Improvements in risk factor control among persons with diabetes in the United States: Evidence and implications for remaining life expectancy

Aims: To examine whether A1c, blood pressure, and cholesterol values changed for U.S. adults with diagnosed diabetes between 1988-1994 and 2005-2006. We then project the impact of these changes on life expectancy and diabetes-related complications. Methods: We estimated changes in hemoglobin A1c, blood pressure, and total cholesterol between 1988-1994 and 2005-2006 using regression analysis and data from the National Health and Nutrition Examination Survey. We projected the potential effects on life expectancy and complications using the CDC-RTI Diabetes Cost-Effectiveness Model. Results: A1c fell by 0.68 percentage points (P = 0.001) among U.S. adults with diagnosed diabetes. Among those with diabetes and hypertension, systolic and diastolic blood pressure fell by 5.66 and 8.15 mmHg, respectively (P = 0.005 and P = 0.001). Among those with diabetes and high cholesterol, total cholesterol fell by 36.41 mg/dL (P = 0.001). These improvements were projected to increase life expectancy for persons with newly diagnosed diabetes by 1.0 year. Conclusions: Risk factor control has improved in the United States. Persons newly diagnosed with type 2 diabetes in 2005 have a better prognosis than persons diagnosed with diabetes 11 years earlier.