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MNT: Weight Management (2015)

Citation:

Jen KL, Djuric Z, DiLaura NM, Buison A, Redd JN, Maranci V, Hryniuk WM. Improvement of metabolism among obese breast cancer survivors in differing weight loss regimens. Obes Res. 2004; 12(2): 306-312. 

PubMed ID: 14981223
 
Study Design:
Randomized Controlled Trial
Class:
A - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To compare the efficacy of three weight loss regimens on body weight loss and metabolic improvement in breast cancer survivors during 12 months.

Inclusion Criteria:
  • Age between 18 to 70 years
  • BMI higher than 30.0kg/m2
  • Stage I cancer (tumor less than 2.0cm that did not spread) or stage II (tumor more than 2.0cm or tumor that had spread to auxiliary lymph nodes on the same side as the breast cancer)
  • Diagnosed within the past four years
  • Free of recurrence at the time of enrollment
  • No chemotherapy or radiation therapy (except tamoxifen) in the last three months.
Exclusion Criteria:

Not mentioned.

Description of Study Protocol:

Recruitment

Subjects were recruited through a direct mailing to Race for the Cure participants or with the use of local press releases and brochures at a breast clinic. 

Design
 

  • Randomized controlled trial.
  • Patients were randomly assigned into four groups:
    • Control
    • Weight Watchers
    • Individualized counseling
    • Comprehensive groups.  
  • Anthropometrics and biochemistry parameters were measured during the study. 

Blinding Used

Implied for laboratory measures.

Intervention

  • The control group received only the National Cancer Institute's "Action Guide to Healthy Eating" and  the "Food Guide Pyramid" pamphlets
  • The Weight Watchers group was provided with free coupons for weekly attendance at Weight Watchers meetings
  • For the individualized group, a registered dietitian provided weekly individualized one-on-one counseling for the first three months, bi-weekly for the next three months and monthly for the last six months. A monthly package information on various weight-loss topics was given to each subject in this group. They were also required to keep exercise and diet records.
  • The Comprehensive group received individualized dietary counseling plus free coupons for weekly Weight Watchers group meetings. Keeping diet and exercise records was required.

Statistical Analysis

  • ANOVA was used to analyze the baseline data and the changes from the baseline level among the four groups
  • When a significant result was obtained, least-square post-hoc test was used for multiple comparisons
  • Within each group, T-test was performed to identify the parameters that had significant changes from baseline to the end of 12 months
  • Relationships between two variables were calculated by Pearson's product moment correlations. The significance level was set at P<0.05. 
Data Collection Summary:

Timing of Measurements

Data collection visits, anthropometric measures and fasting blood samples were obtained at the baseline, three, six and 12 months. A three-day food record log was kept the week before these visits. 

Dependent Variables

  • Body weight (kg) 
  • BMI (kg/m2)
  • Body fat (percent)
  • Total cholesterol (mg per dL)
  • HDL-Cholesterol (mg per dL)
  • LDL-Cholesterol (mg per dL)
  • Total/HDL-Cholesterol (mg per dL)
  • Triglycerides (mg per dL)
  • Glucose (mg per dL)
  • Insulin (mcgU per ml)
  • Leptin (ng per ml).

Independent Variables

  • Control
  • Weight Watchers
  • Individualized counseling with RD
  • Individualized counseling plus Weight Watchers.

Control Variables

  • Energy intake
  • Fat intake
  • Age.

 

Description of Actual Data Sample:

Initial N

N=48 females.

Attrition (Final N)

  • N=39 females (81%). Only data obtained from women who completed the 12 months were calculated.
  • Dropouts:
    • Control group: One
    • Weight Watchers: Three
    • Individualized group: Four
    • Comprehensive group: One.
  • Reasons of dropouts:
    • Too busy
    • Lost interest
    • Other medical problems.

Age

Ages 18 to 70 years.

Other relevant demographics

The demographic characteristics have been reported previously. There was no noticeable difference in exercise patterns at baseline and during the study period, nor was there any difference among the four groups. Exercise data was not presented because of the large variability within each group.

Anthropometrics

There were no differences among the four groups in body weight and BMI at baseline. However, percentage body fat, total cholesterol and LDL-Cholesterol at baseline were significantly different among the groups.

Location

Wayne State University, Detroit, Michigan.

 

Summary of Results:

 

 

Group at Baseline and Changes from Baseline to the End of 12 Months of Four Groups of Subjects

 

Baseline

Changes from baseline to 12 months
Control Weight Watchers Individualized Comprehensive P Control          

Weight Watchers

 Individualized Comprehensive  P
Body weight (kg)  95±3.6 95.5±5 91.4±2.7 100.5±5 NS 1.1±1.7a  -2.7±2.1ac -8.0±1.9bc* -9.5±2.7b* <0.005
BMI (kg/m2)  34.9±1.2 35±1.2  35.5±1.1 36.8±1 NS 0.5±0.9a -1.5±1.0ac -3.0±1.3bc* -3.7±0.8bc*  <0.005
Body fat (percent)  38.2±0.7a 39.3±0.8a  39.8±0.8ac 41.4±0.8bc  <0.05 0.23±0.6a -0.99±0.08ac  -3.17±0.8bc -3.65±1.11.1b#  <0.05

Energy intake (kcal)

 2,246±183 2,106±213  1,812±101  1,899±128  NS  -145±179  -570±58#  -515±118*  -393±163* NS 
Dietary fat intake (percent) 32.8±2.6 33.7±1.7  34.8±1.8  29.5±2.2  NS  5.4±3.7*  -2.6±2.8*  -4.8±1.5*  0.9±3.4  NS 
Total cholesterol (mg per dL) 173±16a 267±31bc  222±13ac  193±14ac  <0.05  -16.4±18.2a -99.3±23.2bc# -59.2±15.4ac* -30.5±10.9a* <0.05
HDL-C (mg per dL) 32.2±6.5 32.2±3.9  46.6±3.9  38.6±5.1  NS  -2±9.1a -0.2±5.9a  -12.9±6.8a  17±6.0b*  <0.05
LDL-C (mg per dL) 111±14a 207±38b  139±11a  123±10a  <0.05  -22±15a  -102±30.2b*  -48.7±14.7a*  -47±9.1a# 

<0.05 

Numbers with different superscripts were significantly different from each other.

*Significantly different from its baseline value at P<0.05; #Significantly different from its baseline value at P<0.01

 Other Findings

  • Subjects in the three intervention groups lost weight (Control: 1.1±1.7kg; Weight Watchers: -2.7±2.1kg; Individualized: -8.0±1.9kg; Comprehensive: -9.5±2.7kg) and percentage body fat, but only the Individualized and Comprehensive groups had significant losses
  • Subjects in the Comprehensive group showed the most improvement in cholesterol levels and had reductions in blood leptin levels
  • The changes in triglycerides, glucose and insulin levels were not different among the groups and not different from their respective baseline levels. Insulin resistance was similar at baseline and the changes were also similar at the end of 12 months among the groups.
  • Leptin levels were reduced only in the comprehensive group when compared with their baseline values; P<0.05
  • The amount of changes in the body weight after 12 months were positively correlated to the changes in the BMI (R=0.99, P<0.001), body fat percentage (R=0.67, P<0.001), dietary fat percentage (R=0.34, P<0.01), energy intake (R=0.46, P<0.01), blood insulin (R=0.75, P<0.05) and leptin levels (R=0.71, P<0.001)
  • Women who lost more than 10% of body weight weighed less (P<0.05), had lower BMI (P<0.01), reduced body fat percentage (P<0.001), consumed fewer calories and dietary fat percentage (P<0.05), had higher HDL-C (P<0.005) and greatest reduction of triglycerides (P<0.01). They also had a reduction of leptin levels compared with women who lost less than 10% of body weight (P<0.001).

 

Author Conclusion:

Individualized counseling combined with attending weekly Weight Watchers meetings was most effective in reducing body weight and fat, energy intake, total cholesterol, LDL-Cholesterol and leptin levels. Because both body fat and blood leptin levels have been associated with breast cancer, weight loss by a comprehensive approach, including individualized nutrition counseling and group meetings, should be encouraged.

Funding Source:
Government: National Cancer Institue
Industry:
The Ford Motor Co.
Other:
In-Kind support reported by Industry: Yes
Reviewer Comments:

Percentage body fat, total cholesterol and LDL-Cholesterol at baseline were significantly different among the groups. The results are based only on patients who finished the intervention period. Because of this, it seems that these specific set of subjects were more self-motivated to adhere the weight loss regimens. Small sample size increases the risk for type 2 error.

 

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? Yes
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? No
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? No
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) Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? No
  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? No
  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? No
  4.4. Were reasons for withdrawals similar across groups? ???
  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? Yes
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? ???
  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.) Yes
  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)? No
  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? 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? Yes
10. Is bias due to study's funding or sponsorship unlikely? ???
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? ???