Out-of-office blood pressure and target organ damage in children and adolescents: a systematic review and meta-analysis

Objective: In children, out-of-office blood pressure (BP) assessment (especially ambulatory monitoring) is regarded as indispensable for accurate hypertension diagnosis. This article reviewed the evidence on the association between out-of-office BP measurements and preclinical organ damage indices in children. Methods: A systematic review and meta-analysis of 93 relevant articles (1974-2012) was performed. Results: Analysis of 10 studies (n = 480, pooled age 14.4 years, with hypertension 33%, renal disease 27%, type 1 diabetes 10%) revealed a significant association between systolic ambulatory BP and left ventricular mass index (LVMI), with pooled correlation coefficient r = 0.40 [95% confidence interval (CI) 0.30-0.50]. Eleven studies reported data on LVMI differences between normotensive (n = 428) and hypertensive children (n = 432), with higher values in the latter group by 6.53 g/m(2.7) (95% CI 4.73-8.33). A moderate association was found between systolic ambulatory BP and carotid intima-media thickness (three studies, n = 231, age 13.3 years, pooled r = 0.32, 95% CI 0.21-0.44), as well as between diastolic ambulatory BP and urine albumin excretion (five studies, n = 355, age 13.1 years, type 1 diabetes 42%, reflux nephropathy 28%, pooled r = 0.32, 95% CI 0.05-0.58). Two studies reported on the association between home BP and LVMI, with one of them showing comparable coefficients as for ambulatory monitoring. Conclusion: The available evidence suggests a moderate but significant association between ambulatory BP and preclinical organ damage, mainly based on studies in nephropathy and/or diabetes. More data are needed in essential hypertension without nephropathy or diabetes, as well as with home measurements.