Further, multivariate logistic regression for the risk factors of DN (Table 5) revealed that each C allele, duration of diabetes, and blood levels of BUN, creatinine, triglycerides, total cholesterol, LDL-C, HDL-C, HbA1c, and serum TNF-α carry the risk for DN; however, there was no independent risk factor as the disease is multifactorial. Here, TNF is linked to diabetes mellitus.