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1.
Nutr Metab Cardiovasc Dis ; 31(4): 1071-1080, 2021 04 09.
Artículo en Inglés | MEDLINE | ID: mdl-33549447

RESUMEN

BACKGROUND AND AIMS: Heart rate variability (HRV) is a main determinant of autonomic function and related to the development of hypertension and cardiovascular (CV) disease. Hypertension develops in black populations at an earlier age, which could be due to differences in the autonomic nervous system activity and sodium/potassium handling in black and white populations. We investigated whether HRV is associated with 24 h urinary sodium and potassium excretion and blood pressure (BP) in a young bi-ethnic cohort. METHODS AND RESULTS: We examined 423 black and 483 white healthy adults (aged 24.5 ± 3.1 years) for 24 h HRV, including standard deviation of normal RR intervals (SDNN) reflecting autonomic variations over time, and root mean square of successive differences (RMSSD) reflecting parasympathetic activity. We measured 24 h urinary sodium and potassium concentration and BP. The black group had lower SDNN and potassium excretion as well as higher RMSSD, sodium and Na/k ratio compared to the white group (all p < 0.05). Only in black individuals, urinary potassium excretion was independently and negatively associated with SDNN (ß[95% CI];-0.26[-0.50;-0.02]ms) and RMSSD (-0.14[-0.27;-0.01]ms, p < 0.05). One unit increase in sodium/potassium (Na/K) ratio was associated with higher SDNN (ß[95% CI]; 3.04[0.89; 5.19]ms) and RMSSD (1.60[0.41; 2.78]ms) in the black cohort only (both p < 0.001). In both groups elevated 24 h diastolic BP was associated with lower RMSSD (p < 0.05). CONCLUSION: Lower potassium excretion and higher Na/K ratio related independently to higher HRV in young and healthy black adults. A better ethnic-specific understanding of sodium and potassium handling is required as part of preventive cardiology, especially in black individuals. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03292094; URL: https://clinicaltrials.gov/ct2/show/NCT03292094.


Asunto(s)
Población Negra , Presión Sanguínea , Disparidades en el Estado de Salud , Frecuencia Cardíaca , Hipertensión/etnología , Potasio/orina , Eliminación Renal , Población Blanca , Adulto , Factores de Edad , Sistema Nervioso Autónomo/fisiopatología , Estudios Transversales , Femenino , Voluntarios Sanos , Humanos , Hipertensión/fisiopatología , Hipertensión/orina , Masculino , Natriuresis , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Sodio/orina , Sudáfrica/epidemiología , Adulto Joven
2.
J Am Coll Nutr ; 38(7): 614-622, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30822227

RESUMEN

Objective: Selenium plays an important physiological role as component for antioxidant selenoproteins such as glutathione peroxidase (GPx). Since oxidative stress contributes to hypertension development, it is likely that selenium deficiency may contribute to the burden of cardiovascular disease. To better understand the involvement of selenium and GPx in the early development of cardiovascular disease, we investigated in young, healthy black and white African men and women whether measures of the micro- and macrovasculature are related to selenium and GPx activity. Methods: In young adults (N = 394; aged 20-30 years) we determined serum selenium, GPx activity, microvascular measures (central retinal artery equivalent, central retinal vein equivalent, arteriolar-to-venular ratio [AVR], and estimated glomerular filtration rate [eGFR]), and macrovascular measures (pulse wave velocity, 24-hour pulse pressure [PP] and augmentation index [Aix]). Results: In multivariable-adjusted regression analyses, there were vasculoprotective associations between serum selenium and a microvascular measure (AVR [ß = 0.23; p = 0.036]) in black African women and with a macrovascular measure (24-hour PP [ß = -0.15; p = 0.048]) in white African women. In turn, GPx activity also showed a protective association with a microvascular measure (eGFR) in white African men (ß = 0.23; p = 0.035), as well as with macrovascular measures (AIx, PP) in the black (ß = -0.25; p = 0.027) and white African men (ß = -0.22; p = 0.035), and black African women (ß = -0.32; p = 0.001). Conclusions: Collectively the findings suggest a protective role for the micronutrient selenium and GPx on both the micro- and macrovasculature in a young, healthy bi-ethnic population.


Asunto(s)
Población Negra , Fenómenos Fisiológicos Cardiovasculares , Sistema Cardiovascular/metabolismo , Glutatión Peroxidasa/metabolismo , Selenio/sangre , Población Blanca , Adulto , Femenino , Humanos , Masculino , Adulto Joven
3.
BMC Cardiovasc Disord ; 17(1): 104, 2017 04 26.
Artículo en Inglés | MEDLINE | ID: mdl-28446166

RESUMEN

BACKGROUND: To investigate if percentage change (%∆) in renin over a 3 year follow-up is associated with %∆ in cardiovascular and inflammatory markers in a low renin bi-ethnic group. METHODS: Blood pressure, active renin, C-reactive protein and interleukin-6 levels of 73 black and 81 white teachers were measured at baseline and after 3 years. RESULTS: In the black group, %∆ renin was inversely associated with %∆ systolic blood pressure (ß = -0.27; p = 0.011). In the white group %∆ renin was inversely associated with %∆interleukin-6 (ß = -0.24; p = 0.005). CONCLUSIONS: These prospective results indicate that a decrease in renin over time is associated with an increase in blood pressure in a low renin black South African cohort.


Asunto(s)
Población Negra , Hipertensión/sangre , Hipertensión/etnología , Mediadores de Inflamación/sangre , Inflamación/sangre , Inflamación/etnología , Interleucina-6/sangre , Renina/sangre , Población Blanca , Adulto , Biomarcadores/sangre , Presión Sanguínea , Femenino , Humanos , Hipertensión/diagnóstico , Hipertensión/fisiopatología , Inflamación/diagnóstico , Masculino , Persona de Mediana Edad , Pronóstico , Factores de Riesgo , Maestros , Sudáfrica/epidemiología , Factores de Tiempo , Salud Urbana
5.
Am J Hum Biol ; 29(6)2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28699683

RESUMEN

OBJECTIVES: To derive percentage body fat (%BF) cut-points according to body mass index (BMI) categories for adult black South African women and to investigate the agreement between adiposity classifications according to WHO BMI and %BF cut-points. The secondary aim was to determine the association between these different adiposity measures and high blood pressure. METHODS: Black women aged 29-65 years (n = 435) from Ikageng, South Africa, were included in this cross-sectional study. Socio-demographic and anthropometric data were collected (weight, height and BMI). %BF using dual-energy X-ray absorptiometry and blood pressure were measured. RESULTS: There was significant agreement between three %BF categories: low/normal (<35.8% age 29-49 years; or <38% age 50-65 years), overweight range (35.8-40.7% age 29-49 years; or 38-42.1% age 50-65 years) and obese (≥40.7% age 29-49 years; or ≥42.1% age 50-65 years) and three BMI categories: low/normal (<25 kg/m2 ), overweight range (25-29.9 kg/m2 ) and obese (≥30kg/m2 ); (κ = 0.62, P < .0001). Despite statistically significant agreement between groups, more than half of overweight individuals were misclassified as having either a normal (30.2%) or obese %BF (25.5%). %BF misclassification was low in the low/normal and obese BMI ranges. After adjustment for confounders, obesity (BMI ≥ 30kg/m2 ), as well as high %BF were significantly associated with high blood pressure (OR = 1.75, 95% CI 1.09-2.81 versus OR = 1.92, 95% CI 1.15-3.23, respectively). CONCLUSION: Despite significant agreement between BMI and %BF categories, considerable misclassification occurred in the overweight range. Participants with excessive %BF had a greater odds of high blood pressure than those in the highest BMI category.


Asunto(s)
Tejido Adiposo/metabolismo , Adiposidad , Antropometría/métodos , Índice de Masa Corporal , Hipertensión/epidemiología , Adulto , Población Negra , Estudios Transversales , Femenino , Humanos , Hipertensión/etiología , Persona de Mediana Edad , Obesidad/epidemiología , Obesidad/etiología , Sobrepeso/epidemiología , Sobrepeso/etiología , Sudáfrica/epidemiología
6.
J Cardiovasc Nurs ; 32(4): 401-408, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27428354

RESUMEN

BACKGROUND: Hypercoagulation is associated with coronary artery disease (CAD). Whether depression symptoms dysregulate inflammatory and hemostatic markers in an African cohort is not known; therefore, we assessed the relationship between depressive symptoms and inflammatory and hemostatic markers as potential CAD risk markers in an African sex cohort. MATERIAL AND METHODS: We included 181 black African urban-dwelling teachers (88 men, 93 women; aged 25-60 years) from the Sympathetic Activity and Ambulatory Blood Pressure in Africans Study. The Patient Health Questionnaire was used to assess depressive symptoms. Fasting plasma concentrations of C-reactive protein, fibrinogen, D-dimer, plasminogen activator inhibitor-1 (PAI-1) and 24-hour blood pressure measures were obtained. RESULTS: Moderately severe depression symptom status was similar in the black sex groups. Both sex groups showed a mean hypertensive state and low-grade inflammation (C-reactive protein > 3 mg/L). Levels of PAI-1 were higher in depressed men, whereas D-dimer levels were lower in depressed women when considering concomitant confounders. In black men only, depressive symptoms were associated with levels of PAI-1 (adj. R = 0.12; ß = .22 [95% confidence interval, .0-.44]; P = .04) and D-dimer (adj. R = 0.12; ß = .28 [95% confidence interval, .08-.48]; P = .01), independent of confounders. CONCLUSION: In black men, depression symptoms accompanied by a mean hypertensive status may up-regulate inflammatory and thrombotic processes. Depression symptoms in black men facilitated hypercoagulation or fibrinolytic dysregulation and potentially increased their CAD risk. Early screening of fibrinolytic markers and for the presence of depressive symptoms is recommended.


Asunto(s)
Proteína C-Reactiva/análisis , Enfermedad de la Arteria Coronaria/sangre , Depresión/sangre , Productos de Degradación de Fibrina-Fibrinógeno/análisis , Hipertensión/sangre , Inhibidor 1 de Activador Plasminogénico/análisis , Adulto , Negro o Afroamericano , Biomarcadores/sangre , Estudios de Cohortes , Enfermedad de la Arteria Coronaria/complicaciones , Enfermedad de la Arteria Coronaria/diagnóstico , Depresión/complicaciones , Depresión/diagnóstico , Humanos , Hipertensión/complicaciones , Hipertensión/diagnóstico , Masculino , Persona de Mediana Edad , Factores Sexuales
7.
Eur J Clin Invest ; 46(11): 901-910, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27600376

RESUMEN

BACKGROUND: The link between impaired lung function and cardiovascular outcome is well established in European and American populations. It is possible that this association may be driven by a systemic spillover of inflammation occurring within the lungs. As several studies have found an increased level of inflammatory markers in African populations, we aimed to establish the contribution of lung function in predicting all-cause and cardiovascular mortality in Africans, whilst taking inflammatory markers into account. DESIGN: We followed 1442 black South Africans from the North West Province participating in the South African leg of the Prospective Urban and Rural Epidemiology (PURE) study, over a five-year period. Spirometry, cardiovascular and metabolic measures were performed, and cardiovascular mortality as well as all-cause mortality used as endpoints. RESULTS: In univariate Cox regression models, both forced expiratory volume in 1-s (FEV1 ) and forced vital capacity (FVC) predicted all-cause (P = 0·022; P < 0·001) and cardiovascular mortality (P = 0·004; P < 0·001). In multivariate adjusted standardized Cox regression analyses, only FVC predicted cardiovascular mortality independent of several covariates (hazard ratio, 0·57 [0·35-0·94]), including C-reactive protein (CRP). When CRP was replaced by interleukin-6 in the model, the significance of FVC was lost (hazard ratio, 0·85 [0·55-1·30]). CONCLUSION: FVC, but not FEV1 , is a strong predictor of both all-cause and CV mortality in black South Africans, which may be mediated by inflammation.


Asunto(s)
Enfermedades Cardiovasculares/etnología , Neumonía/etnología , Adulto , Anciano , Población Negra/etnología , Enfermedades Cardiovasculares/mortalidad , Enfermedades Cardiovasculares/fisiopatología , Femenino , Volumen Espiratorio Forzado/fisiología , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Neumonía/mortalidad , Neumonía/fisiopatología , Estudios Prospectivos , Salud Rural/estadística & datos numéricos , Sudáfrica/epidemiología , Sudáfrica/etnología , Salud Urbana/estadística & datos numéricos , Capacidad Vital/fisiología
8.
Lung ; 194(1): 107-15, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26411588

RESUMEN

INTRODUCTION: Reduced lung function is associated with a risk for the development of cardiovascular disease. This association may be due to chronic inflammation which is often present in those with reduced lung function. PURPOSE: We investigated the possible role of systemic inflammation as the mediator between lung function and arterial stiffness in 1534 black South Africans. METHODS: Spirometric data including forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were obtained. C-reactive protein (CRP), interleukin-6 (IL-6), blood pressure (BP) and carotid-radial pulse wave velocity (PWV) were determined. RESULTS: In multivariable-adjusted models, an independent inverse association was found between IL-6 and FEV1 (ß = -0.20, p < 0.001) and FVC (ß = -0.18, p < 0.001). Similar results were found for CRP. PWV was inversely associated with FEV1 (ß = -0.06, p = 0.037). No association was found between inflammatory markers, BP or PWV. CONCLUSION: Reduced lung function was associated with increased inflammation and arterial stiffness. The lack of association between arterial stiffness and inflammatory markers suggests that inflammation may not be the mediating link between lung and vascular function in this population.


Asunto(s)
Población Negra , Inflamación/fisiopatología , Rigidez Vascular , Adulto , Presión Sanguínea , Proteína C-Reactiva/metabolismo , Femenino , Volumen Espiratorio Forzado , Humanos , Inflamación/sangre , Interleucina-6/sangre , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Análisis de la Onda del Pulso , Sudáfrica , Capacidad Vital
9.
Heart Lung Circ ; 24(6): 573-82, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25648382

RESUMEN

BACKGROUND: In South Africa respiratory diseases are highly prevalent, with cardiovascular disease being a manifestation. However, international reference values for lung function are commonly used, which may not be appropriate to correctly identify reduced lung function. An inverse relationship exists between lung function and blood pressure (BP) but is not investigated extensively in black South Africans. METHODS: We included 2010 Africans from the PURE (Prospective Urban Rural Epidemiology) study (aged > 35 years) in the North West Province. Spirometry was performed and predicted values for forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were calculated from South African, European and United States prediction equations. RESULTS: With the exception of the European predicted values, all other predicted mean FEV1 and FVC were above 80%. South African reference values displayed the highest percentages of the predicted values for FEV1 and FVC (87.9 and 99.7%, respectively.) BP increased from quintiles five to one for both FEV1 and FVC, (p for trend <0.001). After adjustment the differences remained (p<0.05). CONCLUSIONS: South African reference values yielded higher percentages of predicted FEV1 and FVC values than European and US equations suggesting that South African prediction equations may be more useful when investigating lung function in black South Africans. Elevated BP is related to reduced lung function, highlighting the importance in managing both respiratory- and cardiovascular disease.


Asunto(s)
Población Negra/estadística & datos numéricos , Volumen Espiratorio Forzado/fisiología , Capacidad Vital/fisiología , Población Blanca/estadística & datos numéricos , Adulto , Enfermedades Cardiovasculares/etnología , Enfermedades Cardiovasculares/fisiopatología , Estudios Transversales , Europa (Continente) , Femenino , Humanos , Hipertensión/etnología , Hipertensión/fisiopatología , Internacionalidad , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Valores de Referencia , Pruebas de Función Respiratoria , Enfermedades Respiratorias/epidemiología , Enfermedades Respiratorias/fisiopatología , Sudáfrica , Espirometría , Estados Unidos
10.
Clin Exp Hypertens ; 36(1): 70-5, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-23786427

RESUMEN

The purpose of this study was to evaluate whether active renin concentration is associated with markers of end-organ damage in urbanized Africans. This study forms part of the Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) study. For this study, 81 men and 74 women were divided into low- and high-renin groups. Ambulatory blood pressure measurements were conducted. A resting 12-lead ECG was determined in order to determine the gender-specific Cornell voltage. Cardiovascular variables were continuously recorded with the Finometer. Carotid-dorsalis pedis pulse wave velocity was obtained with the Complior acquisition system. The carotid intima-media thickness (CIMT) was obtained with the SonoSite MicroMaxx. Blood samples were collected; serum and plasma were stored at -80 °C for analysis. Anthropometric measurements were taken using standard methods. A general health questionnaire was also completed. The urinary creatinine was determined with a calorimetric method and albumin with a turbidimetric method. The serum sodium and potassium were determined by making use of the Konelab TM 20i Sequential Multiple Analyzer Computer (SMAC). The concentration of active renin in the plasma was analyzed by making use of a high-sensitivity radio-immunometric assay. A negative association (r=-0.29, p<0.01) exists between renal function (ACR) and plasma renin in the low-renin group (<6.18 pg/mL), which was not observed in Africans with high-renin levels. It seems evident that low renin in black South Africans may result in sub-clinical renal damage and impaired vascular function in a group of urbanized black South Africans.


Asunto(s)
Hipertensión/sangre , Hipertensión/etiología , Renina/sangre , Adulto , Biomarcadores/sangre , Población Negra , Monitoreo Ambulatorio de la Presión Arterial , Grosor Intima-Media Carotídeo , Femenino , Humanos , Hipertensión/fisiopatología , Riñón/fisiopatología , Masculino , Persona de Mediana Edad , Sudáfrica , Sistema Nervioso Simpático/fisiopatología , Población Urbana
11.
Heart Lung Circ ; 23(2): 119-26, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23978476

RESUMEN

BACKGROUND: The use of antiretroviral treatment is known to be accompanied by several negative health outcomes and may negatively affect a country such as South Africa, which is the most burdened by the human immunodeficiency virus (HIV) in the world. We aimed to determine whether receiving antiretroviral treatment changes the cardiometabolic profile of HIV-infected South Africans. METHODS: In this sub-study, embedded in the Prospective Urban and Rural Epidemiology (PURE) study, we compared the cardiometabolic profile in a cohort of 66 treated and 71 never treated HIV-infected participants from the North-West province, South Africa. By using standard techniques, these participants' cardiometabolic, biochemical and lifestyle variables were assessed in 2005 and 2010, respectively. RESULTS: The treated group showed a higher percentage change in pulse pressure (13.3%; p = 0.004), systolic blood pressure (4.5%; p = 0.029) and CD4 cell count (9.2%; p = 0.009) levels over five years. During follow-up (2010), lipid variables were worse in the treated group. Further, antiretroviral treatment was associated with the percentage change in pulse pressure (R(2) = 0.24; ß = 0.19; p = 0.020). CONCLUSIONS: We concluded that Africans receiving antiretroviral treatment had a greater increase in pulse pressure and systolic blood pressure, as well as an unfavourable lipid profile when compared to never treated participants. Whether, in the long term, antiretroviral treatment will lead to increased arterial stiffness and/or accelerated atherosclerosis among this HIV-infected African population remains to be seen.


Asunto(s)
Antirretrovirales/administración & dosificación , Población Negra , Presión Sanguínea/efectos de los fármacos , Infecciones por VIH , Lípidos/sangre , Rigidez Vascular/efectos de los fármacos , Adulto , Aterosclerosis/sangre , Aterosclerosis/epidemiología , Aterosclerosis/fisiopatología , Recuento de Linfocito CD4 , Femenino , Estudios de Seguimiento , Infecciones por VIH/sangre , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Infecciones por VIH/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Sudáfrica/epidemiología
12.
Clin Exp Hypertens ; 35(3): 213-9, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-22954159

RESUMEN

Depressive symptoms are associated with an increased risk for developing cardiovascular diseases, driven by its link to the metabolic syndrome (MetS). This phenomenon, however, still needs to be investigated in the African population. The aim of this study is to investigate the association between left ventricular hypertrophy (LVH) and MetS risk markers in a determined sample. The researchers stratified Black African men and women into with depressive symptoms (D) or without depressive symptoms (ND) group, based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria score. Fasting MetS, chronic hyperglycemia (HbA1c), ambulatory blood pressure (BP) and Cornell product-LVH (CP-LVH) in ECG measures were obtained. Depressive symptoms were reported in 45.3% of the sample. Independent of depression status, African men and women revealed a pre-diabetic state (glycated hemoglobin >5.7%). CP-LVH was associated with decreased low high-density lipoprotein cholesterol in D African women. In D African men, systolic BP (P = .001) and HbA1c (P = .08) explained 64% and 31% of the variation in LVH, respectively. In conclusion, depressive symptoms in Black African women were associated with a measure of target end organ damage, CP-LVH, and this association was driven by a metabolic factor. In Black African men, independent of depressive symptoms, LVH, was driven by cardiometabolic factors, namely SBP and HbA1c.


Asunto(s)
Depresión/etnología , Hipertrofia Ventricular Izquierda/etnología , Síndrome Metabólico/etnología , Adulto , Población Negra , Enfermedades Cardiovasculares/etnología , Estudios Transversales , Femenino , Humanos , Hipercolesterolemia/etnología , Hiperglucemia/etnología , Hipertensión/etnología , Hipertrigliceridemia/etnología , Masculino , Persona de Mediana Edad , Obesidad Abdominal/etnología , Análisis de Regresión , Factores de Riesgo , Distribución por Sexo , Fumar/etnología , Sudáfrica/epidemiología
13.
Clin Exp Hypertens ; 35(3): 228-35, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-22994902

RESUMEN

Hypertension (HT) and the metabolic syndrome are major problems in Africa. The role of sex hormones in the cardiovascular profile of black Africans in South Africa has not been studied. Our objective was to study the association between the sex hormones and ambulatory blood pressure and the heart rate (HR) in black and white South Africans. The 24-hour ambulatory blood pressure measurements were performed and the blood samples were taken between 07:00 and 09:00 hours. A total of 80 black and 98 white South African teachers between 25 and 65 years of age from similar socioeconomic backgrounds from the Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) study were included. As a result, a more vulnerable cardiovascular profile was observed in Africans compared with Caucasians. In the African group, low testosterone (T) explained 19%-36% of the variance in systolic blood pressure (SBP), diastolic blood pressure (DBP), and HR, whereas in the Caucasian group non-sex-hormone-binding globulin (non-SHBG)-bound T explained 27% of the variance in HR. In the African males, inverse associations between blood pressure and T (SBP: P = .08; DBP: P = .02) and non-SHBG-bound T (SBP: P < .001; DBP: P < .01) and HR (P < 0.01) were observed. Ambulatory HR predicted a prediabetic state in Africans. In conclusion, low T levels may predispose or result in impaired cardiovascular function in African men. The possibility exists that a prediabetic state, vagal-impaired HR, and hyperkinetic blood pressure responses may predispose or result in low T levels in African men.


Asunto(s)
Frecuencia Cardíaca/fisiología , Hipertensión/etnología , Estado Prediabético/etnología , Testosterona/sangre , Adulto , Anciano , Población Negra , Presión Sanguínea/fisiología , Monitoreo Ambulatorio de la Presión Arterial , Estudios de Cohortes , Estradiol/sangre , Estradiol/fisiología , Hemoglobina Glucada , Humanos , Hipertensión/sangre , Masculino , Persona de Mediana Edad , Estado Prediabético/sangre , Análisis de Regresión , Globulina de Unión a Hormona Sexual , Sudáfrica , Testosterona/fisiología , Población Blanca
14.
Heart Lung Circ ; 22(11): 917-23, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23333076

RESUMEN

BACKGROUND: Research demonstrated a significant relationship between elevated nocturnal blood pressure and sympathetic hyperactivity. The study aimed to investigate possible associations between norepinephrine metabolite, 3-methoxy-4-hydroxyphenylglycol (MHPG), nocturnal BP and carotid intima-media thickness (CIMT) in urban African and Caucasian men. METHODS: The study included 82 African and 100 Caucasian male teachers, aged 33-56 years, recruited in the North-West Province, South Africa. Ambulatory BP and fasting saliva and blood samples were collected. B-mode ultrasound images were obtained to determine CIMT. RESULTS: Despite higher usage of anti-hypertensive medication usage (p=0.039), a large number of the African men were nocturnal hypertensives (75, 61%). The nocturnal systolic blood pressure (SBP) (p<0.001), diastolic blood pressure (DBP) (p<0.001) and heart rate (p<0.001) of the African men were higher. After stratifying groups into only nocturnal hypertensives the trend was the same (SBP p<0.001; DBP p<0.001; heart rate p=0.058). In the African and Caucasian men, CIMT was linearly predicted by SBP (ß=0.33, p<0.001) and DBP (ß=0.24, p=0.016) respectively, but not MHPG. CONCLUSION: No associations were firstly demonstrated between MHPG as sympathetic activity marker and CIMT or secondly, between MHPG and nocturnal blood pressure. Novel findings of elevated nocturnal BP evidently seem to promote structural vascular disease in urban African and Caucasian men.


Asunto(s)
Presión Sanguínea , Grosor Intima-Media Carotídeo , Metoxihidroxifenilglicol/sangre , Adulto , Antihipertensivos/administración & dosificación , Enfermedades del Sistema Nervioso Autónomo/sangre , Biomarcadores/sangre , Población Negra , Humanos , Masculino , Persona de Mediana Edad , Saliva/metabolismo , Sudáfrica , Población Urbana , Población Blanca
15.
Clin Exp Hypertens ; 34(5): 363-9, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22686450

RESUMEN

Silent myocardial ischemia is a predictor of subclinical atherosclerosis driven by increased cardiovascular risk markers, although still unknown in Africans. The aim of this study was to assess if cardiovascular risk markers will be associated with subclinical atherosclerosis. African men were stratified into (i) 24-hour silent ischemia (SI, n = 38) and (ii) without (nSI, n = 40) groups. Ambulatory blood pressure (BP), SI, 12-lead resting electrocardiogram, ultrasound carotid intima-media thickness (CIMT) measurements, and fasting blood samples were obtained. Above-normal cardiovascular risk markers, that is, glucose level, heart rate, BP, and CIMT, were evident in men with SI. Hypertension prevalence was 89% in the African SI men as opposed to 64% in the nSI men. Regression analyses revealed that only SI events in SI men explained 35% (95% confidence interval [CI]: 0.22;0.52) of the variance in CIMT, while in all African men it explained 29% (95% CI: 0.19;0.39). In conclusion, SI was associated with structural vascular disease in African men. This could imply that SI is not necessarily driven by hypertension in African men but through other possible mechanisms such as increased sympathetic nervous system activity.


Asunto(s)
Aterosclerosis/complicaciones , Presión Sanguínea/fisiología , Hipertensión/complicaciones , Isquemia Miocárdica/etiología , Adulto , África/epidemiología , Aterosclerosis/epidemiología , Aterosclerosis/fisiopatología , Monitoreo Ambulatorio de la Presión Arterial , Humanos , Hipertensión/epidemiología , Hipertensión/fisiopatología , Masculino , Persona de Mediana Edad , Factores de Riesgo , Factores Sexuales
16.
J Cardiovasc Dev Dis ; 9(5)2022 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-35621841

RESUMEN

This study aims to compare soluble (pro)renin receptor [s(P)RR] levels between black and white adults and to explore the associations of left ventricular (LV) structure and function with s(P)RR in the total and ethnicity-stratified groups. The study sample included 1172 apparently healthy black (n = 587) and white (n = 585) participants of the African-PREDICT study aged 20−30 years. Echocardiography was performed to determine relative wall thickness (RWT), LV mass index, LV ejection fraction and stroke volume index (SVi). s(P)RR was analyzed from serum samples, while plasma renin activity-surrogate (PRA-S) and eq angiotensin II were determined using the RAS™ Fingerprint. s(P)RR was higher in the white participants compared to the black participants (p < 0.001). In multivariable-adjusted linear regression analyses, we observed a positive association between RWT and s(P)RR (ß = 0.141; p = 0.005) and negative associations of LV ejection fraction (ß = −0.123; p = 0.016) and SVi (ß = −0.144; p = 0.004) with s(P)RR only in white adults. Higher s(P)RR observed in white vs. black participants was associated with higher RWT and poorer LV function only in young white adults but not in their black counterparts. These results suggest that s(P)RR may contribute to LV remodeling and dysfunction in white populations due to its role in volume−pressure regulation and its proinflammatory as well as profibrotic effects.

17.
J Hum Hypertens ; 36(8): 711-717, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-34172825

RESUMEN

Exogenous estrogens and progestins may affect the components of the renin-angiotensin-aldosterone system (RAAS). Changes in ventricular blood volume are associated with increased secretion of N-terminal pro-hormone B-type natriuretic peptide (NT-proBNP), which may also be affected by hormonal contraceptives. In this study, we aimed to compare components of the RAAS and NT-proBNP between groups using different hormonal contraceptives, including the combination pill, the injection or implant, and controls (no contraception) in black and white women of fertile age (20 - 30 years). Secondly, we determined whether blood pressure and NT-proBNP are associated with the RAAS components. We included 397 black and white women not using contraceptives, 120 using the combination pill, and 103 receiving an injection/implant. RAAS Triple-A analysis was carried out with LC-MS/MS quantification, and blood pressure measurements (ABPM) taken over 24 h. We found that serum aldosterone was higher (475.7 vs. 249.2 pmol/L; p < 0.001) in the combination pill group than in the no contraception group of white women. The aldosterone-angiotensin II ratio (AA2) was higher (5.4 vs. 2.5; p < 0.001) in the combination pill group than in the no contraception group. In the black women using the combination pill, we found a borderline-positive and borderline-negative association between 24-h systolic blood pressure and NT-proBNP with equilibrium (eq) Ang II, respectively. In white women using the combination pill, only CRP contributed positively and independently to NT-proBNP. To conclude, activation of RAAS by different hormonal contraceptives may increase future risk for the development of hypertension in young black and white women.


Asunto(s)
Aldosterona , Angiotensina II , Adulto , Cromatografía Liquida , Anticonceptivos/farmacología , Femenino , Humanos , Sistema Renina-Angiotensina , Espectrometría de Masas en Tándem , Adulto Joven
18.
Clin Exp Hypertens ; 33(8): 511-7, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21958364

RESUMEN

In Africans, arterial stiffness progression seems more pronounced compared to Caucasians. We compared the arterial stiffness profiles of different age groups and focused on muscular arteries and two more central arterial segments in African and Caucasian people from South Africa. In African (N = 374) and Caucasian (N = 376) participants (20-70 years), we measured carotid-radial (C-R) and carotid-dorsalis pedis (C-DP) pulse wave velocity (PWV) and aortic characteristic impedance (Zao). Major findings were that normotensive and high-normal/hypertensive (HT) Caucasians indicated increased trends of C-R PWV with aging (P = .029 and P = .067), not seen in the African groups (P = .122 and P = .526). Both ethnic groups showed significant increases of C-DP PWV and Zao with aging. High-normal/hypertensive Africans had significantly stiffer arteries than hypertensive Caucasians for almost all age groups, and for all stiffness measures. African C-R PWV correlated significantly with blood pressure (BP), but not with age. Opposite results were observed for Caucasians. In conclusion, the stiffness of muscular arteries is already elevated in young Africans, in both those with normal or elevated BP. This is possibly due to an earlier deterioration during childhood, or perhaps already present from birth. Also, in Caucasians stiffness seems more age-related, while in Africans it seems to be more pressure-related.


Asunto(s)
Población Negra/estadística & datos numéricos , Hipertensión/etnología , Hipertensión/fisiopatología , Rigidez Vascular/fisiología , Población Blanca/estadística & datos numéricos , Adulto , Distribución por Edad , Aorta/fisiología , Presión Sanguínea/fisiología , Arterias Carótidas/fisiología , Progresión de la Enfermedad , Femenino , Pie/irrigación sanguínea , Humanos , Masculino , Persona de Mediana Edad , Flujo Pulsátil/fisiología , Arteria Radial/fisiología , Distribución por Sexo , Sudáfrica/epidemiología
19.
Clin Exp Hypertens ; 33(3): 159-66, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21513480

RESUMEN

The aim was to determine whether blood glucose or cholesterol is the more prominent contributor to cardiovascular dysfunction in 101 African men and 99 African women. We measured ambulatory daytime blood pressure (BP), carotid intima-media thickness (CIMT), and determined blood glucose and lipids in serum. High-density lipoprotein cholesterol (HDL) (p = 0.002) and HDL: total cholesterol (HDL:TC) (p ≤ 0.001) were significantly lower, while serum glucose (p ≤ 0.001) was significantly higher in men. In single, partial, and multiple regression analysis, BP correlated positively with blood glucose in men. Furthermore, CIMT (B = -0.50; p = 0.009) correlated negatively with HDL:TC in men. While in women CIMT (B = 0.346; p = 0.015) correlated positively with glucose. In conclusion, subclinical atherosclerosis is significantly related to an unfavorable HDL profile in men, whereas in women, this link is stronger with fasting glucose.


Asunto(s)
Población Negra , Glucemia/metabolismo , Sistema Cardiovascular/patología , Sistema Cardiovascular/fisiopatología , Colesterol/sangre , Caracteres Sexuales , Adulto , Presión Sanguínea/fisiología , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/etnología , Sistema Cardiovascular/diagnóstico por imagen , Femenino , Humanos , Hipercolesterolemia/sangre , Hipercolesterolemia/etnología , Hipercolesterolemia/patología , Hiperglucemia/sangre , Hiperglucemia/etnología , Hiperglucemia/patología , Masculino , Persona de Mediana Edad , Análisis de Regresión , Factores de Riesgo , Sudáfrica , Triglicéridos/sangre , Túnica Íntima/diagnóstico por imagen , Túnica Íntima/patología , Túnica Media/diagnóstico por imagen , Túnica Media/patología , Ultrasonografía
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