The American journal of the medical sciences
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Randomized Controlled Trial
A Pilot Study to Determine if Vitamin D Repletion Improves Endothelial Function in Lupus Patients.
The endothelium is important not only in regulating vascular tone but also in modulating inflammation. Patients with systemic lupus erythematosus (SLE) have deficits in these endothelial functions. Vitamin D is a nuclear hormone that regulates vascular endothelial nitric oxide synthase activity and expression. Many SLE patients have insufficient levels of vitamin D. The effect of this hormone on vascular endothelial function in SLE patients is not known. This study was designed to determine the effect size of repleting vitamin D levels on endothelial function in patients with SLE and vitamin D deficiency. ⋯ These results suggest a potential role for vitamin D in SLE-related endothelial dysfunction and that an adaptive, multi-arm, treat-to-target, serum-level trial design may increase the efficiency and likelihood of success of such a study.
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Sarcopenia and cachexia are muscle wasting syndromes associated with aging and with many chronic diseases, such as congestive heart failure (CHF), diabetes, cancer, chronic obstructive pulmonary disease and chronic kidney disease (CKD). While mechanisms are complex, these conditions are often accompanied by elevated angiotensin II (Ang II). Patients with advanced CHF or CKD often have increased Ang II levels and cachexia, and angiotensin-converting enzyme inhibitor treatment improves weight loss. ⋯ Furthermore, Ang II inhibits skeletal muscle stem (satellite) cell proliferation, leading to lowered muscle regenerative capacity. Distinct satellite cell angiotensin receptor subtypes have different effects on different stages of differentiation and are critical for the regulation of muscle regeneration. These data suggest that the renin-angiotensin system plays a critical role in mechanisms underlying cachexia in chronic disease states, and it is a promising target for the treatment of muscle atrophy in patients with diseases such as CHF and CKD.