QTc prolongation, increased NT-proBNP and pre-clinical myocardial wall remodeling in excessive alcohol consumers: The SABPA study

Association of alcohol consumption with circulating biomarkers of atrial fibrillation-related pathways in a population at high cardiometabolic risk

Background

The effect of alcohol consumption on cardiovascular health, including atrial fibrillation risk, remains controversial. Evaluating the association of alcohol consumption with circulating atrial fibrillation-related biomarkers may help better understand the relevant mechanistic underpinnings.

Methods

We studied 523 participants from 3 sites for the PREDIMED-Plus study, a weight-loss randomized intervention trial in metabolically unhealthy adults. N-terminal pro-B-type natriuretic protein (NTproBNP), high sensitivity troponin-T (hsTnT), high-sensitivity C-reactive protein (hsCRP), 3-nitrotyrosine (3-NT), and procollagen type 1 carboxy-terminal propeptide (PICP) were measured in fasting serum samples at baseline and years 3 and 5 of follow-up. We calculated alcohol consumption in drinks/day (1 drink = 14 grams alcohol) with validated food frequency questionnaires at each visit. Using multiple linear regression and mixed models we estimated the association of alcohol consumption with log-transformed biomarkers at baseline and longitudinally adjusting for potential confounders.

Results

Among 523 participants (mean age: 65 years, 40% female), mean alcohol consumption was 1 drink/day. Cross-sectionally, alcohol consumption was not associated with cardiac biomarker concentrations. Longitudinally, compared to non-consumers, heavy drinkers (≥4 drinks/day) had smaller increases in hsTnT (β: -0.11, 95%CI: -0.20, -0.01)and PICP (β: -0.15, 95%CI: -0.30, 0.01) over the 5-year follow-up. In contrast, those who increased alcohol consumption over the 5-year period experienced greater increases in hsCRP (β: 0.42, 95%CI: 0.11, 0.73) compared to those whose drinking behavior stayed the same.

Conclusion

Alcohol consumption was associated with complex changes in circulating biomarkers, including comparatively lower fibrotic and myocardial damage, but higher levels of overall inflammation over time. These results underscore the need for further research to better understand the effects of alcohol on cardiovascular health.

Ethnicity-Specific Changes in Cardiac Troponin T in Response to Acute Mental Stress and Ethnicity-Specific Cutpoints for the R Wave of the aVL Lead

Acute mental stressor-induced cardiac stress responses might contribute to excessive myocardial strain and resultant cardiovascular episode risk. We assessed ethnicity-specific acute cardiac stress (by measuring cardiac troponin T (cTnT) and N-terminal prohormone of brain natriuretic peptide) related to hemodynamic activity. The prospective Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) study was conducted during 2007-2008 in South Africa. In the cross-sectional phase of the SABPA study, 388 black and white participants underwent a 1-minute acute mental stressor, during which blood pressure was continuously measured. Fasting blood samples for cardiac stress markers were obtained before and 10 minutes after stress (% change). Resting 10-lead electrocardiogram measured the R wave of the aVL lead (RaVL). Black participants exhibited greater cardiac stress responses (P < 0.001), diastolic blood pressure, total peripheral resistance, and stroke volume compared with white participants, who displayed decreases in cardiac stress and increases in cardiac output. Prestress and stressor cTnT cutpoints of 4.2 pg/mL predicted 24-hour, daytime, and nighttime diastolic hypertension in black participants (P < 0.001). These cTnT cutpoints were associated with an ethnicity-specific RaVL cutpoint of 0.28 mV (odds ratio = 3.49, 95% confidence interval: 2.18, 5.83; P = 0.021). Acute mental stress elicited an α-adrenergic activation pattern and cardiac stress hyperreactivity only in black participants. Mental stress might increase the black population's risk for ischemic episodes and heart disease.

Prospective associations between cardiac stress, glucose dysregulation and executive cognitive function in Black men: The Sympathetic activity and Ambulatory Blood Pressure in Africans study

OBJECTIVE

Glucose dysregulation is an independent risk factor for cardiovascular and neurodegenerative disease development through synaptic dysfunction resulting in cognitive decline. The aim of this study was to study the interplay between impaired glycaemic metabolism (hyperglycaemia and insulin resistance), cardiac stress (cardiac troponin T and N-terminal brain natriuretic peptide) and executive cognitive function prospectively, in a bi-ethnic sex cohort.

METHODS

Black and White teachers (N = 338, aged 20-63 years) from the Sympathetic activity and Ambulatory Blood Pressure in Africans study were monitored over a 3-year period. Fasting blood samples were obtained for cardiac troponin T, N-terminal brain natriuretic peptide, glycated haemoglobin and the homeostatic model assessment-insulin resistance for insulin resistance. The Stroop colour-word conflict test was applied to assess executive cognitive function at baseline.

RESULTS

Over the 3-year period, Black men revealed constant high levels of cardiac troponin T (⩾4.2 ng/L), pre-diabetes (glycated haemoglobin > 5.7%) and insulin resistance (homeostatic model assessment-insulin resistance >3). %Δ Glycated haemoglobin was associated with %Δ insulin resistance (p < 0.001) and increases in %ΔN-terminal brain natriuretic peptide (p = 0.02) in Black men only. In the latter, baseline Stroop colour-word conflict test was inversely associated with %Δ cardiac troponin T (p = 0.001) and %Δ insulin resistance levels (p = 0.01).

CONCLUSION

Progressive myocyte stretch and chronic myocyte injury, coupled with glucose dysregulation, may interfere with processes related to interference control in Black men.