Background: The extent to which moderate overweight (body mass index [BMI], 25.0-29.9 [calculated as weight in kilograms divided by height in meterssquared]) and obesity (BMI, 30.0) are associated with increased risk of coronary heart disease (CHD) throughadverse effects on blood pressure and cholesterol levels is unclear, as is the risk of CHD that remains after thesemediating effects are considered.Methods: Relative risks (RRs) of CHD associated with moderate overweight and obesity with and without adjustmentfor blood pressure and cholesterol concentrations were calculated by the members of a collaboration of prospective cohort studies of healthy, mainly white persons and pooled by means of random-effects models (RRsfor categories of BMI in 14 cohorts and for continuous BMI in 21 cohorts; total N=302 296).Results: A total of 18 000 CHD events occurred during follow-up. The age-, sex-, physical activity–, and smokingadjusted RRs (95% confidence intervals) for moderate overweight and obesity compared with normal weightwere 1.32 (1.24-1.40) and 1.81 (1.56-2.10), respectively. Additional adjustment for blood pressure and cholesterol levels reduced the RR to 1.17 (1.11-1.23) for moderateoverweight and to 1.49 (1.32-1.67) for obesity. The RR associated with a 5-unit BMI increment was 1.29 (1.22-1.35) before and 1.16 (1.11-1.21) after adjustment for blood pressure and cholesterol levels.Conclusions: Adverse effects of overweight on blood pressureand cholesterol levels could account for about 45% of the increased risk of CHD. Even for moderate overweight,there is a significant increased risk of CHD independent of these traditional risk factors, although confounding(eg, by dietary factors) cannot be completely ruled out.
|Numero di pagine||9|
|Rivista||Archives of Internal Medicine|
|Stato di pubblicazione||Published - 2007|