Blood pressure from childhood to adolescence in obese youths in relation to insulin resistance and asymmetric dimethylarginine.

BACKGROUND AND PROPOSE

Hypertension is the most important cardiovascular complication of obesity, even during childhood. Several studies have demonstrated that there is a natural progression of hypertension from childhood to adulthood. However, there are no data reporting a potential worsening in blood pressure (BP) already moving from the pre-pubertal to the pubertal period in obese youths. The aim of this study was to evaluate early change in BP and its relation to insulin resistance (IR) and asymmetric dimethylarginine (ADMA).

METHODS

Thirty obese children underwent a first assessment when they were pre-pubertal (visit_1) and were re-evaluated after a mean of 4.5 years (visit_2). At both visits, anthropometric parameters were assessed, blood samples were collected for measurement of insulin, glucose and ADMA and a 24-h ambulatory BP monitoring was performed.

RESULTS

At visit_2, the study participants presented increased HOMA-IR and ADMA compared to visit_1 (HOMA-IR: 3.6 ± 2.8 vs 2.8 ± 1.4, p = 0.01; ADMA: 1.57 ± 0.78 vs 0.77 ± 0.52 μmol/l, p < 0.001). Values of 24-h systolic and diastolic BP SDS (0.86 ± 0.79 vs 0.42 ± 0.83, p = 0.001; -0.45 ± 0.82 vs 0.08 ± 0.51, p = 0.001) were significantly increased at visit_2 compared to visit_1. At both visits, BMI-SDS, HOMA-IR and ADMA were associated with 24-h BP. In addition, over-time changes in IR and ADMA influenced changes in systolic blood pressure and diastolic blood pressure from childhood to adolescence (p < 0.05).

CONCLUSIONS

Changes in BP already occur moving from the pre-pubertal to the pubertal period in obese children, and modifications in insulin resistance and ADMA seem to be implicated in this early progression in BP.