Objective
To investigate associations between infant weight gain trajectories and coronary heart disease (CHD).
Study design
We followed 3645 Danish individuals born between 1959 and 1961 with information on weight at birth and at age 2 weeks and 1, 2, 3, 4, 6, or 12 months. Sex-specific weight trajectories were generated using latent class modeling. Cases of CHD (n = 279) were identified from national health registers. Hazard ratios (HRs) were estimated by Cox regression with sequential adjustment for sex, socioeconomic status, prepregnancy body mass index, maternal smoking, preterm birth, parity, and birth weight.
Results
We identified 5 trajectories of weight development in infancy in our cohort: very low–moderate increase (11.5% of the population), low-marked increase (13.9%), low-stable increase (32.4%), average-stable increase (29.8%), and high-moderate increase (12.4%). Compared with the average-stable increasing trajectory, having a very low–moderately increasing weight trajectory in infancy was associated with a higher frequency of adult CHD (HR, 1.56; 95% CI, 1.04-2.33). The higher frequency remained after adjustment for maternal factors but was slightly attenuated after additional adjustment for preterm birth and parity (HR, 1.41; 95% CI, 0.91-2.23) and disappeared after adjustment for birth weight (HR, 0.78; 95% CI, 0.44-1.37). The associations with CHD did not differ between the other trajectories and the average-stable increasing trajectory.
Conclusions
Although a pattern of very low–moderate increasing weight during infancy was associated with a higher frequency of adult CHD, the association did not persist after adjustment for birth weight, highlighting the importance of prenatal exposures.