Blood pressure in young Aboriginal and Torres Strait Islander people: analysis of baseline data from a prospective cohort study

Objective: To assess the distribution of blood pressure levels and the prevalence of hypertension and pre-hypertension in young Indigenous people (10–24 years of age). Study design: Prospective cohort survey study (Next Generation: Youth Wellbeing Study); baseline data analysis. Setting, participants: Aboriginal and Torres Strait Islander people aged 10–24 years living in regional, remote, and urban communities in Central Australia, Western Australia, and New South Wales; recruitment: March 2018 – March 2020. Main outcome measures: Blood pressure categorised as normal, pre-hypertension, or hypertension using the 2017 American Academy of Pediatrics guidelines (10–17 years) or 2017 American College of Cardiology/American Heart Association guidelines (18–24 years); associations of demographic characteristics and health behaviours with hypertension and pre-hypertension, reported as relative risk ratios (RRRs) with 95% confidence intervals (CIs). Results: Complete data were available for 771 of 1244 study participants (62%); their mean age was 15.4 years (standard deviation [SD], 3.9 years), 438 were girls or young women (56.8%). Mean systolic blood pressure was 111.2 mmHg (SD, 13.7 mmHg), mean diastolic blood pressure 66.3 mmHg (SD, 11.0 mmHg). Mean systolic blood pressure was higher for male than female participants (mean difference, 6.38 mmHg; 95% CI, 4.60–8.16 mmHg), and it increased by 1.06 mmHg (95% CI, 0.76–1.36 mmHg) per year of age. Mean systolic blood pressure increased by 0.42 mmHg (95% CI, 0.28–0.54 mmHg) and diastolic blood pressure by 0.46 mmHg (95% CI, 0.35–0.57 mmHg) per 1.0 kg/m² increase in body mass index. Ninety-one participants (11.8%) had blood pressure readings indicating pre-hypertension, and 148 (19.2%) had hypertension. The risks of pre-hypertension (RRR, 4.22; 95% CI, 2.52–7.09) and hypertension (RRR, 1.93; 95% CI, 1.27–2.91) were higher for male than female participants; they were greater for people with obesity than for those with BMI values in the normal range (pre-hypertension: RRR, 2.39 [95% CI, 1.26–4.55]; hypertension: RRR, 3.20 [95% CI, 1.91–5.35]) and for participants aged 16–19 years (pre-hypertension: 3.44 [95% CI, 1.88–6.32]; hypertension: RRR, 2.15 [95% CI, 1.29–3.59]) or 20–24 years (pre-hypertension: 4.12 [95% CI, 1.92–8.85]; hypertension: RRR, 4.09 [95% CI, 2.24–7.47]) than for those aged 10–15 years. Conclusions: Blood pressure was within the normal range for most young Indigenous people in our study, but one in three had elevated blood pressure or hypertension. Community-level, culturally safe approaches are needed to avoid the early onset of cardiovascular risks, including elevated blood pressure.