"Second-meal" phenomenon seen in diabetics

In people with type 2 diabetes, as in healthy people, blood sugar rises much less after the second meal of the day, new research shows.

"The relevance of this observation," Dr. Roy Taylor told Reuters Health, "is that eating a low carbohydrate, high protein snack 1 to 2 hours before a normal meal results in better glucose (sugar) control after the meal. This offers the possibility of using a natural mechanism of the body to get better control rather than using additional drugs."

"The exact impact of such an approach has yet to be tested in longer-term use, but this should now be done," said Taylor, from the Diabetes Research Group, Newcastle University, Newcastle upon Tyne, UK.

"It is important to keep blood glucose levels as low as possible in diabetes to minimize the risk of long-term complications affecting the eye, nerves, the kidneys and blood vessels," Taylor noted.

It's known that in healthy people, the rise in blood sugar after lunch is less if breakfast is eaten. To see if this "second-meal" effect happens in people with diabetes, Taylor's team compared metabolic changes after lunch in eight obese type 2 diabetics on three different test days.

On one test day, the subjects had a standard breakfast followed by a standard lunch; on another test day, breakfast was omitted; and on the final test day, breakfast was omitted but a shot of arginine was given 1 hour before lunch. Arginine is known to boost insulin secretion, which helps regulate blood sugar.

In the latest issue of the journal Diabetes, the researchers report that the rise in blood sugar after lunch was reduced by 95 percent when subjects had eaten breakfast, "confirming the occurrence of the second-meal effect in type 2 diabetes."

"When metabolism has turned itself round (after the normal fast overnight) to deal with food, the body can handle it much more efficiently," Taylor explained.

The investigators also report that pre-meal arginine administration almost halved the post-lunch rise in blood sugar. This tactic "has therapeutic potential," they conclude.

SOURCE: Diabetes Care, July 2009.