Race-Ethnic Differences in the Association Between Lipid Profile Components and Risk of Myocardial Infarction: The Northern Manhattan Study

Study Questions:

Are there race-ethnic differences in the association between plasma lipid components and risk of incident myocardial infarction (MI)?

Methods:

As part of the Northern Manhattan Study, 2,738 community residents without cardiovascular disease were prospectively evaluated. Baseline fasting blood samples were collected, and lipid panel components were analyzed as continuous and categorical variables. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident MI after adjusting for demographic and cardiovascular risk factors.

Results:

The mean age was 68.8 ± 10.4 years; 36.7% were men. Of the participants, 19.9% were non-Hispanic white; 24.9%, non-Hispanic black; and 52.8%, Hispanic (>80% from the Caribbean). Hispanics had lower mean high-density lipoprotein cholesterol (HDL-C) and higher triglycerides (TGs)/HDL-C. During a mean 8.9 years of follow-up, there were 163 incident MIs; 58 (10.6%) MIs in non-Hispanic whites, 33 (4.8%) in non-Hispanic blacks, 68 (4.7%) in Hispanics, and 4 (6.0%) in those with another race-ethnicity. In the whole cohort, all lipid profile components were associated with risk of MI in the expected directions. However, HDL-C (adjusted HR per 10 mg/dl increase, 0.93; 95% CI, 0.76-1.12) and TG/HDL-C >2 (adjusted HR, 0.89; 95% CI, 0.51-1.55) were not predictive of MI among Hispanics, but were predictive among non-Hispanic blacks and whites. TGs/HDL-C per unit increase were associated with an 8% higher risk of MI among Hispanics (adjusted HR, 1.08; 95% CI 1.04-1.12).

Conclusions:

The authors concluded that in Hispanics, low HDL-C and TG/HDL-C >2 were not associated with MI risk. Their data suggest that a different TG/HDL ratio cutoff may be needed among Hispanics to predict MI risk.

Perspective:

That the lipid and nonlipid coronary risk factors and risk markers may vary by race-ethnicity is well known and a concern. The latter may be related to both lifestyle and genetics, such as the variation in functionality of HDL particles. But studies like INTERVENT, have shown that the risk factors for MI are very similar throughout the world, and suggest that lipid risk stratification may be best performed using the nonfasting apolipoprotein (apo)B/apoA-1 ratio.

Keywords: Myocardial Infarction, Follow-Up Studies, Spain, European Continental Ancestry Group, Cardiovascular Diseases, West Indies, Cholesterol, HDL, Lipoproteins, HDL, Triglycerides, Hispanic Americans, African Continental Ancestry Group


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