MEAN PLATELET VOLUME IS A PREDICTOR OF BLOOD PRESSURE NORMALIZATION IN PEDIATRIC HYPERTENSION

Abstract

Objective: Arterial hypertension in adolescents is a risk factor for elevated blood pressure and cardiovascular sequelae in adult life. The study aimed to analyze factors influencing blood pressure tracking in pediatric patients with primary hypertension (PH). Design and method: We analyzed retrospectively 77 children with primary hypertension (53 boys, 24 girls, 13.9 ± 2.7 years) and observation period at least 12 months, in whom we assessed clinical data, anthropometric parameters, office blood pressure, ABPM, and biochemical data, including markers of subclinical inflammation: mean platelet volume (MPV), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR). Results: At the onset of the observation, all patients had arterial hypertension – newly diagnosed (n = 51) or already treated with antihypertensive drugs (n = 26). The observation period was from 1 to 5.25, mean: 2.1 ± 1.0 years. Blood pressure (BP) normalized in 13 (16.9%) patients; seven were previously treated with antihypertensive medications. Patients in whom BP normalized compared to those with sustained hypertension were not-significantly younger (12.9 ± 3.1 vs. 14.1 ± 2.6 [years], p = 0.171), had higher birth weight (3866 ± 425 vs. 3163 ± 614 [g], p = 0.024) and lower initial MPV (9.2 ± 1.4 vs. 10.1 ± 1.3 [fL], p = 0.041) and lower BMI Z-score (0.5 ± 1.0 vs. 1.2 ± 1.2, p = 0.047) and total cholesterol (143.4 ± 26.0 vs. 167.6 ± 33.6 [mg/dL], p = 0.047) after the observation period. Z-score of systolic blood pressure (SBP) at the end of observation correlated with initial values of: BMI Z-score (R = 0.248, p = 0.032), MPV (R = 0.237, p = 0.046), PLR (R = 0.240, p = 0.044), and with nighttime diastolic BP dipping in ABPM (R = -0.309, p = 0.009). SBP Z-score at the end of the observation period also correlated with Z-scores of body weight and BMI (R = 0.327, p = 0.004; R = 0.384, p<0.001) and LDL-cholesterol (R = 0.297, p = 0.031) at the end of observation and with the increase in body weight during the observation period (R = 0.384, p < 0.001). At the end of the observation period, the Z-score of diastolic blood pressure correlated with MPV (R = 0.371, p = 0.003). Conclusions: 1. The chance of normalization of blood pressure in pediatric patients with primary hypertension is influenced by birth weight, body mass loss, and degree of subclinical inflammation. 2. Mean platelet volume might serve as a predictor of blood pressure change in pediatric patients with primary hypertension.