Hypertension guidelines in children should be universal

The effect of applying American instead of European guidelines for the diagnosis of hypertension in childhood was analysed in a cross-sectional study carried out in Italian institutions for treatment of obesity in children. The main difference between the American and the European guidelines is the level of blood pressure (BP) for the diagnosis of hypertension, in that the American guideline suggests a BP of 130/80mmHg, while the European cut-off for the diagnosis of hypertension is 140/90mmHg. The Italian study showed that among 2929 young persons considered non-hypertensive by European criteria, 327 (11%) were reclassified using the lower cut-off point suggested by the American guideline. The authors studied cardio-metabolic risk factors in the reclassified subset and demonstrated that these children in fact had an adverse risk factor profile compared with subjects not diagnosed with hypertension by the European Society of Hypertension (ESH). This observation on different risk profile according to higher hypertension should not come as a surprise. Consequently, by applying the American College of Cardiology (ACC)/American Society of Hypertension guideline more children were eligible for treatment. It should not come as a surprise that lowering BP cutoff limits for the diagnosis of hypertension results in an increase in the number of subjects with the diagnosis. The percentage of re-classified subjects could in other populations be quite different if the distribution of BP was different, for example, higher mean population BP would result in more reclassifications and vice versa. In non-obese children reclassification is likely to be smaller. There are several limitations to the study as expressed by the authors. It is a very special population: obese and overweight children, treated in hospital outpatient clinics; is a cross sectional study without followup; the BP was measured at only one clinical examination without follow-up. The clinical implications are therefore uncertain, in particular with respect to the need for medication. Notwithstanding these reservations, the study points towards a need for consistency in hypertension guidelines in children. The authors of the guideline have access to the same studies, and yet the interpretation of these studies differs. A joint venture seems warranted. In hypertension guidelines in adults, there are similar differences, the main being differences in cutoff limits. The European Society of Cardiology/ESH guideline suggests a cut-off limit of 140/90mmHg, while the ACC/American Heart Association guideline suggests a BP higher than 130/80mmHg for the diagnosis of hypertension. Possible effects have been elucidated by, for example, Gijón-Conde et al. in a study in Spain. The substitution of American for European guidelines would result in a marked increase in subjects diagnosed with hypertension (33.1% vs. 46.9%) and a marked increase in the need for antihypertensive medication. The authors very sensibly suggest that guidelines should also consider public health and cost implications. Similarly, in a study in Chinese nurses, reclassification resulted in a staggering increase in hypertension prevalence from 6.8% to 29%, and a parallel decrease in control and awareness of hypertension. High BP is undoubtedly the leading cause of mortality and morbidity globally. Fortunately, all the guidelines agree on the need for a diet low in sodium and adequate in potassium, body weight reduction, exercise and low alcohol intake for the prevention and nonpharmacological treatment of hypertension.