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Background: Hypertension is the most common cardiovascular disease worldwide and is a major cause of morbidity and mortality. Increased adrenergic activity is thought to play a major role in the initiation and progression of the hypertensive state. Hypertension is more severe in Blacks when compared with White patients. Much of the evidence for the increased adrenergic activity is from studies in predominantly White participants. This study aims to evaluate the adrenergic system in Black Nigerian hypertensives by measuring their plasma catecholamines., Methods: Eighty-two newly diagnosed hypertensives and 51 normal controls were recruited for the study. Blood was obtained from the participants after an overnight fast. Also, a 24-hr urine collection was obtained. Levels of plasma noradrenaline, adrenaline, renin, angiotensin converting enzyme (ACE), atrial natriuretic peptide (ANP), aldosterone and insulin levels were determined using HPLC. Fasting plasma glucose was also determined., Results: Plasma noradrenaline level was higher while plasma adrenaline level was lower in the hypertensives. The hypertensives also had lower levels of plasma renin, ACE, and ANP. Systolic blood pressure negatively correlated with plasma adrenaline (r = -0.29, P < .001) and positively correlated with plasma noradrenaline (r = 0.31, P < .001). Renin and ANP also correlated negatively with blood pressure (r = -0.22, P = .012 and r = -0.34, P < .0001 respectively)., Conclusions: Black Nigerian hypertensives demonstrate elevated levels of plasma noradrenaline when compared with normal controls. This is consistent with the hypothesis of the hyperadrenergic state in hypertension. Further studies are needed to relate the hyperadrenergic state to the racial differences in the severity of hypertension.

Background: The study aimed to determine the frequency and characteristics of heart failure with normal EF in a native African population with heart failure., Methods: It was a hospital cohort study. Subjects were 177 consecutive individuals with heart failure and ninety apparently normal control subjects. All the subjects underwent transthoracic echocardiography. The group with heart failure was further subdivided into heart failure with normal EF (EF > or = 50) (HFNEF) and heart failure with low EF(EF <50)(HFLEF)., Results: The subjects with heart failure have a mean age of 52.3 +/- 16.64 years vs 52.1 +/- 11.84 years in the control subjects; p = 0.914. Other baseline characteristics except blood pressure parameters and height were comparable between the group with heart failure and the control subjects. The frequency of HFNEF was 39.5%. Compared with the HFLEF group, the HFNEF group have a smaller left ventricular diameter (in diastole and systole): (5.2 +/- 1.22 cm vs 6.2 +/- 1.39 cm; p < 0.0001 and 3.6 +/- 1.24 cm vs 5.4 +/- 1.35 cm;p < 0.0001) respectively, a higher relative wall thickness and deceleration time of the early mitral inflow velocity: (0.4 +/- 0.12 vs 0.3 +/- 0.14 p < 0.0001 and 149.6 +/- 72.35 vs 110.9 +/- 63.40 p = 0.001) respectively. The two groups with heart failure differed significantly from the control subjects in virtually all echocardiographic measurements except aortic root diameter, LV posterior wall thickness(HFLEF), and late mitral inflow velocity(HFNEF). HFNEF accounted for 70(39.5%) of cases of heart failure in this study. Hypertension is the underlying cardiovascular disease in 134(75.7%) of the combined heart failure population, 58 (82.9%) of the subjects with HFNEF group and 76(71%) of the HFLEF group. Females accounted for 44 (62.9%) of the subjects with HFNEF against 42(39.3%) in the HFLEF group (p = 0.002)., Conclusion: The frequency of heart failure with normal EF in this native African cohort with heart failure is comparable with the frequency in other populations. These groups of patients are more likely female, hypertensive with concentric pattern of left ventricular hypertrophy.

Background. Hypertension is the most common cardiovascular disease worldwide and is a major cause of morbidity and mortality. Studies have suggested that the activity of the renin-angiotensin-aldosterone system play a major role in the target organ damage such as left ventricular hypertrophy occuring in hypertension. We sought to determine the relationship between plasma aldosterone and left ventricular mass in untreated African hypertensives. Methods.We recruited 82 newly diagnosed and untreated hypertensives and 51 normal controls. Measurements obtained included echocardiographic LV mass index, plasma aldosterone and renin. Results. The hypertensive subjects had lower renin levels (21.03[6.974] versus 26.66[7.592] ng.mL-1, P = 0.0013), higher LV mass index (52.56[14.483] versus 42.02[8.315] g.m-2.7P < 0.0001) when compared with the controls.There were no univariate associations between LV mass index and plasma aldosterone (r = 0.0179, P = 0.57) and between LV mass index and plasma renin (r = 0.0887, P = 0.61). In a multivariate model involving LV mass index and age, sex, body mass index (BMI), plasma aldosterone, plasma renin and systolic blood pressure (SBP), only age (P = 0.008), BMI (P = 0.046), and SBP (P = 0.001) were independently associated with the LV mass index. Conclusions. In this group of hypertensive Africans, there is no independent association of plasma aldosterone with LV mass. The height of the blood pressure, the body mass index and the age of the subjects determined the LV mass. [ABSTRACT FROM AUTHOR]