Leukocyte telomere length and birth characteristics associated with obesity in infancy in a predominantly Latinx cohort.

Background: Previous studies suggest that in utero exposures may impact future weight gain trajectories in infancy. Leukocyte telomere length (LTL) collected at birth may be an additional variable to test in models for childhood obesity as adult studies suggest that LTL may be predictive of metabolic disease.

Methods: Using a primarily Latinx mother-child longitudinal cohort design, we assessed the relationship between newborn LTL measured via quantitative PCR and obesity at 12 months (WFA ≥ 95th percentile). Secondary outcomes included weight-for-age (WFA) Z scores at 12 months and covariates included birth anthropometrics and maternal prenatal health. Logistic and linear regression models were used to assess independent predictors for infant obesity and WFA Z scores.

Results: We followed 302 children until 12 months including 65.89% with Latinx ethnicity and 4.97% had obesity at 12 months. Independent predictors of obesity at 12 months included higher birthweight Z scores (OR 2.24, 1.16, 5.05) and WFA Z scores at 6 months (OR 1.56, 1.19, 2.05). Longer LTL at birth and higher Apgar scores at 5 min were protective (OR 0.04, 95%CI 0.002, 0.79 and OR 0.30, 95%CI 0.13-0.72, respectively). LTL at birth was negatively associated with WFA Z scores at 12 months of age in multivariable models (Coeff = -0.58, 95%CI -1.05, -0.12).

Conclusions: LTL at birth may be a marker, in addition to birthweight, that can be used to assess an infant's risk for subsequent obesity. Future studies are needed to better assess and determine possible maternal exposures associated with shorter newborn LTL.