[Target organ damage in children with newly diagnosed and untreated essential hypertension]

Abstract

Target organ damage in the course of essential hypertension (EH) may develop already in childhood. The aim of the study was to determine the prevalence of left ventricular hypertrophy (LVH) and arterial damage and its main determinants in children with newly diagnosed, untreated EH. PATIENTS (pts): 87 children (22 girls and 65 boys) with EH, age 14.4 +/- 3 (5-18) yrs.

Control group: 104 healthy children (51 girls and 53 boys) aged 13.3 +/- 3.3 (5-20) yrs.

Study design: cross-sectional, controlled study.

Methods: evaluation of anthropometrical data, birth weight, family history towards cardiovascular diseases, serum biochemical cardiovascular risk factors (lipids, sCRP, homocysteine, uric acid), carotid (cIMT) and superficial femoral artery intima-media thickness (fIMT). In EH children ambulatory blood pressure monitoring (ABPM), echocardiography, ophthalmoscopy, microalbuminuria were evaluated.

Results: EH pts were significantly higher, heavier and had greater body mass index (BMI) (p<0.05). 59% of pts were overweight compared to 19% in control group (p<0.05). Carotid (cIMT) and superficial femoral artery intima-media thickness (fIMT) was greater in children with EH (0.47 +/- 0,05 v 0.43 +/- 0.04 and 0.36 +/- 0.04 v 0.33 +/- 0.04) (p<0.05) respectively. 41% and 19% of pts had cIMT and fIMT above 2 SDS of normal values respectively. The prevalence of LVH was 45%, and in 12% of pts severe (left ventricular mass index--LVMi > 51 g/m2.7) LVH was diagnosed. Pts with LVH had higher birth weight than other pts 3525 < or = 598 v 3136 +/- 635 g (p=0.04) and LVMi correlated with higher birth weight (p=0.0001; r=0.358), 24-hour heart rate (p=0.01; r= -0.361), serum uric acid (p=0.01; r=0.286), homocysteine (p=0.01; r=0.309) and apolipoprotein B (p=0.0001; r=0.258). LVMi correlated with fIMT (p=0.02; r=0.292), but not with cIMT. cIMT correlated with 24-hour systolic blood pressure (SBP)(p=0.01; r=0.305), SBP load (p=0.01; r=0.377), puls pressure (PP) (p=0.01; r=0.292), and heart rate (HR) (p=0.01; r=-0.285). 46% of pts had primary retinopathy, and 1 boy had secondary retinopathy. All pts had normal renal function, and mean microalbuminuria was 29.3+/-11.4 mg/d. Positive family history towards EH was confirmed in 80% of pts vs 29% in controls (p<0.05).

Conclusions: 1. Target organ damage is present already at the time of diagnosis in significant number of children with EH. 2. Overweight was 59% of pts and only 19% of healthy children. 3. LVMi and markers of arterial injury correlate with SBP, PP and HR, fIMT, uric acid, homocysteine, apolipoprotein B and birth weight.