Type 2 diabetes, formerly known as adult onset diabetes, is the most common form of diabetes. The chronic condition affects how the body metabolizes glucose (sugar) in the body. Insulin is a hormone that regulates the movement of sugar into the cells to maintain a normal glucose level. Type 2 diabetes occurs when the body is either resistant to the effects of insulin or doesn’t produce enough to maintain normal levels. The condition used to mainly occur in adults, but higher rates of obesity have seen the disease show up in children. There is currently no known cure.
For years, scientists have known there are several risk factors that increase the likelihood of the onset of type 2 diabetes. In addition to obesity, inactivity, age and family history all increase the risk. There is also a large racial disparity as type 2 is more common among all minority groups, with non-Hispanic blacks having the highest rate. The most recent numbers show that nearly 20 percent of all non-Hispanic blacks have some form of diabetes, compared with 10 percent of non-Hispanic whites.
A recent study shows that for black women, the risk may have started at birth.
Researchers looked at 16 years of health data for 21,000 black women. After adjusting for variables including family history and socioeconomic status, the results showed that the risk of type 2 diabetes increased with lower birth weight. Women who had a low birth weight (less than 5.5 pounds) had a 13 percent increase of risk for developing type 2 diabetes later in life. When the birth weight was even lower, the risk went as high as 40 percent. The higher risk remained even when adjusting for being overweight.
The study was done as part of the Black Women’s Health Study, an ongoing research project centered out of Boston University. The project is focused on finding answers to why black women have higher rates of certain illnesses than other groups. The project has been following the health outcomes of 59,000 women for nearly 20 years. This was the first study to highlight the association of low birth weight to type 2 diabetes.
The finding could be significant considering babies born to black mothers are twice as likely to have a low birth weight as those born to white mothers. In fact, black women have the highest incidence of low weight births among all racial groups in the United States. This disparity has persisted for decades.
There are several contributing factors. Poor maternal health, smoking and lack of access to quality prenatal care for poor women all contribute to less healthy pregnancies and an unusually high infant mortality rate for a developed nation. Other studies have shown that large amounts of stress can also lead to lower birth weight.
It’s the last factor that most likely contributes to low birth weight babies for black women.
Studies have shown that when accounting for all the known health and socioeconomic factors, they explained only 10 percent in the disparity in low birth weight. A 2012 survey of black and Latina girls and young women reported a great deal of stress during their pregnancies. This mirrored previous studies that showed chronically high levels of stress for women of color during their pregnancy and lower birth weight babies. The researchers concluded that the contributing factor was the depression they suffered during pregnancy brought on by discrimination and disrespect motivated by racism.
It also appears to be a uniquely American problem.
A 2010 report from a summit about Black Maternal Health noted that “women with very low birth weight babies were three times as likely to have experienced interpersonal racism than women with children of normal birth weights. Foreign-born black women see their rates of infant mortality rise to the same level as U.S.-born black women within a generation.” The daily stresses of just existing as a black woman in American society can lead to depression, which increases the risk of premature and lower birth weight babies. This exists across all socioeconomic groups. Furthermore, new studies have shown that this stress can chemically silence genes and remain in eggs and sperm.
This means the damage caused by stress can be passed on to future generations.
The study did not claim a causal relationship between low birth weight and type 2 diabetes and further research would need to be done to explain why the relationship exists. However, as they note in the conclusion, “very low birth weight and low birth weight appear to be associated with increased risk of type 2 diabetes in African American women, and the association does not seem to be mediated through BMI. The prevalence of low birth weight is especially high in African American populations, and this may explain in part the higher occurrence of type 2 diabetes.”