Hormones that stop insulin working properly can be activated by napping
Taking regular lunchtime siestas could increase the risk of developing Type 2 diabetes, according to research.
The study of 16,480 people, found those who napped were 26% more likely to get the condition than those who did not.
Several factors which may be behind the link included disrupted night-time sleep and an association between napping and reduced physical activity.
But a conference in Glasgow will hear that factors like genetics and being overweight are more significant.
The researchers will tell delegates at the Diabetes UK event that napping during the day may disrupt night-time sleep.
This could have an impact as short night-time sleep duration has been shown to be associated with an increased Type 2 diabetes risk.
Waking up from napping also activates hormones and mechanisms in the body that stop insulin working effectively, the researchers said, and this could predispose people to Type 2 diabetes - which can develop when the insulin the body makes does not work properly.
Dr Iain Frame, director of research at Diabetes UK, said: "We already know that people who are overweight or obese, and therefore more at risk of developing Type 2 diabetes, can have problems sleeping.
"This new research could be another step towards explaining the possible link between disturbed sleep patterns and Type 2 diabetes."
"However, in terms of being major risk factors for developing Type 2 diabetes, disturbed sleep or napping are likely to remain less significant than already established risk factors such as being overweight, being over the age of 40 or having a history of diabetes in the family."
Diabetes is a serious condition that can lead to long-term complications such as heart disease, stroke, blindness, kidney failure and amputation.
Short-term complications include hypoglycaemic episodes, which can lead to unconsciousness and hospitalisation if left untreated, and persistent high blood glucose levels can be fatal if untreated.
The research, conducted by scientists from the University of Birmingham and from Guangzhou Hospital in China, will be presented at Diabetes UK's annual conference in Glasgow's SECC.