Those with higher SD-HbA1c values had higher body weight (P = 0.04) and body mass index (P = 0.004), higher mean and index HbA1c values (P < 0.0001 and P < 0.0001, respectively), higher triglyceride and uric acid levels (P < 0.001 and P < 0.0001, respectively), higher urinary albumin excretion (mg/day), higher albumin-creatinine ratio (mg/mg) (P = 0.008 and P = 0.002, respectively), lower eGFR (P < 0.0001), higher prevalence of hypertension and metabolic syndrome as the underlying disease (P = 0.03 and 0.001), and a higher proportion of insulin therapy as treatment (P = 0.001). Here, INS is linked to metabolic syndrome.