Predicting Type 2 Diabetes: Birth Weight as a Surrogate

Fetal exposure to severe starvation or stress appears to elevate risk of hyperglycemia or type 2 diabetes (T2D) later in life. Similarly, low birth weight has been associated with glucose intolerance, suppressed insulin secretory capacity, and increased risk of T2D. A research team from Harvard has published a prospective cohort study examining birth weight and established lifestyle risk factors in adulthood with incident T2D. It appears in the July issue of the British Medical Journal.

The data employed was mined from the Health Professionals Follow-up Study (1986-2010), Nurses' Health Study (1980-2010), and Nurses' Health Study II (1991-2011). The study size was quite large, with 149,794 men and women without diabetes, cardiovascular disease, or cancer at baseline included. The researchers uses self-report and a supplemental questionnaire to find incident cases of type 2 diabetes.

During up to 30 years of follow-up, 11,709 participants developed T2D. Participants with low birth weights were 1.45 times more likely to develop T2D for every kilogram below normal they were at birth.

Participants were also 2.1 times more likely to develop T2D for every unhealthy lifestyle factor (e.g. obesity, excess caloric intake, alcohol consumption, cigarette smoking, and sedentary lifestyle).

Low birth weights and unhealthily lifestyle factors were more than simply additive. Having both increased risk of T2D by 2.86 times for each unhealthy lifestyle factor. The researchers were able to determine that 22% of the risk was associated with low birth weight. Almost 60% was related to unhealthy lifestyle factors, and 18% was attributed to interaction of the two factors.

This team’s previous work indicated that people who survived the Chinese famine and consumed Western diets as adults were at elevated risk of hyperglycemia. Extending those findings to this study, they wrote, “Poor nutritional conditions in a pregnant woman may influence the development of the fetus to prepare for survival in an environment in which resources are scarce.” Improving prenatal factors could prevent some T2D.

Their main conclusion is no surprise: Healthier lifestyles could prevent most T2D.