Scavenging of Reactive Carbonyl Species by Apple Polyphenols in Human: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Scavenging of Reactive Carbonyl Species by Apple Polyphenols in Human (NCT03911050), a randomized na study. The primary outcome is Maximum Urinary Excretion Rates of Major Reactive Carbonyl Species (RCS) Adducts of Apple Polyphenols Over 24 Hours After One Single Dose of Apple Consumption.

2. Clinical Question

3. Trial Design

The registry describes a completed randomized, double-masked, crossover study. The intervention conditions were apple consumption and a control breakfast without apple-related products. In a crossover design, participants receive more than one condition in sequence, so their observations can potentially be compared within the same participant. General: this can account for stable differences between people when the analysis is designed to make a within-participant comparison. The registry record does not report the condition sequence, the timing between conditions, or the statistical model used to analyze repeated observations.

The apple condition consisted of a single dose of apple blends totaling 600 g, made from two apples with seed removal. The control condition was a single breakfast without apple-related products. Samples of urine, blood, and feces were collected at different timepoints after each condition, according to the arm descriptions. The primary outcome description specifies urine collection intervals from 0-2 through 12-24 h for the excretion-rate measurements. The record does not give further details on the collection schedule for blood or feces.

The study status is completed. The listed study start was 2018-11-26, and primary completion was 2018-12-14. The phase is recorded as NA. The registry lists 12 eligible subjects randomized, with 11 participants completing the entire study and analyzed. It does not report why the remaining randomized participant did not complete the study, or how incomplete sample collections or other missing measurements were handled.

The study is described as investigating formation and pharmacokinetics of reactive carbonyl species adducts of apple polyphenols in humans after a single dose of apple consumption. Its outcomes include urinary excretion rates and plasma levels. Details of the randomization procedure, masking procedures, washout, protocol deviations, and analysis plan are not reported in the registry record. Randomization and masking identify the stated design features, but alone do not establish how well they were implemented.

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.

Before assignment: A one-week wash-in period was implemented.

Wash-in period (1 week)

First intervention (1 day)

Wash-out period (1 week)

Second intervention (1 day)

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: 12 eligible subjects were randomized to the interventions. However, only 11 out 12 participants completed the entire study. Therefore, 11 participants were analyzed in this 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.

Population: This is a crossover study. 12 participants were recruited.

6. Primary Endpoint

The registry lists the primary outcome as Maximum Urinary Excretion Rates of Major Reactive Carbonyl Species (RCS) Adducts of Apple Polyphenols Over 24 Hours After One Single Dose of Apple Consumption, measured over Urinary excretion rates (ERs) of ACR-PPs and MGO-PPs at different time intervals (0-2, 2-4, 4-6, 6-9, 9-12, and 12-24 h) after apple consumption were measured. The maximum ERs at 6 h post-dose for ACR-PPs and 9 h post-dose for MGO-PPs were presented..

The primary endpoint is the maximum urinary excretion rate of major reactive carbonyl species adducts of apple polyphenols over 24 hours after a single dose of apple consumption. The measured conjugates are ACR-PPs and MGO-PPs, and the rate unit is nmol/h. The registry describes excretion-rate measurements across intervals of 0-2, 2-4, 4-6, 6-9, 9-12, and 12-24 h. It reports that the maximum ACR-PPs rate was presented at 6 h post-dose and the maximum MGO-PPs rate at 9 h post-dose.

These measurements are intended to characterize the appearance of the targeted conjugates in urine over time after apple consumption. Considering a maximum rate can describe a peak in the measured excretion profile, while measurements over several intervals provide temporal context. General: pharmacokinetic measurements describe how a substance or related marker changes over time; they are not, by themselves, measures of clinical benefit or harm.

The registry says the endpoint is expressed as a mean with standard error and describes LC-MS analysis of urine samples. It does not report the mean rates, standard errors, participant-level measurements, or a numerical comparison with the control condition. Therefore, the peak timing is described, but the size and precision of the peak measurements cannot be evaluated from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean with standard error describe?

The primary outcome is described as a mean of a continuous measure, with standard error as its dispersion measure. A mean gives a summary of the measured excretion rates. The standard error describes the statistical uncertainty around an estimated mean, rather than the spread of individual observations. General: a standard error is affected by both the variability in the observations and the amount of information contributing to the estimate. It does not show the full range of values among participants.

Standard errors are often used to construct confidence intervals or conduct tests, but those interpretations require the estimate, its standard error, and the analysis assumptions. The registry record does not report numerical means or standard errors for the primary endpoint, nor does it report confidence intervals or tests. Therefore, it is not possible to assess the precision of the endpoint estimates or whether the observed data would support a statistical comparison.

Why do the collection intervals matter?

The registry describes urinary excretion rates at intervals of 0-2, 2-4, 4-6, 6-9, 9-12, and 12-24 h. A series of measurements can describe how an outcome varies over time, while a maximum selects a peak value from that measured profile. Here, the record identifies the maximum ACR-PPs rate at 6 h post-dose and the maximum MGO-PPs rate at 9 h post-dose. These are endpoint timing descriptions; they are not numeric estimates of the rates themselves.

General: repeated observations over time are related measurements, not necessarily independent pieces of information. Analyses may need to account for that dependence. A maximum also has a different interpretation from an average across the entire observation period: it describes the highest measured rate among the specified intervals, rather than the typical rate throughout the period. The registry does not report the statistical procedure used to select or analyze the maxima, or whether the observations were modeled jointly across intervals.

What does the crossover design imply for analysis?

In a crossover design, the same participant can contribute observations under different intervention conditions. General: a within-participant comparison can reduce the influence of stable differences between participants, provided the analysis appropriately accounts for the paired structure. Such a design can also be affected by time trends, order effects, or carryover from an earlier condition. The registry record does not describe the condition sequence, the period between conditions, or the method used to address these possibilities. It is therefore not possible to confirm from the record whether the analysis used a paired comparison or accounted for period or sequence effects.

The trial is described as randomized and double-masked. Random allocation can reduce systematic differences in assignment, while masking can limit some forms of expectation or measurement bias. These general design concepts do not establish that allocation was concealed or that masking was maintained. Operational details are not reported in the registry record.

How should significance and planning calculations be read?

The registry record does not report a statistical test or p-value for the primary outcome. It also lists no analyses. Without a reported estimate and analysis, a claim of statistical significance cannot be evaluated. General: a p-value, when reported, describes how compatible data are with a specified statistical model and null hypothesis; it is not a measure of clinical importance and does not show the probability that a hypothesis is true.

The record describes a sample-size planning illustration based on an observed effect, using a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. It states that the effect to detect is a stated fraction of the observed effect. Such calculations are planning illustrations, not observed power and not evidence that the trial had a particular probability of detecting an effect. No planning result is interpreted as a trial outcome.

The primary outcome has several categories or time points and is not reduced to a single comparison in the registry record. A recalculation based on a single unadjusted comparison is therefore not described. More generally, recalculations from summary statistics, when available, would not replace the sponsor's own analysis if the sponsor's analysis differed. In this record, the necessary numerical outcome summaries and sponsor analysis are not reported, so no result can be recalculated.

Why does multiplicity matter?

The endpoint description includes two conjugate classes and measurements across multiple time intervals. The record also lists secondary outcomes for average urinary excretion rates and average plasma levels of major RCS. General: evaluating multiple outcomes or timepoints can increase the chance of finding an apparently unusual result by chance if many tests are conducted. Statistical plans may address this through prespecified primary comparisons, adjustment procedures, or a clearly limited set of confirmatory tests. The registry does not report a multiplicity strategy, a hierarchy among the outcomes, or which comparisons were formally tested. Since numerical results and tests are absent, the consequences of multiplicity cannot be assessed.

10. Multiplicity, Missing Data and Analysis Populations

The registry record describes the primary outcome across multiple time intervals and for ACR-PPs and MGO-PPs. It also lists secondary outcomes covering average urinary excretion rates and average plasma levels of major RCS over 24 hours. The registry lists five outcome measures, but does not report a full set of numerical results or analyses for them. A multiplicity adjustment or a prespecified hierarchy for interpreting these outcomes is not reported in the registry record.

Missing-data reporting is limited. The record states that 12 eligible subjects were randomized and that 11 participants completed the entire study and were analyzed. It does not report why a participant did not complete, whether all analyzed participants had complete measurements for every time interval and outcome, or how any missing samples were handled. Imputation procedures, sensitivity analyses, and reasons for missing observations are not reported in the registry record.

The described analysis population is the 11 participants analyzed, but the record does not explain whether this population followed an intention-to-treat principle or another definition. It also does not report whether all randomized participants contributed data to any analyses. The registry lists no analyses, and no statistical analysis plan or model is described. It is therefore not possible to determine how the crossover structure, repeated time measurements, incomplete data, or multiple outcomes were handled in the sponsor's analysis.

These omissions limit interpretation rather than demonstrating that any particular method was or was not used. The registry record does not provide enough detail to establish the analysis population rules, the completeness of the outcome data, or the approach to multiplicity.

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 5% reporting threshold.

The safety entries list an at-risk count of 12 for the Apple Consumption row and 12 for the Control row. Each row records zero participants affected by serious adverse events, zero affected by other adverse events, and zero deaths. The registry lists no top serious-event terms.

These are the registry's recorded counts for the intervention group rows. The study is a crossover design, so the row counts should not be added to infer the number of distinct participants. The record does not describe how adverse events were solicited, how long safety monitoring continued, whether events were collected in a standardized way, or how attribution to a condition was determined. It also does not provide event-level descriptions beyond the zero counts.

General: a recorded zero means that no events in that category were entered for the relevant row; it does not establish that an event is impossible or that rare events have been ruled out. Interpretation also depends on the number of participants observed, the duration and completeness of follow-up, and how events were defined and collected. Those details are not reported in the registry record. The counts should therefore be read as the reported safety record, not as a comprehensive estimate of risk.

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

The registry record describes a randomized, double-masked crossover study that examined urinary and plasma measures related to reactive carbonyl species after apple consumption. It specifies the apple dose, the control breakfast condition, the sample types, and the primary urinary endpoint. It also identifies the stated times of the maximum excretion rates for ACR-PPs and MGO-PPs. These details explain the intended measurements, but do not give the numerical values needed to judge how large the measured rates were.

The primary result's mean and standard error are not reported in the registry record. Nor are a condition contrast, confidence interval, or p-value. As a result, the posted information does not establish whether the apple condition differed from control for the primary endpoint, or how precisely any such difference was estimated. The same limitation applies to the listed secondary outcomes: their descriptions are present, but their numeric findings are not reported.

Even if a difference in a urinary or plasma measure were reported, that type of result would describe a biomarker or pharmacokinetic measure, not by itself a clinical outcome. General: statistical evidence about a laboratory measure should be interpreted in relation to the study question, the measurement's properties, the analysis, and the relevance of the measure to health. The registry record does not report clinical outcomes or provide evidence for a clinical benefit or harm.

The sample was limited to 11 analyzed participants, and the record describes a single-dose investigation in healthy human subjects. These features define the scope of the evidence available in this trial record; they do not establish how findings would apply to other populations, repeated consumption, or other circumstances. The information supports a description of the study design and measurement plan, but not a conclusion about the magnitude or importance of an outcome.

13. Why This Trial Matters Statistically

This study is statistically informative as an example of a small human pharmacokinetic investigation using repeated biological measurements after an intervention. It links a defined apple-consumption condition to measurements of reactive carbonyl species adducts in urine and plasma. The use of a crossover design means that the same participants can potentially contribute observations under both conditions, which may make within-participant analysis relevant. Whether that potential was realized depends on the analysis method, which is not reported in the registry record.

The endpoint also illustrates why time matters in biomedical measurement. The registry specifies multiple urinary collection intervals and identifies different peak times for ACR-PPs and MGO-PPs. A peak measurement and an average over a period answer different descriptive questions. Interpreting either requires numerical estimates and a clear account of how repeated measurements were handled.

The record also shows the distinction between a study's measurement plan and its results. It describes the analytical approach and lists the primary and secondary outcomes, but does not report the estimates needed to judge effect size or precision. A well-described endpoint cannot substitute for outcome data, and a recorded absence of adverse events cannot establish comprehensive safety. These are important distinctions when reading registry information: design details explain what a study intended to measure, while results and analysis details are needed to assess what the observations support.

Finally, the reported analyzed population is small and the investigation concerns a single dose in healthy subjects. These characteristics are relevant to the scope of any inferences. The record can help readers understand the design and types of measurements planned, while its missing outcome estimates and analysis details constrain statistical interpretation.

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 main trial-specific limitation is that numeric results for the primary endpoint are not reported in the registry record. The record identifies the endpoint as a mean with standard error and states the peak timing for both conjugate classes, but does not report the actual rates, uncertainty estimates, or a comparison with control. Results for the listed secondary outcomes are also not reported. This prevents assessment of effect direction, magnitude, and precision.

The analyzed population consisted of 11 participants; 12 eligible subjects were randomized. The record does not describe the characteristics of those participants beyond their eligibility, or explain why not all randomized participants completed the entire study. It does not specify whether all measurements were complete for the participants analyzed or how missing data were handled.

Although the design is described as randomized, double-masked, and crossover, key implementation and analysis details are absent. The condition sequence, interval between conditions, potential carryover handling, and statistical model are not reported in the registry record. The measurement plan includes repeated time intervals and multiple outcome measures, but the approach to multiplicity is also not reported.

The investigation concerns a single dose in healthy human subjects, so the record does not address repeated consumption or other populations. The registry describes LC-MS measurement procedures, but does not report validation results or further information on measurement performance. These limitations affect how completely the study can be evaluated from the registry record; they should not be treated as evidence that an unreported procedure was not performed.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Scavenging of Reactive Carbonyl Species by Apple Polyphenols in Human — NCT03911050.
• Registry record last updated 2026-07-02; status last verified 2026-04.
• Results first posted 2026-07-02.
• 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

The registry record describes NCT03911050, titled Scavenging of Reactive Carbonyl Species by Apple Polyphenols in Human. It is listed as a completed, randomized, double-masked crossover study. The intervention conditions were a single dose of apple blends totaling 600 g and a control breakfast without apple-related products. The study began on 2018-11-26, with primary completion on 2018-12-14.

The primary outcome concerns maximum urinary excretion rates of ACR-PPs and MGO-PPs over 24 hours. The record states that 12 eligible subjects were randomized and that 11 participants completed the study and were analyzed. It describes urine, blood, and feces sampling, and LC-MS analysis for the urinary conjugates.

Numeric results for the primary and secondary outcomes, statistical comparisons, confidence intervals, and analysis methods are not reported in the registry record. The safety rows list zero serious adverse events, zero other adverse events, and zero deaths for each intervention condition.