Cortisol level measurements in fingernails as a retrospective index of hormone production.

The cortisol level in fingernails may reflect the hormone's cumulative production over a long period, but the notions have not been fully established. In this study, we investigated the association of cortisol in fingernails with cortisol accumulation over a long period (hair cortisol) and over a relatively short period (salivary cortisol). In study 1, hair and fingernail samples were collected from 58 middle-aged and elderly men. The cortisol level in hair samples was moderately associated with the level in fingernail samples (r = 0.29, p < 0.05 and rs = 0.36, p < 0.01). In study 2, 37 workers provided 4 saliva samples over the course of one day (at awakening, 30 min after awakening, before lunch, and after work) and another set a month later. Further, the workers were asked to provide fingernail samples during a six-month period. We found that the cortisol level in saliva over the whole day (area under the curve for cortisol) was moderately associated with the cortisol level measured in fingernail samples that were collected 4 months (r = 0.43, p < 0.05 and rs = 0.50, p < 0.01) and 5 months later (r = 0.45, p < 0.05 and rs = 0.53, p < 0.01). These results indicated that the cortisol level in fingernail samples might retrospectively represent hormone production during a given period. The cortisol level in fingernail samples may be useful in the investigation of the link between psychosocial stress and health.

Associations between diurnal 24-hour rhythm in ambulatory heart rate variability and the timing and amount of meals during the day shift in rotating shift workers.

It has not hitherto been clarified whether there is an association between dietary behavior and circadian variation in autonomic nervous system activity among shift workers. This study examines diurnal 24-h rhythm in heart rate variability (HRV) and dietary behavior among rotating shift workers, while taking into account the sleep-wake cycle and physical activity. The subjects were 11 female and 2 male nurses or caregivers working in a rotating 2-shift system at a health care facility. All the subjects were asked to undergo 24-h electrocardiograph and step count recordings, and to record the time of each meal and the amounts of each food and beverage consumed. Coarse graining spectral analysis was used for approximately 10-min segments of HRV to derive the total power (TOT: >0.04 Hz) of the periodic components and the integrated power of periodic components in the low-frequency (LF: 0.04-0.15 Hz) and high-frequency (HF: >0.15 Hz) ranges. Then the ratio of HF power to TOT (HF nu) and the ratio of LF power to HF power (LF/HF) were calculated to assess cardiac vagal tone and cardiac sympathovagal balance, respectively. Single cosinor analysis was used to obtain 24-h period variations in both variables of HRV. Acrophases of HF nu and LF/HF expressed in time since awakening were significantly (p<0.05) delayed for subjects having breakfast at a later time after awakening. Multivariable regression analysis indicated that the timing of breakfast, the ratio of energy intake at dinner to total energy intake, and total energy intake were correlated to the acrophases of HF nu and/or LF/HF. These results suggest that the phase angle between circadian variation in cardiac autonomic nervous system activity and the sleep-wake cycle may be associated with dietary behavior in shift workers.

Effects of bright light exposure on the behavioral and psychological symptoms of dementia and the burden on caregivers in institutionalized elderly with cognitive decline.

AIM: The purpose of this study was to examine the effects of bright light exposure on behavioral and psychological symptoms of dementia (BPSD), including sleep disturbances and the burden on caregivers in institutionalized elderly with cognitive decline. METHODS: The subjects included eight people with cognitive decline (mean [SD] age, 79.9 [9.1] years) living in geriatric healthcare facilities for the elderly. BPSD and the burden on caregivers were measured over three weeks using the CMAI (Cohen-Mansfield Agitation Inventory), NPI-NH (Neuropsychiatric Inventory-Nursing Home Version) and J-ZBI (Modified Japanese Version of the Zarit Caregiver Burden Interview) at the end of each week. During the second week, the subjects received either 12,000 K (white) or 2,400 K (orange) of light corresponding to approximately 2,000 lux from a light-emitting diode (LED) device, measured before the eyes in the gaze direction, from 9 : 00 to 9 : 30 during occupational tasks, such as origami and coloring. Differences in the variables obtained at the different weeks were assessed using ANOVA with multiple comparisons. RESULTS: The scores for the severity of BPSD, including sleep disturbances and the burden on caregivers, on the NPI-NH significantly (P<0.05) improved following the treatment with white light exposure, while the scores for the MMSE and J-ZBI did not change over the three-week study period. CONCLUSIONS: These results suggest that exposure to white bright light during occupational tasks in the morning may have a benefit in improving BPSD, including sleep disturbances and the burden on caregivers.

Diurnal 24-hour rhythm in ambulatory heart rate variability during the day shift in rotating shift workers.

Circadian variation in cardiac autonomic nervous system activity and behavior during the day shifts of shift workers has not hitherto been clarified. This study examined diurnal 24-h variation in heart rate variability (HRV), sleep-wake cycle, physical activity, and food intake during the day shift in rotating shift workers. The subjects were female nurses and caregivers working at a health care facility (14 day workers and 13 rotating shift workers). Each subject was asked to undergo 24-h electrocardiograph and step count recordings. Coarse graining spectral analysis was used for approximately 10-min segments of HRV (600 beats) to derive the total power (TOT: >0.04 Hz), integrated power in the low-frequency (LF: 0.04-0.15 Hz) and high-frequency (HF: >0.15 Hz) ranges, the ratio of HF power to TOT (HF nu), and the ratio of LF power to HF power (LF/HF). Double cosinor analysis was used to obtain 24-h and 12-h period variations in variables of HRV and physical activity. While no difference was found in the acrophases of either period for step counts or in the 12-h period of HRV variables between the groups, the acrophases of the 24-h period for HRV variables were delayed by 1.3 to 5.5 h in rotating shift workers, and their differences in HF power, HF nu, and LF/HF reached a significant level (p < 0.05). On the days of the experiment, retiring time, waking up time, total time in bed, sleep efficiency, and mealtimes and energy intake for each diet did not differ between the groups. These results suggest that there is a possibility of an abnormal phase angle between circadian variation in cardiac autonomic nervous system activity and the sleep-wake cycle during the day shift in shift workers.

[Osteoporosis and living of residents in a nursing home].

Residents in a nursing home can become bedridden following fracture caused by osteoporosis or falls. To prevent fall and fracture is important, and conceived to reflect quality of caregiving in individual facilities. The incidence of falling is around 35% in all nursing homes related to our facility. Incidents of falling occur mostly during walking among ambulatory residents, and during performing transfers among residents using wheelchairs. Dementia is suggested to be a factor influencing the incidence of falling. In order to prevent fracture resulting from falling and osteoporosis in nursing homes, it is important that all working members in each facility examine prevention measures comprehensively, while considering characteristics of an environment of their facility and residents therein. All working members should thereby activity interven in the QOL (quality of life) of residents, and assist them to lead a healthy and joyful life n their nursing home.