• Increase Font Size
  • Decrease Font Size
  • View as PDF

FNOA: Assessment of Overweight/Obesity (2012)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

To test the hypothesis that in a population cohort, the baseline DXA-determined "barrel build" of combined high trunk/total fat and low-limb fat mass would be associated with an increased 10-year cardiovascular mortality.

Inclusion Criteria:
  • Resident of Malmo, Sweden
  • Aged between 20 and 89 years
  • Underwent a total body DXA scan.
Exclusion Criteria:
  • Aged less than 20 years or greater than 89 years
  • Unable to obtain total body DXA scan.
Description of Study Protocol:
  • Recruitment: Unclear how subjects were recruited for inclusion in the study
  • Design: Prospective cohort study
  • Blinding used: Assumed in measurements
  • Intervention: Not applicable
  • Statistical analysis: Mortality rates were compared between groups by chi-square analysis for fat plane body composition profiles and by the Fisher exact test for the single variable profiles. Odds ratios for mortality and survival were calculated with 95% confidence intervals from 2x2 tables.
Data Collection Summary:

Timing of Measurements

  • Physical exam, DXA scan and questionnaire completed at baseline
  • Vital status was obtained from the Swedish national registry after 10 years of observation.

Dependent Variables

  • All-cause mortality (Swedish national registry)
  • Cardiovascular cause-related mortality (Swedish national registry).

Independent Variables

  • Body composition profiles (DXA scan: Based on bone mineral content, soft tissue mass, fat mass for the total body, arms, legs and trunk)
  • Weight, height (measured)
  • Gender
  • Age.
Description of Actual Data Sample:
  • Initial N: 324 (173 women, 151 men)
  • Attrition (final N): 324 completed the study; 116 subjects, aged 50 years to 74 years at baseline, were used for the analysis
  • Age: 20 years to 89 years at baseline
  • Ethnicity: Swedish
  • Other relevant demographics: None reported.

Anthropometrics 

Four body composition profiles were tested:

  • "Avocado" (low trunk fat, high limb fat): N=35
  • "Pickle" (low trunk and limb fat): N=23
  • "Mango" (high trunk and limb fat): N=19
  • "Barrel" (high trunk, low limb fat): N=39.

Three single variable profiles were also tested:

  • "Apple" (high trunk fat): N=50
  • "Pear" (high limb fat): N=54
  • "Soft" (low skeletal muscle mass): N=54.

Location

Malmo, Sweden.

Summary of Results:

Key Findings

  • Mortality differed for the fat plane quadrant body composition profiles with a significant excess mortality among the "barrel" profile (13/39 deceased, 33.3%; P=0.019)
  • Total mortality was significantly increased for the single variable profile "soft" (sarcopenia, lower than average skeletal muscle mass; 14/54 deceased, 25.9%; P=0.054)
  • Odds ratios for mortality were significant for the "barrel" body composition profile (OR, 3.2; 95% CI, 1.4 to 7.1) and borderline significant for soft (OR, 2.3; 95% CI, 1.0 to 5.3)
  • Significant excess mortality from cardiovascular cause was noted with the "barrel" profile (8/13 deaths, 72.7%; P=0.041) as well as the single variable profile "apple" [higher than average truncal body fat (includes both "barrels" and "mangos"); 9/14 deaths, 75.0%; P=0.02).

Other Findings

Relative prevalence of body composition profiles did not differ significantly between age groupings (less than 50 years, 50 to 75 years, at least 75 years).

Author Conclusion:
  • Truncal fat distribution is important for predicting the cardiovascular and metabolic consequences of obesity
  • The "barrel" DXA-derived body composition of high trunk fat, in conjunction with low limb fat mass, is associated with increased mortality, predominately from cardiovascular causes
  • Increased 10-year mortality with the "barrel" body composition has an observed significance level similar to relative mortality for metabolic syndrome and low fitness level, as seen in other studies
  • Increased mortality for the "barrel" body composition was statistically significant despite largely normal BMI (24.0±2.4kg/m2)
  • Sarcopenia ("soft" or lower than average skeletal muscle mass) was associated with an overall increased mortality rate (but not cardiovascular mortality).
Funding Source:
University/Hospital: Northpointe Health Center, Berkley, MI; William Beaumont Hospital, Royal Oak, MI; Wayne State University; Malmo University Hospital, Malmo, Sweden
Reviewer Comments:
  • Recruitment methods unknown: Cannot rule out a convenience sample
  • Small sample size for each body composition profile
  • No demographics reported
  • No health information reported, including traditional cardiovascular risk factors or comorbid conditions.
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? 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) 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? 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? 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? ???
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? Yes
  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? Yes
  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? Yes
  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.) Yes
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? Yes
  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? N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? Yes
  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? No
  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? No
  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)? 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? 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