Which methods of monitoring blood glucose and administering insulin are better for patients with type 1 diabetes?

This study compared two methods of monitoring blood glucose and administering insulin to see which was most effective for patients with type 1 diabetes (T1D). The authors found that a continuous glucose monitor paired with an insulin pump was more effective at controlling blood glucose levels.

Patients with T1D have high blood glucose levels. Patients need to constantly monitor their glucose levels before using insulin. There are several ways to monitor blood glucose. Continuous glucose monitor (CGM) uses a sensor under the skin that continuously communicates glucose levels. Self-monitoring blood glucose (SMBG) uses a finger prick device. Based on the results, different amounts of insulin are used.

There are several ways to administer insulin. Multiple daily injections (MDI) involve patients self-injecting. Insulin pumps automatically adjust the level of insulin required and administer it directly to the patient. Insulin pumps were shown to be more beneficial for patients than MDI. However, these trials used two different types of insulin. It is unclear if insulin pumps are better than MDI using the same type of insulin.

28 patients with T1D were divided into two groups. Group 1 (14 patients) were given insulin degludec (Tresiba) in an insulin pump with CGM for 16 weeks and then switched to MDI with degludec with SMBG for 16 weeks. Group 2 (14 patients) received the same treatments but in the reverse order. 

Group 1 saw a significant reduction of 7.5 mmol/mol in HbA1c after the CGM and insulin pump. After switching to SMBG and MDI, patients’ HbA1c increased slightly by 1.6 mmol/mol. Group 2 experienced a reduction of 3.9 mmol/mol after SMBG and MDI. This decreased further by 4.6 mmol/mol after CGM and insulin pump. On average, CGM and insulin pump reduced HbA1c by 6.1 mmol/mol more than SMBG and MDI.

CGM and insulin pump increased patients’ time in the ideal blood glucose range by 9.4%. It also reduced patients’ time spent in hypoglycemia (low blood glucose) by 3.2%. 71% of patients preferred CGM and insulin pump to SMBG and MDI.

The authors concluded that CGM paired with an insulin pump is more effective at controlling patients’ blood glucose.

The manufacturer of the insulin pump used in this trial, Movi SpA, funded this study. This study was limited by its small sample size and lack of a placebo group. Some patients were already taking insulin degludec, which may have affected results.