Study Ties Low Birth Weight to Higher Iincidence of Type-2 Diabetes in African-American Women

Researchers have presented a strong association between low birth weight and increased risk of type-2 diabetes in African-American women.

The study, led by researchers at the Boston University's Slone Epidemiology Center, evaluated more than 21,000 women who were part of the Black Women's Health Study and found that African-American women who were born with low birth weight or very low birth weight faced an elevated risk of developing type-2 diabetes, that is more common than type-1 diabetes and occurs when the body doesn't produce any insulin.

This finding helps explain the large occurrence of type-2 diabetes in African-American population where there is a high prevalence of low birth weight. The researchers followed the participants for 16 years during which they analyzed their birth weight, current age, family history of diabetes, body mass index, physical activity and socioeconomic status.

They noticed that women born at low birth weight suffered a 13 percent higher risk of developing type-2 diabetes when compared to those born with normal birth weight. The risk increased by 40 percent in those born with very low birth weight.

Those born with body weight less than 2.5 kg were defined as having low birth weight and those born with body weight less than 1.5 kg were defined as having low birth weight. They noticed that body size did not play a key role in the association between the two factors as there was a clear link between birth weight and diabetes among women who were not obese.

Studies conducted earlier have shown how birth characteristics like birth weight can have a significant impact on adult health; this is first study to demonstrate this affect in an African American population.

"African American women are at increased risk of developing type-2 diabetes, and also have higher rates of low birth weight than white women," said Edward Ruiz-Narváez, ScD, assistant professor of epidemiology at Boston University School of Public Health. "Our study shows a clear relationship between birth weight and diabetes that highlights the importance of further research for this at-risk group."

The researchers assumed that there exist two leading hypotheses, mainly the 'thrifty phenotype hypothesis' and 'fetal insulin hypothesis'.

The first hypothesis reveals that once the newborn's body realizes that it lacks nutrition, it reprograms itself to take in more nutrition leading to an imbalance in metabolism that causes type-2 diabetes. The second hypothesis reveals that genes that cause impaired insulin secretion also have a negative effect on birth weight.

The finding appears in the Diabetes Care.