Hmong Microbiome ANd Gout, Obesity, Vitamin C (HMANGO-C)

September 6, 2023 updated by: University of Minnesota
Investigators seek to quantify the impact of vitamin C on patient outcomes, including serum urate level, gout-related symptoms, and obesity (measured by BMI) in both healthy Hmong adults and in Hmong patients with hyperuricemia (HU) and/or gout; identify associations between individuals' taxonomic and functional patterns of gut microbiota and its impact on the serum urate-lowering effect of vitamin C; compare taxonomic and functional patterns of gut microbiota between people with HU and/or gout and people without HU and gout; and identify associations between individuals' taxonomic and functional patterns of gut microbiota and self-reported acute gout trigger foods.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Gout, caused by chronic elevation of serum urate (SU), is the most common form of inflammatory arthritis worldwide. About 3.9% of adults in the U.S. suffer from gout and prevalence is even higher in certain ethnicities. Factors that may influence SU include patients' characteristics (gender, weight, renal function, etc.), genetics, and diet. Foods and beverages that have shown positive association with HU and gout are alcohol (particularly beer), purine-rich foods, red meat, seafood, and sugar-sweetened drinks, while inverse association has been found with dairy intake such as skimmed milk and low-calorie yoghurt, coffee and vitamin C. The gut microbiota composition and function have been linked to common chronic human disorders, such as obesity, diabetes, non-alcoholic fatty liver disease, and rheumatoid arthritis. Intestinal microbiota of gout patients were also found highly distinct from healthy individuals in both organismal and functional structures from a small study conducted in China. Strategies to use personal microbiome features to predict glucose response to specific food have been proposed. However, little is known about the impact of microbiota on food and urate-lowering therapy (ULT). The translational significance of a microbiota-guided approach to select appropriate foods and medications that could prevent the elevation of SU for individuals with gout or at high risk for gout is significant. The Hmong are a unique Asian sub-population. Hmong men exhibit a 2-fold higher prevalence of gout, manifesting it earlier in life and experiencing up to 5-fold increased risk of gout-associated complications, compared to non-Hmong in the US. This could lead to higher rates of cardiometabolic diseases (e.g. hypertension, renal disease, type 2 diabetes [T2DM]), which significantly impact morbidity, mortality and healthcare costs. Accordingly, the investigators seek to quantify the impact of vitamin C on patient outcomes, including serum urate level, gout-related symptoms, and obesity (measured by BMI) in both healthy Hmong adults and in Hmong patients with hyperuricemia (HU) and/or gout; identify associations between individuals' taxonomic and functional patterns of gut microbiota and its impact on the serum urate-lowering effect of vitamin C; compare taxonomic and functional patterns of gut microbiota between people with HU and/or gout and people without HU and gout; and identify associations between individuals' taxonomic and functional patterns of gut microbiota and self-reported acute gout trigger foods.

Study Type

Interventional

Enrollment (Actual)

135

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Minnesota
      • Minneapolis, Minnesota, United States, 55455
        • University of Minnesota

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Self-identified Hmong persons whose both parents are Hmong, with and without hyperuricemia (serum urate (UA) ≥ 6.8 mg/dL ) and/or gout (defined by 2020 American College of Rheumatology Guideline for the Management of Gout) are eligible for the study.
  • For those with gout, participants qualify if they have serum UA ≥ 6.8 mg/dL based on the baseline measurement or serum UA < 6.8 mg/dL based on the baseline measurement with at least 1 episode of peripheral joint or bursal swelling, pain, or tenderness (acute gout flare) in their lifetime, (with or without urate-lowering therapy)

Exclusion Criteria:

  • Allergy or sensitivity to vitamin C

  • Diagnosis/history of:

    • Gastrointestinal surgery including colectomy, ileectomy, and gastrectomy
    • Inflammatory bowel disease
    • Auto-immune disease
    • Type I diabetes mellitus
    • Severe kidney disease (i.e., on dialysis)
    • End-stage liver disease (i.e. cirrhosis)
    • Glucose-6-phosphate dehydrogenase deficiency, (due to increased bleeding risk in those with G6PD deficiency when receiving vitamin C)
  • Pregnant or breastfeeding persons

  • Current use of:

    • Antibiotics
    • Probiotics supplement
    • Ketogenic diet

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: People with hyperuricemia (HU) or gout without urate-lowering therapy (ULT)
Participants with HU or gout who are not treated with ULT will take 500 mg of vitamin C twice daily for 8 weeks.
Dietary supplement: Vitamin C
Vitamin C is a commercially available over-the-counter food supplement.
Other Names:
  • L-ascorbic acid
Experimental: People with hyperuricemia (HU) or gout with urate-lowering therapy (ULT)
Participants with HU or gout who are treated with ULT will take 500 mg of vitamin C twice daily for 8 weeks.
Dietary supplement: Vitamin C
Vitamin C is a commercially available over-the-counter food supplement.
Other Names:
  • L-ascorbic acid
Active Comparator: People without hyperuricemia (HU) or gout without urate-lowering therapy (ULT)
Participants without HU or gout who are not treated with ULT will take 500 mg of vitamin C twice daily for 8 weeks.
Dietary supplement: Vitamin C
Vitamin C is a commercially available over-the-counter food supplement.
Other Names:
  • L-ascorbic acid

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in serum urate
Time Frame: 8 weeks
Serum urate levels (mg/dL) will be measured from baseline to end, and the absolute difference will be reported.
8 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Gout Assessment Questionnaire 2.0 score
Time Frame: 8 weeks
The Gout Assessment Questionnaire 2.0 (GAQ2.0) contains 25 items covering the following domains: gout overall concern, medication side effects, perception of unmet needs, wellbeing during acute gout attack, and concerns during gout attack. Items are rated on a 5-point likert scale. Total scores range from 25 to 125 with higher scores indicating more gout symptoms.
8 weeks
Change in body mass index (BMI)
Time Frame: 8 weeks
Change in body mass index (BMI) from baseline to end. BMI is calculated as body weight (in kg) divided by height (in cm) squared. BMI is reported in kg/m^2, and the change will be reported as an absolute value.
8 weeks
Change in Swollen Joint Count (44 Joints)
Time Frame: 8 weeks
Change in gout-related symptoms will be measured from baseline to end using the Swollen Joint Count (44 Joints) post-administration of vitamin C. Scores range from 0-44 with higher scores indicating more swollen joints.
8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Minnesota

Investigators

  • Principal Investigator: Robert J Straka, PharmD, FCCP, Univeristy of Minnesota Department of Experimental and Clinical Pharmacology

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 28, 2021

Primary Completion (Actual)

August 30, 2023

Study Completion (Actual)

August 30, 2023

Study Registration Dates

First Submitted

June 14, 2021

First Submitted That Met QC Criteria

June 23, 2021

First Posted (Actual)

June 24, 2021

Study Record Updates

Last Update Posted (Actual)

September 7, 2023

Last Update Submitted That Met QC Criteria

September 6, 2023

Last Verified

September 1, 2023

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • PHARM-2020-29354

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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