Association of body mass index with risk of major adverse cardiovascular events and mortality in people with diabetes

Background: The relationship between cardiovascular and all-cause mortality and obesity in people with diabetes is still controversial. We investigated the association of body mass index (BMI) with the risk of major adverse cardiovascular events (MACE) and all-cause mortality in people with diabetes. Methods: In total, 48,438 people with diabetes were enrolled in the Korean National Health Insurance Service-National Health Screening Cohort from 2002 to 2003 and were followed until 2013. Baseline BMI was categorized as underweight (<18.5 kg/m²), normal-weight (18.5–22.9 kg/m²), overweight (23.0–24.9 kg/m²), obese class I (25.0–29.9 kg/m²), and obese class II (≥30.0 kg/m²). Results: During a median of 10.7 years of follow-up (interquartile range, 10.2–11.2 years), there were 7,360 MACE and 5,766 deaths. Compared to those in the normal-weight group, the fully adjusted hazard ratios (HRs) for MACE were 1.09 (95% confidence interval [CI], 0.92-1.29), 0.91 (95% CI, 0.85-0.97), 0.93 (95% CI, 0.88-0.98), and 0.95 (95% CI, 0.84-1.06) for underweight, overweight, obese class I, and obese class II groups, respectively. The HRs for all-cause mortality were 1.75 (95% CI, 1.54-1.99), 0.74 (95% CI, 0.69-0.79), 0.67 (95% CI, 0.63-0.71), and 0.73 (95% CI, 0.63-0.85) for underweight, overweight, obese class I, and obese class II groups, respectively. Conclusion: In people with diabetes, underweight people had a higher risk for all-cause mortality, whereas overweight or obese people had a lower risk for MACE and all-cause mortality than those with a normal weight.