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MNT: Disorders of Lipid Metabolism (2015)

Citation:

Woo J, Sea MMM, Tong P, et al. Effectiveness of a lifestyle modification programme in weight maintenance in obese subjects after cessation of treatment with Orlistat. J Eval Clin Pract. 2007; 13 (6): 853-859. doi:10.1111/j.1365-2753.2006.00758.x.

PubMed ID: 18070255
 
Study Design:
Randomized Controlled Trial
Class:
A - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:
To examine the efficacy of a lifestyle modification program in weight maintenance for obese subjects after cessation of treatment with Orlistat.
Inclusion Criteria:
  • Obese adults age between 18 and 50 years being treated at an outpatient clinic of a general hospital with or without type 2 diabetes mellitus
  • Met Asian criteria of obesity (BMI at least 25kg/m2).
Exclusion Criteria:
None specified.
Description of Study Protocol:

Recruitment

Recruited from an outpatient clinic of a general hopsital in Hong Kong.

Design

  • All participants finished a six-month treatment of Orlistat (120mg three times per day) to examine effect on weight, CVD risk, body composition, basal metaboli rate, dietary intake, physical activity and quality of life, prior to randomization (reported separately)
  • In this follow-on study, subjects were randomized to an intervention or control group. The intervention is described below and occured through six monthly visits. The control groups received no additional care but followed up three times during the six-month period.

Intervention

  • Six-month intervention was broken down into groups of five subjects and one nutrition educator (nutritionist), who met monthly
  • Strategies consisted of the following: Dietary management (diet knowledge, food labels, food exchanges, healthy cooking, healthing dining out, etc.), physical activity and exercise management and peer group support.
  • Each subject was provided an individualized eucaloric menu plan calculated by the measured BMR at the end of the Orlistat treatment (x1.4 to estimate total daily energy expenditure)
  • Diet plan was broken into three main meals (with snacks as desired) and consisted of 25% energy from fat, 55% from carbohydrate, 20% from protein and a maximum of 300mg of cholesterol and 2,400mg of sodium per day
  • Alcohol was limited to 150g or less per week
  • Physical activity recommendations: 30 minutes of aerobic exercise two to three times per week and walking 10,000 steps per day (given a Digi-Walker Yamax SW-700)
  • Activity was checked at each monthly visit
  • Peer group support and discussions at each visit focused on healthy lifestyle with techniques of self-monitoring, stimulus control and cognitive restructuring.

Statistical Analysis

  • Statistical Program for Social Sciences (SPSS, v.10.0) unpaired T-test was used for between-group changes pre- to post-test (six-month), between Intervention and Control Group and between diabetic and non-diabetic subjects
  • Paired student's T-test was used to compare baseline values for intervention groups with values before treatment with Orlistat.
Data Collection Summary:

Timing of Measurements

Baseline and six-month end-point.

Dependent Variables

  • Body weight, BMI, waist and hip circumference: Light clothing without shoes (nearest 0.1kg for weight, 0.5cm for height)
  • Body composition: DEXA (QDR 4500 A Hologic)
  • Basal metabolic rate: Indirect calorimetry (Delatrack, TM Datex)
  • Fasting glucose and glycated hemoglobin (HbA1c): Glucose oxidase method (Diagnostic Chemiclas Ltd kit) and automated ion-exchange chromatographic method (Bio-Rd Labs)
  • Fasting plasma total cholesterol, HDL-cholesterol, tryglyceride and calculated LDL-cholesterol: Enzymatic assay kits (Dimensions, Dupont Instruments)
  • Dietary intake: Local FFQ (food item, portion size, frequency on daily and weekly basis) with quantification of nutrients from food tables and charts (Hong Kong and China) 
  • Phyiscal activity levels: Validated questionnaire (duration and frequency of physical activity from sleeping, walking, running, etc. over one week). Calculated metabolic equivalents (MET) for each activity.
  • Quality of life: SF-36 (Chinese) questionnaire (higher scores indicate better quality of life) and ORWELL 97 questionnaire (higher scores indicate lower obesity-related well-being).

Independent Variables

  • Intervention vs. control group assignment
  • Diabetes or non-diabetes category.

Control Variables
None noted.

Description of Actual Data Sample:
  • Initial N: 55; 25 intervention (15 with T2DM); 28 non-intervention (15 with T2DM)
  • Attrition (final N): 55
  • Age: Between 18 and 55 years; mean age and other demographic data were reported in a previous publication
  • Ethnicity: Chinese
  • Other relevant demographics: All had BMI of at least 25kg/m2
  • Anthropometrics: No statistical significant difference between intervention and non-intervention groups in any measured parameter regardless of glucose tolerance status
  • Location: Hong Kong, China.
Summary of Results:

Key Findings

  • After six months, for all subjects in the Control Group (no further intervention), there was a significant increase in weight, BMI, waist and hip circumferences, body fat percentage, fasting glucose, triglycerides, total and LDL-cholesterol and daily total calorie, carbohydrate and fat intake
  • Subjects in the Intervention Group (followed by nutrition educator) maintained their previous loss in weight, waist and hip circumferences from the Orlistat treatment phase and decreased dietary, fat and carbohydrate intake
  • No difference between subjects with or without diabetes was observed.

The table below represents magnitude of change between the Intervention and Control Group after the Orlistat weight loss phase and thus reflects maintenance.

Variables

Intervention Group
Mean±SD

Control Group
Mean±SD
Weight (%) -0.15±0.35 3.3±0.47***
BMI (%) -0.15±0.14 3.2±0.27***
Waist Circumference (%) 0.19±0.23 3.0±0.73***
Hip Circumference (%) 0.17± 0.22 3.0±0.23***
DEXA Body Fat (%) 0.19±0.15 4.4±0.94***
Fasting Glucose (%) 9.2±10.3 25.9±12.8***
Total Cholesterol (%) 6.5±3.5 9.7±3.3***
Triglycerides (%) -3.9±2.7 19.3±7.9***
Energy Intake (kcal) -197±98 103±78**
Carb Intake (g) -17.3±112 7.9±3.7**
Fat Intake (g) -9.3±5.2 5.5±2.3*
Fiber Intake (g) 4.7±2.2 1.2±112*
Physical Activity (kcal) 209±112 -193±123*

 

 

 

 

 

 

 

 

 

 

*P<0.05;
**P<0.01;
***P<0.001.

Other Findings

  • Fiber intake increased in both groups
  • Physical activity increased in the Intervention Group but decreased in the Control Group
  • Quality of life (SF-36) scores significantly decreased for diabetes subjects in the Control Group, with no difference in change of the Orwell score between groups.
Author Conclusion:
  • A nutritionist-led lifestyle intervention program demonstrated effective weight maintenance and improvement in metabolic and CVD risk factor profile after cessation of Orlistat
  • Such a structured program may be incorporated into existing health serivces to improve weight-related health concerns.
Funding Source:
Industry:
Unrestricted Nutrition Grant from Bristol Myers Squibb/Mead Johnson, USA and unrestricted education grant from Roche (HK)
Pharmaceutical/Dietary Supplement Company:
Reviewer Comments:
  • Authors described sample demographics in previuos publication. Used Chinese obese category BMI of at least 25kg/m2 (captures both overweight and obese by US criteria).
  • Limitations addressed by author
    • Small sample size
    • Short duration (six-month)
    • Unknown if subjects are motivated to maintain change once study ends
    • Goals for weight maintenance may differ among genders.
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) Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
 
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? Yes
  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? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? No
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
3. Were study groups comparable? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) Yes
  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.) Yes
  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? N/A
  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.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? Yes
  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%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? N/A
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? N/A
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  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.) ???
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  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? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? Yes
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? N/A
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  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? N/A
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? Yes
  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? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  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)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? Yes
  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? N/A
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? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes