Diabetes and Postural Orthostatic Tachycardia Syndrome (POTS)
As we have discussed previously, type 1 diabetes is associated with related conditions that include autoimmune diseases such as autoimmune thyroiditis (Hashimoto's Thyroiditis and Graves Disease), celiac disease, juvenile rheumatoid arthritis, and adrenal insufficiency (Addison's Disease). Less frequently discussed are other associated disorders that have been noted more frequently in children and adolescents with type 1 diabetes. Over the past 10 years, we have noted anecdotally the increased frequency of an autonomic disorder - postural orthostatic tachycardia syndrome (POTS) concurrent with type 1 diabetes.
What is Postural Orthostatic Tachycardia Syndrome?
According to the NIH, postural orthostatic tachycardia syndrome "is one of a group of disorders that have orthostatic intolerance as their primary symptom." Orthostatic intolerance results when there is a markedly decreased volume of blood that returns to the heart after the person changes position from lying down to standing up resulting in lightheadedness or fainting. In individuals with POTS, the lightheadedness is accompanied by a rapid increased heart rate greater than 30 beats/minute or a heart rate that exceeds 120 beats/minute within 10 minutes of rising. One can resolve the feelings of lightheadedness by lying down. According to the NIH, 75-80% of people who develop POTS are women between the ages of 15-50 years. In addition, based on the literature, the majority of people develop POTS after a major health crisis or event such as surgery, trauma, pregnancy, or a viral illness.
Symptoms of POTS include headache, fatigue, sleep disorders, weakness, difficulty breathing, tremulousness, sweating, anxiety, palpitations, venous pooling in the lower extremities with color changes, dizziness, vertigo, and fainting.
No one is absolutely certain as to the reason one has reduced return of the blood to the heart in association with rapid heart rate. However, several theories are cited:
- peripheral denervation (neuropathic POTS)
- paroxysmal overall activity of the sympathetic nervous system (hyperadrenergic POTS)
- deconditioning features associated with POTS.
Agarwal, Ritch and Sarkar, (Postgrad Med J. 2007 July; 83(981): 478-480.
doi: 10.1136/pgmj.2006.055046) has classified POTS into two main categories:
- Primary forms that include, partial dysautonomic, immune mediated pathogenesis, adolescence and hyperadrenergic state.
- Secondary forms include diabetes, amyloidosis, heavy metal poisoning, Sjogren's syndrome, hypermobility syndrome and paraneoplastic syndrome for a complete listing.
What is the possible POTS association in diabetes?
In children and adolescents with diabetes, based on discussions with my pediatric cardiology colleagues, there may be subtle changes in the autonomic nervous system. Very briefly, the autonomic nervous system is responsible for the activities that occur unconsciously, for example heart rate and blood pressure, as opposed the central nervous system which is responsible for voluntary movement.
The key to diagnosis is to recognize the possibility of postural orthostatic tachycardia syndrome. On many occasions, when my patients have symptoms of which I have no explanation (after ruling out hyper or hypoglycemia, and the other autoimmune disorders), I have sent them to pediatric cardiology to have a diagnostic tilt test. A tilt test will recreate the symptoms due to changes in bodily position.
How is POTS treated?
Most choices of therapy are to improve low blood volume or improved regulation of circulation. Unfortunately, there is no single treatment to fix all forms of POTS. Most cardiologists will add extra salt and ensure that there is increased intake of fluids. Some physicians recommend drinking 16 ounces of water before rising to increase blood pressure. Several drugs such as fludrocortisone and midodrine are employed to increase blood volume and constrict blood vessels. In addition, some patients are improved with the addition of beta- receptor blocking agents such as propranol.
Take Home message:
POTS is often under-diagnosed. If your child or adolescent develops any of the symptoms discussed above, please discuss with your healthcare team. Considering the postural orthostatic tachycardia syndrome as a diagnosis can alleviate much anxiety and concern as to many of these difficult to explain symptoms.