High Insulin in Early Childhood Is Associated With Subsequent Asthma Risk Independent of Body Mass Index

: 49 Background: Asthma and obesity are major, interconnected public health challenges that usually have 50 their origins in childhood, and for which the relationship is strengthened among those with insulin 51 resistance. 52 Objective: To determine whether high insulin in early life confers increased longitudinal risk for asthma 53 independent of body mass index (BMI). 54 Methods: The study used data from the Tucson Children’s Respiratory Study (TCRS) and the Avon 55 Longitudinal Study of Parents and Children (ALSPAC). Non-fasting insulin was measured in TCRS 56 participants at age 6 and fasting insulin in ALSPAC participants at age 8. Physician-diagnosed active 57 asthma was determined at baseline and at subsequent assessments up to age 36 years in TCRS and 17 58 years in ALSPAC. 59 Results: In TCRS, high insulin (upper quartile) at age 6 was associated with increased odds of having 60 active asthma from ages 8 to 36 compared to low insulin (OR 1.98, [1.28-3.05], p=0.002). Similarly, in 61 ALSPAC, high insulin was associated with a significantly higher risk of active asthma from ages 11 to 17 62 compared to low insulin (1.59 [1.12-2.27], p=0.009). These findings were independent of baseline BMI in 63 both cohorts, and were not related to other demographic and asthma risk factors nor other tested 64 markers of systemic inflammation and metabolic syndrome.