Background
Several studies have suggested that smoking may cause insulin resistance. However, the association between smoking and insulin resistance is still controversial. The purpose of this study was to investigate the association between smoking status and insulin resistance in Korean nondiabetic male population.Methods: A total of 5,969 men, aged > 20 years were recruited from those who visited the Health Promotion Center, Samsung Medical Center between 2005 and 2006. All subjects were divided into three categories: on-smokers (n = 2,594), ex-smokers (n = 1,580), and current-smokers (n = 1,795). Fasting values for glucose and insulin were used to estimate insulin resistance by HOMA (homeostasis model assessment). An independent association between smoking status and HOMA-IR (homeostasis model assessment of insulin resistance) was assessed after adjustment for factors infl uencing insulin sensitivity such as age, exercise, alcohol, body mass index, abdominal circumference, and blood pressure.Results: HOMA-IR was signifi cantly higher in ex-smokers and current-smokers than in non-smokers (2.09 ± 0.94 vs. 2.04 ± 0.90, 1.96 ± 0.86, P < 0.01, respectively). After adjustment for factors potentially affecting insulin sensitivity (age, alcohol intake, exercise, BMI, body fat, abdominal circumference, and blood pressure), the association persisted for ex-smokers (P = 0.008). And HOMA-IR was signifi cantly higher in ≥ 40 pack-years smokers than in non-smokersConclusion: Based on HOMA-IR, previous-smoking and chronic smoking were significantly associated with insulin resistance in apparently healthy Korean nondiabetic men.

Background
Insulin resistance is one of the underlying causes for atherosclerosis. The monocyte chemoattractant protein-1 (MCP-1) plays a crucial role in initiating atherogenesis by recruiting monocytes/macrophages to vessel wall. In this study, we investigated the relationship between homeostasis model assessment-estimated insulin resistance (HOMA-IR) and circulating level of MCP-1 in healthy adults. Methods: By reviewing the medical records of 171 healthy adults, we determined the circulating level of MCP-1, body mass index, systolic blood pressure, diastolic blood pressure, triglycerides, total cholesterol, LDL- cholesterol, HDL-cholesterol, fasting glucose, fasting insulin level and HOMA-IR. We studied the relationship between the variables by Pearson correlation coefficients and multiple linear regression analysis. Results: MCP-1 correlated positively with HOMA-IR (r=0.28; P＜0.01). Age, systolic blood pressure, diastolic blood pressure, triglycerides, LDL-cholesterol, fasting glucose and insulin level also showed stastically significant correlation. Age, gender, HOMA-IR were the variables which affected MCP-1 by multiple regression analysis adjusting for body mass index, systolic blood pressure, triglycerides, and LDL-cholesterol. Conclusion: In our study, circulating levels of MCP-1 were associated with insulin resistance. These findings support the potential role of MCP-1 as a biomarker for subclinical atherosclerosis. (J Korean Acad Fam Med 2008;29:189-194)