Changing “white and bright” room light to“dim and umber” one had significant effects on residents’sleep patterns

Japanese people are known for their short sleep time, which is resulting from their late bedtime. Lightexposure, especially with short wave length, has significant effects of delaying circadian rhythms. Room lightsused in Japanese houses are mostly “bright and white” fluorescent or LED devices. There are many laboratory experiments demonstrating the effects of light on sleep and wake patterns, however, light effects have not been confirmed in actual house settings. We conducted an intervention study of changing light condition in actual houses. We provided “dim and umber” type light devices to the house with “bright and white” type light devices. In experimental group, where the lights were changed to the “dim and umber types, sleep and wake patterns were advanced significantly, compared to the control group. While in the control group with “bright and white” light type, the residents showed significant delay in their sleep and wake patterns, only within a week period. In the experimental group, they showed significant improvements in their mental health. There are possibilities of beneficial changes, if the “dim and umber” type light settings are introduced into Japanese houses

Factors associated with long-term use of hypnotics among patients with chronic insomnia.

This study investigated factors associated with long-term use of benzodiazepines (BZDs) or benzodiazepine receptor agonists (BzRAs) as hypnotics in patients with chronic insomnia. Consecutive patients (n = 140) with chronic insomnia were enrolled in this study (68 men and 72 women; mean age, 53.8 ± 10.8 years). All patients filled out a self-assessment questionnaire asking clinical descriptive variables at the baseline of the treatment period; patients received the usual dose of a single type of BZD or BzRA. The Pittsburgh Sleep Quality Index (PSQI) and the Zung Self-Rating Depression Scale were self-assessed at the baseline, and the former was re-evaluated at the time of cessation of medication or at the end of the 6-month treatment period. The PSQI included the following sub-items: evaluating sleep quality (C1), sleep latency (C2), sleep duration (C3), habitual sleep efficiency (C4), frequency of sleep disturbance (C5), use of sleeping medication (C6), and daytime dysfunction (C7). Among the patients, 54.6% needed to continue hypnotics for a 6-month treatment period. Logistic regression analysis revealed that, among descriptive variables, only the PSQI score appeared as a significant factor associated with long-term use {odds ratio (OR) = 2.8, 95% confidence interval (CI) = 2.0-4.0}. The receiver operating curve (ROC) analysis identified that the cut-off PSQI total score at the baseline for predicting long-term use was estimated at 13.5 points (area under the curve = 0.86, 95% CI = 0.8-0.92). Among the sub-items of PSQI, the increases in C1: (OR = 8.4, 95% CI = 2.4-30.0), C3: (OR = 3.6, 95% CI = 1.1-11.5), C4: (OR = 11.1, 95% CI = 3.6-33.9), and C6: (OR = 3.4, 95% CI = 1.9-6.2) scores were associated with long-term use. This study revealed that a high PSQI score at the baseline, particularly in the sub-items relating to sleep maintenance disturbance, is predictive of long-term hypnotic treatment. Our results imply the limitation of the effectiveness of hypnotic treatment alone for chronic insomnia

Logistic regression analysis of the associated factors for discontinuation of hypnotics using PSQI sub-item scores as explanatory variables.

<p>CI denotes confidence intervals.</p><p>ns =  not significant; PSQI =  Pittsburgh Sleep Quality Index.</p><p>Logistic regression analysis of the associated factors for discontinuation of hypnotics using PSQI sub-item scores as explanatory variables.</p

Predictive cut-off point of the Pittsburgh Sleep Quality Index for the long-term use of hypnotics estimated with the receiver operating characteristic (ROC) curve.

<p>CI denotes confidence intervals. AUC =  area under the curve.</p

Comparison of demographic variables between the discontinued group and the long-term use group.

<p>Values are expressed as means ±SD. The Mann-Whitney U test was used for the comparison of continuous variables between the 2 groups as follows: age, duration of insomnia morbidity, dose of hypnotics, and SDS and PSQI scores. The chi-square test was used for the comparison of categorical variables between the 2 groups as follows: sex, marital status, educational background, occupation, and half-life of hypnotic.</p><p>ns =  not significant; SDS =  Zung Self-Rating Depression Scale; PSQI =  Pittsburgh Sleep Quality Index.</p><p>Comparison of demographic variables between the discontinued group and the long-term use group.</p

Logistic regression analysis of the associated factors for the long-term use of hypnotics (n = 140).

<p>CI denotes confidence intervals.</p><p>ns =  not significant; PSQI =  Pittsburgh Sleep Quality Index; SDS =  Zung Self-Rating Depression Scale.</p><p>Logistic regression analysis of the associated factors for the long-term use of hypnotics (n = 140).</p

Comparison of PSQI total and sub-item scores between the baseline and the end of the treatment period, and comparison of changes in these scores between the discontinued group and the long-term use group from the baseline to the end of the treatment period.

a)<p>The Wilcoxon signed rank test was used for comparison of the scores between the 2 time points.</p>b)<p>The Mann-Whitney U test was used for comparison of the changes in these scores between the 2 groups.</p><p>Values are expressed as means ±SD for continuous variables.</p><p>*<i>p</i><0.01;</p><p>**<i>p</i><0.05; PSQI =  Pittsburgh Sleep Quality Index.</p><p>Comparison of PSQI total and sub-item scores between the baseline and the end of the treatment period, and comparison of changes in these scores between the discontinued group and the long-term use group from the baseline to the end of the treatment period.</p