A new study published in the journal Endocrine Practice suggests that vitamin D insufficiency is associated with reduced cardiovascular autonomic function among patients with type 2 diabetes.
Cardiovascular autonomic function refers to the involuntary functions of the heart, such as controlling heart rate and blood pressure. People with type 2 diabetes are at an increased risk for compromised cardiovascular autonomic function, since chronically high blood sugar can result in damage to the nerves that are responsible for autonomic function.
Another common symptom experienced in type 2 diabetes is peripheral neuropathy. Peripheral neuropathy is damage to the nerves of the peripheral nervous system, which is the network of nerves that carry information from the brain and spinal cord to the rest of the body. Cardiovascular autonomic neuropathy is a type of peripheral neuropathy that refers to the damage of autonomic nerves which control the heart and blood vessels.
Cardiovascular autonomic neuropathy can cause irregular heart rate, low blood pressure, exercise intolerance, and an increased risk for mortality.
There are many aspects of cardiovascular autonomic neuropathy that hint at a role for vitamin D. Vitamin D, overall, is associated with diabetes and cardiovascular health. More specifically, vitamin D has been shown to help regulate blood pressure and aid the pumping and contracting of the heart.
In a new study, researchers enrolled 50 patients with type 2 diabetes to evaluate the association between cardiovascular autonomic function and vitamin D status.
The researchers measured vitamin D levels and assessed the patients’ cardiovascular autonomic function by testing their heart rate variability, or the variation in the time intervals between heart beats.
They found that low vitamin D status was associated with decreased heart rate variability.
They also found that participants with vitamin D deficiency (n=26), with deficiency defined as levels below 30 ng/ml, were more insulin resistant and had a higher body mass index.
“The results of this study demonstrated that vitamin D insufficiency is associated with reduced parasympathetic nerve function, with the association being stronger in younger persons with type 2 diabetes than in older individuals,” the researchers concluded.