Masked hypertension in extremely preterm adolescents

Abstract

Aim: Extremely preterm (EPT, born <28 weeks gestation) or extremely low birthweight (ELBW, birthweight <1000 g) individuals are at increased risk of high blood pressure (BP) and cardiovascular disease. We compared office BP measurements with 24-h ambulatory BP measurement (ABP) in EPT/ELBW individuals at age 18 years and term controls, and determined the sensitivity and specificity of office BP in predicting masked hypertension (24-h ABP measurements > 130/80).

Methods: All EPT/ELBW individuals and matched term control adolescents born in Victoria, Australia, between 1991 and 1992 were recruited. A subset of this cohort was seen at 18 years, and researchers blinded to birth status measured office BP and ABP. We established the office BP thresholds that had the highest sensitivity and specificity in predicting masked hypertension.

Results: EPT/ELBW (N = 120) individuals had higher mean BP measurements at 18 years, compared with controls (N = 71). Although there were no significant differences in rates of high BP between groups, high proportions of both EPT/ELBW (43.3%) and term control (36.6%) participants met criteria for masked systolic hypertension. In EPT/ELBW individuals, office systolic BP measurement of ≥122.5 mmHg predicted masked systolic hypertension (sensitivity 79%, specificity 74%). Office diastolic BP measurement of ≥75.5 mmHg predicted masked diastolic hypertension (sensitivity 77%, specificity, 77%).

Conclusions: At age 18 years, EPT/ELBW individuals have higher systolic and diastolic BP, compared with controls. Office BP may be an adequate screen for masked hypertension in EPT/ELBW survivors, but further research is needed to identify accurate ABP thresholds for masked hypertension for young Australians.

Keywords: blood pressure; extremely low birthweight infant; extremely preterm infant; hypertension.