A study by a diabetes research foundation discovered that adults with type 1 diabetes were better at controlling their glucose levels when instead of the traditional method of pricking a finger a few times a day, they used continuous monitors that sampled blood every five minutes through a small tube under the skin and alerted them so they could adjust their eating or take insulin more promptly.
The study was carried out by the Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Study Group and is being presented this week at the 44th European Association for the Study of Diabetes annual meeting in Rome. The results are also published in the 8th September online issue of the New England Journal of Medicine, NEJM.
The researchers tested 3 devices made by Abbott Laboratories, Medtronic and DexCom Inc. The results showed that adults with type 1 diabetes who used the devices consistently kept their blood glucose levels within the desired limits.
The research was done because nobody had yet evaluated the benefit of continuous monitoring in the management of type 1 diabetes mellitus.
Type 1 diabetes is an autoimmune disease that destroys insulin producing cells in the pancreas. Control of blood sugar in diabetes reduces the risk of blindness (diabetic retinopathy), kidney failure, heart disease and amputation.
For the study, the researchers randomly assigned 322 adults and children participating in a multicenter clinical trial and who were already being treated for type 1 diabetes to two groups. One group was fitted with continuous monitoring devices and the other group, the control group, continued to manage their blood glucose with a home monitor as normal (the traditional “finger pricking” method).
The main measurement point was the change in blood glucose after 26 weeks. When they started, all patients had blood glucose (a1c or glycated hemoglobin) levels ranging from 7 to 10 per cent.
The results showed that:
- The changes in blood glucose level in the two groups changed significantly according to age group.
- There was a significant difference among those aged 25 and over that favoured the group using the continuous monitors.
- For the age bands 15 to 25, and 8 to 14, there was no significant difference between the continuous monitor and the conventional monitor groups.
- For the oldest (25 and over) and youngest patients (8 to 14) secondary glycated hemoglobin outcomes were better in the continuous monitoring group than in the control group, but this was not the case for the 15 to 24 year olds.
- A secondary analysis of the oldest age band (25 and over) showed that more patients using continuous monitors had a relative reduction of 10 per cent or more in the mean glycated hemoglobin level, as compared with baseline.
- More of the oldest age band (25 and over) patients in the continuous monitoring group also achieved a blood sugar level of below 7 per cent, as recommended for adults by the American Diabetes Association.
- 83 per cent of the patients in the oldest age band (25 and over) used continuous glucose monitoring for an average of 6.0 or more days a week.
- This was only 30 per cent for the 15 to 24 year olds and 50 per cent for the 8 to 14 year olds.
The researchers concluded that:
“Continuous glucose monitoring can be associated with improved glycemic control in adults with type 1 diabetes.”
As far as younger patients were concerned, they concluded that:
“Further work is needed to identify barriers to effectiveness of continuous monitoring in children and adolescents.”
Dr Aaron Kowalski of the Juvenile Diabetes Research Foundation, which funded and carried out the study, told reporters in a telephone interview reported by Reuters:
“These results are very important because they show that continuous glucose monitors are more than simply devices of convenience for people with diabetes — they are tools that can substantially improve blood sugar control when used regularly.”
“Every 10 percent you lower your a1c [glycated hemoglobin] is about a 40 percent reduction in the risk of diabetic retinopathy,” said Kowalski.
According to the Juvenile Diabetes Research Foundation there are about 3 million Americans living with type 1 diabetes.
“Continuous Glucose Monitoring and Intensive Treatment of Type 1 Diabetes.”
The Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Study Group.
NEJM, Published online September 8, 2008.
DOI: 10.1056/NEJMoa0805017.
Source: NEJM, Reuters.
Written by: Catharine Paddock, PhD