Introduction: Studies in US Hispanic adults indicate no deleterious association between obesity and death. We tested the hypothesis that accounting for weight history would provide more insight into this nonassociation.
Methods: We used the National Health and Nutrition Examination Survey (NHANES) to examine associations between maximum lifetime body mass index (BMI) and all-cause and cause-specific mortality among US-residing Mexican American adults. BMI was classified as underweight (<18.5 kg/m2), normal weight (18.5-24.9), overweight (25.0-29.9), obese class I (30.0-34.9), and obese class II (≥35.0). We used Cox proportional hazards to examine the association between maximum lifetime BMI and BMI at survey and all-cause and specific causes of death (ie, cardiovascular disease, cancer, diabetes, and other) controlling for age, sex, and smoking in 6,242 Mexican American adults enrolled in NHANES III (1988-1994) and NHANES 1999-2010.
Results: Mexican Americans categorized as obese class II at maximum lifetime and time of survey had increased risk of all-cause mortality (hazard ratio [HR], 2.12; 95% confidence interval [CI], 1.54 - 2.93 and HR, 1.52; 95% CI, 1.10-2.10). Those reporting a maximum lifetime BMI of class I or class II obesity but who were classified as normal weight at survey had increased risk of all-cause mortality (HR = 2.49; 95% CI, 1.72-3.61 and HR = 3.56; 95% CI, 1.15-11.06, respectively).
Conclusion: Increased all-cause mortality risk in Mexican Americans with a lifetime BMI of 35 or greater refutes prior studies, suggesting that maximum lifetime BMI should be included when evaluating obesity-mortality associations in this population.