Renin Activity and Aldosterone Assay Among Nigerians with Hypertension and Normotension: An Insight into Normative Values and Clinical Correlates.

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/ demographic associations. 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.

Assessment of Snoring and obstructive sleep apnoea in a Nigerian university: Association with cardiovascular risk factors.

BACKGROUND: Snoring remains under diagnosed in general population. It however has significant morbidity and mortality risk factors with multiple effects on the cardiovascular system. The Berlin questionnaire is a worldwide validated instrument to identify those at increased risk for obstructive sleep apnoea (OSA). MATERIALS AND METHODS: In all, 206 workers of LAUTECH were invited to participate in the study. The Berlin questionnaire was used for this study. It was a cross-sectional study. Socio-demographic and clinical data were taken with a data form. Statistical Package for the Social Sciences software (SPSS 17.0) was used for statistical analysis. P < 0.05 was taken as statistically significant value. RESULTS: The study participants consisted of 96 males (46.6%) and 110 (53.4%) females. The mean age was 45.3 ± 7.9 years. The mean body mass index was 28.5 ± 6.0 kg/m². The frequency of occurrence of snoring was 91 (44.2%) including 50 males (54.9% and 41 females (37.3 %, P <0.05). Using the Berlin score, 63 (30.6%) including 34 females (30.9%) were assessed to be at high risk for OSA. Snorers were more likely to be at higher risk of OSA compared to non snorers: odd risk was 113.8, relative risk was 3.3. Snoring was most likely to be associated with obesity, elevated blood pressure and male gender in this study. CONCLUSION: We concluded that snoring and high risk for sleep apnoea is common among this unselected University population and they are closely related to many conventional cardiovascular risk factors. Appropriate interventional strategies are indicated to reduce the burden of the increased morbidity and mortality associated with sleep apnoea in our population.

Prevalence of metabolic syndrome in a rural community in Nigeria.

BACKGROUND: There has been an increasing interest in metabolic syndrome, but few, if any, epidemiological studies on the subject have been conducted in Nigeria. The purpose of this study was to assess the prevalence of metabolic syndrome in a Nigerian rural community. METHODS: A total of 132 participants from three rural towns in southwestern Nigeria were recruited for the study. Anthropometric variables, fasting blood glucose, triglyceride, total and high-density lipoprotein cholesterol (HDL-C), and blood pressure were assessed. The survey was carried out within 2 months after community mobilization and consent. RESULTS: The mean ages of participants were 58.6 +/- 16.9 males and 46.1 +/- 18.7 females. The overall prevalence of metabolic syndrome was found to be 12.1%, with males and females at 12.7% and 11.8%, respectively. There was no significant difference in males and females with the syndrome. Although the prevalence of abdominal obesity was higher in females than males, 16.9% and 7.3%, respectively, the men exhibited a higher mean serum level of triglyceride (P < 0.05). Only 2 (1.5%) of the males had a high fasting serum glucose level. CONCLUSIONS: These results from a representative sample of the Nigerian rural population show a high prevalence of metabolic syndrome. The large number of Nigerians with the metabolic syndrome may have important implications for the health-care sector.