WASHINGTON (Reuters) — Cutting down on caffeine could help people with the most common form of diabetes better control their blood sugar levels, researchers said.

Giving caffeine to a small group of people with Type 2 diabetes caused their levels of the blood sugar glucose to rise through the day, especially after meals, researchers at Duke University Medical Center in Durham, North Carolina, found.

"Caffeine appears to disrupt glucose metabolism in a way that could be harmful to people with type-2 diabetes," James Lane, a Duke medical psychologist who led the study, said in a telephone interview.

Caffeine is found in coffee, tea and many soft drinks. Diabetes is a condition in which one's blood glucose levels are too high.

Having too much glucose in the blood can damage the eyes, kidneys and nerves, and diabetes can also lead to heart disease, stroke and limb amputations.

Type-2 diabetes is the form closely linked to obesity.

The new findings seem to run counter to previous research regarding diabetes and caffeine. Earlier studies indicated that people who drank coffee had a reduced risk of Type-2 diabetes, and those who drank the most coffee had the lowest risk.

The researchers used new technology — a tiny glucose monitor embedded under the abdominal skin — to monitor the glucose levels continuously in 10 people, average age 63.

On days when the participants were given four tablets containing caffeine equivalent to four cups of coffee, their average daily sugar levels rose eight percent compared to days when the same people were given four placebo tablets, the researchers reported in the journal Diabetes Care.