Recruitment and Participant Flow
A total of 41 participants were recruited and screened (visit 1: baseline physical, vital, and blood indices) between August and September 2004. Of these, 25 consented, met the trial criteria, and were subjected to a blood draw for haematology, endocrine and biochemistry analysis, to establish baseline (pretreatment) values. Thereafter, they were randomized (postbaseline) to receive treatment capsules (n = 12) or placebo control capsules (n = 13) that contained a small amount of dried lettuce leaves twice per day, treated, and assessed (at months 1–3). Participants were given a diary to record the times they took their trial medication, adverse effects they may have experienced, and other medications they may have taken over the course of the trial. During the three-month study period, one adult was lost to follow-up and another withdrew from the treatment group. In the placebo group, two adults withdrew and another became pregnant.
Baseline data for vital, physical, haematological, biochemical, and endocrine indices were similar for the 25 eligible participants ().
Baseline Data (Mean ± Standard Deviation) for Trial Participants
Outcomes and Estimation
In summarising the adverse events reported by participants at any of the follow-up visits, we note that one individual in the placebo group was only in the study for 5 d, with no follow-up data. That individual is not included in the summary given so there are 12 participants in each group. While the number of days in the study did vary from participant to participant, the cumulative number of exposure days for the two groups were similar, with 957 and 972 total days for the treatment and placebo groups, respectively. A count was made of the number of participants who reported a particular type of adverse event at least once. The results are summarized in , where, in addition to the counts, the percentage of participants (out of 12) who experienced the event at least once is given along with an exact 95% confidence interval estimate of the proportion. As shown in the table, the types of events include cardiovascular (e.g., palpitations, nosebleeds), central nervous system (CNS; e.g., headaches, nervousness, insomnia, dizziness), gastrointestinal tract (GIT), infection, allergy, appetite, malaise, or general adverse events. The last line of gives the number of participants who reported any adverse event at any time. We would point out that with the small number of participants, it is unlikely that rare adverse events would be seen in this study.
Counts, Percentages, Group Differences and 95% Confidence Interval Estimates of Proportion of Subjects Reporting at Least One Adverse Event of the Type Described
provides a list of the vital, physical, haematological, biochemical, and endocrine data that were not significantly different between the treatment and placebo groups (p > 0.05).
Vital, Physical, Haematological, Biochemical, and Endocrine Endpoints that Were Not Significantly Different between the Treatment and Placebo Groups (p > 0.05), and within the Normal Physiological Range for Humans
Most of the vital and physical, haematological, biochemical, and endocrine endpoints that were measured were within the normal physiological range and not significantly different for the Sutherlandia and placebo groups. These include: diastolic and systolic blood pressure (BP), electrocardiogram (ECG), heart rate, body temperature (oral), and weight and height; white cell and red cell counts, haemoglobin, haematocrit, mean corpuscular volume (MCV), and red cell diameter and width (RCDW); neutrophil, monocyte, lymphocyte, eosinophil, and basophil counts; CD3, CD4, CD8 counts, and CD4:CD8 ratio; sodium, potassium, and chloride; urea, creatinine, and bilirubin; alkaline phosphatase, T-glutamyl transferase, alanine transaminase, aspartate transaminase, lactate dehydrogenase, creatine kinase, plasma glucose (random), calcium and corrected calcium, magnesium, and phosphorous; free thyroxine, free tri-iodothyroxine, and TSH; and cholesterol, LDL-cholesterol, HDL-chlolesterol, and triglycerides. No canavanine was detected in any of the samples.
contains the data for the six variables that were statistically different between the treatment and placebo groups (p < 0.05). The Sutherlandia group had a lower respiration rate (p < 0.04), but higher platelet count (p = 0.03) than the placebo group. In relation to baseline values, mean corpuscular haemoglobin (MCH; p = 0.01) and mean corpuscular haemoglobin concentration (MCHC; p = 0.02) levels were lower for the Sutherlandia compared to placebo group.
Vital, Physical, Haematological, and Biochemical Endpoints (Mean ± Standard Deviation) that Were Significantly Different between the Treatment and Placebo Groups (p < 0.05), and within the Normal Physiological Range for Humans
In addition, the Sutherlandia group had higher total protein (p = 0.03) and albumin levels (p = 0.03) than the placebo group.
Note that the p-values given are for testing the significance of the group by post interaction term. This is equivalent to a test for group differences in the amount of change from pre-treatment to post-treatment. Despite these differences, all the measurements fell within the normal physiological range for these indices, and were of no clinical relevance.