Clinical trial NCT03649178: Dietary Salt in Rheumatoid Arthritis
Official title: Inflammatory and Vascular Response to Dietary Salt in Rheumatoid Arthritis
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Rheumatoid Arthritis
Lead sponsor: Vanderbilt University Medical Center
Sponsor class: OTHER
Collaborators: name: National Institutes of Health (NIH)
name: National Heart, Lung, and Blood Institute (NHLBI)
First posted: 2018-08-28
Enrollment: 18
Sex: ALL
Minimum age (years): 18
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: This will be a random-order, 2 period crossover study with washout
Primary purpose: OTHER

Brief summary: In this study investigators propose to address the following hypotheses: 1) Reduction in dietary sodium will decrease inflammation in patients with rheumatoid arthritis (RA). 2) Reduction in dietary sodium will decrease blood pressure in patients with RA. 3) Reduction in dietary sodium will decrease tissue sodium in patients with RA.

Detailed description: The study is a random-order, 2 period crossover study with washout. Participants will be randomly assigned to be on the high-sodium diet (200mmol/24hours x 8weeks) or low-sodium diet (50mmol/24hours x 8 weeks ) with crossover separated by 4-week washout period. Investigators will allow a 7-day window on the diet (i.e., to facilitate scheduling the diet can be between 7-9 weeks), and investigators will allow a 1-week window for the washout (i.e., washout can be 3-5 weeks).

Investigators will measure changes in inflammation (as measured by DAS28 (using tender and swollen joint count, disease activity and sedimentation rate)), blood pressure measured over a 24 hour period, and tissue sodium (using Magnetic Resonance Imaging (MRI)).

If a relatively simple dietary modification has a clinically important effect on inflammation and blood pressure regulation in vivo in patients with RA, this will have far-reaching implications for the treatment of RA and prevention of Cardiovascular disease in this population.

Eligibility criteria: Inclusion Criteria:

1. Male and female patients older than 18 years who are willing to participate.
2. Satisfy the ACR criteria for the diagnosis of RA.
3. Have stable disease activity as evidenced by no clinically meaningful change in immunomodulating or corticosteroid therapy in the past 1 month.
4. Have moderate disease activity as reflected by a minimum of 3 swollen and tender joints.

Exclusion Criteria:

1. Pregnancy
2. Receiving dialysis
3. Organ or bone marrow transplant
4. Taking diuretics, uncontrolled hypertension (\>160/100 mmHg), or cardiac failure requiring treatment.
5. Severe edema (as judged by the investigator)
6. Diabetes mellitus treated with an insulin pump
7. Major surgery within the previous 3 months
8. Severe co-morbid conditions such as active cancer likely to compromise study participation
9. Unwillingness, or other inability, to cooperate
10. Contraindication to MRI
11. Presence of a condition that could make 24-hour blood pressure monitoring difficult: atrial fibrillation, inability to operate machine, receiving anticoagulants, presence of a condition that in the opinion of the investigator may be exacerbated by blood pressure cuff inflation (e.g., lymphedema).

Primary outcomes:
measure: Change in Tissue sodium
timeFrame: 2 scans, one at end of low salt diet at week 8, and one at end of high salt diet at week 20
Secondary outcomes:
measure: Change in DAS 28
timeFrame: Will be measured at beginning and end of each diet period at weeks 0, 8, and 12, 20
measure: Change in blood pressure
timeFrame: will be measured at beginning and end of each diet period at weeks 0,8 and 12, 20
Other outcomes:
Locations:
city: Nashville
country: United States
facility: Vanderbilt University Medical Center
state: Tennessee
Study officials:
affiliation: Vanderbilt University Medical Center
name: Charles M Stein, MBChB
role: PRINCIPAL_INVESTIGATOR
References: