Alcohol Consumption and Cardiac Biomarkers: The Atherosclerosis Risk in Communities (ARIC) Study M. Lazo, Y. Chen, J.W. McEvoy, C. Ndumele, S. Konety, C.M. Ballantyne, A.R. Sharrett, and E. Selvin September 2016 www.clinchem.org/content/62/9/1202.full © Copyright 2016 by the American Association for Clinical Chemistry

Introduction Background Aims Moderate alcohol linked to lower risk of cardiovascular disease, but mechanisms remain unclear. Association between alcohol consumption and subclinical cardiovascular disease are not well characterized Cardiac troponin T and N-terminal B-type natriuretic peptide (NT-proBNP) are biomarkers of myocardial damage and cardiac wall stress. Aims Examine the prospective and cross-sectional associations between alcohol consumption: High sensitivity cardiac troponin T N-terminal pro B-type natriuretic peptide

Methods Study Population hs-cTnT and NT-proBNP Alcohol consumption Over 11,000 participants from the Atherosclerosis Risk in Communities (ARIC) Study: a community based study of middle aged adults. Excluded participants with history of cardiovascular disease hs-cTnT and NT-proBNP Measured at 2 time points (ARIC study visits 2 and 4), 6 years apart (baseline 1990-1992; follow up: 1996-1998) Measured using stored serum (visit 2) and plasma (visit 4) samples using Roche Elecsys 2010 Analyzer (visit 2) and Cobas e411 analyzer (visit 4). A calibration study of both hs-cTnT and NT-proBNP demonstrated no significant differences across specimen type and laboratory. Alcohol consumption Self-reported current and past alcohol consumption. Categorized as: never, former, current: ≤1, 2-7, 8-14, and ≥15 drinks/week.

Methods Outcomes: Cross-sectional analyses: Prospective analyses Increased hs-cTnT (≥14 ng/L) Increased NT-proBNP (≥300 ng/L-primary; ≥100 ng/L-secondary) hs-cTnT and NT-proBNP continuously (log transformed) Prospective analyses Incident increased hs-cTnT (≥14 ng/L) Incident Increased NT-proBNP (≥300 ng/L-primary; ≥100 ng/L-secondary) Statistical analyses Cross-sectional: Multivariable logistic and robust regression Prospective: Multivariable multinomial models.

Questions Why are biomarkers of subclinical myocardial damage and wall stress of interest for research in the effects of alcohol consumption? What are the advantages of examining prospectively the associations of alcohol consumption with these biomarkers, in addition to the cross-sectional associations?

Current Drinkers (drinks/week) Table 1. Characteristics of study participants without clinical cardiovascular disease according to categories of alcohol consumption at baseline, the Atherosclerosis Risk in Communities Study, 1990-1992 Former drinker Never drinks Current Drinkers (drinks/week)   ≤1 2-7 8-14 ≥15 N (%) 2,284 (19.7%) 2633 (22.7%) 3295 (28.4%) 2013 (17.4%) 812 (7.0%) 560 (4.8%) Mean (SD) Age (years) 57.0 (5.7) 57.3 (5.7) 56.2 (5.7) 56.4 (5.7) 56.2 (5.5) 56.9 (5.7) African-American, % 36.6 37.3 13.5 15.0 14.3 17.0 Female, % 50.0 78.8 63.9 48.2 34.5 16.3 Family income <$35000, % 62.9 64.4 41.8 35.1 34.6 42.3 Education less than high school, % 13.7 10.6 3.5 4.0 4.7 8.2 Obesity (BMI≥30), % 33.9 35.3 26.5 19.4 20.2 17.1 Hypertension, % 37.6 38.0 26.3 29.0 32.4 Mean (SD) HDL-cholesterol (mg/dL) 46.8 (15.2) 51.4 (15.9) 50.1 (16.2) 52.3 (17.6) 54.1 (19.3) 53.4 (19.9) Mean (SD) LDL-cholesterol (mg/dL) 136.0 (36.3) 135.5 (37.7) 132.1 (35.5) 130.5 (35.4) 130.7 (37.4) 128.7 (39.5) Median [P25-p75] Triglycerides (mg/dL) 112.0 111.0 113.0 106.0 116.0 Mean (SD) C-reactive protein (mg/L) 4.9 (8.0) 4.6 (6.6) 3.9 (7.2) 3.4 (5.2) 3.5 (6.2) 3.8 (6.6) Diabetes, % 21.1 19.0 11.4 9.9 10.1 Median [P25-p75] GGT (U/L) 22.0 [15.0-33.0] 20.0 [14.0-30.0] 18.0 [13.0-28.0] 21.0 [14.0-31.0] 27.0 [17.5-44.0] 34.0 [21.0-55.0] Current smoker, % 24.0 21.0 25.2 33.1 39.3 Left ventricular hypertrophy, % 2.6 3.4 1.2 1.4 1.6 2.7 Median [P25-p75] hs-cTnT (ng/L) 3 [1.5-6] 1.5 [1.5-6] 1.5 [1.5-5] 3.5 [1.5-6] Increased hs-cTnT (≥ 14 ng/L), % 7.1 3.8 2.8 3.6 Median NT-proBNP (ng/L) [p25, p75] 45.8 [14.5-87.0] 54.1 [28.8-95.6] 51.9 [28.6-89.2] 49.2 [24.9-89.6] 43.6 [24.0-84.5] 44.9 [23.9-80.5] NT-proBNP ≥300 ng/L, % 3.1 2.2 NT-proBNP ≥100 ng/L, % 20.5 22.4 20.6 28.8 19.6 History of excessive drinking §, % 12.7 0.2 5.0 29.1

Figure 1. Cross-sectional and prospective association of alcoholic drinks per week (among current drinkers) and hs-cTnT (log transformed and elevation)

Figure 1 cont. Cross-sectional and prospective association of alcoholic drinks per week (among current drinkers) and NT-proBNP (log transformed and elevation)

Increased NT-proBNP (≥300 ng/L) Table 2. Cross-sectional associations* of baseline alcohol consumption groups and increased baseline hs-cTnT or NT-proBNP. N=11,579. ARIC 1990-1992 Alcohol consumption category Increased hs-cTnT OR (95% CI)   Increased NT-proBNP (≥100 ng/L) Increased NT-proBNP (≥300 ng/L) Former drinker 1.37 (1.03-1.83) 1.17 (1.00-1.36) 1.12 (0.78-1.60) Never drinker 1 (Reference) Current, ≤1 drink/week 0.78 (0.57-1.08) 0.99 (0.86-1.14) 0.94 (0.65-1.35) Current, 2-7 drinks/week 0.67 (0.46-0.96) 1.17 (1.00-1.38) 1.23 (0.83-1.83) Current, 8-14 drinks/week 0.78 (0.49-1.24) 1.33 (1.07-1.65) 0.99 (0.56-1.75) Current, ≥15 drinks/week 0.64 (0.38-1.07) 1.49 (1.16-1.93) 1.47 (0.83-2.59)

Incident increase in hs-cTnT Incident increase in NT- proBNP ≥300 ng/L Table 3. Adjusted* risk ratios (95% confidence intervals) for the association of alcohol consumption categories with incident increased hs-cTnT (≥14 ng/L), incident increased NT-proBNP (≥100 ng/L), and incident increased NT-proBNP (≥300 ng/L). ARIC 1990-1992 Alcohol consumption category Incident increase in hs-cTnT N=9476 Incident increase in NT-proBNP ≥100 ng/L N=7785 Incident increase in NT- proBNP ≥300 ng/L N=9587 Former drinker 0.98 (0.71-1.36) 0.97 (0.80-1.18)   1.37 (0.96-1.97) Never drinker 1 (Reference) Current, ≤1 drink/week 0.91 (0.66-1.24) 0.99 (0.83-1.18) 1.22 (0.87-1.70) Current, 2-7 drinks/week 0.70 (0.49-1.00) 0.84 (0.68-1.03) 1.07 (0.72-1.58) Current, 8-14 drinks/week 0.73 (0.46-1.14) 0.92 (0.69-1.21) 2.01 (1.28-3.16) Current, ≥15 drinks/week 0.83 (0.52-1.32) 1.10 (0.80-1.50) 2.38 (1.43-3.96)

Questions In the main analyses, the models were adjusted for sex, race, education, and smoking, why do you think this is appropriate? What would happen to the effect sizes if the models further adjusted for factors that may be in the causal pathway (e.g. diabetes, blood pressure, lipids)? Compare and contrast the results of the cross-sectional and prospective associations of alcohol consumption and 2 different cut-points of elevation of NT-proBNP (Tables 2 and 3)? What are potential explanations for these differences?

Conclusions There were significant inverse associations between moderate drinking and presence or development of subclinical myocardial damage, as measured using hs-cTnT On the other hand, there were positive cross-sectional and prospective associations between alcohol consumption and wall stress, as measured using elevated NT-proBNP.

From the Editorial by R. Lawler and B. Everett These findings highlight the differential effects of alcohol on CVD Example of mechanistic biomarker study nested in an epidemiological, population based study, to expand our understanding of the mechanisms behind health-related behaviors