Body Mass Index Is Not Associated With Cardiovascular Mortality in Long-Term Follow-Up. Ehuh 1 Study

Objective: The aim of this study was to examine the association between BMI and all-cause and cardiovascular (CV) mortality in a nationally representative cohort of Croatian adults with long-term follow-up. Design and method: We conducted a cross-sectional analysis within the nationwide EH-UH 1 survey. The study included a representative sample of non-institutionalized Croatian adults. This study investigated if elevated BMI is associated with greater risk of death from any cause or cardiovascular disease. Participants were followed for 17 years. Mortality data were obtained from the records of the Croatian Institute of Public Health. Only participants with complete data for all variables included in the multivariable Cox proportional hazards model were eligible. The Cox regression model used cause of death, BMI, age, gender, hypertension, diabetes, dyslipidemia, and histories of myocardial infarction and stroke as variables. Results: The study included 1,169 subjects (median age 52 years, 41.1% men). Over 17 years, 208 participants (17.8%) died; 106 deaths (9.1%) were from CV causes. At baseline, the observed prevalence rates were 43.9% for hypertension, 39.9% for overweight, 25.3% for obesity, 19.7% for dyslipidemia, and 9.6% for diabetes. Myocardial infarction and stroke were reported in 2.1% and 1.7% of subjects, respectively. In the adjusted Cox proportional hazards model, BMI was independently associated with all-cause mortality (p=0.016). In the combined model, BMI remained a significant predictor (p=0.008) of all-cause mortality alongside hypertension status (p=0.018). However, BMI was not independently associated with CV mortality in either the adjusted or combined models, where only age emerged as a significant predictor (p<0.001). Kaplan-Meier survival analysis showed no significant differences in overall or CV mortality across BMI categories (p=0.113 and p=0518, respectively). Conclusions: Body mass index emerged as an independent predictor of all-cause mortality in selected multivariable models, but not of CV mortality. These findings highlight the limitations of BMI as a crude anthropometric measure that does not account for body fat distribution or metabolic heterogeneity. Measures such as a body shape index or direct assessments of visceral fat volume, may more accurately reflect the pathophysiological mechanisms linking adiposity to CV risk.