The study was an 8 week randomized, double-blind, placebo-controlled study with a pre-study 2 week washout period. The study was conducted at a single site: Medicus Research, LLC, in Northridge, Ca. Sample size was not calculated as this was an exploratory trial to compare three concentrations of the target product to placebo. The study was approved by the Copernicus Group IRB (Cary, NC) prior to the initiation the study.
Subjects were serially recruited if they were between 30-75 years of age, had a body mass index (BMI) ≥ 30 and ≤ 45 kg/m2 (obese), a HS-CRP of ≥ 3, agreed to discontinue anti-inflammatory medications and supplements (other than daily 81 mg aspirin which was allowed), agreed to use approved birth control methods if a female of childbearing age, and agreed to not initiate or change any exercise or diet programs during the study. Subjects were excluded if they had consumed the test product in the past, had allergies to the test product, using any drugs that can affect CRP, were taking hormone replacements, anticoagulant or anti-platelet therapy, had surgery in the past 6 months, smoked cigarettes, known alcohol or drug abuse, had major systemic, inflammatory or chronic disease, untreated depression, active eating disorder, were unable to understand or follow study protocol, were pregnant or lactating and had any medical condition which in the opinion of the investigator might interfere with the subject's ability in the trial.
Clinical Study Process
The subjects in the study came to the research clinic for a total of 4 visits (V0-V3). At (V0), the screening visit, subjects were screened for eligibility according to the inclusion/exclusion criteria. Subjects gave their informed written consent before any procedures were conducted. There was a 2 week washout phase between screening and enrollment during which subjects were asked to refrain from consuming dietary supplements (including anti-oxidants) and anti-inflammatory medications. The baseline visit (V1) took place after the washout period with subjects in a fasted state (10 hours). During this visit, the subjects underwent a physical examination, had their blood drawn and were randomized into groups. The laboratory tests and procedures included HS-CRP and a cytokine panel via Sandwich Immunoassay (Panomics, Inc., San Diego, CA), Urine F2 isoprostane (Kronos Science Laboratory, Phoenix, AZ), and safety laboratory assessments including complete blood count (CBC), comprehensive metabolic panel (CMP), and urinalysis (Primex Labs, Northridge, CA) and platelet aggregometry (Plateletworks, Helena Laboratories, Beaumont, TX). These lab tests were repeated at the 4 week (V2) and 8 week (V3) visits. An EKG was performed at baseline (V1) and again at 8 weeks (V3). During all 4 visits, anthropomorphic measures (hip and waist measurements, and weight) were obtained and vital signs (blood pressure, temperature, pulse, and respiration) were checked. Adverse event monitoring was performed at each visit using a standardized set of questions. Subjects were instructed not to change their diet nor start any new exercise program during the course of the study. In order to assess compliance, subjects were required to return all unused investigational product at each visit.
The primary outcome measure of this study was HS-CRP, a marker of cardiac health related to inflammation. Secondary outcome measures were inflammatory cytokines, urine F2 isoprostane (a measure of lipid peroxidation) and anthropomorphic measures (weight, waist and hip measurements, BMI, and body fat percentage). Safety evaluations included CBC, CMP, EKG, urinalysis and platelet aggregation, as well as particular attention to potential gastrointestinal or cardiovascular related signals.
Subjects were randomized using a table of random numbers derived from a random number generating program. A simple randomization schema utilizing 4 groups was given to the clinical staff. A single master sheet was used to randomize subjects if they were eligible for inclusion in the study following the clinical screen. The master sheet included subject number, coordinator initials and date of randomization was used to track the process and insure no duplications of assignment. None of the clinical staff had access to the assignment code key.
The test product was XanGo Juice™ produced by XanGo, LLC. The primary ingredient of XanGo Juice was mangosteen (Garcinia mangostana L.) whole fruit puree. XanGo Juice also contained apple fruit juice, pear fruit juice, grape fruit juice, pear fruit puree, blueberry fruit juice, raspberry fruit juice, strawberry fruit juice, cranberry fruit juice, and cherry fruit juice. The placebo consisted of water, sucrose (3 g/30 ml), citric acid, red grape juice concentrate, fiber complex, grape skin, natural flavors, red #40, cloud (ester gum), whey protein isolate, sodium benzoate, xanthan gum, blue #1, and caramel color.
Three different dosages of the juice were tested and compared to placebo. The product doses tested were 3 oz, 6 oz and 9 oz. All doses and placebo were consumed in a total of 9 oz of liquid in identical bottles. The placebo was used to make up the volume for the lower doses. Subjects were instructed to consume the assigned drink twice a day, once in the morning and again in the evening. They therefore took a total of 0 to 18 oz of active product per day in 18 oz of fluid.
The data from the field activity at the Northridge, CA. site was received at the CRO facility of Medicus Research, LLC in Midlothian, VA using password protected electronic transfer. The Data Management staff logged in the data files as they were received; code books were developed to facilitate smooth and accurate editing and data entry. Statistician and Data Analyst trained the data entry personnel using the codebook as the guideline for instruction on operational processes for this data. Data was analyzed using paired sample t-tests for within subject means comparisons, independent sample t-tests for between group comparisons (Placebo vs. each of the active groups individually), t-tests of difference scores for both within and between group comparisons (Placebo vs. each of the active groups individually).
Data was analyzed with the CRO team continuing the 'blinded' structures concerning group assignment. The analysis team only had the Placebo group identified to them so that they would know how to organize the statistical comparisons. Only after the analysis was completed was the 'blind' broken in order to properly report relationships between the 3 different strengths of the product being tested and placebo.
Excel 2003 (Microsoft Corp, Redmond WA), was used for data entry, validation, restructuring, calculating changes in variables over time, reorganizing and reformatting results, and preparing graphs. Statistical analyses (descriptive statistics and means comparison tests, both within and between group, were performed using SPSS Base System ver. 16 (SPSS Inc., Chicago IL.)