A new study by the Harvard School of Public Health finds that people with lower birth weights and more diabetes may be at greater risk of dying early.
A paper published Monday in the Journal of the American Medical Association (JAMA) found that a person with an average birth weight of 1.5 pounds was 20 times more likely to die at or before age 65 than a person whose birth weight was between 1.0 and 1.25 pounds.
“There is a clear public health benefit for infants and young children whose birth weights are under 1.75 pounds,” the researchers wrote.
“In our study, we used the most recent data from the 2010 National Health and Nutrition Examination Survey (NHANES) to identify the most common birth weight in the United States for each age group.”
Birth weight data is available through the NHANES, which is the longest-running population-based survey in the U.S. The paper, led by Harvard epidemiologist Anantha Narayanan and lead author Shaina M. Brown, a postdoctoral fellow in the Department of Epidemiology and Biostatistics at Harvard Medical School, found that birth weight is closely associated with the risk of mortality.
“The average American is born at 1.7 pounds, so we know from NHANE that the average American has an average of 1 in 100,000 chance of dying before age 75,” Brown said in a statement.
“Our study found that those born at or below the 1.6 mark had the highest risk of death, followed by those born between 1 and 1:50.
For example, among infants born to women between the ages of 0 and 19, the risk was 0.6 per 1,000.
By contrast, among those born to men between the age of 0 to 19, that risk was 1.2 per 1.000.
We found that the risk for those born in the lowest birth weight range was almost twice as high as the risk in the highest birth weight group.”
For women, the study found, the greatest risk of premature death is found among those with a birth weight between 1:45 and 1 1/2 pounds, and among the women with a body mass index (BMI) of 25 to 29.9.
For men, the most dangerous birth weight ranges from 0 to 1 1 1 / 2 pounds.
For infants born under the 1 1 kg birth weight, the average risk of survival is 0.8 per 1 million live births, while for those who were born between 2 and 4 pounds, the odds of survival was 2.5 per 1 000.
“While our study does not provide a definitive explanation for the increase in risk, it provides evidence that the increasing prevalence of low birth weight infants is linked to the increasing rate of diabetes and metabolic syndrome,” Brown added.
“Given the rising rates of obesity in the American population, it is critical that we focus on the health of children and adults and consider the possibility that this increased risk could be the result of a variety of factors that are currently unknown.”
“Our findings support recommendations that we make in the National Childhood Diabetes Data Bank that children and adolescents who have the lowest body weight in childhood be encouraged to participate in weight loss programs and follow the Dietary Guidelines for Americans and the Diabetes Prevention Program guidelines,” Narayanunan said.
The authors of the study did not identify any other factors that could contribute to the increased risk of early death.
Brown and Narayanonan noted that the research does not determine the cause of the increased mortality risk.
However, the authors note that there is growing evidence that a variety, or at least an increase in, the prevalence of obesity and diabetes are associated with increased risk for death and premature death.
“We believe that we have identified a risk factor that may be related to the association between low birth weights in childhood and later mortality,” Narayananan said in the statement.