Evaluation of the relationship between insulin resistance and nicotine dependence: A cross-sectional study

The mechanisms underlying the association between insulin resistance and nicotine dependence remain incompletely understood. This study aimed to examine the association between insulin resistance, assessed by the triglyceride-glucose (TyG) index, and nicotine dependence, measured by the Fagerström test for nicotine dependence (FTND), among adult exclusive combustible cigarette smokers.

This cross-sectional study was conducted between February and June 2025 in a tertiary care setting and included 169 adult exclusive combustible cigarette smokers aged 18-80 years. Individuals with diabetes mellitus or those receiving lipid-lowering therapy were excluded. Nicotine dependence was assessed using the Fagerström test for nicotine dependence (FTND), and insulin resistance was estimated using the triglyceride-glucose (TyG) index. Correlation analyses and multivariable linear regression were performed to examine factors associated with the TyG index.

The mean age of the participants was 40.23 ± 12.95 years, and 55.6% were male. The mean TyG index was 8.51 ± 0.56, and the mean FTND score was 4.86 ± 2.32. The TyG index showed positive correlations with FTND score (r=0.280; p<0.001), age (r=0.261; p=0.001), and pack-years (r=0.218; p=0.004), and was significantly higher in males than in females (p<0.001). In multivariable linear regression analysis, older age, male sex, and higher FTND scores were independently associated with higher TyG index values.

The findings suggest a potential association between nicotine dependence and insulin resistance among adult exclusive combustible cigarette smokers. Prospective studies are needed to clarify the direction and clinical significance of this association.