Insufficient sleep and circadian rhythm disruption are associated with health problems including obesity, cardiovascular disease, and cognitive impairment. Analysis of blood RNA samples showed that after just one week, 711 genes are affected by insufficient sleep.
The affected genes were associated with circadian rhythms, sleep homeostasis, oxidative stress, and metabolism. Biological processes affected included chromatin modification, gene-expression regulation, macromolecular metabolism, and inflammatory, immune and stress responses.
A study of 420 people who followed a 20-week weight-loss treatment found that late lunch eaters lost less weight.
Approximately half the people ate lunch before 3pm and half afterwards. Energy intake, dietary composition, energy expenditure, appetite hormones, and sleep duration were similar in both groups. Late eaters were more likely to be evening types, had less energetic breakfasts, and skipped breakfast more frequently that early eaters. However, neither sleep duration nor CLOCK SNPs were independently associated with weight loss.
Eating patterns have changed considerably over the last few centuries.
Japanese scientists have found that biological clock dysfunction exacerbates contact hypersensitivity in mice.
CLOCK mutant mice showed an increased immune response that exacerbated contact hypersensitivity (CHS), suggesting that circadian rhythm might be an important factor in the regulation of CHS via corticosterone level.