Appeal type: Medical necessity
Decision: Upheld

Diagnosis: Type 2 Diabetes (GLUT1 deficiency syndrome)
Treatment: Continuous Glucose Monitor
The insurer denied: Continuous Glucose Monitor
The denial is upheld

This is an adult male diagnosed with type 2 diabetes mellitus (T2DM). This request is for a continuous glucose monitor (CGM). As reported; the patient has glucose transporter protein type 1 (GLUT1) deficiency. He does not take insulin to keep his glucose levels within target range. 

The proposed treatment is not medically necessary.

Continuous glucose monitoring systems including real-time systems have Food Drug Administration approval (1, 2). They are not the subject of Phase I-III clinical trials. The peer reviewed literature supports the long-term use of continuous glucose monitoring systems (CGMSs) in adults (25-year-old) patients. The American Diabetes Association (ADA) position statement on standards of medical care in diabetes published in 01/2011 (3), states, "Continuous glucose monitoring (CGM) in conjunction with intensive insulin regimens can be a useful tool to lower A1C in selected adults (age 25 years) with type 1 diabetes." The American Diabetes Association considers this to have a level of evidence of "A" which is "Clear evidence from well-conducted, generalizable, randomized controlled trials that are adequately powered." A recent large-scale trial published in the New England Journal of Medicine showed that continuous glucose monitoring system (CGMS) is effective in reducing glycated hemoglobin (HbA1c) in adults with type 1 diabetes over a six-month period (4). The 2011 American Diabetes Association statement on the standards of medical care in diabetes states the following regarding the use of continuous glucose monitors (CGMs) in children and adolescents (3): "Although the evidence for A1C lowering is less strong in children, teens, and younger adults, CGM may be helpful in these groups. Success correlates with adherence to ongoing use of the device." A recent trial published in the New England Journal of Medicine (5) showed benefit of continuous glucose monitor in children and adolescents with type 1 diabetes who are not well controlled. In addition, the peer reviewed literature supports the use of long-term continuous glucose monitoring systems (CGMS) in patients with type 1 diabetes with hypoglycemia unawareness and episodes of hypoglycemia (6). The American Diabetes Association position statement on standards of medical care in diabetes published in 01/2009 (7) states, "CGM may be a supplemental tool to SMBG (self-monitoring of blood glucose) in those with hypoglycemia unawareness and/or frequent hypoglycemic episodes." There is evidence that real-time continuous glucose monitoring systems (CGMSs) with an alarm function detects hypoglycemia (8), lead to an improvement in glycemic excursion, lead to a reduction in duration of hypoglycemia prevents hypoglycemic reactions in adult patients with type 1 diabetes (9-12). Although not all episodes were detected (13), the majority were detected. This represents a 60% reduction in patients with complete hypoglycemia unawareness. This patient does not have documentation of type 1 rather than type 2 diabetes in the form of a low c-peptide with positive autoantibodies. Long term continuous glucose monitoring system (CGMS) use in type 2 diabetes has not been shown to improve outcomes except in patients on multiple daily injections of insulin. The patient is not on multiple daily injections of insulin. The request does not meet the standard of care and is therefore not medically necessary.