Epidemiology & Public Health

Obesity and its complication such as cardiovascular diseases are increasing all over the world and they are becoming the serious causes of mass mortality. Various strategies focusing on prevention of such metabolic disorders have being developed in advanced countries. Consequently, evidence-based measures are demanded for examining the risk factors of lifestyle diseases. In Japan, people are recommended not for going asleep within two hours of dinner as a measure of maintaining healthy eating habits. However, the timing of dinner and bedtime on Hemoglobin A1c (HbA1c) level is still yet undiscovered even though those factors are investigated during health examinations. Lifestyle and anthropometric information of middle aged and elderly (40 to 74 years old) who were free from pre-diabetic and diabetic conditions were collected for producing statistical models by multilevel analysis. Univariate analysis of variance was done for assessing the influence of each lifestyle variable firstly. Then, 2-level random intercept models were developed. Total population were 1573 in 2012. Two thirds of them were female. Mean ages were 65.0 years for male and 64.8 years for female at baseline. Mean HbA1c level were 5.20% in 2012, and 5.58% in 2013 and 2014. Males 16.1% and females 7.5% were fell asleep within two hours of dinner. However, the influence of two hours duration between dinner and bedtime did not produce remarkable effect on increasing HbA1c level. Smoking, alcohol drinking, and higher BMI could variate the trend of HbA1c. Rather than paying attention to not to sleep within short period of dinner, eating healthy portion of last meal and getting adequate sleep are important for maintaining stable metabolic process.