EAL

H/A: Caloric Needs (2007)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To investigate whether the hormones modulating adipose tissue metabolism could be implicated in the development of body-fat alterations.

Inclusion Criteria:

None specifically mentioned
Body modifications included an increase of abdominal girth in all cases.

Exclusion Criteria:

None specifically mentioned
No patient was taking corticosteroids, androgens or any other drug known to alter metabolism, nor was affected by any recent opportunistic infection or malignancy.

Description of Study Protocol:

Recruitment

Patients consecutively referred to the Department of Endocrinology between January and June 1998, due to alterations of their body appearance over the previous months.

Design

Case-control study.

Statistical Analysis

Comparisons between numerical variables were assessed by Student's T-test
Correlations were assessed by simple linear regression after the completion of the Kolmogorov-Smirnov goodness of fit test.

Data Collection Summary:

Timing of Measurements

Measurements made in cases and controls and compared.

Dependent Variables

Weight, height, BMI
Body composition assessed by bioelectrical impedance analysis
Subcutaneous and visceral compartments of total adipose tissue were measured by computed tomography
RMR assessed by indirect calorimetry
Endocrine investigations included plasma thyroid hormones, cortisol, testosterone, estradiol and 24-hour urinary free cortisol and catecholamines.

Independent Variables

Body fat redistribution.

Description of Actual Data Sample:

Initial N: 28 HIV-infected patients, 12 HIV-infected controls
Attrition (final N): 28 cases (18 male, 10 female), 12 controls (six male, six female)
Mean age

Cases: 40.5±9.9 years
Controls: 38.0±8.3 years.

Ethnicity: Not mentioned
Anthropometrics: Controls were matched for age, disease duration, CD4 count and plasma HIV-1-RNA level
Location: France.

Summary of Results:

	Cases (N=28)	Controls (N=12)	P-Value
BMI	22.8±2.8	22.5±2.9	NS
Fat free mass (kg)	53.5±8.8	50.6±11.5	NS
Fat mass % - men	17.3±3.3	19.0±4.0	NS
Fat mass % - women	22.5±5.6	26.7±4.1	NS
Total adipose tissue (cm2)	248±103	230±108	NS
Visceral adipose tissue (cm2)	122±57	69±35	P=0.002
Subcutaneous adipose tissue (cm2)	127±90	161±87	NS
Visceral:total adipose tissue ratio	0.52±0.19	0.30±0.11	P=0.0001
RMR (kJ/d)	7,598±1,141	6,910±1,354	NS
Estimated basal EE (kJ/d)	6,358±766	6,274±999	NS

Other Findings

Despite similar BMI, the patients with body-fat alterations showed significantly larger visceral adipose tissue (P=0.002) and higher visceral-to-total adipose tissue ratio (P=0.0001) than controls
In these patients, RMR was significantly higher than estimated, according to the Harris-Benedict formula (+19.7±11.6%, P=0.0001) and correlated with visceral adipose tissue (R=0.58, P=0.003) and 24-hour urinary output of catecholamines (R=0.67, P=0.002) that was significantly increased, in comparison with controls (1,737±1,228 vs. 476±292nmol, P=0.013)
There was also a significant correlation between visceral adipose tissue and 24-hour urinary-free cortisol (R=0.41, P=0.042) that was absent in controls, although levels of 24-hour urinary-free cortisol were similar in the two groups.

Author Conclusion:

Our data suggest that body-fat redistribution may involve cortisol and catecholamine actions
While high release of catecholamines may enhance RMR through increased lipolysis, cortisol may promote central fat storage and these effects might be related both to persistent hormonal responses to stress becoming inappropriate while disease control improved and to an increased sensitivity of visceral adipose tissue to cortisol in affected patients.

Funding Source:

Reviewer Comments:

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?		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)	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?	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.)	Yes
	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?	N/A
	5.4.	In case control study, was case definition explicit and case ascertainment not influenced by exposure status?	Yes
	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?		N/A
	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?	N/A
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	N/A
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	N/A
	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)?	N/A
	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?	No
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