Study Links Diabetes With Weight

Researchers have found that low birth weight in mice can hinder the pancreas’ ability to produce enough insulin, causing an increased risk of developing type 2 diabetes, according to researchers at the Joslin Diabetes Center, which is affiliated with Harvard Medical School (HMS).

Because studies of mice are generally good predictors of human biology, the study has implications for people born with low birth weights, according to the Center’s press release.

Low birth weight is defined as less than five-and-a-half pounds.

“We were trying to find out the mechanism by which low birth weight increases diabetes risk,” said lead investigator and HMS Associate Professor of Medicine Mary-Elizabeth Patti.

In their investigation, researchers experimented with two groups of pregnant mice. The control group of pregnant mice were fed well during the entire pregnancy. The second group of mice were not fed adequately during their final week of pregnancy.

At birth, the babies of the second group of mice weighed 23 percent less than the control group.

After birth, the mothers and their children were allowed to eat a full diet. But even as the young mice matured, the mice of the two groups exhibited differences in blood sugar levels.

“By six months, these levels had spiked abnormally, to...the equivalent of serious, full blown diabetes in humans,” said Patti in a press release.

According to Patti, while many other studies focus on premature births, this study focused on baby mice born after full-term pregnancies.

“Even if someone is full-term, if their birth weight is low, that increases their risk for diabetes,” Patti said.

According to the Centers for Disease Control and Prevention (CDC) website, the percentage of low birth weight babies has increased by almost 12 percent between 1980 and 2000. The CDC reported that low birth weight babies represented 7.8 percent of births in 2002.

Patti explained that people can get diabetes because of two factors.

“The first factor is insulin resistance—the body makes insulin but doesn’t respond to it. The second problem is inadequate insulin production in the pancreas,” she said.

According to Patti, “you have to have both of these things to have diabetes.”

The Joslin study, which was published in the March edition of the journal Diabetes, found a link between low birth weight and the second cause of diabetes: inadequate insulin production.

Since low birth weight impairs the pancreas’ ability to secrete insulin and regulate blood sugar levels, it is important to prevent insulin resistance.

Patti pointed to obesity as the driving factor in insulin resistance.

She suggested that to help prevent developing diabetes, people born with low birth weights should not “become obese or inactive.”