Estimated benefits of glycemic control in microvascular complications in type 2 diabetes.
BACKGROUND
The benefits of intensive glycemic control in patients with type 2 diabetes are not well quantified. It is therefore not clear which patients will benefit most from aggressive glycemic control.


OBJECTIVE
To evaluate the efficacy of glycemic control in type 2 diabetes.


METHODS
Markov decision model.


METHODS
Diabetic patients at a health maintenance organization.


METHODS
Risks for developing blindness and end-stage renal disease; number of patients and patient-years needed to treat to prevent complications.


RESULTS
For a patient in whom diabetes developed before 50 years of age, reducing hemoglobin A1c levels from 9% to 7% results in an estimated 2.3-percentage point decrease (from 2.6% to 0.3%) in lifetime risk for blindness due to retinopathy. The same change in a patient with diabetes onset at 65 years of age would be expected to decrease the risk for blindness by 0.5 percentage points (from 0.5% to < 0.1%). However, the Markov model predicts substantially greater benefit when moving from poor to moderate glycemic control than when moving from moderate to almost-normal glycemic control. Targeting less than 20% of the patients at one health maintenance organization for intensified therapy may prevent more than 80% of the preventable patient-time spent blind. The risks for end-stage renal disease and the risk reduction provided by improved glycemic control are lower than those for blindness.


CONCLUSIONS
This probability model, based on extrapolation from the experience with type 1 diabetes, suggests that patients with early onset of type 2 diabetes will accrue substantial benefit from almost-normal glycemic control. In patients with later onset, moderate glycemic control prevents most end-stage complications caused by microvascular disease. These results have important implications for informing patients and allocating health care resources.
Vijan
S
S
Veterans Affairs Center for Practice Management and Outcomes Research, Ann Aroor, Michigan, USA.
Hofer
T P
TP
Hayward
R A
RA
D000328:Adult; D001766:Blindness / Q000209:etiology / Q000517:prevention & control; D001786:Blood Glucose / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000150:complications* / Q000628:therapy; D003925:Diabetic Angiopathies / Q000209:etiology / Q000517:prevention & control*; D003930:Diabetic Retinopathy / Q000209:etiology / Q000517:prevention & control*; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007676:Kidney Failure, Chronic / Q000209:etiology / Q000517:prevention & control; D008390:Markov Chains; D008875:Middle Aged; D012307:Risk Factors; D012680:Sensitivity and Specificity
D001786:Blood Glucose; D006442:Glycated Hemoglobin