Objective: To examine the effect of intensified self-monitored blood glucose (SMBG) testing on glycemic control.
Research design and methods: Subjects with stable, insulin-treated type 2 diabetes performed SMBG using an electronic blood glucose meter before all meals and at bedtime for 8 weeks. Baseline data were collected on demographics, clinical characteristics, diet, and exercise. HbA(1c) was measured at baseline, at 4 weeks, and at 8 weeks. After the intensified monitoring period, subjects resumed their usual monitoring. HbA(1c) was then measured at 24, 37, and 52 weeks. Multivariate linear regression was used to determine the effect of monitoring on glycemic control.
Results: A total of 201 subjects completed the monitoring period. The baseline HbA(1c) (8.10 +/- 1.67%) decreased during the monitoring period by 0.30 +/- 0.68% (P < 0.001) at 4 weeks and by 0.36 +/- 0.88% (P < 0.001) at 8 weeks. Although entry HbA(1c) and compliance independently predicted the week 8 HbA(1c) (r = 0.862, P < 0.001), standardized regression analysis found that compliance with the SMBG protocol influenced the week 8 HbA(1c) more than age, sex, BMI, exercise level, carbohydrate consumption, or treatment intensity at baseline. However, SMBG benefited only subjects whose testing compliance exceeded 75% or with an entry HbA(1c) >8.0%. Decreases in HbA(1c) (-0.31 +/- 1.17%, P = 0.001) persisted in the 159 subjects followed for 52 weeks.
Conclusions: Intensified blood glucose monitoring improved glycemic control in a large cohort of stable, insulin-treated veterans with type 2 diabetes. SMBG provided a strong stimulus for improved self-care resulting in clinically important and sustained reductions in HbA(1c).