The Diet Gout Trial

Study Overview
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Brief Summary
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Unhealthy diet has long been associated with high uric acid levels and gout. The DASH diet may lower uric acid levels. This study will examine the effects of the DASH diet on uric acid in adults with a history of gout.

Detailed Description
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The public health burden of gout is substantial. Several lines of evidence suggest that a DASH diet might lower uric acid. However, there are no trials of the DASH diet in adults with gout. This trial is a cross-over study of the effects of a DASH-like diet on uric acid in adults with gout and hyperuricemia, who are not taking urate-lowering therapy. Perpetuated by the Western lifestyle and resulting obesity epidemic, the prevalence of gout has increased over the past few decades to 3.9% of US adults (8.3 million individuals). This prevalence increases with age to 9.3% of US adults over 60 years (4.7 million). Participants will be community-dwelling adults, aged 18+ with a baseline serum uric acid level of 7 mg/dL, who have a self-reported history of gout and are not taking urate lowering medications (e.g. allopurinol, febuxostat, probenecid). This trial is comprised of two study periods: (1) a dietitian-directed diet (DD) or (2) self-directed usual diet (SD). Each period lasts 4 weeks. All participants will participate in both periods, but half will undergo the dietitian-directed diet first while the other half will undergo the self-directed diet first. During the dietitian-directed diet, participants will receive $105/week of foods in a pattern that conforms to the DASH diet. The DASH diet emphasizes fruit, vegetables, lean meat, low fat dairy, and high fiber, while restricting red meat, sweets, and sugary beverages. During the self-directed diet, participants will be asked to eat their typical diet outside of the study. Investigators anticipate 40 participants in this study. The primary outcome is uric acid. Secondary outcomes of this study include: body mass index, systolic and diastolic blood pressure, fasting cholesterol, and fasting blood glucose. Both primary and secondary outcomes will be measured 3 times: (1) before the study begins (baseline), (2) after period 1 (at 4 weeks), and (3) after period 2 (at 8 weeks). Patient-reported outcomes, dietary compliance, and urine electrolytes will be assessed throughout the study as well. The primary comparison will be serum uric acid concentrations measured after the 4-week dietitian-directed diet versus uric acid concentrations measured after the 4-week self-directed diet (DD vs. SD). Comparisons will be made within person using generalized estimating equations (GEE) with and without adjustment for baseline uric acid concentration. Investigators will use GEE models for secondary outcomes as well.

Official Title
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Dietary Approaches to Stop Hypertension (DASH) Diet Effects on Serum Uric Acid (SUA) in Adults With Hyperuricemia and Gout

Conditions
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Gout, Hyperuricemia

Intervention / Treatment
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* Other: Subsidy for food purchases and dietitian education


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age > 18-100 years Self-reported gout diagnosis Serum Uric Acid > 7 mg/dL Exclusion Criteria: Recent or planned changes to urate lowering therapies (e.g. allopurinol, febuxostat, probenecid) Recent or planned changes to hypertension, lipid, or diabetes medications Patients with hyperkalemia (>5 mmol/L) Chronic kidney disease (GFR < 30 cc/min), kidney transplant, dialysis Gastro-intestinal conditions (e.g. history of gastric bypass surgery, active inflammatory bowel disease, malabsorption, or major GI resection) Active cancer treatment (e.g. radiation or chemotherapy) Diagnosis of any of the following in the past 6 months: heart attack, heart failure, angina, coronary bypass or angioplasty, or Chronic Obstructive Pulmonary Disease (COPD) Alcohol use over 14 drinks per week Inability to give informed consent Active use of warfarin, insulin, or chronic steroids (like prednisone) Terminal or mental illness

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Half of participants will be randomly assigned 1 of 2 potential sequences. All participants will ultimately participate in each study period, but the order will be randomly assigned 1:1.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Dietitian-Directed Diet<br>Participants will be provided $105/week ($15/day) to purchase foods in servings that correspond to the DASH diet and thus include fruits, vegetables, lean meat, low fat dairy, and high fiber foods. Participants will also be asked to restrict red meat, sweets, and sugary beverages during this intervention period. A dietitian will help participants order foods from a digital supermarket. Foods will be delivered to the Johns Hopkins ProHealth Research Clinic for weekly pick-up. This study period will last 4 weeks. | Other: Subsidy for food purchases and dietitian education<br>* $105/wk of DASH-like foods over 4 weeks purchased with the help of a dietitian in a proportion that reflects the DASH diet.<br>|
| No Intervention: Self-Directed Diet<br>Participants will be asked to consume their typical diet for 4 weeks. There will be no subsidy during this period. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Uric Acid Level | Measured in serum | Baseline | 
| Uric Acid Level | Measured in serum | At 4-weeks | 
| Uric Acid Level | Measured in serum | At 8-weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Systolic Blood Pressure (mm Hg) |  | Baseline, 4-weeks, 8-weeks | 
| Diastolic Blood Pressure (mm Hg) |  | At baseline, 4-weeks, 8-weeks | 
| Fasting Blood Glucose (mg/dL) | Measured in serum | Baseline, 4-weeks, 8-weeks | 
| Low Density Lipoprotein Cholesterol (mg/dL) | Measured in serum | Baseline, 4-weeks, 8-weeks | 
| Body Mass Index (kg/m^2) | Derived from baseline height, and serial weight measurements | Baseline, 4-weeks, 8-weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Blood pressure, Diet, Nutrition, DASH, Gout, Hyperuricemia, Potassium, Uric acid, Trial, Glucose, Lipid, Cholesterol, Weight, Arthritis, BMI, Body mass index, Fruit, Vegetable, Low fat dairy, Lean meat, Fiber