Improve your Health with the Right Amount of Sleep

Daniel J. Gottlieb, MD, MPH; Naresh M. Punjabi, MD, PhD; Ann B. Newman, MD, MPH; Helaine E. Resnick, PhD; Susan Redline, MD, MPH; Carol M. Baldwin, RN, PhD; F. Javier Nieto, MD, PhD. Association of Sleep Time With Diabetes Mellitus and Impaired Glucose Tolerance. Arch Intern Med. 2005;165:863-867.

ABSTRACT

Background Experimental sleep restriction causes impaired glucose tolerance (IGT); however, little is known about the metabolic effects of habitual sleep restriction. We assessed the cross-sectional relation of usual sleep time to diabetes mellitus (DM) and IGT among participants in the Sleep Heart Health Study, a community-based prospective study of the cardiovascular consequences of sleep-disordered breathing.

Methods Participants were 722 men and 764 women, aged 53 to 93 years. Usual sleep time was obtained by standardized questionnaire. Diabetes mellitus was defined as a serum glucose level of 126 mg/dL or more (>=7.0 mmol/L) fasting or 200 mg/dL or more (>=11.1 mmol/L) 2 hours following standard oral glucose challenge or medication use for DM. Impaired glucose tolerance was defined as a 2-hour postchallenge glucose level of 140 mg/dL or more (>=7.8 mmol/L) and less than 200 mg/dL. The relation of sleep time to DM and IGT was examined using categorical logistic regression with adjustment for age, sex, race, body habitus, and apnea-hypopnea index.

Results The median sleep time was 7 hours per night, with 27.1% of subjects sleeping 6 hours or less per night. Compared with those sleeping 7 to 8 hours per night, subjects sleeping 5 hours or less and 6 hours per night had adjusted odds ratios for DM of 2.51 (95% confidence interval, 1.57-4.02) and 1.66 (95% confidence interval, 1.15-2.39), respectively. Adjusted odds ratios for IGT were 1.33 (95% confidence interval, 0.83-2.15) and 1.58 (95% confidence interval, 1.15-2.18), respectively. Subjects sleeping 9 hours or more per night also had increased odds ratios for DM and IGT. These associations persisted when subjects with insomnia symptoms were excluded.

Conclusions A sleep duration of 6 hours or less or 9 hours or more is associated with increased prevalence of DM and IGT. Because this effect was present in subjects without insomnia, voluntary sleep restriction may contribute to the large public health burden of DM.

COMMENT: It seems that sleep is important in diabetes and other diseases known as the 'diseases of civilisation' such as heart disease, cancer, obesity and so on. So things that disturb your sleep should be modified. These include such things as eating late in the evening (within 3 hours of going to bed), worrying, having a stressful lifestyle or job.

Answers might be to have a good (by which I mean high-protein/fat) breakfast, as that will make you more bright and alert during the day, enabling you to work and think better. And learn to relax – that is learn to switch off, particularly for an hour before going to bed. And that includes eating a diet that does not increase your weight or make you go hungry as both these are likely to be stressful.