Introduction: The distribution of blood pressure in Portuguese children and adolescents remains relatively unknown. Given the prevalence of hypertension in Portugal and the epidemiological trends for most cardiovascular diseases, it is important to ascertain blood pressure distribution at young ages, which constitutes the main objective of this registry.
Methods: A sample of 1618 children and adolescents from the Central region of Portugal was included in this survey. The sample's mean age was 12.98 +/- 3.12 years (range: 5-18 years), body mass index 19.85 +/- 3.55 (range: 12.71-38.46); 1438 were male, mean age 12.39 +/- 3.35 years, and 180 female, mean age 13.05 +/- 3.07 years. Blood pressure and heart rate were measured three times after a 10-minute resting period. The measurements were performed with a validated automatic blood pressure monitor (Colson MAM BP 3AA1-2; Colson, Paris) and with an appropriately sized cuff over the brachial artery. All subjects were involved in amateur sports, with 80% of the sample beginning their activity at the time of evaluation.
Results: The overall prevalence of hypertension was 9.8%, and high-normal blood pressure was found in 18.2%. Hypertension prevalence was higher in females (15.0% vs. 9.1% in males; p < 0.05). Comparison between registered athletes and subjects beginning their sports activity revealed similar hypertension prevalence (9.1% vs. 9.9% respectively; p = NS). Obesity was found in 5.3%, 3.9% in females and 5.5% in males. The prevalence of hypertension was greater in obese subjects (23%) than in overweight (14%) and normal weight (8%) subjects, clearly suggesting a relation between weight profile and blood pressure levels.
Conclusions: Our results reveal that a significant proportion of the children studied have blood pressure levels above the 90th percentile, with an overall prevalence of hypertension of 9.8%, more pronounced in females and related to overweight. The implications of these observations are even more important when we consider the epidemiology of hypertension in Portugal and its link with stroke as the leading cause of death and disability.