Correlation between HDL-C and Smoking in Teachers Residing in Shiraz, Iran

Background: It has been established that serum HDL-C is a main predictor for cardiovascular diseases. The aim of this study was to assess the relationship of HDL-C to smoking in teachers residing in Shiraz in order to improve the health status of the group under study and community as a whole.

Methods: The present study comprised a total of 3115 teachers working in Shiraz recruited in a prospective cohort study. Of these, two groups of 235 smokers and 235 non-smokers were randomly selected for evaluation of cardiovascular risk factors, and to determine any association between serum HDL-C, LDL, triglyceride (TG), systolic and diastolic blood pressure with smoking, gender and BMI. One way ANOVA, Pearson correlation and independent sample t tests by SPSS version 16 were used for statistical analysis and all means were followed by SD.

Results: Mean age of subjects was 45.5±6.7 years. Of smokers 4.7% were females. Among smokers males had a significantly higher mean of HDL (P=0.002) compared to females (42 vs. 32.4 mg/dl). HDL level was significantly lower (P<0.001) in heavy smokers compared to non-smokers and light smokers (36.5 vs 41.7 and 43.5). However, light smokers had a higher mean of HDL than non-smokers, although the difference was not statistically significant (43.5 vs. 41.7 mg/dl, P=0.131). Serum HDL was not affected by other factors.

Conclusion: Smoking was associated with a low serum HDL in the subjects under study who were intellectual class of the population. It is thus warranted to take preventive measures to combat cardiovascular diseases in this sector of community.