SCI: Physical Activity (2007)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To assess the effectiveness of a modified weight management program in various health outcomes over a 6-month period.
Inclusion Criteria:
  • Age 19 years or older
  • Traumatic or nontraumatic SCI for more than 1 year
  • BMI ≥ 25 kg/m2
  • Not currently enrolled in a weight loss program, receiving weight loss medication, or taking medication that would influence weight change.
Exclusion Criteria:
Pregnancy or concurrent medical conditions for which changes in exercise or diet would be contraindicated.
Description of Study Protocol:

Recruitment

Subjects were recruited at the community level.

Design

  •  Four cohort groups (including the pilot test group) were established between 2001 and 2003.

Blinding used (if applicable)

Information obtained previously was blind to data collectors at each assessment visit.

Intervention (if applicable)

  • Once a week for 12 weeks, participants and their spouses or attendents attended a 90-min group class primarily lead by a registered dietitian. These classes were intended to increase the knowledge of nutrition and exercise on weight control, setting goals on weight reduction, provide skill training on change of health behaviors, and enhance social support. 
  • In week 6, a 30-min exercise session of home-based exercise for persons with SCI was incorporated into each weekly class. Importance of injury prevention, body temperature regulation, and monitoring exercise intensity was reviewed.
  • Psychologists were consulted for stress management, relaxation techniques, problem-solving, and behavior change strategies.

Statistical Analysis

  • Paired t-tests or equivalent nonparametric method (Wilcoxon's signed rank sum test) were used to determine significance of change between initial and follow-up assessments in each of the health outcomes. 
  • The association of weight change with participants' characteristics and other health outcomes was examined by the Pearson's correlation analysis. A correlation coefficient greater than 0.40 or less than -0.40 was considered as important association regardless of the significance level.
  • No adjustment was made for multiple comparisons in the analysis. A probablility of < 5% was considered to be statisitcally significant.
Data Collection Summary:

Timing of Measurements

  • A face-to-face interview was conducted on the initial visit to obtain information on sociodemographic characteristics, weight history, medical history and medication use.
  • Data on health outcomes were collected over a 6-month period: at baseline, week 12 (immediately after intervention), and week 24 (12 weeks after intevention).
  • Body weight was measured to the nearest 0.1 kg on a scale adapted to wheelchairs.  Participants were asked to wear light clothing and no shoes for these measures.
  • Height was measured to the nearest 0.1 cm in a supine postion with legs outstretched and feet in dorsiflexion.
  • Measurements of waist and neck were taken to the nearest 1mm in the sitting position using a nonstretchable tape measure.
  • Skinfold thickness was examined over chest, biceps, triceps, subscapula, and suprailiac on the right side of the body by the same researh personnel throughout the 6-month period according to standard procedures.
  • Dual energy X-ray absorptiometry (DXA) was used to estimate fat mass, lean mass, and bone mineral content (not performed onthe pilot test group).
  • Blood pressure was taken on the left arm with a mercury manometer after the subject had been sitting quietly for 10 min.
  • Serum lipids were determined in venous blood sample using standardized laboratory techniques.
  • Hemoglobin and albumin were monitored to assess the nutritional safely of the intervention.
  • Usual food intake was measured by the Health Habits and History Questionnaire developed by the National Cancer Institute.
  • Subjective feelings of wellness and distress during the last month were assessed by the General Well-Being Schedule.

Dependent Variables

  • Body Mass Index (kg/m2)
  • Body Composition (kg)
  • Anthropometrics to include waist and neck circumferences (cm) and skinfold thickness (mm)
  • Blood pressure (mmHg)
  • Lipid profile (mg/dL) to include total cholesterol, HDL and LDL-cholesterol
  • Safety profile to include Hemoglobin (gm/dL0 and albumin (mg/dL)
  • Diet behaviors to include total calories (kcal/d), saturated fat (gm/d), cholesterol (gm/d), fiber (gm/d), confidence of weight control, self-rated knowledge of nutrition, self-rated nutritional quality of diet, self-rated eating habit
  • Psychological and physical functioning to include general well-being schedule, troubled by heartburn, difficulty transferring, difficulty putting on/taking off clothing, don't feel sexually attractive, self-esteem not what it should be, duration of bowel program (min)

Independent Variables

  •  Weight management program participation 

Control Variables

 None noted

Description of Actual Data Sample:

Initial N: 17 (9 males, 8 females)

Attrition (final N): 16 (9 males, 7 females) at 12 weeks, 13 participants at 24 weeks.

Age: Mean 43.8 years (range 21.0 - 66.0 years)

Ethnicity: white 13 (81%), African American 3 (19%)

Other relevant demographics:

15 subjects had traumatic SCI , 1 had spina bifida

Marital status: Married or living as married 6 (37.5%), divorced 6 (37.5%), never married 4 (25%)

Education: High school graduate or less; 5 (31%), some college or technical school; 6 (38%), College graduate or higher; 5 (31%)

Employment status: Employed; 6 (38%), retired; 5 (31%), student; 2 (12%), unemployed; 3 (19%)

Family history of overweight/obesity: yes; 11 (69%), No; 5 (31%)

Level of injury: tetraplegia; 4 (25%), Paraplegia; 12 (75%)

ASIA Impairment Scale: A; 9 (56%), C; 3 (19%), D; 4 (25%)

Years since injury: mean 17.5 years (range 1.7 - 60.3 years)

Anthropometrics

One subject had spina bifida as compared to traumatic SCI

Location:

 University of Alabama at Birmingham, Birmingham, Alabama

Summary of Results:

 

Variables

Change in mean ± SD  at weeks

p

Change in mean ± SD at 24 weeks

p

Weight

-3.5 ± 3.1 0.0004

 -2.9 ± 3.7

 0.01

BMI

 -1.3 ± 1.2

 0.0005

 -1.1 ± 1.4

 0.01

Total fat mass

 -2.9 ± 4.6

0.05 

 -2.2 ± 1.8

 0.007
Waist circumference  -4.1 ± 5.0  0.005  -3.3 ± 5.2  0.04
Neck circumference  -.0.9 ± 1.4  0.02  -1.1 ± 2.1  0.08
Skinfold thickness  -10.7 ± 9.7  0.0005  -13.2 ± 10.6  0.0007
HDL cholesterol  -3.2 ± 5.4  0.03  -0.9 ± 5.4  0.59
Total Calories  -219.5 ± 664.1  0.21  -315.8 ± 567.2  0.07
 Saturated fat  -8.7 ± 10.9  0.006  -5.6 ± 8.1  0.03
Cholesterol  -77.2 ± 78.3  0.001  -39.7 ± 86.0  0.12
Fiber (gm/d)  7.6 ± 7.2  0.0007  3.1 ± 6.8  0.13
Confidence of weight control  1.1 ± 1.1  0.002    
Self-rated knowledge of nutrition  0.6 ± 0.7  0.01    
Self-rated nutritional quality of diet  0.9 ± 0.9  0.002    
Self-rated eating habit  0.6 ± 0.6  0.006    
Troubled by heartburn  -0.9 ± 1.2  0.008  -0.3 ± 0.5  0.13
DIfficulty transferring  -1.1 ± 1.3  0.004  -1.1 ± 1.3  0.02
Difficulty putting on/taking off clothing  -0.9 ± 1.2  0.02  -0.9 ± 1.0  0.02
Self-esteem not what it should be  -1.0 ± 1.0  0.02  -0.6 ± 1.2  0.13
Duration of bowel program (min)  -27.5 ± 86.1  0.004  -22.5 ± 96.0  0.48

Weight loss averaged 3.5 ± 3.1 kg at week 12 and 2.9 ± 3.7 kg at week 24. There was a significant reduction from baseline values at weeks 12 and 24 in BMI, anthropometric measurements, and fat mass and improvement in diet behavior and psychosocial and physical functioning, while lean mass and albumin and hemoglobin levels were maintained. Correlation analysis showed that a greater weight loss was associated with a greater reduction in total cholesterol at 12 and 24 weeks and in systolic and diastolic blood pressure at week 24. Age, race, marital and employment status, family history of overweight/obesity, level and duration of injury, and cholesterol level at baseline were associated with success in weight loss.

Other Findings

Success in maintaining weight below the initial level at week 24 was importantly associated with being older (r=-0.45), of longer duration postinjury (r=-0.49), tetraplegic (r=-0.42), employed full-or part-time (r=-0.45), without family history of overweight/obesity (r=-0.46), and with lower total or  LDL- cholesterol level at baseline (r=-0.53 and r=-0.46, respectively).  Only LDL-cholesterol reached significance (p=0.04).

Author Conclusion:
A carefully planned program with time-calorie displacemnt dietary approach is effective for overweight/obese individuals with SCI to lose weight at an acceptable rate without compromising total lean mass and overall health.
Funding Source:
Government: NIDRR, NIH
Reviewer Comments:
  • There was no control or comparison group to determine if participants would have responded in the same manner if there had been no intervention or an intervention just on nonspecific factors such as group support and attention from professionals.
  • The sample was selective with a high education level.
  • The model precluded persons from participation who could not travel to the clinic once a week for 12 weeks.
  • The program may need modification for socio-culturally diverse groups.
  • A large variation in measurements was observed in a small sample size therefore the precision for the estimate of the effect sizes was decreased.

 

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? 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? Yes
  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) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) No
  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? ???
  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? Yes
  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? N/A
  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