Objective: The aim of the present study was to evaluate whether insulin resistance [as measured by Homeostasis Model Assessment (HOMA) index] has an effect on prehypertension and hypertension risk in children after acknowledging the role of BMI and waist-to-height ratio.
Methods: We studied a sample of 377 children 10.5 ± 2.3 years old who had a first diagnosis of hypertension or family history of cardiovascular disease. In this sample all weight classes were represented. The HOMA index was standardized by a linear regression model including BMI, waist-to-height ratio and pubertal status.
Results: The role of BMI and waist-to-height ratio on the risk of prehypertension and hypertension was confirmed by univariate logistic regression models, odds ratio of 1.59 [95% confidence interval (CI) = 1.27-2.00] for BMI, and 1.56 (95% CI = 1.06-2.31) for waist-to-height ratio (>50 vs. ≤50%). When standardized HOMA index was added to BMI or waist-to-height ratio in a multivariate model, it gave a significant independent contribution to explain the risk of prehypertension and hypertension. Odds ratio was 1.23 (95% CI = 1.01-1.51) in the model with BMI, and 1.23 (95% CI = 1.01-1.50) in the model with waist-to-height ratio. The role of HOMA index was confirmed when continuous values of systolic and diastolic blood pressure (standardized by age, sex and height) were analysed, instead of hypertension category.
Conclusions: These results strongly support the hypothesis that in children, insulin resistance plays a role on hypertension independently from obesity, fat distribution and puberty across weight classes.