GLP-1 Receptor Agonist Therapy and Albuminuria in Patients With Type 2 Diabetes: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for GLP-1 Receptor Agonist Therapy and Albuminuria in Patients With Type 2 Diabetes (NCT03029351), a randomized phase 4 study. The primary outcome is Change From Baseline in Urinary Albuminuria Levels.

2. Clinical Question

3. Trial Design

This was a phase 4, randomized, parallel-group study sponsored by the University at Buffalo. The registry describes quadruple masking, meaning the design was recorded as masked across four roles or groups; the specific people or procedures covered by that designation are not reported in the registry record. The planned comparison was extended-release exenatide against placebo, with each treatment described as lasting one year.

The registry lists an enrollment of 15. The study began on 2017-01-10, had a primary completion date of 2019-07, and is marked terminated. The reason for termination, whether recruitment ended as planned, and the timing or circumstances of termination are not reported in the registry record. No conclusion about why the study stopped can be drawn from the status alone.

The primary outcome was change from baseline in urinary albuminuria at week 52. The outcome listing reports five participants in each treatment arm. Those outcome counts are not the same as the overall enrollment entry, and the registry does not explain the relation between them, such as which participants contributed endpoint data or why the reported counts differ. Safety entries use different at-risk counts, discussed separately.

One primary outcome measure is listed, and no secondary outcome measures are posted. The record contains no posted statistical analyses for the primary endpoint. It also does not report an analysis population, a detailed statistical plan, allocation procedures, masking procedures, or a reason for termination. These omissions limit how fully the intended design and conduct can be reconstructed from the registry record.

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

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.

6. Primary Endpoint

The registry lists the primary outcome as Change From Baseline in Urinary Albuminuria Levels, measured over baseline and 52 weeks.

The primary endpoint was change from baseline in 24-hour urinary albuminuria at week 52, reported in microgram/mg creatinine. Albuminuria refers to albumin measured in urine; expressing it relative to creatinine helps describe the albumin concentration in relation to urine concentration. The registered outcome description identifies the measurement as albumin/creatinine and names the result as urinary albuminuria.

In general, urinary albumin is used as an indicator of kidney involvement, including in people with diabetes. Following change over time can describe whether the measured level moved upward or downward during a study period. Here, the registry defines the comparison period as baseline to week 52, following extended-release exenatide or placebo treatment. The endpoint is continuous, and the posted group summaries are means with standard errors.

A change score is not the same as a final measurement: it expresses the difference from each participant’s baseline value, summarized at group level. The posted means are -32.0 for exenatide and -12.0 for placebo. These summaries alone do not establish whether the groups differed statistically. The registry record does not provide a two-arm estimate, confidence interval, or inferential test for this endpoint.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The endpoint is continuous: it measures a quantity on a numerical scale rather than recording a category or event. The registry identifies the parameter as a mean and the dispersion as a standard error. The unit is microgram/mg creatinine, and the measurement period is baseline to week 52. These details identify what the summaries represent, but they do not specify the full statistical model used for any formal comparison.

What does a mean change describe?

In general, a mean change is formed by summarizing participants’ follow-up values relative to their baseline values. A negative group mean represents an average decrease on the measured scale, while a positive group mean represents an average increase. A mean can conceal considerable differences between individual participants: some values may move in one direction and others in another. Without participant-level results or a distributional summary, the range and shape of individual changes are not known.

The posted means are -32.0 for extended-release exenatide and -12.0 for placebo. These are separate within-arm summaries. A randomized trial’s main comparative question ordinarily concerns the difference between groups, not whether either group’s mean change is individually above or below zero. The registry indicates that values are missing or not estimable for a two-arm comparison, so no comparative estimate is reported. The group means should therefore not be converted into an unadjusted treatment contrast.

How should the standard errors be read?

In general, a standard error describes the sampling uncertainty of an estimated mean. It is different from a standard deviation, which describes variation among participant measurements. The reported standard errors are 122.0 for the exenatide mean and 132.0 for the placebo mean. They are large relative to the corresponding mean values, indicating that the group means are imprecisely estimated. A standard error alone is not a confidence interval and does not provide a test of the difference between randomized groups.

A confidence interval, when reported, gives a range of values compatible with the estimate under the stated statistical assumptions. No confidence interval for either group mean or for the between-group comparison is posted. Nor is a p-value reported. It is not possible to recover a sponsor analysis from the means and standard errors alone, and no such reconstruction is appropriate when the registry explicitly says a two-arm comparison is not estimable.

What does the reported endpoint count mean?

The outcome listing records five participants in each arm. In general, an outcome count identifies the number contributing to that particular summary, but it does not necessarily describe every participant randomized or enrolled. The registry separately lists enrollment of 15. It does not explain the relationship between enrollment and endpoint counts, identify an analysis population, or state why the counts differ. These figures should be read as separate registry entries rather than combined or reconciled by assumption.

What can be inferred from the trial design?

Randomization is intended, in general, to make treatment groups comparable at the start of a study by allocating participants without choosing treatment according to their characteristics. Masking is intended to reduce the influence of knowledge about assigned treatment on care, measurement, or assessment. The registry classifies this study as randomized and quadruple-masked, but details about implementation are not reported. Design labels alone do not establish that allocation and masking were successful in practice.

The phase 4 designation, parallel-group model, and placebo comparator describe the registered trial structure. They do not supply an analysis method. The registry does not report whether the primary comparison used adjustment for baseline values, a particular variance model, a specific missing-data method, or an intention-to-treat or other analysis population. Those choices can affect interpretation and should not be inferred.

What do planning assumptions mean?

The registry’s planning description states that sample-size illustrations use a two-sided significance level of 0.05, equal allocation between arms, a normal approximation, and a target effect expressed as a fraction of the observed effect. In general, such calculations illustrate how many participants per arm might be needed under specified assumptions. They are planning illustrations, not observed power and not evidence that the trial was designed or conducted to those specifications. The registry does not report a trial-specific sample-size justification. Numeric planning results are not reported in the registry record.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Exenatide Extended Release", "Placebo")
n   <- c(5, 5)
m   <- c(-32, -12)
sp  <- c(122, 132)
sd  <- sp * sqrt(n)      # standard errors converted to SDs
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Exenatide Extended Release  5  -32.000  272.800  -370.726  306.726
CARM  Placebo  5  -12.000  295.161  -378.491  354.491

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome measure and no posted secondary outcome measures. It records no posted statistical analyses. Because the record does not report inferential results, there is no reported set of tests from which to determine whether multiplicity adjustments were used or needed. The statistical plan for handling multiple outcomes, time points, or analyses is not reported in the registry record.

Missing data are also not described. The endpoint listing reports five participants per arm, while the overall enrollment entry is 15. The registry does not identify whether the endpoint counts reflect all randomized participants, a subset with available measurements, or another analysis population. It does not state how many measurements were missing, why they were missing, or whether any values were excluded.

In general, missing measurements can affect a change-from-baseline analysis if the likelihood of missingness is related to outcome values, treatment assignment, or participant characteristics. Appropriate interpretation depends on knowing the analysis population and assumptions used to address missingness. No such information is reported, so the amount and possible influence of missing data cannot be assessed from the registry record.

The record also does not specify an intention-to-treat population, a per-protocol population, or another analysis set. It gives no information about baseline adjustment, sensitivity analyses, interim analyses, or the prespecified statistical test. These are not details that can be reconstructed from arm means and standard errors. The absence of these details means the posted endpoint summaries are not accompanied by enough information to evaluate the planned or performed inferential analysis.

12. 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.

The registry reports serious adverse events for seven participants at risk in the extended-release exenatide group and eight at risk in the placebo group. Serious adverse events affected zero participants in each group. Deaths are reported as zero in both groups. For other adverse events, the at-risk counts are seven in the exenatide group and eight in the placebo group, with zero affected participants in either group.

These are safety counts as entered in the registry, not evidence that no adverse events occurred outside the categories or observation period captured by those entries. The registry does not report event definitions, the safety observation period, event collection procedures, or detailed event terms; no top serious-event terms are listed. Zero affected participants in these entries should therefore be read narrowly as no events recorded in the stated categories for the listed at-risk groups.

The safety at-risk counts differ from the endpoint counts, and the registry does not explain the relationship between them. They should not be used to infer endpoint participation or reconciled with the outcome summaries. The posted counts also do not establish comparative safety, particularly without event-level detail, a defined observation period, or an inferential analysis.

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

The registry record describes a randomized, quadruple-masked, parallel-group phase 4 study comparing extended-release exenatide with placebo for one year in patients with type 2 diabetes and micro- or macroalbuminuria. Its primary outcome was change from baseline in 24-hour urinary albuminuria at week 52. The posted mean changes are -32.0 microgram/mg creatinine in the exenatide group and -12.0 microgram/mg creatinine in the placebo group, with standard errors of 122.0 and 132.0, respectively.

These summaries show the reported direction and imprecision of the group means. They do not provide a formal comparison between randomized groups. The registry states that values are missing or not estimable for a two-arm comparison and lists no analyses. There is no posted comparative estimate, confidence interval, or test result. Consequently, the group means cannot establish whether the treatments differed, how large any difference might be, or how uncertain a comparative effect would be.

The figures also do not establish whether either treatment changed albuminuria relative to what would have happened without treatment. A within-group change is not, by itself, evidence of a treatment effect. The randomized comparison is the relevant basis for estimating a treatment difference, but that estimate is not available in the posted results.

The record does not state why the trial was terminated, explain the discrepancy between overall enrollment and endpoint counts, describe missing-data handling, or identify an analysis population. Those gaps constrain interpretation. The safety entries report zero affected participants and zero deaths in the listed categories, but do not establish an absence of all possible adverse events. Overall, the posted information is descriptive and incomplete for judging the comparative endpoint or drawing broader conclusions.

14. Why This Trial Matters Statistically

This trial is statistically notable because its registry record contains arm-level endpoint summaries but no estimable two-arm result. Randomization is intended to support a causal comparison, yet the central comparative estimate is absent. The distinction between a group’s mean change and the difference between randomized groups is fundamental: the former describes an arm, while the latter addresses the trial’s treatment question.

The reported standard errors are large relative to the mean changes, and the endpoint counts are small. In general, estimates based on small samples can be sensitive to individual observations and imprecisely estimated. These features make it especially important to distinguish descriptive summaries from inferential evidence. Without a confidence interval or test for the between-group comparison, precision and compatibility with a range of treatment effects cannot be assessed.

The record also illustrates why different participant counts need careful interpretation. Overall enrollment, endpoint counts, and safety at-risk counts are listed separately. Their relationship is not explained, and none should be substituted for another or combined to create a new total. An analysis population and account of missing endpoint data would be needed to understand who contributed to each result.

Finally, the registry marks the study terminated but does not report why. The status, small endpoint counts, and absent comparison are relevant context, but do not explain one another. Statistical interpretation depends on the actual analysis and data flow, not on assumptions about why a trial ended. This record is therefore a useful example of why numerical summaries, design labels, and a trial’s status must be read together but kept conceptually distinct.

15. 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 main limitation is that the registry does not report an estimable two-arm comparison for the primary endpoint. Although group means and standard errors are posted, there is no comparative estimate, confidence interval, or inferential test. As a result, the central randomized question cannot be answered from these results.

The endpoint counts are five per arm, while overall enrollment is listed as 15. The record does not explain these different entries, identify who contributed to the endpoint, or report missing measurements and their handling. It also does not specify the analysis population or whether the primary analysis adjusted for baseline values. These omissions prevent assessment of how representative the endpoint summaries are of the enrolled population.

The study is marked terminated, but the reason and circumstances are not reported. The record does not state whether the study stopped early, whether the planned recruitment target was reached, or whether termination affected data collection or analysis. No reason should be inferred from the status label.

Additional limitations include the absence of posted secondary outcomes and analyses, no detailed protocol or statistical plan in the registry entry, and no reported account of allocation or masking procedures. The safety record provides counts but no event definitions, observation period, or detailed event terms. Together, these gaps mean the posted information supports only a narrow description of group means and recorded safety counts, not a full assessment of efficacy, comparative safety, or robustness.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: GLP-1 Receptor Agonist Therapy and Albuminuria in Patients With Type 2 Diabetes — NCT03029351.
• Registry record last updated 2024-04-16; status last verified 2024-03.
• Results first posted 2024-04-16.
• 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.

19. Record Summary

NCT03029351 is a phase 4 randomized, quadruple-masked, parallel-group trial sponsored by the University at Buffalo. It compared one year of extended-release exenatide with placebo in patients with type 2 diabetes and micro- or macroalbuminuria. The registry lists enrollment of 15, a start date of 2017-01-10, primary completion in 2019-07, and terminated status.

The primary endpoint was change from baseline in 24-hour urinary albuminuria at week 52, in microgram/mg creatinine. The posted means were -32.0 for exenatide and -12.0 for placebo, with standard errors of 122.0 and 132.0. The record says a two-arm comparison is not estimable and lists no analyses. The reason for termination, analysis population, missing-data handling, and explanation for the different endpoint and enrollment counts are not reported in the registry record.