Factors that may Account for Cardiovascular Risk Reduction with a Dipeptidyl Peptidase-4 Inhibitor, Vildagliptin, in Young Patients with Type 2 Diabetes Mellitus

INTRODUCTION: In a meta-analysis, we observed a significant 37% relative risk reduction in prospectively adjudicated major adverse cardiac events [MACEs, comprising of non-fatal myocardial infarction, non-fatal stroke, cardiovascular (CV) death] with vildagliptin vs. comparators in younger (< 65 years) patients with type 2 diabetes mellitus (T2DM), while the risk was similar in older patients (≥ 65 years). We carried out an exploratory analysis to identify the patient characteristics and on-treatment effects that may have contributed to the different outcomes in the two age groups. METHODS: On-treatment differences (vildagliptin vs. comparators) for the change from baseline in CV risk factors were analyzed using an analysis of covariance model with the baseline value for each variable of interest, treatment and study as covariates. Additional adjustments for background antihypertensive and statin use were performed when analyzing changes in blood pressure and lipids, respectively. Baseline characteristics and patient demographics were analyzed using descriptive statistics. RESULTS: Patients aged < 65 years had shorter diabetes duration (4.4 vs. 8.2 years) and slightly higher glycated hemoglobin (HbA1c) at baseline (8.3% vs. 8.0%) than patients aged ≥ 65 years. More patients in the ≥ 65 year age group had hypertension (73.1% vs. 51.3%), dyslipidemia (53.3% vs. 43.9%) and a history of CV events (32.2% vs. 12.9%). There were small, but statistically significant differences in the change in HbA1c and total cholesterol in favor of vildagliptin relative to comparators, which were similar in both age groups. Significant differences were observed in the reduction in systolic blood pressure (SBP) (- 0.52 mmHg; 95% CI - 0.97, - 0.07; p = 0.023), low-density lipoprotein (LDL cholesterol) (- 0.12 mmol/l; 95% CI - 0.19, - 0.04; p = 0.002) and weight (- 0.48 kg; 95% CI - 0.95, - 0.01; p < 0.047) in patients < 65 years, but not in patients ≥ 65 years. The incidence of hypoglycemic events was lower in patients treated with vildagliptin [2.1 and 3.5 per 100 subject years exposure (SYEs) in < 65 and ≥ 65 years, respectively] than with comparators (5.8 and 7.5 per 100 SYEs, respectively). CONCLUSION: Based on our findings, it can be hypothesized that the positive effects of vildagliptin on SBP, LDL cholesterol, hypoglycemia and weight observed in younger, but not in older patients could be associated with the lower risk of MACE in younger patients with T2DM. FUNDING: Novartis.