Four modifiable lifestyle risk factors account for a substantial proportion of gout cases in the United States, suggesting greater public health efforts could reduce the frequency of the condition, according to a paper published Sept. 4 in Arthritis & Rheumatology.
Dr. Hyon K. Choi
Hyon K. Choi, MD, DrPH, of the department of medicine at Massachusetts General Hospital, Boston, and his coauthors analyzed data from 14,624 adults involved in the third National Health and Nutrition Examination Survey. From this, they calculated prevalence ratios for hyperuricemia, the population attributable risks, and the variance associated with the risk factors of body mass index, alcohol intake, nonadherence to a Dietary Approaches to Stop Hypertension (DASH) diet, and diuretic use.
They found that 21% of men and 19% of women in the study were hyperuricemic, which they defined as having a serum urate level greater than 417 micromol/L (7.0 mg/dL) for men and greater than 340 micromol/L (5.7 mg/dL) for women.
BMI was the most important risk factor for hyperuricemia, accounting for 44% of cases overall. The prevalence of hyperuricemia was 85% higher in individuals with a BMI of 25.0-29.9 kg/m2, 2.72-fold higher in those with a BMI of 30.0-34.9, and 3.53-fold higher for those with a BMI of 35.0 or above when compared against people with a BMI less than 25.0.
The researchers found that adherence to a DASH-style diet could have prevented 9% of hyperuricemia cases, as those in the lowest quintile of DASH-style dietary score had a 22% higher prevalence of hyperuricemia, compared with those in the highest quintile.
There was also a dose-response relationship between alcohol intake and hyperuricemia prevalence, and the authors calculated that 8% of cases could have been avoided through abstaining from alcohol consumption.
Individuals taking diuretics had a 2.24-fold greater risk of gout, and the population attributable risk for diuretic use was 12%.
However the authors noted that the serum urate variance explained by these individual risk factors was very small; for example, the serum urate variance attributed to the DASH diet was just 0.1%.
“How can dietary changes over time (together with a Western lifestyle) be associated with obesity and gout epidemics, yet also paradoxically appear extremely insignificant according to the variance measure?” they asked. “This occurs because the variance measure does not incorporate how common the exposure is (i.e., its prevalence).”
In contrast, the population attributable risk of these factors did reflect the contribution of effect size as well as the high prevalence, particularly with respect to dietary factors, where less than 1% of the U.S. population is believed to be adherent to the DASH diet.
“These data collectively indicate there is substantial room for improvement in dietary factors to help prevent hyperuricemia and gout, as well as hypertension and related cardiovascular outcomes.”
The study and one author were supported by the National Institutes of Health. Two authors were also supported by awards from the Canadian Institutes of Health Research. No conflicts of interest were declared.
SOURCE: Choi H et al. Arthritis Rheumatol. 2019 Sep 4. doi: 10.1002/art.41067.