Insomnia symptoms associated with hyperglycemia

In recent years, insomnia and short sleep duration have been reported to worsen glucose tolerance. Because only a few prospective studies have investigated this issue in Japan, various aspects have yet to be elucidated. Therefore, we conducted a 2-year prospective study of Japanese local residents in order to examine the association between the onset of glucose tolerance disorders and insomnia/short sleep duration. In 2005 and 2007, residents of a rural community in Aomori Prefecture, Japan, were sent a self-administered questionnaire, and peripheral blood samples were collected to measure their fasting plasma glucose levels. A total of 497 residents participated in both of the surveys. The incidence of hyperglycemia was calculated as the number of people who had had neither hyperglycemia nor diabetes mellitus at the baseline survey but had eventually developed hyperglycemia at the time of the follow-up survey. Logistic regression analyses were used to examine the association between the onset of hyperglycemia and insomnia/sleep duration. Depression status, which had not been adjusted for in previous studies, was included as a covariate in the logistic regression analyses. A total of 429 participants had neither hyperglycemia nor diabetes mellitus at the baseline; of these, 12 were found to have hyperglycemia at the follow-up survey. Thus, the calculated incidence of hyperglycemia was 2.8%. Multiple logistic regression analyses revealed that the odds ratio for difficulty in initiating sleep with regard to the onset of hyperglycemia was 5.27 (95% confidence interval, 1.48-18.77; P = 0.01). Difficulty in initiating sleep is a risk factor for hyperglycemia.