Glucose sensors give non-insulin type 2 diabetes patients about five more hours a day in range, NEJM trial finds

A randomised controlled trial published in the New England Journal of Medicine suggests that continuous glucose monitors (CGMs) can help people with type 2 diabetes who do not take insulin — a large group that guidelines have so far covered only with weaker evidence.

The study

• 283 adults in 22 US primary-care practices were followed for 26 weeks; participants were randomly assigned to use a CGM or to receive routine care.
• CGM users spent about five more hours a day within their target blood-sugar range.
• Their A1c (average blood sugar over about three months) improved by 0.9 percentage points more than in the comparison group, a difference the authors call clinically meaningful.
• Nearly twice as many CGM users reached an A1c below 7%, a common treatment goal.
• The University of Colorado Anschutz team, led by family physician Tamara Oser, describes it as the first large multicentre randomised trial of CGM in this population.

Why it matters

An estimated 20 million US adults have type 2 diabetes and do not use insulin. The American Diabetes Association’s standards give the highest evidence grade (Level A) for CGM in people using insulin, but only Level C for those who do not. The authors hope the results will strengthen guidelines and insurance coverage.

Limitations

The trial lasted six months, so it cannot show whether better glucose numbers translate into fewer heart, kidney or eye complications over years. It was done in US primary care, and results may differ elsewhere or without the support that trial participants received. Cost and coverage of sensors remain practical barriers. People with diabetes should discuss CGM with their own clinician.