Clinical Research

The Division of Nephrology and Hypertension has a number of research programs that are closely interrelated and collaborative:

• Microvascular disease in patients with hypertension, kidney and vascular disease or HIV. Dr. Wilcox directs this program with Dr. Wang. Gluteal skin biopsies are obtained from patients and controls under local anesthesia. They are studied in the laboratory for function (endothelial function and contractile responses), mediator release (nitric oxide, reactive oxygen species), calcium signaling and gene and micro RNA expression. The goal is to understand the mechanisms of microvascular dysfunction in human disease.
• The current focus of the laboratory is on non-invasive methods to assess microvascular disease. The laboratory uses Laser Doppler flowmetry to measure skin blood flow in response to local heating or to iontophorese acetylcholine, both of which assess endothelial function. Large vessel function is assessed from pulse wave velocity and ankle brachial pressure index. Peripheral capillary rarefaction is assessed by nail fold capilloscopy and cardiac output by impedance cardiography. There is a quantitative ergometric stationary bicycle and metabolic cart to study exercise physiology and ambulatory monitors to track BP, pulse wave velocity and cardiac output. Novel methods of intradermal drug delivery by an implanted permeable porous catheters are being developed to test the effects of drugs on the peripheral circulation in human subjects.
• Diuretic drug development studies: Dr. Wilcox is leading a project supported by an NIH grant to investigate a new extended release formulation of a diuretic. Phase 1 studies have been completed and the drug has FDA approval. Phase 3 studies in patients with CHF or CKD are underway.
• COVID-19 projects include an experimental study investigating the role of spironolactone in enhancing host defense mechanisms against COVID-19, as well as a planned clinical study that will investigate microvascular dysfunction as an underlying cause of the post-COVID syndrome.
• Human Cardiovascular Function Laboratory: Drs. Wilcox and Wang are establishing the new, fully equipped human physiology lab to study renal and circulatory function in humans with hypertension or CKD.
• Multicenter studies of treatment for hypertension or kidney disease. Dr. Papademetriou directs this program at the Washington VAMC. He participates in many multi-center clinical outcome trials.