Why missing out on a good night's sleep could give you ulcers

Dramatic diurnal variation in the concentration of the human trefoil peptide TFF2 in gastric juice 2001; 48: 648-55

Missing out on a good night's sleep through long haul travel, shift work, or partying could increase the risk of ulcers. Research in Gut shows that levels of a chemical, produced by the stomach and small intestine to repair tissue damage, are highest at night, and are suppressed after a meal.

Twelve healthy, 20 to 24 year old non-smokers were monitored for 24 hours to check their digestive response to food intake, including levels of a protein called TFF2. High levels of TFF2 are found around breaches in the gut lining, and it is thought that the protein activates tissue repair, which begins a few minutes after injury.

The volunteers all ate at 1.15 pm and 5.15 pm, went to bed at 11.30 pm, and were all asleep by 1.00 am. Samples of their gastric juice were collected every two hours during the study.

TFF2 levels followed a circadian rhythm. They were lowest during the afternoon and early evening, rising gradually between 7 and 11 pm. After 1 am, they rose sharply, peaking at around 5 am. During sleep, TFF2 levels increased by up to 340 times.

After lunch, TFF2 levels were between two and 10 times lower, and after supper, were up to seven times lower. And the authors suggest, this may be because production of the protein is suppressed during active digestion. And in those volunteers in whom pepsin production was highest, TFF2 levels were lowest.

The authors conclude that TFF2 is at its most active during inactivity or sleep, and that its activity is suppressed when food is being digested.

Contact: Dr Felicity May, Department of Pathology, University of Newcastle upon Tyne, Royal Victoria Infirmary. F.E.B.MAY@ncl.ac.uk