Elevated parathyroid hormone predicts high asymmetric dimethylarginine (ADMA) concentrations; independent of vitamin D status

Vitamin D deficiency and secondary hyperparathyroidism, either in combination or independently, have been associated with increased cardiovascular (CV) events. We have demonstrated that low 25-hydroxyvitamin D3 (25(OH)D3) concentrations are associated with increased concentrations of asymmetric dimethylarginine (ADMA), an eNOS inhibitor and biomarker of increased CV morbidity and mortality. It remains unclear if this relationship is independent of parathyroid hormone (PTH). Obese diabetic subjects frequently have low vitamin D and high parathyroid hormone (PTH) concentrations. We have currently sought to evaluate the PTH:ADMA relationship in normal subjects and compare this relationship with obese diabetics (a group characterized by vitamin D deficiency and high PTH levels).