A Study to Evaluate Fasting/Postprandial Serum Apolipoprotein B-48 (ApoB-48) Levels in Diabetic Participants With Normal to Moderately High Low Density Lipoprotein-C (LDL-C) Levels (MK-0653A-259 AM1): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study to Evaluate Fasting/Postprandial Serum Apolipoprotein B-48 (ApoB-48) Levels in Diabetic Participants With Normal to Moderately High Low Density Lipoprotein-C (LDL-C) Levels (MK-0653A-259 AM1) (NCT01333436), a non-randomized na study. The primary outcome is Postprandial Incremental Area Under the Curve From 0-6 Hours (iAUC)[0-6] of Apolipoprotein B-48 (ApoB-48).

2. Clinical Question

3. Trial Design

NCT01333436 is described as a multicenter, cross-sectional study of plasma ApoB-48 concentration among Korean diabetic patients with normal to moderately high LDL-C levels. It was completed, with a reported enrollment of 93. The study record lists dyslipidemia and hypercholesterolemia as conditions. Its stated focus was comparing diabetic participants with nondiabetic participants in the same LDL-C range, rather than assigning participants to a treatment.

The design was non-randomized, unmasked, and parallel. The two groups were diabetic participants with normal to moderately high LDL-C and nondiabetic participants with normal to moderately high LDL-C. Because assignment was not random, differences between the groups could reflect characteristics other than diabetes status. The registry record explicitly cautions that the arms are not a like-for-like control comparison. It does not report a matching procedure or adjustment method that would make the groups equivalent.

The listed intervention was a test meal. ApoB-48 measurements were taken after the meal at 1, 2, 3, 4, and 6 hours. The primary endpoint was postprandial incremental area under the curve from 0-6 hours. Secondary outcomes were postprandial mean ApoB-48 peak levels and fasting ApoB-48 levels.

The registry record does not report the primary or secondary outcome estimates, group-level means, variability estimates, confidence intervals, or statistical tests. It also does not report a protocol rationale for the enrollment target, the planned statistical analysis, or whether any interim analyses were conducted. The design therefore establishes what comparison was intended, but the available record does not establish the observed size or precision of any group difference.

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

Analysis population for the primary outcome, as defined in the registry: Full-Analysis-Set (FAS) population defined as all participants who had valid postprandial ApoB-48 measurements for all specified time points to calculate iAUC.

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 Postprandial Incremental Area Under the Curve From 0-6 Hours (iAUC)[0-6] of Apolipoprotein B-48 (ApoB-48), measured over up to 6 hours after Test Meal.

The primary endpoint was postprandial incremental area under the curve from 0-6 hours for ApoB-48, reported in μg/mL x h. ApoB-48 levels were measured at 1, 2, 3, 4, and 6 hours after the test meal. The analysis population was defined as participants with valid postprandial ApoB-48 measurements at all specified time points needed to calculate the endpoint.

In general, an area-under-the-curve measure combines values across a specified period, so it represents the post-meal pattern over time rather than a single measurement. An incremental area-under-the-curve measure focuses on change relative to a reference level; the registry record does not describe the precise calculation method or reference used in this study. The endpoint is intended to summarize the postprandial ApoB-48 response across the observation period. It complements fasting ApoB-48, which is a single-state measure, and the separately listed peak-level outcome.

The registry record does not report the endpoint values or a between-group estimate. Consequently, it is not possible from the record to describe the direction, magnitude, or precision of the observed group difference.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary measure is a continuous outcome: postprandial iAUC from 0-6 hours for ApoB-48. The registry record says the endpoint was summarized as a mean with standard deviation. It does not report the observed mean or standard deviation for either group, nor an estimated difference between groups.

What does an area-under-the-curve measure represent?

General: An area-under-the-curve measure combines repeated measurements across a defined period. It can capture the overall pattern of a response across that period, rather than relying on one measurement alone. An incremental version is generally intended to represent change relative to a reference level. The registry record does not describe the exact reference or calculation procedure used for this endpoint, so those details should not be inferred. In this study, the stated observation period was up to 6 hours after the test meal, with measurements at 1, 2, 3, 4, and 6 hours.

Why report a mean and standard deviation?

General: For a continuous measure, the mean describes the average level in a group. The standard deviation describes how dispersed the individual values are around that average. These summaries help characterize the data, but they do not by themselves quantify the uncertainty in a between-group comparison. That comparison is usually described with an estimated difference and a confidence interval, or another uncertainty measure. The registry record does not report these endpoint summaries or comparison estimates.

How should a confidence interval be understood?

General: A confidence interval expresses the precision of an estimate by giving a range of values compatible with the observed data under the analysis assumptions. A narrower interval indicates greater precision than a wider interval. It is not a guarantee that the true value lies within a particular interval. No confidence interval for the primary endpoint is reported in the registry record, so the precision of the intended comparison cannot be evaluated.

Why does non-randomized allocation matter?

General: Random allocation can help balance measured and unmeasured characteristics between groups, on average. In a non-randomized comparison, group membership may be related to other characteristics that also relate to the outcome. This can complicate interpretation of an observed difference. Here, the groups were diabetic and nondiabetic participants, and the registry record explicitly cautions that they are not a like-for-like control comparison. It does not report the analysis approach, covariate adjustment, or other methods used to address group differences.

What can be said about sample-size planning?

The registry record describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between the arms, and a normal approximation. The illustration is framed around detecting stated fractions of the observed effect and reports participants per arm for 80% power or 90% power, as applicable to those calculations. The numerical planning results and the observed effect are not reported in the registry record. These calculations are planning illustrations, not observed power, and they do not establish the precision of the study's actual comparison. The registry record does not report that these assumptions were the study's original design assumptions or provide a sample-size justification.

General: Over-dispersion occurs when variability is greater than a model assumes. If it is ignored, uncertainty can be understated and tests can be too optimistic. Whether over-dispersion is relevant depends on the outcome and model. The registry record does not report a model specification or diagnostics, so no conclusion about over-dispersion can be made for this analysis.

The registry record lists three outcome measures and three analyses, but does not give the statistical test or model for the primary endpoint. It also does not report whether estimates were adjusted, whether assumptions were checked, or how uncertainty was calculated. Those methodological details are needed to assess whether the analysis appropriately reflects the measurement structure and the non-randomized comparison.

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("Diabetic Participants", "Nondiabetic Participants")
n   <- c(42, 46)
m   <- c(63.4, 41.7)
sp  <- c(42.4, 30.9)
sd  <- sp      # posted standard deviations
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  Diabetic Participants  42  63.400  42.400  50.187  76.613
CARM  Nondiabetic Participants  46  41.700  30.900  32.524  50.876

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists three outcome measures: postprandial iAUC from 0-6 hours, postprandial mean ApoB-48 peak levels, and fasting ApoB-48 levels. It also lists three analyses. The analysis results are not reported in the registry record, and it does not describe a testing hierarchy or a plan for controlling multiplicity. General: When several outcomes or comparisons are tested, the chance of finding at least one apparently unusual result can increase. A prespecified hierarchy or adjustment can help clarify how multiple tests are handled. No such approach is reported, so multiplicity cannot be assessed.

The primary analysis population was defined as all participants with valid postprandial ApoB-48 measurements at every specified time point needed to calculate iAUC. This definition indicates that complete measurements at the required time points were needed for inclusion in that endpoint analysis. The registry record does not report how many participants met this definition, how many measurements were missing, or whether missingness differed between groups.

It also does not report how missing measurements were handled for secondary outcomes, whether any imputation was used, or whether sensitivity analyses were performed. General: Missing-data methods can affect estimates when the availability of measurements is related to participant characteristics or outcome values. Without counts and handling details, the extent and potential influence of missing data cannot be evaluated.

The record does not report additional analysis populations, deviations from the planned analysis, or the statistical plan. Those items are therefore not reported in the registry record, and the robustness of the findings cannot be assessed from the posted information.

12. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

The registry record reports no serious adverse events among the 43 diabetic participants at risk and no serious adverse events among the 50 nondiabetic participants at risk. It also reports zero other adverse events in each group: 43 diabetic participants at risk and 50 nondiabetic participants at risk. Death counts are not reported in the registry record.

These figures describe the adverse-event entries reported for the study groups. They do not establish that no adverse events occurred outside the categories or reporting period represented in the registry record, and they do not quantify the completeness of event collection. General: A zero count in a study group means that no event was entered for that category in the reported data; it does not prove that an event is impossible or that a larger population would have no events.

The study was a cross-sectional biomarker comparison involving a test meal, rather than a randomized therapeutic trial. The registry record does not provide event definitions, the safety observation period, or further details about safety monitoring. The reported counts should therefore be read narrowly as registry entries, not as a full characterization of safety.

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

The study was designed to compare fasting and postprandial ApoB-48 measures between diabetic and nondiabetic participants with normal to moderately high LDL-C levels. Its primary endpoint was postprandial iAUC from 0-6 hours after a test meal. This describes the question the study set out to address, not the answer: the primary endpoint result is not reported in the registry record.

Without group-level estimates or a between-group comparison, the direction and size of any difference cannot be stated. The registry record also does not provide confidence intervals or other uncertainty estimates, so the precision of an effect cannot be judged. The absence of posted outcome results is not evidence that groups were the same, nor is it evidence that they differed.

The comparison was observational and non-randomized. The record warns that the arms are not a like-for-like control comparison. Any difference, if reported, would need to be considered in light of possible group differences beyond diabetes status. The registry record does not report an adjustment strategy that could clarify the extent to which such factors were addressed.

The broader study aim refers to using ApoB-48 along with LDL-C to identify potential cardiovascular disease risk. The listed endpoint is a biomarker measure, and the registry record does not report cardiovascular outcomes or a predictive analysis. It therefore cannot establish that ApoB-48 improves risk identification, nor can it establish a relationship with clinical events from the information reported.

The record supports a description of the study question, groups, measurement schedule, and planned endpoint. It does not support a conclusion about the result of the primary comparison or the implications of ApoB-48 for cardiovascular risk. Those outcomes and analyses are not reported in the registry record.

14. Why This Trial Matters Statistically

This study is statistically notable for asking a biomarker question within a defined LDL-C range and measuring ApoB-48 both in fasting conditions and after a test meal. Its primary endpoint combines post-meal measurements across time, which addresses a different aspect of the response than a single fasting value. The design therefore makes the measurement schedule and endpoint definition central to interpreting the intended comparison.

The registry record also illustrates why design labels matter. Participants were not randomized to groups; they were classified as diabetic or nondiabetic. This means the comparison can describe differences between the groups, but causal interpretation would require caution. The registry record itself says the arms are not a like-for-like control comparison, and does not report adjustments that might address group differences.

A further statistical issue is that a well-defined endpoint does not substitute for a posted result. Interpreting a comparison requires estimates of the groups or their difference, along with measures of uncertainty. The registry record gives the primary endpoint definition and analysis population but not the numerical results. It is therefore not possible to assess the effect's direction, magnitude, or precision.

Finally, the study's stated interest in potential cardiovascular disease risk extends beyond the primary biomarker comparison. A biomarker result alone would not establish clinical risk prediction or an association with cardiovascular events. The registry record does not report those outcomes or analyses. The distinction between an intended research question, a measured biomarker, and a demonstrated clinical prediction is important when describing what the study can establish.

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 principal limitation for interpreting the results is that the primary and secondary outcome values are not reported in the registry record. Group means, standard deviations, between-group estimates, confidence intervals, and p-values are absent. As a result, neither the size nor precision of the planned comparison can be assessed.

The non-randomized design limits causal interpretation. Participants were grouped by diabetes status, and the registry record warns that the arms are not a like-for-like control comparison. It does not report adjustment methods or characteristics that would allow readers to assess how comparable the groups were beyond their stated LDL-C range.

The primary analysis required valid ApoB-48 measurements at every specified post-meal time point. The number of participants meeting that requirement and the amount and handling of missing data are not reported in the registry record. The exact method for calculating incremental area under the curve is also not reported, including the reference used for the incremental calculation.

The registry record does not report the statistical plan, analysis method, multiplicity strategy, or whether assumptions were checked. It does not provide a sample-size justification; the planning illustration described in the record is based on the observed effect and is not evidence of the study's original design rationale. Death counts are not reported, and the adverse-event reporting period and definitions are not described. These gaps limit interpretation of both the efficacy-related biomarker question and the safety entries.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Study to Evaluate Fasting/Postprandial Serum Apolipoprotein B-48 (ApoB-48) Levels in Diabetic Participants With Normal to Moderately High Low Density Lipoprotein-C (LDL-C) Levels (MK-0653A-259 AM1) — NCT01333436.
• Registry record last updated 2024-05-13; status last verified 2022-02.
• Results first posted 2013-04-09.
• 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

NCT01333436 was a completed, multicenter, cross-sectional study with enrollment of 93. It compared diabetic and nondiabetic participants with normal to moderately high LDL-C levels. The listed intervention was a test meal, followed by ApoB-48 measurements at 1, 2, 3, 4, and 6 hours.

The primary endpoint was postprandial ApoB-48 iAUC from 0-6 hours, expressed in μg/mL x h. Secondary outcomes were postprandial mean ApoB-48 peak levels and fasting ApoB-48 levels. The primary analysis population required valid measurements at all specified time points used to calculate iAUC.

The comparison was non-randomized, and the registry record cautions that the groups are not a like-for-like control comparison. The primary and secondary outcome results, analysis methods, and uncertainty estimates are not reported in the registry record. Serious and other adverse-event counts were zero in both groups; death counts are not reported.