NEW YORK – The prevalence of gout has increased by 40% over almost 2 decades, judging from recent data discussed by Dr. Michael Pillinger at a rheumatology meeting sponsored by New York University. At the same time, other research has shown that there is greater recognition of its ill effects, including increased risk of osteoarthritis, heart failure, and death.
"Gout continues to be on the rise," according to Dr. Pillinger, citing the results of a recently published analysis of gout prevalence based on two large nationally representative samples (Arthritis Rheum. 2011;63:3136-41). By comparing data from 5,707 participants of the National Health and Nutrition Examination Survey (NHANES, 2007-2008) to 18,825 participants in NHANES-III (1988-1994), the researchers found that the prevalence of gout increased by 1.2%, from 2.7% to 3.9%. The rise was greater for men than women, with an increase of 2.1% for men and 0.4% for women. The most striking gain was found in those over the age of 80 years old (men and women), which saw an increase of 6.7% (from 5.9% to 12.6%).
"Something very significant is going on," says Dr. Pillinger, suggesting that factors such as longer life span, kidney disease, increased diuretic use, diet, and obesity may all be contributing to the findings.
While few patients die as a result of a gout attack, just having the disease shortens survival by 10% to 15%, says Dr. Pillinger, director of the rheumatology fellowship program at New York University and director of rheumatology at the Manhattan campus of the VA New York Harbor Healthcare System.
An examination of the National Death Registry of Taiwan of 6,631 people who were diagnosed with gout in 2000 and followed for 8 years (representing 53,048 person-years of follow-up) showed that crude mortality for men and women combined was 21.3 per 1,000 patient-years, which was significantly higher than that of the national population (Joint Bone Spine 2011;78:577-80). The all-cause standardized mortality ratio was 1.29 for men and 1.70 for women, with higher mortality ratios due to death from kidney diseases, endocrine and metabolic, and cardiovascular diseases in both sexes.
Gout is often accompanied by several serious comorbidities. Results from the New York Veterans Affairs Gout Cohort, a database analysis of 575 people with gout in the VA system, found that the average gout patient has four or five comorbidities. In their sample, nearly 90% were found to have hypertension, 60% hyperlipidemia, and 40-50% chronic kidney disease, diabetes, and coronary artery disease (Am. J. Med. 2011;124:155-63). The presence of comorbidities result in a high frequency of contraindications to approved gout medication, so these patients can be difficult to treat, says Dr. Pillinger, a coauthor of the study.
Now heart failure can be added to the list of gout-related comorbidities. In a post-hoc, longitudinal and cross-sectional analysis of 4,989 patients enrolled in the Framingham Offspring Study (BMJ Open 2012 Feb. 15 [doi: 10.1136/bmjopen-2011-000282]), the researchers found that those with gout (n = 228) had two to three times higher incidence of clinical heart failure compared with those without. Examining the cardiac characteristics of patients with and without gout (2,326 had echocardiograms), those with gout were four times more likely to have systolic dysfunction (P less than .001) and three times more likely to have low ejection fraction (P less than .001).
The study began in 1971 and patients were examined approximately every 4 years, with the last data collection in 2008. Longitudinal analysis showed that the risk of clinical heart failure did not become apparent until after the patients had gout for 10 or 12 years. These findings suggest that while clinical heart failure is not a problem when patients with gout are first seen when they are younger, the risk of clinical heart failure as patients age should be something to be cognizant of for possible early intervention, says Dr. Pillinger.
Participants with gout had greater mortality than those without (adjusted hazard ratio, 1.58; 95% confidence interval, 1.40 to 1.78). In those with heart failure, those with gout were more likely to die than those without the disease (adjusted HR, 1.50; 95% CI, 1.3 to 1.73). "This study adds to the growing body of evidence suggesting that gout has major consequences on the cardiovascular system," according to Dr. Krishnan.
Gout appears to also increase the prevalence and severity of osteoarthritis (OA). Using both ACR clinical and radiographic criteria, the prevalence of OA in both knees was significantly higher in those with gout compared to normal controls or those with asymptomatic hyperuricemia (68% vs. 28%, P less than or equal to .05), according to data presented at the 2011 annual meeting of the American College of Rheumatology. The severity of osteoarthritis was also higher in those with gout compared to normal controls using both Kellgren-Lawrence and Western Ontario and McMaster Universities Arthritis Index scores, but differences between groups did not reach statistical significance.