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a Human Nutrition Unit
b Pediatrics Department, Hospital Universitari de Sant Joan de Reus, Departament de Bioquímica i Biotecnologia, Universitat Rovira i Virgili, Reus, Spain
c Research Department, Madaus, SA, Barcelona, Spain
| ABSTRACT |
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METHODS. Using a parallel, randomized, double-blind, controlled trial, we conducted an interventional study to evaluate the efficacy of a supplement of cocoa husk rich in dietary fiber on intestinal transit time and other indices of constipation in children with constipation. After screening, the patients were randomly allocated to receive, for a period of 4 weeks, either a cocoa husk supplement or placebo plus standardized toilet training procedures. Before and after 4 weeks of treatment, we (1) performed anthropometry, a physical examination, and routine laboratory measurements, (2) determined total and segmental colonic transit time, (3) evaluated bowel movement habits and stool consistency using a diary, and (4) received a subjective evaluation from the parents regarding the efficacy of the treatment. The main variable for verifying the efficacy of the treatment was the total colonic transit time.
RESULTS. Fifty-six chronically constipated children were randomly assigned into the study, but only 48 children completed it. These children, who were aged between 3 and 10 years, had a diagnosis of chronic idiopathic constipation. With respect to total, partial colon, and rectum transit time, there seemed to be a trend, although statistically nonsignificant, toward faster transit times in the cocoa husk group than in the placebo group. When we analyzed the evolution of the intestinal transit time throughout the study of children whose total basal intestinal transit time was >50th percentile, significant differences were observed between the groups. The total transit time decreased by 45.4 ± 38.4 hours in the cocoa husk group and by 8.7 ± 28.9 hours in the placebo group (38.1 hours). In the case of the right colon, changes in transit time also were significant between groups. Mean changes tended toward faster transit times in the left colon and the rectum, although the differences were not statistically significant. The children who received cocoa husk supplements tended to increase the number of bowel movements by more than that of the children of the placebo group. We also observed a reduction in the percentage of patients who reported hard stools (hard scybalous or pebble-like stools), although this reduction was significantly greater in the cocoa husk group. At the end of the intervention, 41.7% and 75.0% of the patients who received cocoa husk supplementation or placebo, respectively, reported having hard stools. Moreover, a significantly higher number of children (or their parents) reported a subjective improvement in stool consistency. No significant adverse effects were reported during the study.
CONCLUSIONS. This study confirms the beneficial effect of a supplement of cocoa husk that is rich in dietary fiber on chronic idiopathic constipation in children. These benefits seem to be more evident in pediatric constipated patients with slow colonic transit time.
Key Words: fiber constipation children cocoa husk transit time
Abbreviations: CTTcolonic transit time
Chronic constipation is a common problem in the pediatric population. Constipation accounts for 3% of all pediatric outpatient visits and 25% of visits to the pediatric gastroenterologist.1 Series from the primary care setting show symptoms of constipation in 16% to 34% of infants and children (from 22 months to 12 years of age).25 As a symptom, constipation can be caused by various disorders, but >90% of all children with this problem have chronic idiopathic constipation that cannot be attributed to any identifiable organic cause or to medication.6,7
A low intake of dietary fiber has been considered an important causative factor in constipation in both adults and children. A higher intake of fiber therefore is a major therapeutic recommendation in such cases. Some studies have suggested that a low dietary fiber intake may help to explain the development of chronic constipation,811 but others have failed to find a significant association between fiber intake and constipation.12,13
A wide range of therapeutic strategies for treating constipation have been proposed, but the efficacy of many of them has not been supported by randomized, controlled, clinical trials. This is the case of fiber supplements.6 Fiber frequently is used to treat constipation in children by extrapolating results from heterogenic experimental studies that have been performed in healthy or constipated adult patients14,15 to children. Recommendations to use fiber to treat constipation therefore still are based on experts' opinions and clinical experience, descriptive adult series, or communications from committees of experts (III evidence level category).6,16,17 The aim of the present study was to evaluate the effect of a palatable cocoa husk supplement that is rich in fiber on intestinal transit time and other indices of constipation in children with idiopathic chronic constipation.
| METHODS |
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Exclusion criteria for the study were (1) the presence of fecal impaction that required enema in the 7 days before the start of the study; (2) treatment with dietary fiber, bulk-forming agents, or laxatives in the 2 weeks before the start of the study; (3) constipation attributable to organic or anatomic causes (Hirschsprung disease, hypothyroidism, mental deficiency, psychiatric illnesses, chronic debilitating diseases, neurologic abnormalities, or previous surgery of the colon or anus); (4) renal insufficiency, hypocalcemia, hyperkalemia, or any other metabolic diseases at the start of the study; (5) long-term use of drugs that affect gastrointestinal motility (eg, imipramine, iron or calcium supplements, anticonvulsants); and (6) inability to adhere to the study's medications or procedures.
The study protocol was approved by the Ethical Committee of the Hospital Universitari de Sant Joan de Reus. Written informed consent was obtained from all parents, and assent was obtained from children who were older than 7 years.
Study Design and Intervention
At the screening, a complete medical history of the patients was taken. A physical examination, including a rectal examination to rule out anorectal lesions, also was given. The patients' age, gender, weight, and height; the presence and duration of symptoms; the frequency and the size of bowel movements; the consistency of stools; and intake of medications were recorded. In the event of rectal impaction, at the initial evaluation, the patients were disimpacted with physiologic saline (0.9% NaCl) enema.
In the week before randomization, the patients recalled their dietary intake and received routine laboratory tests (hemogram, glucose, total cholesterol, triglycerides, transaminases, urea, creatinine, serum iron and zinc, and ferritin). In addition, they received tests for serum calcium, potassium, sodium anti-endomysial immunoglobulin A antibodies and total immunoglobulin A, thyroxine, and thyrotropin to detect other causes of constipation.
The patients were randomly assigned to receive, for a 4-week period, (1) a cocoa husk supplement that is rich in dietary fiber and linked to standardized toilet training procedures or (2) a placebo that is linked to standardized toilet training procedures. Treatment was blinded to both patients and investigator until the study was completed and analyzed.
Eligible patients were randomly assigned to treatment 1 or 2 in a ratio of 1:1. A randomization list was designed by the manufacturers of the supplement and the placebo (Madaus SA) using a computer random-number generator in 20 blocks of 4 patients each. The details of the randomization codes were kept in sealed envelopes away from the investigators. Only in cases of the utmost necessity (eg, serious adverse events) did the coordinator of the study allow the investigator to know the treatment assigned to the patient.
The standardized toilet training procedures involved instructing parents and children on the most physiologic position for facilitating defecation (squatting). Parents also were instructed to modify their children's behavior through regular toileting (1015 minutes after each main meal) and positive motivational reinforcement. Unhurried time on the toilet after meals was recommended. Information about these standardized toilet training procedures was given to the family in writing.
The fiber supplement and the placebo were administered as a soluble powder in sachets of identical weight and presentation. Each sachet of the fiber supplement weighed 5.2 g and contained 4 g of cocoa husk and 1 g of betafructosans. The placebo sachets also weighted 5.2 g. These sachets contained glucose, cocoa flavoring, and excipients. Children who were aged between 3 and 6 years were instructed to take 1 sachet before lunch and 1 sachet before dinner. Children who were aged between 7 and 10 years were instructed to take 2 sachets before lunch and dinner. Parents were instructed to dissolve the content of the sachets in 200 mL of whole milk before ingestion.
The fiber supplement of cocoa husk contains 53.2 g of fiber (39.6 g of total fiber and 13.6 g of betafructosans) per 100 g of product. Insoluble fiber represents 37.2% and soluble fiber represents 2.4% of the total fiber (method of the Association of Official Analytical Chemists). Cellulose and uronic acids were the main type of insoluble fiber and soluble fiber, respectively.19
| METHODS |
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We chose CTT as the primary outcome measurement to verify the efficacy of the treatment. CTT was measured after the intake of 10 radio-opaque markers. No laxative treatment was allowed 10 days before the test, and when the child had fecal impaction on rectal examination, a cleansing enema was administered the day before the test to prevent retained feces from interfering with colonic transit. Children were instructed to swallow the markers with liquid at 9 AM for 6 days. Anteroposterior abdominal radiograph plain films were taken at 9 AM on day 7. CTT was calculated by counting the total number of markers on the plain abdominal radiograph. Segmental CTT was calculated using the number of markers in the 3 segments identified according to Arhan et al.20 The central point was the fifth lumbar vertebra. A line from the fifth lumbar vertebrae to the pelvic outlet was assigned to the right colonic segment. Another line from the fifth lumbar vertebrae to the anterior superior iliac crest was assigned to the left colonic segment. The distal part was the rectosigmoid area. To calculate the CTT, we used the modified Meatcalf formula: CTT = (sum of the markers x [time between administration ÷ number of markers ingested]) = sum of the markers x 2.4).21,22 Adherence to the intervention was evaluated by the same investigator using a visual analogic scale (in the case of standardized toilet training procedures) and counting the empty sachets that were returned to the investigator.
Statistical Methods
Because of the lack of previous studies to assess the effect of fiber supplements on intestinal transit time in children with chronic constipation and the likelihood of methodologic difficulties (in the evaluation of the main parameters) in carrying out a study on this kind of population, we designed a pilot study with a minimum sample from the statistical point of view. In this way, we were able to tackle these problems and find the best solutions for a future study involving a sample size calculated on the basis of these results.
Statistical analysis of the data was conducted using the statistical software package SPSS (version 12.0; SPSS, Inc, Chicago, IL). The results are expressed as mean ± SD or as a percentage. For comparisons between groups, the Mann-Whitney U nonparametric test was used for quantitative variables, and the
2 test was used for categorical variables. Changes in the parameters studied from the beginning to the end of intervention were calculated and compared between groups using an analysis of covariance model adjusted for basal values and group. The level of statistical significance was set at P < .05.
| RESULTS |
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Adherence to the standardized toilet training procedures (evaluated by a visual analogic scale from 0 to 10) in both groups was rated at the same level by the study investigators (
5 of 10) during the study intervention. Adherence to the supplements was very high. In both intervention groups, the children's families returned empty >80% of the supplement packages. No child failed to take the supplements on >3 consecutive days throughout the study.
Changes Produced After the Intervention
Total CTT decreased with both the cocoa supplement intervention (from 61.4 ± 34.1 to 43.6 ± 24.5 hours) and the placebo (from 71.5 ± 35.1 to 61.5 ± 39.6 hours), although the change difference (12.8; 95% confidence interval: 29.7 to 4.0) between groups was not statistically significant. With respect to total, partial colon, and rectum transit time, there seemed to be a trend, although statistically nonsignificant, toward faster transit times in the cocoa husk group than in the placebo group. However, when we analyzed the evolution of the intestinal transit time throughout the study of children whose total basal intestinal transit time was >50th percentile, significant differences were observed between the groups (Table 3). The total transit time decreased by 45.4 ± 38.4 hours in the cocoa husk group and by 8.7 ± 28.9 hours in the placebo group (38.1 hour; 95% confidence interval: 67.9 to 8.4; P < .015 for changes). In the case of the right colon, changes in transit time also were significant between groups (P = .014). Mean changes also were higher in the left colon and rectum, although the differences were not statistically significant.
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| DISCUSSION |
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Controlled clinical trials to evaluate the efficacy of fiber supplements on health are scarce in the pediatric population. Especially scarce are those that analyze the effect of fiber on constipation. Only 3 pediatric studies have shown the beneficial effect of a fiber supplement on this condition, and only 1 of these was performed in a healthy pediatric population such as ours. Tse et al23 examined the use of fiber to improve stooling in 20 constipated children with severe developmental disabilities. After increasing the fiber content of diet to an average of 21 g/day using All-Bran (Kellogg Company, Battle Creek, MI) and some desserts that are rich in fiber, relief of constipation and a significant reduction in the use of laxatives was demonstrated. In a recent double-blind, crossover study, Loening-Baucke et al1 found that glucomannan was beneficial in the treatment of constipation with and without encopresis in healthy children. Children who received a glucomannan supplement had more frequent and softer stools and responded better to laxative treatment.24 Unlike in our study, neither intestinal transit nor stool characteristics were measured. Staiano et al25 also demonstrated an improvement in stool frequency in a small sample of 20 neurologically impaired children after glucomannan supplementation but did not report any effect on CTT.
This is the first double-blind, randomized, controlled trial to evaluate the effect of a fiber supplement on CTT and the evolution of several symptoms of constipation in a pediatric population with chronic functional constipation. We considered CTT as the main primary outcome measurement for verifying the efficacy of the treatment because it is objective and correlates well with the pattern of defecation.26 Mean changes in total intestinal and partial colon and rectum transit times were greater in the cocoa husk group than in the placebo group, although significant differences between these 2 groups of children could not be demonstrated, possibly because total intestinal transit time varies enormously between individuals with constipation. In fact, Gutierrez et al22 reported a total CTT of 49.6 ± 25.4 hours (range: 16122) in constipated children compared with 29.2 ± 8.3 hours (range: 1450) in healthy children. Similarly, the upper limit of the total CTT reported by Zaslavsky et al27 in healthy nonconstipated children was 50 hours. In fact, when we analyzed the evolution of intestinal transit time throughout the study of children with prolonged total basal intestinal transit time (>50th percentile, or >51 hours), significant differences were observed between the groups. Total and right CTT decreased significantly more in the cocoa husk group than in the placebo group. Mean changes also were higher in the left colon and rectum, although the differences were not statistically significant. In view of these results, we suggest that children with idiopathic constipation and prolonged transit time are the ones who benefit most from dietary fiber supplements.
The action mechanism of fiber therapy on constipation largely has been attributed to increased fecal mass related to bacterial proliferation and fiber's inherent water-holding properties. However, mechanisms other than bulk must be involved because the therapeutic effect of fiber increases progressively over a period of several weeks,28 and, in some cases, fiber has no effect on stool weight when intestinal transit time decreases.29 Dietary fibers in fact modify several colonic functions such as (1) bacterial fermentation and metabolite absorption, including secondary bile acids, (2) gas and water concentration in the large bowel contents, and (3) intraluminal pressure. The therapeutic effects of dietary fibers therefore may derive from several of these factors as well as from unknown relationships between them that need to be explored in future studies. One limitation of our study is that we directly measured stool characteristics during a 3-day collection period, whereas other studies analyzed periods of 7 or more days. In our study, therefore, stool weights varied considerably between individuals. Some patients reported no stools, and others reported 2 large stools per day during the collection period. Only a few children volunteered to collect feces, and some of these reported incomplete stool collection, which makes it difficult to demonstrate significant changes in the weight or hydration of the feces as a result of treatment. In fact, we were unable to demonstrate any significant effect of treatment on these parameters and therefore cannot hypothesize that the decrease in intestinal transit time observed in this study can be explained by this mechanism.
In this study, we used the Rome II criteria to define chronic constipation in children. However, there is no consensus on the definition of chronic constipation. According to a recent study that compared the Rome II criteria and the classical definition of constipation,30 the Rome II18,31 definition is insufficient.32 New definitions were proposed recently by the North American Society of Pediatric Gastroenterology, Hepatology and Nutrition and the Paris Consensus on Childhood Constipation Terminology Group.33,34 If we used these new criteria, then all of the patients in this study would satisfy these new definitions.
Finally, we should point out that 1 of the main factors that limit the long-term efficacy of dietary fiber is the poor adherence to the supplements, especially in children. Several authors have reported poor subject compliance to fiber treatments11,35 because of the physical and organoleptic characteristics of the supplement and, in some cases, because of the adverse effects, such as abdominal pain or distension, excessive gas production, or diarrhea. In our study, no significant adverse effects were observed in relation to cocoa husk consumption. Moreover, adherence to this source of fiber was excellent, as high as adherence to the placebo supplement, and the number of dropouts was similar in both groups. This high level of compliance probably was helped by the supplement's chocolate flavor and its solubility in milk. However, long-term compliance to cocoa husk needs to be confirmed in future studies.
| CONCLUSIONS |
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| ACKNOWLEDGMENTS |
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We thank Alberto Ameijide for invaluable assistance in the statistical analysis and María Chine, MD, for technical assistance.
| FOOTNOTES |
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Address correspondence to Jordi Salas-Salvadó, MD, PhD, Unitat de Nutrició, Facultat de Medicina de Reus, C/Sant Llorenç, 21, 43201 Reus, Spain. E-mail: jordi.salas{at}urv.net
Financial Disclosure: Dr Salas-Salvadó has received consulting or lecture fees from Madaus Laboratories. Dr Anguera belongs to Madaus Laboratory.
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