The Diet Gout Trial (DIGO)
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ClinicalTrials.gov Identifier: NCT03569020 |
Recruitment Status :
Completed
First Posted : June 26, 2018
Results First Posted : March 30, 2021
Last Update Posted : March 30, 2021
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Condition or disease | Intervention/treatment | Phase |
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Gout Hyperuricemia | Other: Subsidy for food purchases and dietitian education | Not Applicable |
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.
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 43 participants |
Allocation: | Randomized |
Intervention Model: | Crossover Assignment |
Intervention 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 (Investigator, Outcomes Assessor) |
Masking Description: | Investigators will not know which assignment the participants were given. The laboratory measuring uric acid will not know which intervention the participants were assigned. |
Primary Purpose: | Treatment |
Official Title: | Dietary Approaches to Stop Hypertension (DASH) Diet Effects on Serum Uric Acid (SUA) in Adults With Hyperuricemia and Gout |
Actual Study Start Date : | August 7, 2018 |
Actual Primary Completion Date : | July 23, 2019 |
Actual Study Completion Date : | July 23, 2019 |
Arm | Intervention/treatment |
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Experimental: Dietitian-Directed Diet
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.
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Other: Subsidy for food purchases and dietitian education
$105/wk of DASH-like foods over 4 weeks purchased with the help of a dietitian in a proportion that reflects the DASH diet. |
No Intervention: Self-Directed Diet
Participants will be asked to consume their typical diet for 4 weeks. There will be no subsidy during this period.
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- Uric Acid Level [ Time Frame: Baseline ]Measured in serum
- Uric Acid Level [ Time Frame: At 4-weeks ]Measured in serum
- Uric Acid Level [ Time Frame: At 8-weeks ]Measured in serum
- Systolic Blood Pressure (mm Hg) [ Time Frame: Baseline, 4-weeks, 8-weeks ]
- Diastolic Blood Pressure (mm Hg) [ Time Frame: At baseline, 4-weeks, 8-weeks ]
- Fasting Blood Glucose (mg/dL) [ Time Frame: Baseline, 4-weeks, 8-weeks ]Measured in serum
- Low Density Lipoprotein Cholesterol (mg/dL) [ Time Frame: Baseline, 4-weeks, 8-weeks ]Measured in serum
- Body Mass Index (kg/m^2) [ Time Frame: Baseline, 4-weeks, 8-weeks ]Derived from baseline height, and serial weight measurements

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Gender Based Eligibility: | Yes |
Accepts Healthy Volunteers: | Yes |
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

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03569020
United States, Maryland | |
Johns Hopkins ProHealth Research Clinic | |
Woodlawn, Maryland, United States, 21207 | |
United States, Massachusetts | |
Massachusetts General Hospital | |
Boston, Massachusetts, United States, 02114 |
Principal Investigator: | Edgar Miller | Johns Hopkins University |
Documents provided by Johns Hopkins University:
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: | Johns Hopkins University |
ClinicalTrials.gov Identifier: | NCT03569020 |
Other Study ID Numbers: |
IRB00153409 |
First Posted: | June 26, 2018 Key Record Dates |
Results First Posted: | March 30, 2021 |
Last Update Posted: | March 30, 2021 |
Last Verified: | November 2019 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
Diet Nutrition DASH Gout Hyperuricemia Potassium Uric acid Trial Blood pressure Glucose Lipid |
Cholesterol Weight Arthritis BMI Body mass index Fruit Vegetable Low fat dairy Lean meat Fiber |
Gout Hyperuricemia Arthritis Joint Diseases Musculoskeletal Diseases Crystal Arthropathies |
Rheumatic Diseases Purine-Pyrimidine Metabolism, Inborn Errors Metabolism, Inborn Errors Genetic Diseases, Inborn Metabolic Diseases Pathologic Processes |