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 dollars/patient. Improved SBP led to improvements in LE and QALE of 0.67 and 0.55 years respectively and decreased TC of 7,049 dollars. Decreased T-CHOL led to improvements in LE and QALE of 0.29 and 0.20 years, respectively, and increased TC of 1,923 dollars. Increased HDL led to improvements in LE and QALE of 0.28 and 0.18 years respectively, and increased TC of 2,162 dollars. 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 dollars.
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.