Obayashi Kenji, Saeki Keigo, Iwamoto Junko, Ikada Yoshito, Kurumatani Norio
Department of Community Health and Epidemiology, Nara Medical University School of Medicine , Nara , Japan .
Chronobiol Int. 2014 Apr;31(3):394-400. doi: 10.3109/07420528.2013.864299. Epub 2013 Dec 11.
Circadian misalignment between internal and environmental rhythms dysregulates glucose homeostasis because of disruption of the biological clock, and increases risk of diabetes. Although exposure to evening light and decreased melatonin secretion are both associated with the circadian misalignment, it remains unclear whether they are associated with diabetes. In this cross-sectional study on 513 elderly individuals (mean age, 72.7 years), we measured ambulatory light intensity during the 4 h prior to bedtime at 1-min intervals during two consecutive days and overnight urinary 6-sulfatoxymelatonin excretion (UME) along with glucose metabolism. The median average intensity of evening light exposure and UME were 25.4 lux (interquartile range 17.5-37.6) and 6.6 μg (interquartile range 3.9-9.7), respectively. Both log-transformed average intensity of evening light exposure and log-transformed UME were significantly associated with diabetes in a multivariate logistic regression model adjusted for covariates, including gender, body mass index, duration in bed, and night-time light exposure [adjusted odds ratio (OR), 1.72; 95% confidence interval (CI), 1.12-2.64; p = 0.01; and adjusted OR, 0.66; 95% CI, 0.44-0.97; p = 0.04; respectively]. An increase in evening light exposure from 17.5 to 37.6 lux (25-75th percentiles) was associated with a 51.2% (95% CI, 8.2-111.4%) increase in prevalent diabetes, and an increase in UME from 3.9 to 9.7 μg (25-75th percentiles) was associated with a 32.0% (95% CI, 1.9-52.8%) decrease in prevalent diabetes. In conclusion, this study in elderly individuals demonstrated that evening light exposure in home settings and UME were significantly and independently associated with diabetes.
由于生物钟紊乱，体内与环境节律之间的昼夜节律失调会破坏葡萄糖稳态，并增加患糖尿病的风险。虽然暴露于夜间光线下和褪黑素分泌减少均与昼夜节律失调有关，但它们是否与糖尿病相关仍不清楚。在这项针对513名老年人（平均年龄72.7岁）的横断面研究中，我们在连续两天的睡前4小时内，以1分钟的间隔测量了动态光照强度，并测量了夜间尿6-硫酸氧褪黑素排泄量（UME）以及葡萄糖代谢情况。夜间光照暴露的平均强度中位数和UME分别为25.4勒克斯（四分位间距17.5 - 37.6）和6.6微克（四分位间距3.9 - 9.7）。在对包括性别、体重指数、卧床时间和夜间光照暴露等协变量进行调整的多因素逻辑回归模型中，经对数转换的夜间光照暴露平均强度和经对数转换的UME均与糖尿病显著相关[调整后的比值比（OR）分别为1.72；95%置信区间（CI）为1.12 - 2.64；p = 0.01；以及调整后的OR为0.66；95%CI为0.44 - 0.97；p = 0.04]。夜间光照暴露从17.5勒克斯增加到37.6勒克斯（第25 - 75百分位数）与糖尿病患病率增加51.2%（95%CI为8.2 - 111.4%）相关，而UME从3.9微克增加到9.7微克（第25 - 75百分位数）与糖尿病患病率降低32.0%（95%CI为1.9 - 52.8%）相关。总之，这项针对老年人的研究表明，家庭环境中的夜间光照暴露和UME均与糖尿病显著且独立相关。
