Pediatric Weight Management

Pediatrics and Physical Activity

Citation:

Sasaki J, Shindo M, Tanaka H, Ando M, Arakawa K. A long-term aerobic exercise program decreases the obesity index and increases the high density lipoprotein cholesterol concentration in obese children. Int J Obesity 1987;11(4):339-45.

 
Study Design:
Non-Randomized Controlled Trial
Class:
C - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:
To study effects of long-term supervised moderate aerobic exercise therapy in obese children.
Inclusion Criteria:

Obese boys and girls living in Kitakyushu, Japan area and voluntarily participating in the aerobic exercise therapy class at Kokura Elementary School for obese children at the age of 11.

Criteria of obesity based on obesity index – having 20% excess of average body weight; average weights obtained from standard height and weight charts for Japanese school children (Ministry of Education and Welfare, 1984).

Exclusion Criteria:
None specified
Description of Study Protocol:

Non-obese age and sex matched controls obtained from same school; mean height and body weight comparable with average Japanese children at same age.

Intensity of aerobic exercise therapy determined for each individual by measuring running velocity at blood lactate threshold (VLT) predicted from 5 minute running performance. Blood samples for blood lactate determination obtained from ear lobe immediately after every exercise period.

Both obese and non-obese children had regular school program including school lunch; additional special exercise for obese children only.

2 year exercise program was almost 100% aerobic exercise; consisted of running for 20 minutes, four times a week in the morning and three times a week in the afternoon for two years. Gymnasium exercise consisting of skipping, jumping, muscle strengthening, and some calisthenics involved in every afternoon running program.

Running supervised by two physical education instructors.

Running velocity kept constant for 4 weeks and then readjusted every 4 weeks based on results of 5 minute run; total running distances for 1 year about 400-900 km.

Calorie expenditure of approx. 300 kcal/day estimated for the exercise program.

All subjects advised to maintain previous exercise habits.

No dietary intervention made throughout study.

Average caloric intake at entry was 1990 kcal/day and at end of first year was 1970 kcal/day.

Serum lipoprotein analysis done every March.

Statistical Analysis

Two-tailed Student’s t-test.

Data Collection Summary:

Dependent Variables

Fat and lean body mass (measured by skinfolds); maximal oxygen uptake (measured by submaximal bicycle ergonometer test with Monark ergonometer); obesity index (20% in excess of average body weight); serum lipoprotein levels, including total cholesterol (TC), triglyceride (TG), free fatty acid (FFA), high density lipoprotein cholesterol (HDL-C).

Independent Variables

Additional special exercise program or regular school program.

Control Variables

Age, sex

Description of Actual Data Sample:

Original Sample: 41 obese children (21 boys, 20 girls) selected for treatment; 19 non-obese controls from same school

Withdrawals/Drop-Outs: None.

Final Sample: 41 obese children (21 boys, 20 girls); 19 non-obese controls (12 boys, 7 girls).

Location: Kitakyushu, Japan

Race/Ethnicity: Japanese

SES: Not specified.

Summary of Results:

Body fat decreased by 40% for boys, 31% for girls after 1 year of training.

Lean body mass increased 29% for boys, 37% for girls after 1 year of training.

Maximal oxygen uptake (for 6 boys and 6 girls) increased from 1.76 l/min to 2.11 l/min after 1 year training.

Mean obesity index at entry was 39%; 36.8 +/- 3.8% for boys and 41.2 +/- 4.9% for girls. In obese children, obesity index decreased significantly within 1 year of exercise therapy by 55% in obese boys and 48% in obese girls. Little but further decrease in obesity index found during second year.

Exercise resulted in increases in HDL-C levels of 16% in boys and 19% in girls within 1st year; in second year, HDL-C levels decreased for boys and girls, but remained significantly higher than initial levels.

No significant change in TC observed in either boys or girls; TG concentration tended to decrease during training and was decreased significantly (33%) in girls by second year.

Significantly decreased concentration of FFA observed in boys during both years and in girls in the second year compared with entry values.

(Obese children had similar TC, TG, HDL-C at entry compared to controls)

In control group, body height and body weight increased properly, but no significant differences in obesity index, TC, TG and HDL-C observed.

Author Conclusion:

Study results demonstrate that supervised aerobic exercise program for obese children performed as part of the regular school life over 2 years is effective in decreasing the obesity index.

Overall compliance to the program close to 100%.

Dietary factor for decrease in obesity index is unlikely in this study; conclude that long-term regular aerobic exercise is effective in loss of body weight in obese children.

In addition, increased HDL-C, decreased TG and FFA observed.

Difficult to assess whether weight reduction or exercise responsible for increased HDL-C levels, but both factors may have contributed.

Funding Source:
University/Hospital: Fukouka University
Reviewer Comments:

Strengths:

Long study duration

Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) N/A
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? N/A
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? N/A
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) N/A
 
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? ???
2. Was the selection of study subjects/patients free from bias? ???
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? ???
  2.2. Were criteria applied equally to all study groups? ???
  2.3. Were health, demographics, and other characteristics of subjects described? ???
  2.4. Were the subjects/patients a representative sample of the relevant population? ???
3. Were study groups comparable? ???
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) ???
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? ???
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) ???
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? ???
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) ???
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? No
4. Was method of handling withdrawals described? No
  4.1. Were follow-up methods described and the same for all groups? No
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) No
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? No
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? No
5. Was blinding used to prevent introduction of bias? No
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? No
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) No
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? No
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? No
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? ???
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? ???
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? ???
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? ???
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? ???
  6.6. Were extra or unplanned treatments described? ???
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? ???
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? ???
  7.2. Were nutrition measures appropriate to question and outcomes of concern? ???
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? ???
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? ???
  7.5. Was the measurement of effect at an appropriate level of precision? ???
  7.6. Were other factors accounted for (measured) that could affect outcomes? ???
  7.7. Were the measurements conducted consistently across groups? ???
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? ???
  8.1. Were statistical analyses adequately described and the results reported appropriately? ???
  8.2. Were correct statistical tests used and assumptions of test not violated? ???
  8.3. Were statistics reported with levels of significance and/or confidence intervals? ???
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? No
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? No
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? No
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? ???
10. Is bias due to study's funding or sponsorship unlikely? ???
  10.1. Were sources of funding and investigators' affiliations described? ???
  10.2. Was the study free from apparent conflict of interest? ???