Smoking during the first trimester may increase risk of type 2 diabetes later in life….
Smoking can affect the anatomy, physiology, and metabolism of the organ systems of a fetus. Previous studies have shown the steady associations of low birth weight with increased risks of type 2 diabetes and cardiovascular disease later in life. Cigarette smoke contains different harmful substances such as nicotine, carbon monoxide, cadmium and other toxic factors that may cause restricted blood flow in the specific fetal organs.
A cohort study used data from the Nurses’ Health Study II. A total of 34,453 participants were analyzed for the incidence of maternal and paternal smoking during pregnancy and the risk of type 2 diabetes in daughters. Mothers were asked to report whether they ever smoked cigarettes during pregnancy; if they stopped, during what trimester; and how many cigarettes per day they smoked. The same questions were asked about the fathers.
Results indicate that maternal smoking during the first trimester only was associated with an increased incidence of type 2 diabetes in the daughters compared with no maternal smoking during pregnancy (HR 1.32; 95% CI 1.02, 1.72), independent of birth weight and later life BMI. Also, continued maternal smoking of less than 15 cigarettes per day (HR 1.22; 95% CI 1.04, 1.43) and paternal smoking of greater than 15 cigarettes per day (HR 1.21; 95% CI 1.06, 1.37) were each associated with the risk of diabetes. However, maternal smoking greater than 15 cigarettes per day was not significant (HR 1.16; 95% CI 0.95, 1.42) and there was a similar pattern for paternal smoking less than 15 cigarettes per day. In adjusted models for weight at birth and BMI in adult women, paternal smoking only (HR 1.08; 95% CI 0.95, 1.24) and maternal or two-parent smoking (HR 1.13; CI 0.98, 1.31) were no longer associated with the risk of type 2 diabetes in women.
In conclusion, maternal and paternal smoking during pregnancy is associated with the risk type 2 diabetes in the female offspring, which may explain a higher BMI in adulthood. Fetal exposure to smoking during the first trimester only can lead to fetal complications and long-term consequences of body fat and metabolic outcomes.
- More studies need to be done to explore the role of maternal smoking during the first trimester on insulin resistance in daughters.
- Smoking not only affects the mothers, but the fetus resulting in negative metabolic outcomes.
Jaddoe V.W, Jonge L, Dam R, et al. “Fetal exposure to parental smoking and the risk of type 2 diabetes in adult women.” Aug, 2014 “http://care.diabetesjournals.org/content/37/11/2966.full”