Interview with Dr. Long Davalos, Editor, Nerve Connect

What is your research focus within diabetic neuropathy?

Diabetic neuropathy has been, from the beginning of my career, the main field of my research, educational activities, and clinical practice. Regarding autonomic neuropathy, my research has focused on the role of diabetic autonomic neuropathy in the progression of diabetic nephropathy, the changes in the circadian pattern of blood pressure in relation to those of sympathovagal activity, and the testing modalities for cardiovascular autonomic neuropathy (CAN), sudomotor function, and autonomic symptoms.

My clinical experience with autonomic neuropathy patients has allowed me to understand how disabling this complication is, how it can disrupt the patients’ quality of life, and the impact it has in prognosis. The premature deaths and the highly troubled life of a few patients with type 1 diabetes and severe autonomic neuropathy indelibly remain in my memory.

As member of the Executive Committees of national and international study groups for the diabetic neuropathy, I contributed with other multidisciplinary experts to define the standards of autonomic testing. Those guidelines are still the reference for many researchers in the field.

Thus, my career was tuned into the scientific interest for such an intriguing complication, the clinical experience of its devastating effects, and the engagement in scientific societies and education activities to provide clinicians and trainees with clear definitions and indications on diagnosis and management of this complication.

What are the main findings of your study and how do you think it will impact clinical practice?

There is a wide underdiagnosis of diabetic autonomic neuropathy. This might be partially due to the persistent prejudice that effective treatment options for this complication are lacking and the limited accessibility to cardiovascular autonomic tests (CARTs).

When considering the diabetes epidemic, it is evident that a universal screening of asymptomatic autonomic neuropathy in patients with diabetes is not feasible. Thus, our study aim was to identify, in a well-characterized diabetic population, the clinical phenotype of patients with CAN (according to standard CARTs) and build a clinical scoring system to assess the risk of CAN using clinical information that was already available from a regular diabetes visit, with the only addition of resting heart rate.

How to calculate it?

The calculation is very easy.  The score components include heart rate, glycemic control as HbA1c, retinopathy, nephropathy, cardiovascular disease plus HDL cholesterol, systolic blood pressure, and smoking in type 1 or insulin treatment and physical activity in type 2 diabetes. Each component was included as a categorical variable (yes/no) with a different weight. The overall score ranges from 0 to 10, with a cutoff of 4 for positivity.

How to use it?

The CAN risk score has a high diagnostic accuracy and good sensitivity in diabetes type 1 and type 2. It provides risk information with no additional cost or burden to the patients and clinicians.

Recognizing patients at high risk of CAN will help determine who needs priority for CARTs, will increase the awareness of this complication among clinicians and patients, and might reduce clinical inertia and improve adherence.

We encourage clinicians to score the risk of CAN for their patients with diabetes using this simple algorithm based on parameters easily accessible in clinical practice. Identifying individuals at a higher risk of CAN is the first step in the strategy for CAN screening and diagnosis, possibly leading to a more effective pathway to appropriate treatment, as well as management of diabetes and cardiovascular risk.