Cardiac output is increased in young people with elevated BP

Background: The relationship between Blood Pressure (BP) and cardiovascular risk is continuous. Here, we examined haemodynamic characteristics across a range of BP categories, to determine kihaemodynamic mechanisms associated with early elevations of BP and whether these differ by gender. Methods: 2618 apparently healthy subjects aged 18–40 years were grouped according to gender and BP category, following the recent reclassification of BP as part of AHA/ACC 2017 guidelines. All individuals undertook a lifestyle and medical history questionnaire, together with detailed metabolic and haemodynamic assessments. Results: Hypertension (HT), stage 1 was the most common BP phenotype in males (29%), whereas normal BP was the most common BP phenotype in females (68%). In both males and females, cardiac output (CO) was significantly increased in subjects with elevated BP and HT versus normotensives (P < 0.001 for all). Stroke volume (SV) was increased in hypertensive males compared with those with elevated or normal BP. In contrast, peripheral vascular resistance (PVR) and pulse wave velocity (PWV) were significantly increased in hypertensive females (P < 0.001 for all) compared with the other BP categories. Conclusion: In young adults, increased CO is evident at the elevated BP stage and this could represent an initiating mechanism involved in the onset of HT. SV, PVR and PWV might play different roles in females and males in the development of later sustained HT. Elevated CO may be an important risk stratifier for future HT in young people.