Intensive Structured Self-Monitoring of Blood Glucose and Glycemic Control in Noninsulin-Treated Type 2 Diabetes: The PRISMA randomized trial

OBJECTIVE: We aimed to evaluate the added value of intensive self-monitoring of blood glucose (SMBG), structured in timing and frequency, in noninsulin-treated patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: The 12-month, randomized, clinical trial enrolled 1,024 patients with noninsulin-treated type 2 diabetes (median baseline HbA(1c), 7.3% [IQR, 6.9–7.8%]) at 39 diabetes clinics in Italy. After standardized education, 501 patients were randomized to intensive structured monitoring (ISM) with 4-point glycemic profiles (fasting, preprandial, 2-h postprandial, and postabsorptive measurements) performed 3 days/week; 523 patients were randomized to active control (AC) with 4-point glycemic profiles performed at baseline and at 6 and 12 months. Two primary end points were tested in hierarchical order: HbA(1c) change at 12 months and percentage of patients at risk target for low and high blood glucose index. RESULTS: Intent-to-treat analysis showed greater HbA(1c) reductions over 12 months in ISM (−0.39%) than in AC patients (−0.27%), with a between-group difference of −0.12% (95% CI, −0.210 to −0.024; P = 0.013). In the per-protocol analysis, the between-group difference was −0.21% (−0.331 to −0.089; P = 0.0007). More ISM than AC patients achieved clinically meaningful reductions in HbA(1c) (>0.3, >0.4, or >0.5%) at study end (P < 0.025). The proportion of patients reaching/maintaining the risk target at month 12 was similar in ISM (74.6%) and AC (70.1%) patients (P = 0.131). At visits 2, 3, and 4, diabetes medications were changed more often in ISM than in AC patients (P < 0.001). CONCLUSIONS: Use of structured SMBG improves glycemic control and provides guidance in prescribing diabetes medications in patients with relatively well-controlled noninsulin-treated type 2 diabetes.