Introduction

The current dietary recommendations for gout include limiting purine-containing foods, and protein and alcohol intake; sufferers are also advised to lose weight. However, there are several similarities between the insulin-resistance (IR) syndrome and findings in persons with gout that have led to the pilot study summarized here. For instance, obesity, hypertension, glucose intolerance, coronary artery disease, hyperlipidemic changes and increased uric acid are found in both gout and the IR syndrome. Dr Dessein and his colleagues at Witwatersrand, Johannesburg, South Africa, postulate that IR may be a modifiable pathogenic mechanism in gout, and therefore evaluated the effects of dietary modification on serum uric acid and the frequency of attacks in patients with gout.

Method

Thirteen non-diabetic men with acute intermittent gout (at least two gout attacks in the 4 months prior to enrollment) had their diet modified as follows: calorie restriction to 1600 kcal/day with 40% derived from carbohydrate, 30% from protein and 30% from fat; replacement of refined carbohydrates with complex carbohydrates, and saturated fats with mono- and polyunsaturated fats. The body mass index (BMI), fasting lipid profiles and uric acid levels were measured at baseline. The subjects returned at 4, 10 and 16 weeks. At each visit the number of gout attacks was recorded, the diet evaluated by 24-hour recall, and counseling was given. At the final visit, the BMI was calculated and the blood tests were repeated.

Results

At enrollment, the median age of the subjects was 50 years, their median BMI was 30.5 kg/m², and 10 (77%) were alcohol users. Seven (54%) were hypertensive. They had suffered from gout for a median of 7 years.
After 16 weeks on the modified diet, the median BMI was reduced by 2.7 kg/m², and the median serum uric acid levels were lowered by 18% - they were normalized in 7 of the 12 subjects with an initially raised level. The frequency of gout attacks fell from a median of 2.1 per month to 0.6 per month, a reduction of 67%. All these findings were statistically significant (p < 0.001 to 0.002). High serum uric acid concentrations at enrollment and high frequencies of gout attacks correlated significantly with large decreases at 16 weeks.
Improvements in the frequencies of dyslipidemia, hypertension, and coronary artery disease were also reported. Nine of the subjects were followed up for a further 3 to 14 months; in 8 of these, improvements in serum uric acid levels and frequency of attacks were maintained.

Comment

The diet used in this study, similar to that recommended for the IR syndrome, was associated with a significant reduction in serum uric acid levels and the frequency of gout attacks. Foods low in purines are often high in carbohydrate and saturated fats. The participants here were encouraged to limit dairy products (low in purines) and increase their intake of fish and poultry, which are relatively high in purines. Thus increased purine intake, classically contraindicated in gout management, was associated with a beneficial effect in these patients. Earlier studies have shown that weight loss is associated with a decrease in uric acid levels. However, the present findings are the first to seriously challenge the "low-purine, high- carbohydrate" usually recommended for the control of gouty attacks. It seems probable, indeed, that the regimen followed in these patients was responsible for their improvement. Further studies are warranted. In the meantime, physicians may perhaps relax their strictures to gout sufferers to avoid purine-rich foods.