All-cause and cardiovascular mortality among diabetic participants in the San Antonio Heart Study: evidence against the "Hispanic Paradox"

Abstract

Objective: The observation that Hispanics have lower all-cause and cardiovascular mortality, despite increased diabetes and obesity, lower socioeconomic status (SES), and barriers to health care, has been termed the "Hispanic Paradox." We examined the relationship between ethnicity and all-cause and cardiovascular mortality in Mexican Americans (MAs) and non-Hispanic whites (NHWs) with diabetes.

Research design and methods: In the San Antonio Heart Study, a prospective cohort, we compared the mortality in 554 U.S.-born MAs, 95 Mexico-born MAs, and 178 NHW participants with diabetes aged 25-72 years. Over an average of 10.4 years, 188 deaths occurred: 115 from cardiovascular disease (CVD) [death certificate ICD-9 codes 401-414 or 420-447 (excluding 427.5)]. Because of potential differences between migrants and nonmigrants, hazard ratios (HRs) were calculated comparing U.S.-born MAs and Mexico-born MAs with NHWs.

Results: The age- and sex-adjusted HR for all-cause mortality comparing U.S.-born MAs with NHWs was 1.66 (95% CI 1.15-2.40), while comparing Mexico-born MAs with NHWs was 1.14 (95% CI 0.63-2.06). Cardiovascular mortality HRs were 1.66 (95% CI 1.04-2.65) and 0.89 (95% CI 0.40-2.01), respectively. After adjusting for possible confounders, such as fasting glucose and diabetes duration, the hazard of all-cause and cardiovascular mortality (although not statistically significant) appeared higher in U.S.-born MAs than in the other two groups.

Conclusions: We found it important to differentiate MAs by birthplace. Among diabetic participants, contrary to the prediction of the "Hispanic Paradox," compared with NHWs, U.S.-born MAs were at greater risk of all-cause and cardiovascular mortality, while Mexico-born MAs appeared to be at similar risk.