A new study just published in the journal BMC Medicine has connected maternal body mass index to newborn telomere length. Telomeres, which represent the molecular age of cells, shorten as people age. In the study, researchers found that women with a higher BMI were more likely to give birth to infants with shortened telomeres. This was the first study to connect BMI to molecular health.
Telomeres are segments of repetitive non-coding DNA sequences. They’re found at the end of chromosomes and help prevent damage to coding DNA. Cells with longer telomeres can live longer and divide more times. While telomeres can be repaired, telomere length is often considered the “biological age” of a cell. A team of researchers investigated maternal factors that may affect the telomere lengths in the DNA of newborns.
The team studied a group of 743 pregnant women, ranging in age from 17 to 44 years. After controlling for factors such as smoking, birth complications, and birthweight, the team compared maternal body mass index (BMI) with newborn telomere lengths. This was accomplished by taking samples from the umbilical cord and placental tissue. The researchers found that as the mother’s BMI increased, the average telomere length of her infant decreased. For each point increase in maternal BMI, the telomeres shortened by about 50 base pairs. This is enough to potentially make cells more vulnerable to certain diseases later in life, including type 2 diabetes and cardiovascular disease. The team speculates that nutritional deficiencies are involved since a higher BMI is correlated with poor nutrition.
This was the first study to focus on newborn telomere lengths. While the study was limited in that paternal BMI wasn’t taken into account, the findings suggest a link between BMI and the length of an infant’s telomeres. The team believes that further research should be conducted since nearly a third of reproductive-aged women are overweight.
Dries S. Martens et al. Maternal pre-pregnancy body mass index and newborn telomere length. BMC Medicine (2016).