Objectives: Plasma renin activity (PRA) and aldosterone tend to differ between Blacks
and Caucasians and studies are very scarce among Africans. We therefore aimed to determine the
normative value of plasma renin activity and serum aldosterone among school teachers in Nigeria
with normal blood pressure compared with their hypertensive counterparts and relevant clinical/
Methods: Plasma renin activity and serum aldosterone were measured using the kits provided by
Diagnostic Biochem, Canada among randomly selected school teachers recruited as part of a study
to assess their total cardiovascular risks. Mean serum values were compared between normotensive
and hypertensive participants and were correlated with clinical and demographic parameters. Statistical
analysis was done using SPSS 17.0, Chicago, Ill, USA. P <0.05 was taken as statistically significant.
Result: The mean PRA level of all study participants was 0.80 ± 0.85 ng/mL.h (mean ± SD) while
the mean serum level of aldosterone was 93.9 ± 60.9 pg/ml. The mean aldosterone: renin ratio was
446.5 ± 958.2. The frequency of occurrence of hypertension was 29%. Only plasma renin activity
was significantly correlated with systolic and diastolic blood pressure, age and the rate pressure
product (a measure of cardiovascular risk). The finding of a higher mean PRA among hypertensive
subjects is definitely related to the antihypertensive medications being taken including beta blockers
and angiotensin converting enzyme inhibitors among others. The prevalence of high aldosterone/
renin ratio which could reflect the proportion of primary aldosteronism was 10.8%.
Conclusion: Nigerians have a low renin activity compared to their Caucasian counterpart. PRA
may be an important determinant of blood pressure among Nigerians. Appropriate drugs that target
phenotypic status of PRA and aldosterone may be useful in the management of hypertension and
the choice of pharmacotherapy among Nigerians.