Implementing the VA/DoD Type 2 Diabetes Mellitus Clinical Practice Guideline

Dr. Conlin. In the VA/DoD CPG, the HbA_1c target range for individuals with limited life expectancy extends to 9%. That may seem high for some, since most other guidelines propose lower HbA_1c levels. How strong are the data that a person with limited life expectancy, say with end-stage renal disease or advanced complications, could be treated to a range of 8% to 9%? Shouldn’t lower levels actually improve life expectancy in such people?

Dr. Colburn. There’s much less data to support this level, which is why it’s cited in CPG as having weaker evidence. The reason it’s proposed is the experience of the workgroup and the evidence that is available of a high risk for patients with low life expectancy when they reduce their HbA_1c greatly. One of the concerns about being at that level might be the real issue of renal glycosuria for individuals when their blood glucose is reaching above 180 mg/dL, which correlates to the 8% to 9% HbA_1c range. You may have renal loss and risk of dehydration. It is an area where the clinician should be cautious in monitoring a patient in the 8% to 9% HbA_1c range. With that being said, a patient who is having a lot of challenges in their health and extremely advanced conditions could be in that range. We would not expect a reversing of a micro- or macrovascular disease with glycemia control. We’re not going to go back from that level of disease they have. The idea about keeping them there is to prevent the risks of overtreatment and harm to the patient.

Dr. Conlin. Since patients with diabetes can progress over their lifetime from no complications to mild-to-moderate complications to advanced complications, how does the HbA_1c target range evolve as a patient’s condition changes?

Dr. Colburn. As we check for evidence of microvascular disease or neuropathy signs, that evidence often is good for discussion between the clinician and patient to advise them that better control early on may help stem off or reverse some of that change. As those changes solidify, the patient is challenged by microvascular conditions. I would entertain allowing more relaxed HbA_1c ranges to prevent harm to the patient given that we’re not going back. But you have to be careful. We have to consider benefits to the patient and the challenges for controlling glucose.

I hope that this table doesn’t make providers throw up their hands and give up. It’s meant to start a conversation on safety and benefits. With newer agents coming out that can help us control glucose quite well, without as much hypoglycemia risk, clinicians and patients potentially can try and get that HbA_1c into a well-managed range.

Dr. Conlin. The CPG discusses various treatment options that might be available for patients who require pharmacologic therapy. The number of agents available is growing quite markedly. Dr. Colburn, can you describe how the CPG put together the pharmacologic therapy preferences.

Dr. Colburn. The CPG expressively stayed away from trying to promote specific regimens of medications. For example, other guidelines promote starting with certain agents followed by a second-line agent by a third-line agents. The concern that we had about that approach is that the medication landscape is rapidly evolving. The options available to clinicians and patients are really diverse at this moment, and the data are not concrete regarding what works best for a single patient.

Rather than trying to go from one agent to the next, we thought it best to discuss with patients using the SHARE decision-making model, the adverse effects (AEs) and relative benefits that are involved with each medication class to determine what might be best for the person. We have many new agents with evidence for possible reductions in cardiovascular outcomes outside of their glycemic control properties. As those evidences promote a potentially better option for a patient, we wanted to allow the room in management to make a decision together. I will say the CPG as well as all of the other applicable diabetes guidelines for T2DM promote metformin as the first therapy to consider for somebody with newly diagnosed T2DM because of safety and availability and the benefit that’s seen with that medication class. We ask clinicians to access the AHRQ website for updates as the medicines evolve.

In a rapidly changing landscape with new drugs coming into the market, each agency has on their individual website information about individual agents and their formulary status, criteria for use, and prior authorization requirements. We refer clinicians to the appropriate website for more information.