Metabolic abnormalities, insulin resistance, and metabolic syndrome in children with primary hypertension.

BACKGROUND: We sought to describe the prevalence of metabolic abnormalities and of metabolic syndrome (MS) and its relationship to target-organ damage in children with primary hypertension (PH).
METHODS: Patients included 113 children with untreated PH at a mean age of 14.6 years (range, 5 to 18 years). The control group consisted of 134 healthy children at a mean age of 13.5 years (range, 5 to 20 years). We performed a cross-sectional assessment of anthropometric and biochemical cardiovascular risk factors, homeostatic metabolic assessment (HOMA-IR), the insulin sensitivity index (ISI[0,120]), and adiponectin.
RESULTS: Metabolic syndrome, as defined by classic criteria, was present in 4 of 134 (3%) of controls versus 23 of 113 (20.4%) patients (P=.0001), but when PH was not taken as a criterion of MS, MS was diagnosed in 6.2% of patients (no significance). Left-ventricular hypertrophy (LVH) was found in 46 of 113 patients (40.7%), and severe LVH was found in 14 of 113 patients (12.5%). Patients with LVH had a greater body mass index, greater waist-to-hip-ratio, and greater number of parameters of metabolic syndrome (overall P<.05). Carotid (cIMT) and femoral superficial artery intima-media thicknesses correlated positively with HOMA-IR and negatively with ISI[0.120] and serum adiponectin (P<.05). The main predictor for cIMT was adiponectin (R2=0.178, beta=-0.466, P=.002). Left-ventricular hypertrophy was predicted (R2=0.332) by body mass index-standard deviation score (beta=0.551, P=.005) and HOMA-IR (beta=0.380, P=.04).
CONCLUSIONS: Metabolic syndrome, as defined by classic criteria, was diagnosed in 20% of children with PH, but when PH was not a criterion, MS was present in 6.2% of patients. Irrespective of the definition of MS, the applied markers of MS and insulin resistance were the main predictors of target-organ damage.