Evaluating the association of APOA2 polymorphism with insulin resistance in adolescents

Abstract

Background: 265T>C SNP in the APOA-II gene promoter may be associated with obesity risk and insulin resistance (IR). This study aims to analyze the association between the APOA2 - 265T>C SNP and risk for obesity and IR in adolescents.

Material and methods: The study was conducted on 500 adolescents. They were 240 obese and 260 non-obese individuals, aged 16-21 years old. Their mean age was 18.25 ± 2.54 years. Variables examined body weight, height, waist circumference (WC), systolic and diastolic blood pressure (BP), body fat percentage (BF%), and abdominal visceral fat layer. Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) was used as a biomarker for IR. BF% was assessed by body composition analyzer and abdominal visceral fat thickness was determined by ultrasonography. The APOA2 - 265T>C polymorphism genotype was analyzed by PCR amplification of a 273-bp fragment.

Results: Genotype frequencies were in Hardy-Weinberg equilibrium. The frequency of the mutant C allele was significantly higher in obese cases than non-obese cases. After multivariate adjustment, waist, BF%, visceral adipose layer and HOMA-IR were significantly higher in homozygous allele CC carriers than TT + TC carriers. Homozygous individuals for the CC allele had statistically higher values of energy intake, total fat (g/day) and saturated fat (SATFAT) than carriers of the T allele.

Conclusions: Homozygous individuals for the C allele had higher obesity risk than carriers of the T allele and had elevated levels of visceral adipose tissue. Moreover, the present study shows that the CC polymorphism is associated with the development of IR [OR 1.89 (1.35-2.91), P = .012] and remains significant after adjusting for gender, age and body mass index.

Keywords: APOA2 polymorphism; Adolescents; Anthropometry; Insulin resistance; Obesity; Visceral fat.