Impact of changes in HbA1c, lipids and blood pressure on long-term outcomes in type 2 diabetes patients: an analysis using the CORE Diabetes Model

Objectives: Various factors influence the risk of complications in type 2 diabetes patients. The isolated impact of single risk factors on long-term outcomes is unclear. The aim of this study was to calculate the projected effects on life expectancy (LE), quality-adjusted LE (QALE) and total costs of complications (TC) of 10% improvements in baseline levels of either total cholesterol (T-CHOL), high-density lipoprotein cholesterol (HDL), systolic blood pressure (SBP), glycosylated haemoglobin (HbA1c), and all four parameters combined. Methods: A cohort of newly diagnosed patients (baseline age 52 years, HbA1c 9.1%, SBP 137 mmHg, T-CHOL 212 mg/dL, and HDL 39 mg/dL) was defined. The CORE Diabetes Model was used to simulate LE, QALE and TC (US third-party payer perspective discounted at 3% annually) over patients' lifetimes, assuming no change in risk factors, an isolated 10% improvement in each parameter, or a 10% improvement in all parameters simultaneously. Results: Improved HbA1c led to increases in LE and QALE of 1.00 and 0.81 years respectively, and decreased TC of (US) $10,800/patient. Improved SBP led to improvements in LE and QALE of 0.67 and 0.55 years respectively and decreased TC of $7,049. Decreased T-CHOL led to improvements in LE and QALE of 0.29 and 0.20 years, respectively, and increased TC of $1,923. Increased HDL led to improvements in LE and QALE of 0.28 and 0.18 years respectively, and increased TC of $2,162. Simultaneous improvements in all parameters led to projected improvements in LE and QALE of 2.17 and 1.72 years respectively, and decreased TC of $14,533. Conclusions: Combined improvements in HbA1c, lipid levels and SBP produced the greatest benefits in terms of LE, QALE and TC. A 10% improvement in HbA1c had the greatest impact on these three outcomes.