Impact of systemic inflammation on the relationship between insulin resistance and all-cause and cancer-related mortality.

BACKGROUND

Insulin resistance and inflammation play an important role in a variety of chronic diseases.

OBJECTIVE

We investigated the influence of systemic inflammation on the relationship between insulin resistance and mortality risk in apparently healthy adults.

METHODS

This study examined the mortality outcomes for 165,849 Koreans enrolled in a health-screening program. The subjects were divided into four groups according to their homeostatic model assessment of insulin resistance (HOMA-IR) and high-sensitivity C-reactive protein (hs-CRP) levels: group 0, HOMA-IR <75% and hs-CRP <2.0mg/L; group 1, HOMA-IR ≥75% and hs-CRP <2.0mg/L; group 2, HOMA-IR <75% and hs-CRP ≥2.0mg/L; and group 3, HOMA-IR ≥75% and hs-CRP ≥2.0mg/L. The Cox proportional hazard models were used to assess hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause, cardiovascular disease, and cancer-related mortality.

RESULTS

During the follow-up period of 1,417,325.6person-years, a total of 1316 deaths (182 from cardiovascular disease) occurred. The multivariate-adjusted HRs for all-cause mortality were significantly higher in groups 2 (HR 1.40; 95% CI: 1.19-1.64) and group 3 (HR 1.68; 95% CI: 1.34-2.10) than that in group 0. For cardiovascular mortality, the sex-adjusted hazards were also significantly higher in groups 2 and 3 than that in group 0; however, this increased risk disappeared during multivariate analysis. Groups 2 and 3 had significantly higher risk for cancer-related mortality than group 0, with multivariate-adjusted hazard ratios of 1.48 (95% CI: 1.18-1.86) and 1.84 (95% CI: 1.35-2.51), respectively.

CONCLUSIONS

Systemic inflammation can be used to stratify the subjects according to the all-cause and cancer-related mortality risks, irrespective of the insulin-resistance status. And this tendency is most pronounced in cancer-related mortality.