Cord Blood Insulin Concentration and Hypertension among Children and Adolescents Enrolled in a US Racially Diverse Birth Cohort

Background: Although insulin resistance is closely related to hypertension, the debate continues as to whether insulin resistance is a cause or a consequence of hypertension. This study investigated the associations of cord blood insulin concentration with blood pressure (BP) and hypertension in childhood and adolescence. Methods: This study included 951 children enrolled from 1998 to 2012 and followed from birth onwards at the Boston Medical Center, Boston, MA. Cord blood insulin concentration was measured using a sandwich immunoassay. Hypertension in childhood and adolescence was defined based on the 2017 American Academy of Pediatrics Clinical Practice Guidelines. Results: The median (interquartile range) for cord blood insulin concentration was 12.1 (7.2-19.0) µIU/mL. The age range of BP measurements was 3 to 18 years (median, 10.6 years). Cord blood insulin concentration was positively associated with systolic and diastolic BP as well as the risk of hypertension at age 3 to 18 years. Compared with the lowest tertile of cord blood insulin concentration, the top tertile insulin concentration was associated with a 5.18 (95% CI, 1.97-8.39) percentile increase in systolic BP, 4.29 (95% CI, 1.74-6.84) percentile increase in diastolic BP, and 1.62-fold (95% CI, 1.27-2.08) higher risk of hypertension. The association between insulin and hypertension was stronger among children born preterm (P for interaction=0.048). Furthermore, preterm birth and childhood overweight or obesity enhanced the associations. Conclusions: Our results suggest that elevated insulin concentration at birth plays a critical role in the early life origins of hypertension and support the hypothesis implicating insulin resistance in the etiology of hypertension.