Background Isolated systolic hypertension (ISH) of the young has been associated with both normal and increased cardiovascular risk, which has been attributed to differences in central systolic blood pressure and arterial stiffness. Methods We assessed the prevalence of ISH of the young and compared differences in central systolic blood pressure and arterial stiffness between ISH and other hypertensive phenotypes in a multi-ethnic population of 3744 subjects (44% men), aged <40 years, participating in the HELIUS study. Results The overall prevalence of ISH was 2.7% (5.2% in men and 1.0% in women) with the highest prevalence in individuals of African descent. Subjects with ISH had lower central systolic blood pressure and pulse wave velocity compared with those with isolated diastolic or systolic-diastolic hypertension, resembling central systolic blood pressure and pulse wave velocity values observed in subjects with high-normal blood pressure. In addition, they had a lower augmentation index and larger stroke volume compared with all other hypertensive phenotypes. In subjects with ISH, increased systolic blood pressure amplification was associated with male gender, Dutch origin, lower age, taller stature, lower augmentation index and larger stroke volume. Conclusion ISH of the young is a heterogeneous condition with average central systolic blood pressure values comparable to individuals with high-normal blood pressure. On an individual level ISH was associated with both normal and raised central systolic blood pressure. In subjects with ISH of the young, measurement of central systolic blood pressure may aid in discriminating high from low cardiovascular risk.
Keywords: HELIUS study; Isolated systolic hypertension; central blood pressure.