‘Urgent effort’ needed to combat high blood pressure among teens in sub-Saharan Africa

Key takeaways:

• One in 10 adolescents living in sub-Saharan Africa is estimated to have high blood pressure.
• More granular reporting of BP is needed across low-income countries.

Approximately one in 10 adolescents aged 10 to 19 years living in sub-Saharan Africa has elevated BP, increasing their risk for premature CVD due to underlying hypertension, data show.

Overall, the natural history of hypertension and subsequent end-organ damage across the lifespan in Africa remains poorly understood, Simon Stewart, MD, DMSc, FESC, FHFA, a National Health & Medical Research Council (NHMRC) of Australia senior principal research fellow at the Institute of Health Research, University of Notre Dame Australia, and colleagues, wrote in The Lancet Global Health.

Simon Stewart

“More people from sub-Saharan Africa aged between 20 years and 60 years are affected by end-organ damage due to underlying hypertension than people in high-income countries,” the researchers wrote. “However, there is a paucity of data on the pattern of elevated BP among adolescents aged 10 to 19 years in sub-Saharan Africa.”

In a systematic review and meta-analysis, Stewart and colleagues analyzed data from 36 observational studies published between 2010 and 2021 including 37,926 randomly selected adolescents aged 10 to 19 years who lived in 10 sub-Saharan African countries. The studies included the pooled prevalence of elevated BP or had enough data for the researchers to compute the estimates.

“The most common definition of elevated BP, used in 30 studies, was derived from the guidelines of the American Academy of Pediatrics,” the researchers wrote. “Overall, 28 studies provided specific information on the prevalence of elevated BP based on normative sex, age and height-adjusted BP levels. All 36 studies applied (and reported data for) the 95th percentile threshold or higher for participants younger than age 13 years, and an absolute threshold of 120/80 mm Hg or higher for those aged 13 to 19 years.”

The researchers independently extracted relevant data from individual studies and used a random-effects model to estimate the pooled prevalence of elevated BP (n = 29,696) and mean systolic and diastolic BP (n = 27,155), both overall and on a sex-specific basis.

Within the cohort, sex data was available for 26,818 adolescents for the prevalence of elevated BP (53.6% female) and for 23,777 adolescents for mean BP (54.1% female).

The reported prevalence of elevated BP ranged from 0.2% to 25.1% across studies, for a pooled prevalence estimate of 9.9% (95% CI, 7.3-12.5; I² = 99%; P for heterogeneity < .0001). In sex-stratified analyses, there was no difference in the percentage of male vs. female participants with elevated BP.

The pooled systolic BP was 111 mm Hg (95% CI, 108-114; P for heterogeneity < .0001) and pooled diastolic BP was 68 mm Hg (95% CI, 66-70; P for heterogeneity < .0001). Additionally, researchers found that, for every unit increase in age (year), systolic BP increased by 3.5 mm Hg (95% CI, 2-5) and diastolic BP increased by 1.7 mm Hg (95% CI, 0.3-3.1). For every unit increase in BMI, systolic and diastolic BP increased by 1.9 mm Hg (95% CI, 0.7-3.1).

“Overall, study methodology varied; not all studies provided sex-specific data or actual BP measurements,” the researchers wrote. “Despite consistent reports that women in sub-Saharan Africa are more likely to have hypertension than men, we were unable to identify definitive sex-specific differences in blood pressure levels within adolescents living in sub-Saharan Africa that could explain the difference later in life. However, increasing age and BMI positively correlated with both increasing systolic BP and diastolic BP levels.”

The researchers noted that the data reinforce the need for more systematic and granular reporting of BP, applying minimum standards, against important factors such as age, sex, anthropometric profile and socioeconomic status. Additionally, a high proportion of the population across sub-Saharan Africa, including many low-income countries, were not represented.

“To support our findings, a wider geographical distribution of methodologically standardized studies in this potentially vulnerable and pivotal age group should be conducted,” the researchers wrote. “In the meantime, there is sufficient evidence to prompt urgent efforts to proactively detect and optimally treat elevated BP and hypertension in young individuals living across sub-Saharan Africa.”