Self-monitoring of blood glucose reduced HbA1c in noninsulin-treated patients
Self-monitoring of blood glucose 8 to 11 times a week was more effective than doing so more or less frequently, according to a new meta-analysis.
Self-monitoring of blood glucose (SMBG) 8 to 11 times a week helped control glycemia in noninsulin-treated patients with diabetes, an analysis found.
Researchers conducted a meta-analysis of randomized controlled trials comparing SMBG with no SMBG or structured SMBG (defined as SMBG with defined timing and frequency of glucose measurements) to determine efficacy, optimal frequency, and the most appropriate population. They reviewed 22 studies with 6,204 participants, including 17 comparing SMBG with no SMBG and four comparing SMBG with structured SMBG. Results were published Nov. 20 by the Journal of General Internal Medicine.
SMBG reduced HbA1c levels (mean difference [MD], −0.30%; 95% CI, −0.42% to −0.17%) with high heterogeneity (I2=81%) compared with no SMBG, as did structured SMBG compared to unstructured SMBG (MD, −0.23%; 95% CI, −0.38% to −0.07%) with no significant heterogeneity (I2=0%). SMBG was also associated with reductions in body mass index (−0.18 kg/m2; 95% CI, −0.31 kg/m2 to −0.04 kg/m2), weight (−0.33 kg; 95% CI, −0.62 kg to −0.05 kg), fasting plasma glucose level (−0.27 mmol/L [−4.9 mg/dL]; 95% CI, −0.43 mmol/L to −0.12 mmol/L [−7.7 mg/dL to −2.2 mg/dL]), and waist circumference (−1.12 cm; 95% CI, −2.17 cm to −0.06 cm) compared to no SMBG. SMBG was not associated with significant benefit in total cholesterol level, systolic blood pressure, or diastolic blood pressure.
There was a significant difference (P=0.03) in the effect of SMBG based on monitoring frequency. HbA1c control was better among patients who checked their glucose more than 7 times per week (MD, −0.39%; 95% CI, −0.54% to −0.23%) compared with less frequently (MD, −0.17%; 95% CI, −0.29% to −0.05%), but there was no significant difference (P=0.75) in the control between 8 to 11 times per week (MD, −0.35%; 95% CI, −0.51% to −0.20%) and 12 or more times per week (MD, −0.40%; 95% CI, −0.65% to −0.15%).
Adjusting one's lifestyle based on SMBG reduced HbA1c more substantially (MD, −0.37%; 95% CI, −0.50% to −0.23%) compared with not doing so (MD, −0.09%; 95% CI, −0.18% to −0.01%; P<0.01). No significant difference in the effect on HbA1c level was observed based on treatment adjustment by physicians (P=0.85), baseline HbA1c (≤8% and >8%; P=0.63), diabetes duration (≤6 and >6 years; P=0.72), intervention duration (3, 6, and 12 months; P=0.46), or diabetes education (P=0.50).
Structured SMBG appears “more efficient, technological, and resource-saving than normal SMBG, considering the frequency and time of self-monitoring of blood glucose,” the study authors wrote. They noted that only two studies in the meta-analysis did not specify the monitoring time and frequency in detail.