Haptoglobin Phenotypes Are Associated with the Postload Glucose and Insulin Levels in Pediatric Obesity

Abstract

<jats:p><jats:italic>Purpose</jats:italic>. Haptoglobin (Hp) is a protein involved in the acute-phase reaction of inflammation. Humans have three major phenotypes (Hp1-1, Hp1-2, and Hp2-2). Several studies have shown altered Hp regulation in adults with obesity and metabolic alterations. The Hp2-2 phenotype is associated with a high cardiovascular risk. Our aim was to investigate if Hp levels and the Hp2-2 phenotype are associated with glucose metabolism in pediatric obesity. <jats:italic>Methods</jats:italic>. We retrospectively studied 192 participants (92 males and 100 females), aged 4–18 years. Clinical and biochemical data were collected. The Hp phenotype (Hp1-1, Hp1-2, and Hp2-2) was identified through Western immunoblot. <jats:italic>Results</jats:italic>. Subjects carrying Hp1-1, Hp1-2, and Hp2-2 phenotypes were 13.6, 50.8, and 35.6%, respectively. Hp serum, fasting glucose, and insulin levels, as well as HOMA-IR, were similar among groups. Postload glucose and insulin levels (as insulin AUC) were progressively higher from the Hp1-1 to Hp2-2 phenotype. <jats:italic>Conclusion</jats:italic>. To our knowledge, this is the first study on Hp phenotypes conducted in a pediatric population with obesity. We showed that the presence of Hp2 allele is associated with a worse response of glucose load in terms of both glucose and insulin levels. Thus, the Hp2-2 phenotype could predispose in pediatrics, at the same degree of obesity, to a worse glycemic and insulinemic compensation.</jats:p>

Relation between haptoglobin polymorphism and oxidative stress status, lipid profile, and cardiovascular risk in sickle cell anemia patients

“…Hp2‐2 is characterized by a higher risk of mortality in tuberculosis and HIV 51 . It is a major risk factor for (a) vascular complications and retinopathy in diabetics, 52 (b) cardiovascular disease in diabetes mellitus, 53 (c) developing refractory hypertension in hypertensive patients, (d) severity and extent of myocardial damage after myocardial infarction, 54 (e) the prediction of atherosclerosis in patients with ischemic stroke, 55 (f) non‐muscle invasive bladder cancer incidence and progression, 56 and (g) worse glycemic and insulinemic compensation in pediatric obesity 57 . In the present study, TAC and GSH levels were significantly lower in Hp2‐2 subjects (AA and AS) than in those carrying Hp1‐1 and Hp2‐1.…”