Effectiveness of second-line agents in the treatment of uncomplicated type 2 diabetes mellitus: An observational tertiary-care based study

Background: The rational prescribing of second-line drugs in type 2 diabetes mellitus (DM) require clear guidelines. There is no sufficient empirical evidence to support the use of one second-line agent over the other and when to initiate second-line drug is still under discrepancy. Objectives: To analyze the utilization pattern and effectiveness of second-line agents in uncomplicated type 2 DM. Methodology: 240 uncomplicated type 2 DM patients who were ≥ 18 years receiving either metformin/sulfonylurea or metformin+sulfonylurea was divided into four add-on treatment group 1, 2, 3, 4; that were added pioglitazone, dipeptidyl peptidase-4(DPP-4) inhibitor, voglibose, and insulin [pre-mixed insulin (30%regular/70%NPH)] respectively and received the second-line agents for a duration of 6 months or longer. Effectiveness was based on the reduction in glycosylated hemoglobin (HbA_1C), fasting plasma glucose (FPG) and postprandial blood glucose (PPBG) values over 3 and 6 months was done using repeated measures analysis of variance (ANOVA). Results: The mean difference for reduction in HbA_1C (%) values at 3^rd and 6^th month with respect to baseline values was 1.32±0.72 and 2.11±0.97; 1.19±0.27 and 1.81±0.53; 1.16±0.41 and 1.66±0.63; 0.97±0.16 and 1.46±0.47 for pioglitazone, DPP-4 inhibitor, voglibose, insulin respectively. The mean difference in FPG and PPBG levels at the 6^th month from baseline was 75±31.06 and 115.3±40.32; 77.91±37.95 and 117±41.27; 85.87±21.75 and 118.75±55.86; 91.38±31.8 and 132.03±56.24 for pioglitazone, DPP-4 inhibitors, voglibose and insulin respectively. Reduction in HbA_1C, FPG, and PPBG was statistically significant within each group at each time interval with p-value < 0.001. Conclusion: All the add-on groups exhibited a significant reduction in HbA_1C, FPG, and PPBG over 3 and 6 months. DPP-4 inhibitors exhibited least hypoglycemic episodes. DPP-4 inhibitors are trending and marginally more effective second-line OHA in uncomplicated type 2 DM.