Smoking combined with overweight or obesity markedly elevates cardiovascular risk factors

Overweight, obesity and smoking are well-established risk independent factors for cardiovascular diseases. The combination of overweight or obesity with smoking may modify other cardiovascular disease risk factors. We examined the impacts of smoking, overweight and obesity on cardiovascular risk factors: total cholesterol, high-density lipoprotein (HDL)-cholesterol, non-HDL-cholesterol, C-reactive protein and fibrinogen.

Data from 5460 adults who participated in the cross-sectional Scottish Health Survey 1998 were analysed. In multivariable analysis body mass index and smoking were the most important risk factors for cardiovascular disease. Smoking was independently associated with higher C-reactive protein and fibrinogen concentrations in both sexes, and lower HDL cholesterol and higher non-HDL cholesterol in females (P<0.001). Overweight or obesity (body mass index 25-30 or > or = 30 kg/m) were independently associated with higher C-reactive protein, total cholesterol, non-HDL-cholesterol and lower HDL-cholesterol in both sexes, and higher fibrinogen in females (P<0.001). Overweight or obese current smokers had higher C-reactive protein and fibrinogen and lower HDL-cholesterol concentrations than the reference group of never-smokers with body mass index below 25 kg/m (P<0.001). Obese current smokers had the highest mean value and odds ratio (OR) for the risk factors across the categories, particularly for lower HDL cholesterol (OR=11) and elevated C-reactive protein (OR=9) (P<0.001).

The combination of smoking and overweight or obesity aggravates cardiovascular disease risk factors, particularly HDL-cholesterol and C-reactive protein. These results justify early intervention for overweight/obese current smokers.