Vitamin D status and its association with cardiovascular function in patients with ME/CFS
Investigator
Dr Faisel Khan
Institution
Vascular and Inflammatory Diseases Research Unit, The Institute of Cardiovascular Research, University of Dundee, Ninewells Hospital and Medical School, Dundee, UK
Background and aims
Vitamin D is receiving increased attention for its role in maintaining optimal health. Serum concentration of 25-hydroxyvitamin D [25(OH)D] provide a good indication of vitamin D stores, which are highest in July–September and lowest in January–March. During the shorter day-lengths of winter, the UK population relies on stored and dietary vitamin D to maintain vitamin D status.
The 3rd National Health and Nutrition Examination Survey in the USA reported that serum 25(OH)D levels are associated with important cardiovascular risk factors. Low levels of 25(OH)D are associated with hypertension, increased vascular resistance, increased left ventricular mass index, and increased coronary calcification.
A recent ME Research UK-funded project in the University of Dundee recently reported a strong positive correlation between levels of inflammation and arterial stiffness in a population of 41 well-characterized patients with ME/CFS compared to 30 healthy subjects but vitamin D levels were not measured as part of this study. The researchers now wish to further investigate the relationship between vitamin D and arterial stiffness and inflammation and to further examine various parts of the vitamin D pathway.
Methods
The researchers propose to measure the main circulating form of serum vitamin D, i.e. 25-hydroxyvitamin-D3 [(25(OH)D] (measured by ELISA) and the active hormone 1,25-dihydroxy vitamin D3 [1,25-(OH)2D3], and to examine their relationship to vascular function in 2 ME/CFS and control populations.
The measurements will be made on samples acquired from two separate studies previously funded by ME Research UK: (i) stored blood samples from previous ME/CFS patients and control cohorts (n=50 in each group) in whom endothelial function was assessed by iontophoresis of acetylcholine, arterial wave reflection using pulse wave analysis, and inflammation was determined by measurement of high-sensitivity C-reactive protein (hsCRP), and (ii) a new cohort of ME/CFS patients and control subjects (n=30 in each group) in whom examinations of carotid to femoral pulse wave velocity and global and large vessel endothelial function are ongoing. The study of vitamin D status in these 2 different study populations will provide data for a solid pilot investigation of the association between vitamin D status, inflammation and various markers of cardiovascular risk.
