INS and type 2 diabetes mellitus: Interestingly, in T2DM patients on insulin therapy, significant positive correlation was observed for gingival index with HbA1c (r = 0.21, p < 0.01), pocket depth (r = 0.57, p < 0.001), and clinical attachment level (r = 0.73, p < 0.001) but not for fasting blood glucose and triglycerides (Table 7).