Obesity Paradox and Recurrent Coronary Heart Disease in a Population-Based Study: Tehran Lipid and Glucose Study

BACKGROUND: Although current data shows a positive association between obesity and development of coronary heart disease (CHD) in general population, there is limited data on the important protective role of central or general obesity in patients with prevalent CHD or the “obesity paradox”, from this region. OBJECTIVES: The objective of the present investigation was to describe the relationship between BMI categories and the recurrence of CHD in patients with a history of CHD using data from a large population-based study, the Tehran lipid and glucose study (TLGS). PATIENTS AND METHODS: The study was conducted on 440 adults, aged ≥ 30 years, with a history of CHD at baseline who attended the first (1999 - 2001) or second (2001 - 2003) phases of the Tehran Lipid and Glucose Study and had at least one year of follow-up until March 31, 2010. Cox proportional hazard models were used to evaluate the association among various BMI groups and recurrent CHD incidence. RESULTS: During a median follow-up of 8.44 years, 169 new cases of CHD occurred (incidence density of: 54.53 per 1000 person-years). The incidence of recurrent CHD was higher in the normal BMI compared with overweight and obese categories (68.71, 47.56 and 54.46 per 1000 person-years, respectively). In multivariable models, using the forward stepwise selection approach, compared to the overweight group (0.48 95% CI, 0.30-0.80), the obese group (0.55 95% CI, 0.28-1.06) lost its significant protective effect. CONCLUSIONS: Results of this study demonstrated an apparently protective effect for overweight in comparison with normal weight against long-term recurrent CHD in patients with history of CHD.