Medications commonly prescribed for gout are linked to a reduced risk of suffering a heart attack or stroke, according to a new cohort study of over 100,000 patients with the common form of inflammatory arthritis. "People with gout are at an increased risk of illnesses such as heart disease and stroke," says rheumatologist Abhishek Abhishek, from the University of Nottingham in the UK.
That higher risk may be due to sporadic bursts of inflammation. But what hasn't been clear previously is whether reducing the deposition of needle-shaped crystals behind gout's inflammation would also affect cardiovascular risks.
Drugs to prevent gout target a waste product in the blood called uric acid (usually present as urate). When uric acid isn't properly cleared, it can form crystals around the joints, causing painful inflammatory flares, and it can also contribute to kidney stones.
The international team behind the new research studied 109,504 people who were just starting urate-lowering treatment, with allopurinol prescribed in 99.2 percent of cases. This provided an opportunity to compare individuals with uric acid levels above and below the medically recognized threshold of 6 mg/dL, as doctors adjusted their doses.
The data showed that those whose uric acid levels dropped below 6 mg/dL in the first 12 months also had a 9 percent lower risk of a significant cardiovascular event over the 5-year study period, compared with those who missed the target. "This is the first study to find that medicines such as allopurinol that are used to treat gout reduce the risk of heart attack and stroke if they are taken at the right dose," says Abhishek.
The lower the uric acid levels, the greater the health benefit, the data showed – both in terms of fewer gout flares (which is the intended effect of the drug treatments) and cardiovascular issues like heart attacks and strokes. Another interesting finding is that those already at higher risk of cardiovascular problems saw a greater protective effect from the gout treatment.
The next question is why this association exists.
The researchers point to previous studies in which using allopurinol to lower uric acid levels in people without gout wasn't linked with a reduced risk of major cardiovascular events. That suggests it's the intense flare-ups of inflammation that come with gout that are responsible for the heart-related issues, which would explain why a single treatment can affect both. However, further study will be needed to know for sure – this research doesn't show a direct cause-and-effect relationship.
