Low Grade Inflammation and ECG Left Ventricular Hypertrophy in Urban African Males: The SABPA Study

Longitudinal changes of cardiac troponin and inflammation reflect progressive myocyte stretch and likelihood for hypertension in a Black male cohort: The SABPA study

Inflammation was cross-sectionally associated with subclinical wall remodeling and hypertension. Whether longitudinal changes (∆) in inflammation, myocyte injury (troponin T), and stretch (N-terminal-pro-B-type natriuretic peptide) are associated with hypertension and ECG left ventricular hypertrophy (ECG-LVH) is unclear. The first prospective analysis in Africa assessing these associations included a cohort of Black and White teachers (N = 338; aged 20-63 years). Fasting blood samples were obtained to measure tumor necrosis factor-alpha (TNF-α), cardiac troponin T (cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP). Ambulatory blood pressure, 2-lead ECG and resting 10-lead ECG values were obtained. A higher mean hypertensive status (62%) was evident in Blacks compared to Whites (44%, p < 0.001). Over 3-years, NT-proBNP increased in both ethnic groups. No associations were evident in women or in White men. In Black men, ECG-LVH at follow-up was positively associated with baseline cTnT (Adj R² 0.43; β = 0.48; 95% CI 0.28-0.68, p < 0.001) and baseline SBP (Adj R² 0.43; β = 0.29; 95% CI 0.09-0.49, p = 0.006). In Black men, baseline TNF-α (OR = 1.49, 95% CI 1.05-2.14, p = 0.03) and decreased ΔTNF-α (OR = 2.07, 95% CI 1.26-3.40, p = 0.004) increased the likelihood for cTnT levels ≥ 4.2 ng/L. Here, baseline NT-proBNP (OR = 1.12, 95% CI 1.01-1.23, p = 0.03) and ΔNT-proBNP progression (OR = 1.09, 95% CI 1.00-1.81, p = 0.04) increased the likelihood for 24-h hypertension. In conclusion, chronically increased levels of markers of myocyte injury accompanied by progressive myocardial stretch, reflective of cardiac metabolic overdemand, may ultimately increase hypertension and ischemic heart disease risk in a cohort of Black males.

Coping and Cardiac Troponin T - A Risk for Hypertension and Sub-Clinical ECG Left Ventricular Hypertrophy: The SABPA Study

BACKGROUND

Defensive coping (DefS) was associated with cardiovascular disease (CVD) susceptibility in Blacks. Whether coping strategies will associate with sub-clinical left ventricular hypertrophy (electrocardiographic-left ventricular hypertrophy [ECG-LVH] or Cornell product), cardiomyocyte injury and blood pressure (BP), is unclear. Therefore, we assessed relationships between ECG-LVH, cardiac troponin T (cTnT) and 24-hour BP in bi-ethnic groups when habitually utilising a certain coping style, and these groups when having a stress-related cTnT cut-point of 4.2ng/L.

METHODS

A target population study included a Black (n=190) and White (n=204) teachers' gender cohort (20-65years) from South Africa. The Coping Strategy Indicator determined DefS, social support and avoidance coping scores. Fasting blood samples, 10-lead ECG, 24-hour BP and ECG data were obtained.

RESULTS

Interaction effects showed no gender, social support and avoidance coping differences. Stratification of groups was done for ethnicity and DefS. Blacks sought more social support, used less avoidance coping and presented with higher CVD susceptibility. Hypertension prevalence and ECG-LVH levels in DefS Blacks (63%) were higher compared to DefS Whites (40%). Multivariate regression analyses showed positive associations between Cornell product, cTnT and BP [p≤0.05] in DefS Blacks only. Their 24-hour systolic blood pressure (SBP) was associated with time-domain depressed heart-rate-variability and prolonged ST-segment-depression especially when applying an established stress-related cTnT ≥ 4.2ng/L cut-point.

CONCLUSIONS

Defensive coping facilitated autonomic hyperactivity, myocardial injury and subsequent compensatory BP elevations as possible homeostatic reflexes to alleviate myocardial perfusion deficits. The resulting pressure overload increased sub-clinical wall remodelling and ischaemic heart disease risk in Blacks utilising habitual defensiveness. We therefore recommend regular ECG and high sensitivity cTnT screening in asymptomatic patients with emotional stress susceptibility. Longitudinal evidence is needed to confirm causality and progression of cardiomyopathy risk.

The relationship between hydration status, male sexual dysfunction and depression in hemodialysis patients

Background

Disturbances in sexual function are common among dialysis patients. Normal erections require a complex balance of physiological, psychological, emotional, hormonal, neurological and vascular factors. This study examined a possible association of overhydration (OH) with male sexual dysfunction and depression in hemodialysis (HD) patients.

Patients and methods

This cross-sectional study assessed hydration status by whole-body bioimpedance spectroscopy in patients on maintenance HD for more than 12 months. Patients were categorized according to OH to extracellular water (ECW) ratio: OH/ECW ratio >0.15 and OH/ECW ratio ≤0.15. Sexual function was assessed using the International Index of Erectile Function (IIEF) score. Psychological status was evaluated using the Beck Depression Inventory (BDI) score. Serum sex hormones were determined.

Results

Of 39 stable participants on HD, 53.8% were overhydrated (OH/ECW ratio >0.15) and 46.2% not overhydrated (OH/ECW ratio ≤0.15). Of participants with OH/ECW ratio >0.15, 85.7% had mild to severe ED, and 71.4% had abnormal BDI scores, ranging from mild mood disturbance to severe depression. Compared to patients with OH/ECW ratio ≤0.15, BDI scores, serum estradiol and plasma hsCRP were higher (18.48±8.34 vs 10.61±5.46, p<0.001; 140.10±44.51 vs 126.10±32.26, p=0.034; and, 17.70±12.14 vs 9.76±8.79, p=0.013; respectively) in those with OH/ECW ratio >0.15, while their IIEF score, serum total testosterone and dehydroepiandrosterone (DHEA) were lower (12.81±7.31 vs 41.44±23.79, p<0.001; 8.97±5.43 vs 14.10±8.30, p=0.013; and 85.31±55.14 vs 133.3±95.48, p=0.029; respectively). The OH/ECW ratio correlated inversely with the IIEF score (r=−0.69, p<0.001) and positively with BDI scores (r=0.64, p<0.001). IIEF scores were inversely correlated with BDI scores (r=−0.54, p<0.001).

Conclusion

OH in HD patients was found to be associated with a higher prevalence of sexual dysfunction and depression, lower serum levels of total testosterone and DHEA, and higher levels of serum estradiol.

Hypervolemia, hypoalbuminemia and mitral calcification as markers of cardiovascular risk in peritoneal dialysis patients

INTRODUCTION

Mortality in patients with end-stage renal disease is higher than in the general population. This is linked to traditional and non-traditional cardiovascular (CV) risk factors, as well as with risk factors associated with end-stage renal disease itself. The aim of this study is to identify CV risk markers in patients beginning peritoneal dialysis (PD) and their association with CV events and CV mortality.

METHODS

This was a retrospective cohort study of 112 incident PD patients, in which demographic, clinical and laboratory parameters, valvular calcifications, types of PD solutions, hospitalizations, CV events and death were analyzed. Occurrence of CV events or death due to a CV event after PD initiation was defined as the primary endpoint. The use of icodextrin solution was taken as a marker of hypervolemia.

RESULTS

Mean age was 53.7±16.1 years. Patients were treated with PD for 29.3±17.4 months. Eighteen patients (16.1%) had valvular calcifications at baseline, 15 patients (13.4%) had major CV events and 11 patients (9.8%) died from CV-related causes. Cox proportional hazards analysis of CV events or CV-related mortality revealed that mitral calcification, use of icodextrin solution and low albumin were independent predictors of CV events or mortality.

CONCLUSIONS

Traditional CV risk factors appear to have little impact on CV complications in PD patients. Nevertheless, hypervolemia, hypoalbuminemia and mitral calcifications were independent predictors of CV events or mortality in this group of patients.

The aetiology of cardiovascular disease: a role for mitochondrial DNA?

Cardiovascular disease (CVD) is a world-wide cause of mortality in humans and its incidence is on the rise in Africa. In this review, we discuss the putative role of mitochondrial dysfunction in the aetiology of CVD and consequently identify mitochondrial DNA (mtDNA) variation as a viable genetic risk factor to be considered. We then describe the contribution and pitfalls of several current approaches used when investigating mtDNA in relation to complex disease. We also propose an alternative approach, the adjusted mutational load hypothesis, which would have greater statistical power with cohorts of moderate size, and is less likely to be affected by population stratification. We therefore address some of the shortcomings of the current haplogroup association approach. Finally, we discuss the unique challenges faced by studies done on African populations, and recommend the most viable methods to use when investigating mtDNA variation in CVD and other common complex disease.

Change in renin, cardiovascular and inflammatory markers over three years in a black and white population: the SABPA study

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 (β = −0.27; p = 0.011). In the white group %∆ renin was inversely associated with %∆interleukin-6 (β = −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.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-017-0538-x) contains supplementary material, which is available to authorized users.

Defensive coping and essential amino acid markers as possible predictors for structural vascular disease in an African and Caucasian male cohort: The SABPA study

Defensive coping (DefS), oxidative stress, inflammation, and related amino acids (phenylalanine [Phe] and tyrosine [Tyr]) have been implicated in cardiovascular disease. This study assessed whether inflammation, oxidative stress, changes in essential amino acids, and altered coping strategies are correlated with subclinical vascular changes in African (n = 82) and Caucasian (n = 100) men from the Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) study. The Coping Strategy Indicator questionnaire identified DefS participants. Ambulatory blood pressure (BP) was monitored for 24 h, whereas carotid intima media thickness (CIMT) and cross-sectional wall area (CSWA) were determined ultrasonically. Essential amino acids were analyzed with a liquid chromatography tandem mass spectrometry method. Oxidative-inflammatory markers were measured by spectrophotometry. African men had poorer health than Caucasian men, including higher alcohol abuse, elevated BP, abdominal obesity, physical inactivity, and elevated inflammation. Phe (p < .001) and Phe/Tyr ratio (p = .006) as well as CIMT (p = .032) were higher in African men. DefS African men had higher levels of Phe (p = .002) and Phe/Tyr (p = .009) compared to DefS Caucasian men; these differences were not observed in non-DefS men. Systolic BP and inflammation (C-reactive protein) were positively associated with left (L-) CSWA, while Phe/Tyr was negatively associated with L-CSWA in DefS African men. African males presented with elevated Phe and Phe/Tyr ratio, catecholamine precursors, worsening during DefS-possibly driven by inflammation and BP contributing to structural vascular abnormalities.

Serum Soluble Urokinase-Type Plasminogen Activator Receptor Is Associated with Low Left Ventricular Ejection Fraction and Elevated Plasma Brain-Type Natriuretic Peptide Level

BACKGROUND

Recent studies have suggested that soluble urokinase plasminogen activator receptor (suPAR), a biomarker of subclinical levels of inflammation, is significantly correlated with cardiovascular events.

PURPOSE

We investigated the association between suPAR and left ventricular ejection fraction (LVEF), left ventricular mass index (LVMI), and plasma B-type natriuretic peptide (BNP) among cardiac inpatients.

METHODS AND RESULTS

In total, 242 patients (mean age 71.3 ± 9.8 years; 70 women) admitted to the cardiology department were enrolled in the study. suPAR was significantly correlated with LVEF (R = -0.24, P<0.001), LVMI (R = 0.16, P = 0.014) and BNP (R = 0.46, P<0.001). In logistic regression analysis, the highest suPAR tertile (> 3236 pg/mL) was associated with low LVEF (< 50%) and elevated BNP (> 300 pg/mL) with an odds ratio of 3.84 (95% confidence interval [CI], 1.22-12.1) and 5.36 (95% CI, 1.32-21.8), respectively, after adjusting for age, sex, log-transformed estimated glomerular filtration rate (log(eGFR)), C-reactive protein, and diuretic use. The association between suPAR and LVMI was not statistically significant. In multivariate receiver operating characteristic analysis, addition of log(suPAR) to the combination of age, sex, log(eGFR) and CRP incrementally improved the prediction of low LVEF (area under the curve [AUC], 0.827 to 0.852, P = 0.046) and BNP ≥ 300 pg/mL (AUC, 0.869 to 0.906; P = 0.029).

CONCLUSIONS

suPAR was associated with low LVEF and elevated BNP, but not with left ventricular hypertrophy, independent of CRP, renal function, and diuretic use among cardiac inpatients who were not undergoing chronic hemodialysis.

Fibrosis and coronary perfusion - a cardiovascular disease risk in an African male cohort: The SABPA study

Low-grade inflammation has been correlated with risk factors of cardiovascular diseases (CVD). Whether the pro-inflammatory and thrombotic ratio (fibrosis) may contribute to CVD is not known. We therefore aimed to assess whether Cornell Product left ventricular hypertrophy (LVH) is associated with fibrosis and coronary perfusion (silent ischemia) in a bi-ethnic male cohort from South Africa. A cross sectional study was conducted including 165 African and Caucasian men between the ages of 20-65. Fasting blood samples were obtained to measure fibrinogen, C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor (TNF-α). Ambulatory blood pressure, ECG and 12 lead ECG measures were obtained to determine silent ischemic events (ST events) and LVH, respectively. Africans revealed more silent ischemia, higher 24 h blood pressure, inflammatory, coagulation as well as fibrosis levels than Caucasians. In a low-grade inflammatory state (CRP > 3 mg/l), Africans revealed higher fibrosis (p ≤ 0.01) values, but lower IL-6 and TNF-α values than Caucasians. Linear regression analyses in several models demonstrated positive associations between silent ischemia and fibrosis [Adj. R(2) 0.23; ß 0.35 (95% CI 0.13, 0.58), p ≤ 0.01]. In a low-grade inflammatory state (CRP>3mg/l), fibrinogen predicted AV-block in African men [OR 3.38 (95% CI 2.24, 4.53); p = 0.04]. Low-grade inflammation may induce AV-block through mechanisms involving fibrosis and ischemia to increase the burden on the heart in African men.

Hyperpulsatile pressure, systemic inflammation and cardiac stress are associated with cardiac wall remodeling in an African male cohort: the SABPA study

Inflammation may contribute to an increase in cardiac wall stress through pathways related to cardiac remodeling. Cardiac remodeling is characterized by myocyte hypertrophy, myocyte death and modifications of the extracellular matrix. We sought to explore associations among cardiac remodeling, inflammation and myocardial cell injury in a bi-ethnic cohort of South African men and women. We included 165 men (76 African and 89 Caucasian) and 174 women (80 African and 94 Caucasian) between 20 and 65 years of age. Inflammatory markers used were C-reactive protein (CRP), interleukin-6 and tumor necrosis factor-alpha (TNF-α), whereas troponin T (Trop T) and the N-terminal of pro B-type natriuretic peptide (NT-proBNP) were used as cardiac markers. The frequency of ischemic events (ST segment depression) and left ventricular strain (left ventricular hypertrophy: LVH) were monitored by a 24-h recording of ambulatory blood pressure (BP), ECG and 12-lead standard ECG. Hypertension diagnosed with ambulatory monitoring was more frequent in Africans (53.85 vs. 24.59%; P<0.001), as was the number of ischemic events (6±15 (1; 5) vs. 3±6 (0; 3)). Inflammatory markers (CRP, IL-6 and TNF-α) and the degree of LVH were all significantly higher in Africans (P<0.05). BP was associated (P<0.05) with Trop T in men across ethnic groups. In African men, cardiac stress (NT-proBNP) was associated with TNF-alpha (P<0.001), Trop T (P<0.001) and pulse pressure (P=0.048; adjusted R(2)=0.45). The susceptibility for cardiac wall remodeling appears to increase with hyperpulsatile pressure, low-grade systemic inflammation and ventricular stress, and may lead to the development of future cardiovascular events in African men.

The impact of oxidized serum albumin on the oncotic pressure and hydration status of peritoneal dialysis patients

Objective

Hypoalbuminemia, fluid overload (FO), and oxidative stress (OS) may be related to cardiovascular morbidity and mortality in peritoneal dialysis (PD) patients. OS produces molecular modifications of serum albumin that interfere with its quantification by the commonly used bromocresol green assay. This study evaluated the impact of oxidized serum albumin (OSA) on oncotic pressure (OP) and hydration status.

Patients and methods

Twenty-four stable hypoalbuminemic PD patients were enrolled in the study. After performing physical examination, assessment of the hydration status using a whole-body bioimpedance spectroscopy technique was performed, and blood samples were drawn for determination of OP, serum albumin levels, and OSA.

Results

Extracellular to total body water (E/TBW) ratio was higher in patients with FO ≥1.5 L with or without edema than in patients with FO <1.5 L (P≤0.043). E/TBW ratio was higher in patients with FO ≥1.5 L and edema compared to those with FO ≥1.5 L but without edema (P=0.004). OP was significantly higher in patients with FO ≥1.5 L and without edema compared to those with FO ≥1.5 L and with edema (P<0.001). Albumin-detection index (ADI) in patients with FO ≥1.5 L and without edema was similar to ADI in patients with FO <1.5 L (P=0.520). ADI was significantly lower in patients with FO ≥1.5 L and without edema compared to those with FO ≥1.5 L and edema (P=0.034). E/TBW ratio correlated positively with the ADI (r=0.60, P=0.001) and inversely with the OP (r=−0.54, P=0.002).

Conclusion

Overhydration may be clinically undetectable in PD patients. Assessing the hydration status and measuring the total serum albumin levels, including the oxidized fraction, should be considered in evaluating hydration status in PD patients.

Predictors of left ventricular hypertrophy and their cutoffs in peritoneal dialysis patients

Cardiovascular complications are the main cause of morbidity and mortality in peritoneal dialysis (PD) patients. Left ventricular hypertrophy (LVH) is a major predictor of the development of cardiovascular events. This study aimed to identify risk factors that contribute to the development of LVH and to determine their cutoffs in patients on maintenance peritoneal dialysis.In this cross sectional study we evaluated the association of 23 variables including age, PD vintage, ultrafiltration, urine volume, residual renal function, mean daily SBP, mean daily DBP, fasting glucose, HbA1c, peritoneal glucose load index (PGLI), fluid overload (FO), plasma brain natriuretic peptide (BNP), plasma hsCRP and IL-6, serum albumin, white blood cell (WBC) count, hemoglobin, hematocrit, triglycerides, LDL-C (low density lipoprotein cholesterol), HDL-C (high density lipoprotein cholesterol), and PTH with LVH in 38 stable patients on maintenance PD ≥ 24 months.LVH was detected in 57.9% of patients. Logistic regression and receiver operating characteristics (ROC) analysis revealed that HbA1c, PGLI, FO, plasma BNP, hsCRP and IL-6 seem to be possible predictors of LVH. The cutoffs associated with the presence of LVH were: 7.5%, 3.2 g/kg/day, 1.7 L, 330 pg/mL, 7.5 mg/dL and 3.3 pg/mL for HbA1c, PGLI, FO, plasma BNP, hsCRP and IL-6, respectively (sensitivity 72.8 to 81.8% and specificity 75.0 to 93.8%).The results suggest that efforts should be made to reduce the peritoneal glucose load (PGL), to improve the hydration status, and to attenuate the inflammatory process in order to reduce the risk of the development of LVH among PD patients.