to 74 and 0.46 and 0.47 for those aged 75 to 89.
The reliability of the IPAQ was not sufficient, but the validity was adequate. Although there were some limitations with regard to repeatability and agreement in classification, the IPAQ was a useful tool for assessing physical activity among elderly adults.
Journal of Epidemiology 09/2011; 21(6):459-65. · 2.11 Impact Factor
[show abstract][hide abstract] ABSTRACT: It has been reported that tooth loss is associated with Alzheimer's disease (AD) and dementia. The purpose of this study was to investigate the association between tooth loss and mild memory impairment (MMI) among the elderly. We examined 3,061 community residents aged 65 years or older who had a score of 24 or more on the Mini-Mental State Examination. The subjects were divided according to their score for the three-word delayed recall test into control (score: 3 or 2) and MMI (score: 1 or 0) subjects. The subjects underwent a dental examination, an interview to determine their medical history, a self-administered questionnaire (inclusive of higher-level functional capacity, drinking and smoking habits, and frequency of going out), and a 10-m walking test. Fewer remaining teeth, going out once a week or less frequently, and a slow walking speed on a 10-m walking test were found at a significantly higher prevalence in the MMI group (n=101) than in the control group (n=2,960), after adjustment for sex, age, and the level of education. Multiple logistic regression analysis using these items revealed that the odds ratio of 0-10 remaining teeth for MMI was 1.71 (95% CI 1.05-2.78), compared to individuals with 22-32 remaining teeth. A significant increase was also found in a trend test to examine the increasing odds ratios of 22-32, 11-21, and 0-10 remaining teeth. We consider that tooth loss is associated with MMI later in life.
Brain research 08/2010; 1349:68-75. · 2.46 Impact Factor
[show abstract][hide abstract] ABSTRACT: This cross-sectional study investigated the relationship between the number of remaining teeth to mild memory impairment (MMI), which is a preclinical stage of dementia, and to cognitive impairment.
The subjects were aged 65 years or older and were grouped according to their score for the Mini-Mental State Examination (MMSE), the three-word delayed recall test in the MMSE, and the Geriatric Depression Scale into the control group (n = 3,696), the MMI group (n = 121), and the low MMSE score (23 or lower) group (n = 214). We collected data on the number of remaining teeth, the length of the edentulous period, health-related lifestyle, medical history, blood pressure, height, and body weight. Fasting venous blood samples were also obtained.
Multiple logistic regression analysis, adjusted for depressive symptoms, age, sex, length of education, and other explanatory variables, revealed that the odds ratios of 0-10 remaining teeth to 22-32 remaining teeth were 1.679 (95% CI 1.073-2.627) for MMI and 2.177 (95% CI 1.510-3.140) for a low MMSE score. A significant relationship was also found between the length of the edentulous period and the risk of a low MMSE score (odds ratio 3.102, 95% CI 1.432-6.720) (15 years or more/less than 15 years).
Our findings suggest that tooth loss is associated with cognitive function.
Behavioral and Brain Functions 01/2010; 6:77. · 2.79 Impact Factor