Our study has several strengths and limitations. To our knowledge, this is the first study to assess loci recently discovered through GWA studies in a multiethnic cohort. Next, compared to prior studies assessing few variants in multiethnic cohorts, our study queried a larger set of lipid loci. Finally, because the NHANES III cohort over-sampled minority groups in the U.S. population, our sample includes a large number of African-Americans and Mexican Americans. That being said, due to the modest contribution of each polymorphism to trait variation, low statistical power is a key limitation. Lipids in NHANES III were measured in both fasting and non-fasting samples and our use of both may have further reduced statistical power, particularly for lipid variables sensitive to fasting status such as triglycerides. In addition, in NHANES III, ethnic groups are designated by self-reported ethnicity and this assessment is not always accurate. For a more precise assessment of ethnicity using genetic data, ancestry-informative markers are necessary. Lastly, we did not evaluate a comprehensive set of 'tag' SNPs across each of the 19 loci. Such an effort would be required to definitively study each locus in African-Americans and Mexican-Americans.
