The study was conducted in two centers according to a randomized, double-blind, placebo-controlled design and in accordance with the requirements of the Directive 92/43/EEC and DIN EN ISO 14155-1 and in conformance with the provisions in the current version of the Declaration of Helsinki. The Federal Data Protection Act/Italian Personal Data Protection Code including other applicable laws, regulations, mandatory standards and commendations were also taken into consideration.
The patients were randomized to receive in addition to standard treatment (ST) either PG or placebo, 2 x 2 tablets before the daily meals containing the highest fat content.
The trial protocol was submitted to the relevant Ethics Committee of the State Chambers of Physicians in Frankfurt, Germany for evaluation, consideration and review and given a favorable opinion before the study began.
In Italy, the trial protocol was sent for approval to the Comune di Rende. The approval N14 was given according to art. 48 del D. Lgs n 267/2000 at 28th January 2010.
The patients in Germany were recruited into the clinical trial from the surrounding area of Salztalklinik, Bad Soden-Salmünster [Center 1] and the patients in Italy were recruited during the MAP Study (Monitoraggio Alimenti e Patologie) in the center of Rende, province of Cosenza [Center 2].
Altogether 115 participants were included in the study, 36 of whom were men and 79 were women between the ages of 21 to 75 years.
Inclusion criteria were as follows: BMI > 26 and < 45; waist circumference of more than 88 cm for women and greater than 102 cm for men.
Exclusion criteria were: pregnancy or breast-feeding; alcohol abuse, drug abuse or drug addiction; inability to fulfill the criteria of the trial protocol; cancer diseases, malignant tumors; pre-existence of chronic intestinal disease and known hypersensitivity reactions to crustaceans.
Another exclusion criterion was the use of disease modifying anti-diabetic drugs. Patients undergoing treatment for chronic cardiovascular diseases were accepted, provided no modification of the type of medication and dosage regimen were undertaken during the trial.
Each patient took 2 tablets of placebo or 850 mg of PG twice daily before the two meals containing the highest fat content.
PG consists of the combination of a 125–145 kD chitosan (low molecular weight chitosan or LMWC) with ascorbic acid and tartaric acid. The combination of these substances forms a linear polymer [4,5] that is defined as PG. Due to the fat binding capacity of the product, patients were instructed to take lipophilic medications of at least four hours apart. As a preventive measure, at least one meal should be taken with high-quality oils (extra virgin) and fats to provide the body with fat-soluble vitamins as well as essential fatty acids.
When the study started, weekly counseling and physical activity sessions were provided to the patients to achieve an average 6–7 MET-h/week (daily cycling, aerobic dance, Nordic walking or swimming 2–3 times a week). They also received a CD with information about instructions regarding daily physical activity.
In order to achieve an energy deficit of 500 kcal/day, all patients were advised to reduce their dietary fat intake by making changes to their diet according to the requirements and recommended guidelines for foods to be reduced or avoided.
Treatment began immediately after the enrollment and each subject received 3 packs of 48 tablets (about 36 days of treatment). They were requested to return for more product supply at the end of each month.
The adverse events or reactions experienced were asked at every visit and documented.
After the enrollment (visit 0 as t0), 16 visits were completed during the study period of about 26 weeks (from t1 to t16). The treatment started at visit t2 (baseline).
The number of patients that was required to justify the difference in weight loss between groups ST + PG and ST + PL was determined based on the calculation according to Cohen’s d with an effect size of 1.0. At a significance level of 5 % with a statistical power of 80 %, 18 patients were required in each group as determined by the Mann-Whitney-test according to the study protocol. Considering a dropout rate of up to 20 %, the enrollment target in each center was fixed to at least 23 cases / treatment group. All participants were informed that they would be free to discontinue the study at any time without giving any reason and without bearing any negative consequences.
The random process using computer-generated block randomization with a block size of four (program BiAS Version 9.0) was not performed by a study staff but an employee of Medizin & Service GmbH. It was implemented by means of an allocation list. The study medications (verum and placebo) were packaged in blisters of identical appearance by the manufacturer.
Patients were screened at visit 0 (week 0) to see if they fulfilled the inclusion and exclusion criteria and the baseline variables were taken again at the start of the treatment. Compliance was measured by counting the residual tablets. Patients not reaching at least 90 % of the compliance rate were excluded from the evaluation.
The evaluation of compliance in relation to caloric restriction and physical exercise was not possible.
The data were analyzed using both non-parametric (primary) and parametric (only explorative) statistics. The averages and standard deviations were calculated for all variables at the different times of observation. Differences in the time needed to achieve 5 % reduction of body weight (5R) were measured according to Nonparametric Survival Analysis (Kaplan-Meier) followed by the log-rank test. At each visit, the differences in 5R were measured according to Fisher’s exact test without correction for multiple testing.
Mann-Whitney-U test and (only exploratory) t test for independent data were used to calculate the differences between the variables pertaining to the two groups. The differences between baseline value and the value at a given follow-up visit were taken as variables to compare the two groups of treatment. Body weight reduction, BMI, waist circumference and the time needed to achieve 5R were taken as main variables. Due to the small sample size, the non-parametric tests were performed as exact tests.