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OBJECTIVES Hypertension phenotypes differ between Africans and Europeans, with a greater prevalence of low renin salt-sensitive hypertension and greater predisposition to adverse cardiac remodelling in Africans. To elucidate the roles of inheritance and environment in determining hypertension phenotypes in sub-Saharan Africans and white-Europeans, we compared phenotypes in white individuals in the UK (n = 132) and in African individuals in the UK (n = 158) and Nigeria (n = 179). METHODS Biochemistry, blood pressure, left ventricular structure (echocardiography) and 24-h urinary collections of sodium and potassium were measured. RESULTS Twenty-four-hour urinary sodium/potassium ratio was lower in individuals living in Europe (both African and white: 2.32 ± 0.15 and 2.28 ± 0.17) than in individuals in Nigeria (4.09 ± 0.26, both P

Aim : Although plasma NT-proBNP differentiates hypertension (HT) with or without left ventricular hypertrophy (LVH) from hypertensive heart failure (HHF), most of the published data are based on studies in Western populations. Also, most previous studies did not consider left ventricular (LV) diastolic function and right ventricular (RV) function. We therefore examined the relation between NT-proBNP on LV and RV remodelling in an African hypertensive cohort. Methods : Subjects were subdivided into three groups after echocardiography: hypertensives without LVH (HT) (n = 83); hypertensives with LVH (HT+LVH) (n = 50); and those with hypertensive heart failure (HHF) (n = 77). Results : Subjects with HHF had significantly higher NT-proBNP levels compared to the HT+LVH group (p < 0.0002). NT-proBNP correlated positively with right atrial area, an indirect measure of RV function. Conclusions : NT-proBNP is proposed as a useful biomarker in differentiating hypertension with or without LVH from hypertensive heart failure in black hypertensive subjects.

Soluble ST2 is a biomarker of cardiomyocyte stretch that is useful in the diagnosis and prognosis of coronary artery disease. Its role in the field of hypertension and hypertensive heart failure (HHF) has not yet been well investigated. We studied the effect of left ventricular remodelling on the concentration of soluble ST2 in a cohort of 210 subjects with hypertension (HT). Left ventricular hypertrophy (LVH) was considered present when echocardiographic left ventricular mass indexed for height in metres (m) was greater than 46.2 g m(-1 2.7) in women and 49.2 g m(-1 2.7) in men. Subjects were subdivided into three groups: those without LVH (HT, n = 83); those with LVH (hypertension with left ventricular hypertrophy (HTLVH), n = 50) and those with HHF, n=77). Plasma ST2 and NT-pro BNP were measured using electrochemiluminescence type immunoassay. Subjects with HHF had higher plasma ST2 concentrations compared to HTLVH (134.7 ± 57.3 ng ml(-1) versus 23.0 ± 8.3 ng ml(-1), P < 0.001) and those with HT (134.7 ± 57.3 ng ml(-1) versus 14.5 ± 4.9 ng ml(-1), P < 0.0001). NT-pro BNP levels were similar when HTLVH was compared with HT (P = 0.68), but subjects with HHF had significantly higher NT-pro BNP compared to HTLVH (P < 0.0002). Soluble ST2 had strong correlation with clinical and echocardiograhic parameters, and correlated well with NT-pro BNP (r = 0.41, P < 0.0001). Plasma ST2 is a useful biomarker in not only differentiating HHF from HT with or without LVH, but also distinguishes hypertensive LVH from HT without LVH.

Left ventricular (LV) hypertrophy (LVH) is classified according to geometric pattern into 4 types: concentric hypertrophy, eccentric hypertrophy, concentric remodeling, and normal geometry. Prevalence of death and cardiovascular complications associated with hypertension depend on the geometric pattern. Although soluble ST2 levels, a novel cardiac biomarker of mechanical strain is increased in hypertension, the relationship with hypertensive LV geometric patterns has not been studied. The authors investigated the relationship between soluble ST2 levels and LV geometric patterns in a cohort of hypertensive patients. LVH was considered present when echocardiographic LV mass index exceeded 49.2 g/m(2.7) in men and 46.2 g/m(2.7) in women. Patients with concentric hypertrophy had higher soluble ST2 levels compared with patients with normal geometry (20.4±8.4 ng/mL vs 14.3±5.4 ng/mL, P

Dike B Ojji,1,2 Sandrine Lecour,2 Olusoji M Adeyemi,3 Karen Sliwa2,4 1Cardiology Unit, Department of Medicine, University of Abuja Teaching Hospital, Gwagwalada, Abuja, Nigeria; 2Department of Medicine, Faculty of Health Sciences, Hatter Institute for Cardiovascular Research in Africa, University of Cape Town, Cape Town, South Africa; 3Department of Medical Laboratory Sciences, University of Abuja Teaching Hospital, Gwagwalada, Abuja, Nigeria; 4Mary McKillop Institute for Health Research, ACU, Melbourne, VIC, Australia Purpose: ST2 receptor, which is a member of the Toll-like/interleukin-1 (IL-1) receptor family, has been found to be increased in the serum of patients 1day after myocardial infarction. Several other studies have shown that soluble ST2 levels correlate with severity of heart failure (HF), left ventricular ejection fraction, creatinine clearance, B-type natriuretic peptide and C-reactive protein, and are predictors of mortality in HF. Most of these studies were not only limited to ischemic heart disease but also concentrated on left-sided HF. We therefore decided to study the relationship between soluble ST2 and some markers of right ventricular (RV) function in a cohort of hypertensive HF subjects.Patients and methods: This is a prospective cohort study of hypertensive HF patients presenting to the University of Abuja Teaching Hospital, Abuja, over a 12-month period. ST2 was measured in plasma sample by the enzyme-linked immunosorbent assay (ELISA) method. Right ventricular diameters in diastole (RVDD) and right atrial area (RAA) were obtained on echocardiography, while right ventricular systolic pressure (RVSP) was estimated from echocardiography by the addition of the pressure gradient between the right ventricle and right atrium (RA) to the pressure in the RA.Results: There was a significant correlation between RVSP and soluble ST2 (t=0.75, p

This study was aimed at finding a relationship between pain modulators in the blood and physiological pain in apparently healthy Nigerians. It also aimed at establishing a pilot study for finding reference values for plasma levels of substance P, serotonin and tryptophan for the first time among Nigerians. Volunteers were made up of 110 residents of Abuja, aged between 21 and 50 years. Cold pressor test was used to induce pain assessing pain intensity, threshold and tolerance. ELISA was used to assay for plasma substance P, serotonin and tryptophan. Pain parameters from cold pressor test were correlated with plasma pain modulators measured. Results from cold pressor test revealed pain intensity to be 5.79±0.25cm, pain threshold 28.77±2.32s and pain tolerance 143.62±24.39s. Blood plasma level of substance P was 116.52±20.53pg/mL, serotonin 454.18±30.16ng/mL and tryptophan 12.77±0.67μg/mL. There was negative correlation between pain threshold and plasma substance P, pain tolerance and plasma substance P and pain threshold and plasma serotonin. There was however a positive correlation between pain intensity and plasma serotonin. In conclusion, the regression formulas may aid in using cold pressor test to predict blood substance levels of the measured pain modulators in a low resource setting like Nigeria where ELISA test is very expensive.