ESPE Abstracts

Background: The innate immune system is one of the first lines of host defense against invading pathogens. Pro-inflammatory α-defensins (mainly DEFA1–3) and anti-inflammatory bacterial/permeability-increasing protein (BPI) are antimicrobial peptides predominantly produced by neutrophils which have been recently related to obesity, type 2 diabetes and cardiovascular risk.

Objective and hypotheses: The aim of our study was to test whether α-defensins and BPI could be new biomarkers of obesity and cardiovascular risk in children.

Method: We performed a cross-sectional and longitudinal study in asymptomatic prepubertal Caucasian children. Plasma α-defensins and BPI (ELISA), BMI, waist circumference, systolic blood pressure (SBP), carotid intima media thickness (cIMT), HOMA-IR, and HMW-adiponectin were cross-sectionally assessed in 250 children at age 7 years (50% girls, 21% overweight subjects). α-defensins and BPI were also longitudinally assessed in a subset of these children (n=89) at age ~10 years.

Results: In the cross-sectional study, higher α-defensins concentrations were associated with a poorer cardiometabolic profile, showing positive associations with BMI, waist, SBP, cIMT, HOMA-IR, and negative correlations with HMW adiponectin (all between r=0.191 and r=0.377; P<0.01 and P<0.0001). Conversely, higher plasma BPI concentrations were associated with a better cardiometabolic phenotype showing negative associations with BMI, waist, SBP, cIMT, HOMA-IR, and positive correlations with HMW adiponectin (all between r=−0.124 and r=−0.329; P<0.05 and P<0.0001). In the longitudinal study, plasma concentrations of α-defensins, but not of BPI, at age 7 were associated with BMI (β=0.189, P=0.002; overall R²=0.847) and waist (β=0.241, P=0.001; overall R²=0.754) at age ~10 years.

Conclusion: We suggest that α-defensins and BPI may be new biomarkers of childhood obesity. Increased concentrations of α-defensins may predict weight gain and abdominal fat deposition in prepubertal children.