Insulin resistance in childhood obesity: The role of dietary habits and their association with novel markers of cardiovascular disease

Abstract

Background

Childhood obesity presents numerous comorbidities such as insulin resistance (IR) and dyslipidemia, and could be associated with alterations in novel markers of cardiovascular (CV) risk like: (1) the activities of associated enzymes such as lipoprotein associated phospholipase A₂ (Lp-PLA₂) and paraoxonase 1 (PON 1), (2) reverse cholesterol transport (RCT), which comprises cellular cholesterol efflux (CCE), in addition to lecithin:cholesterol acyltransferase (LCAT) and cholesteryl ester transfer protein (CETP) activities, and (3) high density lipoprotein (HDL) antioxidant capacity. Moreover, IR could worsen these cardiometabolic alterations. The objective of the present study was to characterize the effect of IR on novel CV markers in a pediatric population with obesity.

Methods

Twenty-five obese children and adolescents with IR, and 25 without IR took part in the study. Anthropometric parameters, Tanner stage and dietary habits were registered. Glucose, insulin, non-esterified fatty acid (NEFA), lipid, and high sensitivity C reactive protein (hsCRP) levels, plus Lp-PLA₂, LCAT, CETP and PON 1 activities, as well as CCE and HDL antioxidant capacity were measured. A cutoff point of 3.16 in Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) determined the presence of IR.

Results

No differences were observed in age, sex and Tanner stage. Expectedly, the group with IR displayed higher insulin and NEFA levels (p < 0.05). They also presented increased Lp-PLA₂ and decreased PON activities (p < 0.05). Importantly, these differences were associated with dietary habits (p < 0.05).

Conclusion

IR present in pediatric obesity associated with vascular specific inflammation and reduced PON 1 activity, in addition to alterations in glucose metabolism, thus increasing CV risk in adulthood. These proatherogenic disturbances were conditioned by dietary habits.