Impact of Liraglutide 3.0 on Body Fat Distribution: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Impact of Liraglutide 3.0 on Body Fat Distribution (NCT03038620), a randomized phase 4 study. The primary outcome is Relative Percent Reduction in Visceral Adipose Tissue Mass Measured by MRI.

2. Clinical Question

The primary endpoint is reported separately for each group among participants with interpretable scans at both assessment times. The registry does not post a comparative effect estimate or a p-value for this primary outcome. Therefore, the arm-level results describe each group’s observed mean and its confidence interval, but do not by themselves provide the registry’s formal estimate of the between-group contrast. The enrollment figure describes the study overall; it is not the number contributing to the primary endpoint.

3. Trial Design

This was a phase 4, randomized, quadruple-masked, parallel-group study sponsored by the University of Texas Southwestern Medical Center. The registry lists 235 participants as enrolled and records the study status as completed. The study began in 2017-01, and its primary completion date was 2020-10-13. These record-level details describe the trial’s design and chronology, but do not establish how many participants were assigned to each group or completed every study procedure.

The active group received liraglutide 3.0 mg, with dose escalation from 0.6 mg/day in weekly 0.6 mg/day steps over a 4 week period, by subcutaneous injection. The comparator was placebo. The study summary describes assessment of visceral adiposity measured by MRI after 40 weeks on treatment. The primary endpoint record specifies measurements at baseline and 40 weeks.

Randomization and masking are important design features, but the registry record does not provide the allocation ratio, the sequence-generation method, the concealment procedure, or details about who was masked. It also does not report the protocol’s sample-size justification, recruitment targets by group, or rules for treatment discontinuation. Those design details should not be inferred from the total enrollment or from the endpoint sample counts.

The primary endpoint population consisted of participants who completed the study endpoint assessment and had interpretable MRI at both baseline and study end. The reported arm sizes for this endpoint were 73 for liraglutide and 55 for placebo. The adverse-event record lists 92 participants at risk in the liraglutide group and 93 in the placebo group. These are different analysis populations for different purposes; the registry does not explain the participant flow that produced them.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Those who completed study endpoint assessment (interpretable MRI at baseline and at study end).

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

Population: Participants analyzed if they completed an endpoint assessment and had interpretable imaging data.

6. Primary Endpoint

The registry lists the primary outcome as Relative Percent Reduction in Visceral Adipose Tissue Mass Measured by MRI, measured over Baseline, 40 weeks.

The primary endpoint was relative percent reduction from baseline in visceral adipose tissue mass measured by MRI, with assessments at baseline and 40 weeks. The registry defines positive values as a reduction from baseline expressed as a percentage of the baseline value. In this convention, a value near zero represents little average change, while a negative value represents an increase rather than a reduction.

MRI provides an imaging-based measurement of visceral adipose tissue, the fat depot named in the endpoint. The endpoint is a continuous measure, and the registry reports a mean for each group with a 95% confidence interval. The endpoint is restricted to participants with interpretable MRI at both assessment times, so its results describe that assessed population rather than necessarily every enrolled participant.

The registry states that reduction in this variable is believed to be associated with lower cardiovascular risk. That statement gives the biological and clinical motivation for measuring visceral adiposity, but the endpoint itself is not a cardiovascular event, a diagnosis, or a direct measure of long-term risk. The registry record does not report a direct cardiovascular outcome as the primary endpoint. It also does not report the instrument’s detailed MRI acquisition or image-reading procedures.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry reports the primary endpoint as a mean with a 95% confidence interval for each group. The endpoint is continuous: it is a numerical measure of relative percent reduction in visceral adipose tissue mass. A mean gives a group-level summary, while the confidence interval conveys uncertainty in that estimated mean. It does not describe the full spread of individual participant values. The registry does not give a standard deviation for the primary endpoint.

What does the confidence interval communicate?

In general, a confidence interval is a range of estimates compatible with the observed data under the statistical method used. A narrower interval indicates greater precision for the quantity being estimated; a wider interval indicates less precision. The primary record’s intervals are for separate arm means, not for the difference between arms. Separate intervals cannot be treated as a direct test of the between-group contrast. The registry record does not report a primary contrast interval or p-value, and its statistical plan is not reported in the registry record.

How should the direction of the endpoint be read?

The registry defines positive primary endpoint values as reductions from baseline and negative values as increases. This sign convention is essential: a larger positive value denotes a larger reduction on this measure, while a value below zero is not a reduction. The endpoint is relative percent reduction, so its unit is a percentage of reduction in visceral adipose tissue. It is not the absolute amount of tissue removed or a percentage change in cardiovascular events.

What are the secondary recalculations?

For selected secondary continuous outcomes, unadjusted recalculations use the posted arm means, standard deviations, and sample sizes to estimate a difference in means and its confidence interval. These are simple summaries from posted statistics, not analyses listed by the sponsor. Their p-values are unadjusted, meaning no adjustment for testing multiple outcomes is incorporated into those reported calculations. The registry lists zero reported analyses for these secondary outcomes. The sponsor’s own analysis takes precedence if a discrepancy is flagged; no discrepancy is flagged for the posted results.

A standard deviation describes how dispersed participant values are around a group mean. It differs from the standard error, which describes the precision of an estimated mean. General statistical principle: increasing variation among participants tends to make a group mean less precisely estimated if the sample size is unchanged. The secondary outcomes report standard deviations, while the primary endpoint record reports confidence intervals instead.

What do the planning illustrations mean?

Sample-size illustrations based on secondary outcomes are planning exercises, not observed trial results and not observed power. They use a two-sided significance level of 0.05, equal allocation between two groups, a normal approximation, and a target effect defined as a stated fraction of the observed effect. The resulting figures are participants per arm for 80% power or participants per arm for 90% power under those assumptions. For example, the visceral adipose tissue volume illustration gives 20 participants per arm for 80% power when planning for 100% of the observed effect, and 35 participants per arm for 80% power when planning for 75% of the observed effect. Such calculations are sensitive to the assumed effect and variability. They do not show the probability that the completed trial detected an effect, and they do not establish the trial’s original design rationale.

General statistical principle: smaller assumed effects usually require larger samples to distinguish them from random variation at a specified error threshold, all else equal. The illustrations are not the protocol’s sample-size justification; that justification is not reported in the registry record. The assumptions also do not establish that the trial’s actual allocation, analysis method, missing-data handling, or endpoint population matched the planning illustration.

Why does over-dispersion matter?

General explanation: over-dispersion occurs when observed variation is greater than a statistical model expects. If a method assumes less variability than is actually present, it can understate uncertainty and make estimates appear more precise than warranted. The posted outcomes are continuous, and their secondary summaries include standard deviations. The record does not state that over-dispersion was assessed or that a specialized variance model was used. The term should therefore be understood as a general statistical consideration, not a reported feature of this trial.

10. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when a study evaluates more than one outcome or makes multiple statistical comparisons. Even if each unadjusted test uses the same significance threshold, looking across many tests can increase the chance that at least one appears statistically notable by chance. General statistical principle: adjustment procedures or a prespecified testing hierarchy can help control that risk, but their use and the hierarchy need to be documented to interpret results accurately.

The registry lists 37 outcome measures and reports 35 secondary outcomes as posted. The record does not report a multiplicity adjustment, a hierarchical testing sequence, or which secondary outcomes were confirmatory. The displayed secondary p-values are unadjusted recalculations, and the registry lists zero reported analyses for the secondary outcomes. They should be treated as exploratory context rather than as a collection of independent confirmatory findings. The primary outcome’s comparative analysis is not posted either, so the record does not establish how the primary and secondary hypotheses were connected in the original statistical plan.

Missing-data information is also limited. The primary endpoint population is explicitly defined as participants who completed endpoint assessment with interpretable MRI at baseline and study end. Its group sizes are 73 and 55. The study enrolled 235 participants overall, but the registry record does not report the reasons participants did not contribute primary endpoint data, the amount or pattern of missing MRI data, or whether missingness differed by assigned group. It does not report an imputation method, sensitivity analyses for missing data, or an analysis population that includes participants without interpretable paired MRI.

These omissions matter because a completer-based estimate can differ from the result that would have been obtained had all enrolled participants contributed endpoint data. Whether such a difference is likely cannot be determined from the record. The registry also does not report interim analyses, stopping rules, a detailed analysis plan, or a sample-size justification. These items are not inferable from the completed status or the planning illustrations.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry lists 92 participants at risk for serious adverse events in the liraglutide group and 93 in the placebo group. It records zero serious adverse events in each group and zero deaths in each group. No serious adverse-event terms are listed. These are the event figures in the registry record; they do not establish that no other safety events occurred.

For other adverse events, the registry records 53 participants affected in the liraglutide group and 34 in the placebo group, among the respective groups listed at risk. These counts are not the same as counts of serious events, and the record does not provide event-level details, severity breakdowns, or an exposure-adjusted analysis. It also does not report the duration of safety follow-up or explain how these safety populations relate to the primary endpoint population.

Safety counts should be read in light of their population and reporting definitions. A zero serious-event count in a group does not prove that the underlying risk is zero, especially when the number observed is finite. The registry record does not provide enough information to assess the comparative safety profile comprehensively or to make recommendations for individual care.

12. What the Result Does, and Does Not, Mean

The primary results describe average MRI-measured visceral adipose tissue reductions among participants who had interpretable scans at baseline and study end. The arm-level means are 12.49 for liraglutide and 1.63 for placebo, with their respective 95% confidence intervals reported separately. These numbers convey group averages and uncertainty around those averages, not individual outcomes or a direct estimate of the between-group effect.

The record does not report the primary comparative estimate, confidence interval for the contrast, or p-value. Therefore, the primary results should not be presented as a registry-reported statistical test of a treatment difference. The endpoint’s association with lower cardiovascular risk, as described in the registry, does not establish that a change in this MRI measure leads to fewer cardiovascular events. The primary outcome is a body-fat measure, not an event-based cardiovascular endpoint.

The secondary summaries provide additional measurements related to adiposity and body weight, and their unadjusted recalculations point in a similar descriptive direction. Because many secondary outcomes are listed, their multiplicity is not addressed in the record, and the sponsor’s reported analyses are absent, those calculations have limited confirmatory force. They cannot repair missing details about the primary analysis or establish a broader treatment effect.

The results also apply to a defined endpoint subset, not automatically to every enrolled participant or to other populations. The registry does not explain missing MRI assessments, report detailed eligibility criteria in this record, or describe the analysis plan. These gaps leave uncertainty about generalizability, missing-data sensitivity, and the intended inferential framework. The findings are best understood as the posted endpoint summaries and secondary descriptive pattern, with their scope and uncertainty kept explicit.

13. Why This Trial Matters Statistically

This trial illustrates why statistical interpretation depends on more than a comparison of two reported means. The primary endpoint record provides arm-specific estimates and confidence intervals, but not a between-group estimate. A reader can describe each group’s observed mean and the uncertainty around it, yet cannot recover the registry’s intended comparative analysis from those summaries alone. Keeping descriptive evidence separate from a formal contrast prevents an unsupported claim of statistical significance.

It also highlights the importance of defining the analysis population. The study enrolled 235 participants, while the primary endpoint includes only participants with interpretable MRI at baseline and study end. The record gives the endpoint group sizes but not the reasons for absent endpoint data. This difference makes missing-data reporting central to understanding whom the primary results represent.

The secondary outcomes show another recurring issue in clinical research: multiple measurements can tell a broadly consistent descriptive story without each serving as independent confirmatory evidence. Unadjusted recalculations may be useful for orientation, but they do not replace a prespecified analysis plan or multiplicity strategy. Planning illustrations derived from observed effects can also be informative as hypothetical design exercises, but they are not observed power and are not evidence of the original sample-size rationale.

Finally, the study connects a surrogate-like body-composition measure with cardiovascular-risk motivation while keeping the measured endpoint distinct from clinical events. Statistical clarity about that distinction helps readers avoid extending an imaging result beyond what the registry actually records.

14. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The registry record leaves important trial-specific details unavailable. It does not report the primary between-group estimate, its confidence interval, or its p-value, so the primary comparison cannot be quantified from the posted arm-level summaries alone. It also does not provide the detailed statistical analysis plan, the sample-size justification, or any interim-analysis procedures.

The primary endpoint is limited to participants with interpretable MRI at baseline and study end. The reasons for missing or uninterpretable scans, the participant flow by group, and the methods for handling missing endpoint data are not reported in the registry record. As a result, the record does not show whether the endpoint subset differs from the enrolled population in ways relevant to interpretation.

Although the study is described as randomized and quadruple-masked, the record does not state the allocation ratio, who was masked, or detailed randomization and concealment procedures. It also does not provide the full eligibility criteria or MRI acquisition and reading procedures in this record. These omissions limit assessment of design implementation and reproducibility.

Secondary numerical comparisons are unadjusted recalculations from group summaries, rather than analyses listed by the sponsor. The registry does not describe multiplicity control or a hierarchy for secondary outcomes. The adverse-event record provides counts but not detailed event terms for serious events, duration of follow-up, or a comprehensive account of the safety analysis population. These limitations constrain interpretation of both efficacy-related comparisons and safety reporting; they do not establish that unreported procedures or outcomes were absent from the underlying study.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Impact of Liraglutide 3.0 on Body Fat Distribution — NCT03038620.
• Registry record last updated 2021-11-19; status last verified 2021-10.
• Results first posted 2021-11-19.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

NCT03038620 is a completed phase 4 randomized, quadruple-masked, parallel-group study sponsored by the University of Texas Southwestern Medical Center. It enrolled 235 participants and compared liraglutide 3.0 mg with placebo. The study began in 2017-01, with primary completion on 2020-10-13.

The primary endpoint was relative percent reduction in MRI-measured visceral adipose tissue mass from baseline to 40 weeks. Primary results are reported for participants with interpretable MRI at both time points: 73 in the liraglutide group and 55 in the placebo group. The registry reports arm means and 95% confidence intervals, but no primary comparative estimate or p-value.

Secondary outcomes include visceral adipose tissue volume and body-weight measures. Their unadjusted recalculations are not sponsor-reported analyses, and the record does not report multiplicity handling. Safety figures list no serious adverse events or deaths in either group and report other adverse-event counts for both groups. Missing-data methods and the detailed statistical plan are not reported in the registry record.