Abstract: Women are exposed to indoor and outdoor artificial light at night (ALAN) in urban and rural environments. Excessive exposure to hazardous ALAN containing short wavelength light may suppress pineal melatonin production and lead to an increased breast cancer (BC) risk. Our objective was to address the differences in BC risks related to light exposure in urban and rural communities. We examined indoor and outdoor light habits of BC patients and controls that had lived in urban and rural areas in a 5-year period, 10 to 15 years before the time of the study. Individual data, night time sleeping habits and individual exposure to ALAN habits were collected using a questionnaire. A total of 252 women (110 BC patients and 142 controls) participated in this study. The sample was divided to subgroups according to dwelling area and disease status. Age matching was completed between all subgroups. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated for urban and rural women separately, using binary logistic regression. OR results of urban population (92 BC patients and 72 control) revealed that BC risk increases with daily use of cellphone (OR = 2.13, 95% CI = 1.01-4.49, P < .05) and residence near strong ALAN sources (OR = 1.51, 95% CI = 0.99-2.30, P < .06). Nevertheless, BC risk decreases if a woman was born in Israel (OR = 0.44, 95% CI = 0.21-0.93, P < .03), longer sleep duration (OR = 0.75, 95% CI = 0.53-1.05, P < .1), and reading with bed light illumination before retiring to sleep (OR = 0.77, 95% CI = 0.61-0.96, P < .02). Furthermore, in the rural population (18 BC patients and 66 control) BC risk increases with the number of years past since the last menstruation (OR = 1.12, 95% CI = 1.03-1.22, P < .01). However, BC risk decreases with longer sleep duration (OR = 0.53, 95% CI = 0.24-1.14, P < .1), reading with room light illumination before retiring to sleep (OR = 0.55, 95% CI = 0.29-1.06, P < .07), and sleeping with closed shutters during the night (OR = 0.66, 95% CI = 0.41-1.04, P < .08). These data support the idea that indoor and outdoor nighttime light exposures differ between urban and rural women. Therefore, we suggest that women can influence BC risk and incidence by applying protective personal lighting habits. Further studies with larger sample sizes are needed to strengthen the results.

Abstract: PURPOSE: Although sleep is important for healing, sleep deprivation is a major concern for patients in hospitals. The purpose of this review is to consolidate the observational and interventional studies that have been done to understand exogenous, non-pharmacological strategies for improving sleep in hospitals. DATA SOURCES: We searched Medline, CINAHL, PsycINFO and the Web of Science databases for peer-reviewed articles published between 1970 and 2015 in English. STUDY SELECTION: A title review of 13,113 articles from four databases resulted in 783 articles that were further culled to 277 based on a review of the abstracts. The net result after reading the articles and a hand search was 42 articles. DATA EXTRACTION: From each article we recorded the independent variables, methods used for measuring sleep and specific sleep outcomes reported. RESULTS OF DATA SYNTHESIS: Noise is a modifiable cause of some sleep disruptions in hospitals, and when reduced can lead to more sleep. Earplugs and eye masks may help, but changing the sound and light environment is more effective. Calming music in the evening has been shown to be effective as well as daytime bright light exposure. Nursing care activities cause sleep disruption, but efforts at limiting interventions have not been demonstrated to improve sleep conditions. CONCLUSION: The research is hard to consolidate due to the multitude of independent variables and outcome metrics, but overall points to the potential for making meaningful improvements in the quality of patient sleep.

Abstract: BACKGROUND: Worldwide overweight and obesity rates are on the rise, with about 1 900 billion adults being defined as overweight and about 600 million adults being defined as obese by the World Health Organization (WHO). Increasing exposure to artificial light-at-night (ALAN) may influence body mass, by suppression of melatonin production and disruption of daily rhythms, resulting in physiological or behavioral changes in the human body, and may thus become a driving force behind worldwide overweight and obesity pandemic. METHODS: We analyzed most recent satellite images of night time illumination, available from the US Defense Meteorological Satellite Program (DMSP), combining them with country-level data on female and male overweight and obesity prevalence rates, reported by the WHO. The study aims to identify and measure the strength of association between ALAN and country-wide overweight and obesity rates, controlling for per capita GDP, level of urbanization, birth rate, food consumption and regional differences. RESULTS: ALAN emerged as a statistically significant and positive predictor of overweight and obesity (t>1.97; P<0.05), helping to explain, together with other factors, about 70% of the observed variation of overweight and obesity prevalence rates among females and males in more than 80 countries worldwide. Regional differences in the strength of association between ALAN and excessive body mass are also noted. CONCLUSIONS: This study is the first population-level study that confirms the results of laboratory research and cohort studies in which ALAN was found to be a contributing factor to excessive body mass in humans.International Journal of Obesity advance online publication, 23 February 2016; doi:10.1038/ijo.2015.255.