Cardiovascular mortality in Hispanics compared to non-Hispanic whites: A systematic review and meta-analysis of the Hispanic paradox

Background Hispanics, the largest minority in the U.S., have a higher prevalence of several cardiovascular (CV) risk factors than non-Hispanic whites (NHW). However, some studies have shown a paradoxical lower rate of CV events among Hispanics than NHW. Objective To perform a systematic review and a meta-analysis of cohort studies comparing CV mortality and all-cause mortality between Hispanic and NHW populations in the U.S. Methods We searched EMBASE, MEDLINE, Web of Science, and Scopus databases from 1950 through May 2013, using terms related to Hispanic ethnicity, CV diseases and cohort studies. We pooled risk estimates using the least and most adjusted models of each publication. Results We found 341 publications of which 17 fulfilled the inclusion criteria; data represent 22,340,554 Hispanics and 88,824,618 NHW, collected from 1950 to 2009. Twelve of the studies stratified the analysis by gender, and one study stratified people by place of birth (e.g. U.S.-born, Mexican-born, and Central/South American-born). There was a statistically significant association between Hispanic ethnicity and lower CV mortality (OR 0.67; 95% CI, 0.57-0.78; p < 0.001), and lower all-cause mortality (0.72; 95% CI, 0.63-0.82; p < 0.001). A subanalysis including only studies that reported prevalence of CV risk factors found similar results. OR for CV mortality among Hispanics was 0.49; 95% CI 0.30-0.80; p-value < 0.01; and OR for all-cause mortality was 0.66; 95% CI 0.43-1.02; p-value 0.06. Conclusion These results confirm the existence of a Hispanic paradox regarding CV mortality. Further studies are needed to identify the mechanisms mediating this protective CV effect in Hispanics.