NEW YORK — Urate, the culprit of gout, affects the vasculature in multiple ways that can raise cardiovascular risk (CV) in an individual with gout, and following guidelines for gout treatment, including the use of colchicine, can be the key to reducing those risks.
“Guideline-concordant gout treatment, which is essentially an anti-inflammatory urate-lowering strategy, at least improves arterial physiology and likely reduces cardiovascular risk,” Michael H. Pillinger, MD, told attendees at the 4th Annual Cardiometabolic Risk in Inflammatory Conditions conference. Dr. Pillinger is professor of medicine and biochemistry and molecular pharmacology at New York University Grossman School of Medicine, New York City, who has published multiple studies on gout.
NYU Grossman School of Medicine
Dr. Michael H. Pillinger
He cited evidence that has shown soluble urate stimulates the production of C-reactive protein (CRP), which is a predictor of cardiovascular disease (CVD). Another study, in which Dr. Pillinger participated, demonstrated that gout patients have impaired vascular endothelial function associated with a chronic, low-level inflammatory state, he said.
“There’s good evidence that urate itself affects the vasculature in multiple ways, and I suspect this may be a model for other metabolic effects on vasculature,” Dr. Pillinger said. “Patients with gout have abnormal endothelium in ways that really convey vascular risk.”
Gout, Inflammation, and CVD
However, for rheumatologists to study the association between gout-related inflammation and CVD is “very, very hard,” Dr. Pillinger added. “But I do think that the mechanisms by which gout induces biological changes in the vasculature may provide insights into cardiovascular disease in general.”
One way to evaluate the effects of gout on the endothelium in the clinic is to measure flow-mediated dilation. This technique involves placing an ultrasound probe over the brachial artery and measuring the baseline artery diameter. Then, with the blood pressure cuff over the forearm, inflate it to reduce flow, then release the cuff and measure the brachial artery diameter after the endothelium releases vasodilators.
Dr. Pillinger and colleagues evaluated this technique in 34 patients with gout and 64 controls and found that patients with gout had an almost 50% decrease in flow-mediated dilation, he said. “Interestingly, the higher the urate, the worse the flow; the more the inflammation, the worse the flow, so seemingly corresponding with the severity of the gout,” he said. That raised an obvious question, Dr. Pillinger continued: “If you can treat the gout, can you improve the flow-mediated dilation?”
His group answered that question with a study in 38 previously untreated patients with gout, giving them colchicine 0.6 mg twice daily for a month plus a urate-lowering xanthine oxidase inhibitor (allopurinol or febuxostat) to treat them to a target urate level of < 6 mg/dL. “We saw an increase in endothelial function, and it normalized,” Dr. Pillinger said.
However, some study participants didn’t respond. “They were people with well-established other cardiovascular comorbidities — hypertension, hyperlipidemia,” he said. “I think some people just have vessels that are too damaged to get at them just by fixing their gout problem or their inflammation.”
That means patients with gout need to be treated with colchicine early on to avoid CV problems, Dr. Pillinger added. “We ought to get to them before they have the other problems,” he said.
Managing gout, and the concomitant CV problems, requires vigilance both during and in between flares, Dr. Pillinger said after his presentation.
“We have always taught that patients between flares basically look like people with no gout, but we do know now that patients with gout between flares tend to have what you might call ‘subclinical’ inflammation: CRPs and ESRs [erythrocyte sedimentation rates] that are higher than those of the general population, though not so excessive that they might grab attention,” he said. “We also know that many, if not all, patients between flares have urate deposited in or around their joints, but how these two relate is not fully established.”
Better treatment within 3 months of an acute gout flare may reduce the risk for CV events, he said, but that’s based on speculation more so than clinical data.