Introduction: Type 2 diabetes mellitus (T2DM) is an increasing problem worldwide and a leading risk factor for cardiovascular disease. As beta cell function declines, the management of T2DM typically comprises of escalations in treatment from diet and exercise to oral therapies and eventually insulin. Treatment algorithms based on the attainment of blood glucose targets may not account for changes in other cardiovascular risk factors. The objective of this study is to describe unmet clinical need, defined as failure to reduce weight or meet targets for blood pressure, total cholesterol or glycated hemoglobin (HbA1c) levels.
Methods: Anonymized UK patient data for those (1) initiating oral antidiabetic drug (OAD) monotherapy, (2) escalating to dual therapy, (3) escalating to triple therapy, and (4) escalating to insulin therapy over the study period (01/01/2005-31/12/2009) were obtained from The Health Improvement Network (THIN). Changes in risk factors were evaluated before and after therapy escalation, and the attainment of targets, assessed at the last recorded measurement, as follows: HbA1c <7.5%, systolic blood pressure (SBP) <140 mmHg, total cholesterol (TC) <5 mmol/L, and reduction in weight.
Results: Prior to therapy escalation, mean HbA1c in each subgroup exceeded 7.5% and was higher respective to the number of OADs being used (monotherapy: 8.03%; double: 8.48%; triple: 8.71%). Insulin users displayed the highest HbA1c prior to treatment escalation (9.78%). Following escalation, a decline in HbA1c was observed in all subgroups. By contrast, mean SBP and TC levels decreased prior to the addition of a second and third oral therapy. Consistent improvements following treatment escalation were not observed across the other risk factors following therapy escalation. Overall, the proportion of subjects that attained all four targets ranged from 3% (monotherapy and insulin) to 6% (dual therapy).
Conclusion: The potential unmet clinical need among conventionally treated T2DM patients is significant, with respect to the control of blood glucose and other cardiovascular risk factors: SBP, TC, and weight. There clearly remains the need for new therapeutic approaches to alleviate the burden associated with T2DM.