Initial monotherapy with either metformin or sulphonylureas often fails to achieve or maintain current glycaemic goals in patients with Type 2 diabetes in UK primary care

Abstract

To describe initial achievement of glycaemic targets and subsequent hyperglycaemia in patients with Type 2 diabetes managed with oral agent monotherapy in UK primary care from 1998 to 2004. Electronic medical records of patients initiating metformin (n = 3362) or a sulphonylurea agent (n = 3070) in 290 UK primary care practices were retrieved from the General Practice Research Database (GPRD). Patients included had an HbA(1c) recorded 0-90 days before and 90-365 days after initiating monotherapy. The probability of achieving glycaemic thresholds in the first year, and for those achieving such targets, the probability of inadequate glycaemic control (HbA(1c) > 6.5%, > 7.0%, > 7.5%) over time is described. Low baseline HbA(1c) and drug initiation within 3 months of diabetes diagnosis were the strongest predictors of initial achievement of glycaemic targets. The proportion of patients with diabetes duration > or = 4 months who achieved HbA(1c) < 7% in the first year ranged from 24% to 88% for highest to lowest baseline HbA(1c) category in sulphonylurea initiators and from 19% to 86% in metformin initiators, with slightly higher proportions for newly diagnosed patients. Kaplan-Meier analyses suggested that 55% and 70% of patients who initially achieved glycaemic targets had HbA(1c) measurements above these targets at 2 and 3 years. Many patients fail to achieve glycaemic goals with initial monotherapy and, of those who achieve current goals, few consistently maintain these targets over 3 years. Research is needed to evaluate whether more aggressive treatment or alternative treatments can improve the long-term maintenance of glycaemic control in patients with Type 2 diabetes.