Low vitamin D levels may increase heart disease risk in diabetics

A new US study indicates that teens and young adults with type 2 diabetes who also have low vitamin D levels are at elevated risk for developing arterial stiffness, an established heart disease risk factor.

The observational study measured arterial stiffness (using pulse wave velocity, PWV) and serum vitamin D concentrations of 189 type 2 diabetes patients, 190 non- diabetic obese participants, and 191 non- diabetic people with normal body weight (1). Participants were between 14 to 21 years of age, 66% were female, and 55% African American. The study results showed that arterial stiffness was significantly worse among obese participants (2.5%) and obese participants with type 2 diabetes (5.7%) compared with the normal weight controls (-1%). Average vitamin D levels in the normal weight group were 21 ng/ml, 14 ng/ml in the obese group, and 14 ng/ml in the type 2 diabetes group. For every 3 ng/ml increase in vitamin D status, PWV improved by 1%.

The researchers concluded that based on these results, an optimization of serum vitamin D levels may have a beneficial effect on arterial stiffness in young people with type 2 diabetes, thereby affecting their cardio-vascular outcome, which is the major cause of morbidity. Clinicians may consider routine screening for vitamin D deficiency in patients with type 2 diabetes because 80% of these patients also have very low vitamin D levels. Animal trials have demonstrated that vitamin D has anti-inflammatory and anti-proliferative effects on vascular endothelial and smooth muscle cells. As a result, vitamin D is considered cardio-protec-tive. Studies in adults have shown an association between low serum levels of vitamin D and increased arterial stiffness in healthy, obese, and type 2 diabetic adults, establishing low vitamin D levels as an independent risk factor for arterial stiffness (2, 3).

1. Jha P. et al. Low serum vitamin D levels are associated with increased arterial stiffness in youth. Data presented at the Endocrine Society's Annual Meeting in San Francisco, USA; June 2013.
2. Mayer O. Jr. et al. The association between low 25-hydroxyvitamin D and increased aortic stiffness. J Hum Hypertens. 2012; 26(11):650-655.
3. Jee-In L. et al. Serum 25-hydroxyvitamin D concentration and arterial stiffness among type 2 diabetes. Diabetes Res Clin Pract. 2012; 95(1):42-47.