Composition & Function of Sarcoplasmic Reticulum in Persons With the Metabolic Syndrome: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Composition & Function of Sarcoplasmic Reticulum in Persons With the Metabolic Syndrome (NCT02122666), a registered phase not stated study. The primary outcome is Sarcoplasmic Reticulum Composition.

2. Clinical Question

3. Trial Design

This is a completed human study of sarcoplasmic reticulum composition and function in people with metabolic syndrome and controls. The sponsor is Washington University School of Medicine. The record lists a start date of 2014-03 and a primary completion date of 2024-02-15. Enrollment is listed as 27. The intervention entry is a muscle biopsy, and both arm descriptions include the same set of study procedures: muscle biopsy, an oral glucose tolerance test with insulin levels measured at time points, and a DEXA scan.

The registry identifies the two groups as Metabolic Syndrome and Control. It does not state the method by which participants entered or were assigned to these groups. The record cautions that this is not a randomized comparison and that the arms are not a like-for-like control comparison. Accordingly, the group contrast should be understood as an observational comparison as recorded, not as evidence from random assignment. The registry record does not report additional design details that would clarify recruitment, matching, or adjustment for differences between the groups.

The primary outcome is sarcoplasmic reticulum composition, measured as the PC:PE ratio in a thigh muscle sample at Study Visit Week 4. The primary population description says that samples lost during tissue processing were not included; the analyzed sample counts are 10 for Metabolic Syndrome and 13 for Control. The record also lists Insulin Sensitivity and Lean and Fat Body Mass as secondary outcomes. It reports three outcome measures overall, but does not provide a statistical analysis for any of them in the registry record in the registry record.

The registry lists the study status as COMPLETED. Completion indicates the recorded status of the study; it does not by itself establish that all planned measurements were analyzed or that results were reported. The registry record does not report a protocol, a sample-size justification, an allocation procedure, or a statistical analysis plan.

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: Samples not included were lost during tissue processing. Metabolic syndrome (n=10); Control (n=13)

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 Sarcoplasmic Reticulum Composition, measured over Study Visit Week 4.

The primary endpoint is the mean phosphatidylcholine-to-phosphatidylethanolamine ratio in the sarcoplasmic reticulum of thigh muscle. The description specifies a tissue sample from the vastus lateralis and places measurement at Study Visit Week 4. The PC:PE ratio characterizes the relative amounts of two phospholipid components in the sampled sarcoplasmic reticulum. The registry uses the abbreviation PC:PE and identifies the unit as PC:PE ratio.

The study’s stated rationale is to examine whether particular muscle lipid signatures suggested by previous research in mice also occur in humans, including in people with metabolic syndrome. Measuring a tissue composition feature provides a way to investigate that biological question directly in muscle, rather than relying only on a broader clinical label or a blood-based measurement. The endpoint is therefore a composition measure, not a clinical event or a direct measure of treatment benefit.

The specified summary statistic is a mean, with standard error as the dispersion measure. A mean describes the group’s average observed ratio. A standard error describes the statistical uncertainty around an estimated mean, rather than the spread of individual participant values. The registry record does not report the observed mean or standard error for either group, nor a contrast between groups. It therefore does not permit assessment of the direction, magnitude, or precision of the endpoint result.

The population note reports samples lost during tissue processing and gives the included sample counts as 10 for Metabolic Syndrome and 13 for Control. The record does not describe whether the loss was related to participant characteristics or to the measurement value, so the possible effect of this loss on the endpoint cannot be determined from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is a continuous measurement summarized by a mean. General statistical explanation: a mean represents the average of the measured values in a group. It can be useful for describing a group’s central level, but it does not show how widely individual observations vary. The registry specifies standard error as the dispersion measure. General statistical explanation: the standard error describes uncertainty in an estimated mean, rather than the variability among individual participants. To understand a group contrast, readers would ordinarily need the group estimates and a direct estimate of the difference, accompanied by uncertainty information. Those numerical results are not reported in the registry record.

A confidence interval is a range of values compatible with the data and the statistical model at a stated confidence level. General statistical explanation: its width helps convey precision, while its location indicates which effect sizes remain compatible with the data. A confidence interval is not reported for the primary outcome in the registry record in the registry record. Without it, the precision of any group contrast cannot be assessed. A p-value, if reported, would address compatibility with a specified null model; it would not by itself describe the size or practical importance of an observed difference. No p-value for the primary comparison is reported in the registry record.

The endpoint is a PC:PE ratio measured from thigh muscle tissue. The record describes sample processing and says some samples were lost during tissue processing. This matters because a statistical result is based on the measurements that remain available for analysis. General statistical explanation: if missing measurements are related to participant characteristics or to the unobserved measurement itself, the analyzed group may not represent everyone enrolled. If loss is unrelated to those features, the effect may be different. The registry does not report why the samples were lost beyond tissue processing, whether the loss differed by group, or how the missing samples were handled beyond exclusion from the endpoint population.

The analysis population is described by group as 10 participants with metabolic syndrome and 13 controls. These are the sample counts for the primary measure, not a complete account of every participant’s data. The total enrollment is 27. The registry record does not report a participant flow, missingness by outcome beyond the primary population note, or a rule for handling other incomplete measurements. It also does not report whether analyses used all available observations, a prespecified subset, or any additional adjustment.

The record describes an observational group comparison, not randomized assignment. General statistical explanation: randomization, when used, can help balance measured and unmeasured characteristics across groups on average. In an observational comparison, group differences may be entangled with other characteristics. A statistical adjustment can address specified measured differences, but it cannot automatically eliminate unmeasured confounding. The registry record does not report an adjustment model, covariates, matching, stratification, or another approach to account for group differences. The registry also warns that these are not like-for-like control arms. Any interpretation of a group contrast should therefore be descriptive and should not be treated as a causal effect.

The registry lists three outcome measures, including the primary composition measure and secondary outcomes of insulin sensitivity and lean and fat body mass. It records zero analyses. No detailed analysis plan is reported in the registry record. In particular, the record does not report the model used for the primary outcome, whether assumptions were checked, whether any transformation was used, or how potential outliers were handled. These omissions limit reproducibility and make it impossible to determine whether the reported endpoint summary, if reported elsewhere, arose from a prespecified analysis.

General statistical explanation: continuous measurements may sometimes show greater variability than a simple model assumes, or may have a distribution that does not fit a model’s assumptions. Over-dispersion, in settings where a model assumes a particular level of variability, can make standard errors too small if it is ignored. This concept is not a claim that over-dispersion occurred in this study. The registry record does not report diagnostics or a model that would allow readers to assess distributional assumptions for the PC:PE ratio.

The sample-size assumptions describe a planning illustration based on the observed effect, with two-sided significance level 0.05, equal allocation, and a normal approximation. The stated effect to detect is a fraction of the observed effect. This is a planning exercise, not a report of the trial’s original design justification and not observed power. The registry does not report the original sample-size justification, and the numerical planning results are not included in the registry record for this explanation. General statistical explanation: planning calculations depend on their assumptions about the target effect, variability, allocation, and error rates; they do not show that a study had a particular probability of obtaining a statistically significant result after it was completed.

The record does not report interim analyses or a multiplicity adjustment. Their absence from the registry record should not be interpreted as proof that no such procedures existed; their status is simply not reported. These details are relevant because repeated testing or testing multiple outcomes can affect the interpretation of nominal statistical evidence. With no numerical endpoint analyses or detailed statistical plan in the registry record, readers cannot assess these issues for the study’s reported findings.

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("Metabolic Syndrome", "Control")
n   <- c(10, 13)
m   <- c(2, 2.2)
sp  <- c(0.2, 0.2)
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  Metabolic Syndrome  10  2.000  0.632  1.548  2.452
CARM  Control  13  2.200  0.721  1.764  2.636

11. Multiplicity, Missing Data and Analysis Populations

The registry lists three outcome measures and identifies sarcoplasmic reticulum composition as the primary outcome. Insulin Sensitivity and Lean and Fat Body Mass are named as secondary outcomes. However, the registry record does not report the statistical results for these outcomes, nor does it provide a detailed analysis plan. It does not report whether a multiplicity adjustment was used, whether outcomes were tested in a specified hierarchy, or whether any additional outcomes were analyzed. These procedures are not reported in the registry record.

General statistical explanation: when researchers test multiple outcomes or make multiple comparisons, the chance of seeing at least one apparently notable result can increase. Prespecifying a primary endpoint and an analysis plan can help readers distinguish the main question from exploratory analyses. An adjustment may be used in some settings, but whether it is appropriate depends on the study question and analysis strategy. This general point does not establish that multiplicity affected this study. Because the registry does not report the relevant plan or results, the impact cannot be evaluated.

Missing data are directly relevant to the primary endpoint. The population note states that samples lost during tissue processing were not included and reports 10 metabolic syndrome and 13 control samples. Enrollment is listed as 27. The registry does not report why each sample was lost, whether loss varied by group, or whether missingness was related to a participant’s characteristics or underlying PC:PE value. It does not report a sensitivity analysis or an imputation method. The effect of the excluded samples on the result therefore cannot be assessed from this record.

The registry lists zero analyses. It does not provide a full analysis population definition for the secondary outcomes or describe how missing values for those outcomes were handled. General statistical explanation: an analysis population defines whose measurements contribute to a particular estimate; different definitions can produce different results if observations are excluded for reasons associated with the outcome. Without more detail, the analysis population and missing-data handling cannot be independently assessed.

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 serious adverse event record lists 12 participants at risk in the Metabolic Syndrome group and 15 in the Control group. It records zero serious adverse events in each group and zero deaths in each group. The figures describe what is entered in the registry safety record for these groups; they do not provide event rates over a stated follow-up duration or further detail about how safety events were collected.

The record also lists zero other adverse events in both groups, with the same at-risk counts. No serious adverse event terms are listed. These entries should be read as registry counts, not as proof that no adverse experiences of any kind occurred. The registry record does not report definitions, collection procedures, follow-up time for adverse events, or a narrative explaining whether all expected safety information was collected. The study’s listed intervention is a muscle biopsy, and its group descriptions also include glucose testing and a DEXA scan, but the safety entries do not separately attribute events to specific procedures.

General statistical explanation: an observed count of zero in a group does not establish that the underlying risk is zero. It means no events were recorded in that group under the recorded safety process and observation period. With no event timing, exposure duration, or detailed ascertainment methods reported, the figures should not be used to compare safety between groups or to generalize beyond the registry record.

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

The registry record establishes that the study set out to measure sarcoplasmic reticulum composition in muscle tissue and compare people with metabolic syndrome with controls. It names the PC:PE ratio as the primary endpoint and specifies a mean with standard error. It also describes related measurements of insulin sensitivity and body composition. This defines a research question about a tissue composition feature and its relationship to group membership.

The record does not provide the primary group means, standard errors, or a comparison estimate. It therefore does not show whether the observed PC:PE ratio was higher, lower, or similar between groups, and it does not show how precisely a difference was estimated. The absence of numerical findings in the registry record is not evidence of no difference. It is a limit on what can be concluded from the posted record.

Even if a group difference were reported elsewhere, the design caveat would remain important. The registry says allocation was not stated, the comparison was not randomized, and the arms were not a like-for-like control comparison. Differences in measured or unmeasured characteristics could contribute to a contrast. The registry record does not report an analysis strategy that adjusts for such differences. An association between group status and a tissue measure would not by itself establish that metabolic syndrome caused the difference.

The study’s stated motivation refers to previous research in mice and asks whether specific fat signatures translate to humans. The record gives the human research question and measurement approach, but the numerical results needed to answer that question are not reported in the registry record. The listed secondary outcomes likewise do not have numerical results in the registry entries. Thus, the record supports describing the study’s aims and procedures, but not a conclusion about the observed biological pattern or its relationship to insulin sensitivity.

The serious adverse event entries report no events or deaths in the listed groups, but those counts should be interpreted in light of the limited safety detail. They do not establish a general safety profile. Overall, the appropriate reading is narrow: the registry documents a completed observational study, its measured outcomes, the included primary endpoint samples, and the recorded safety counts. It does not provide enough statistical results to judge the primary comparison’s magnitude or precision.

14. Why This Trial Matters Statistically

This study illustrates how a registry can identify a precise measurement question without providing the results needed to evaluate it. The endpoint is not simply a broad diagnosis or a clinical event; it is the PC:PE ratio in a defined muscle tissue compartment. That specificity is useful for understanding what the investigators intended to measure. At the same time, without group estimates and their uncertainty, readers cannot tell whether the collected measurements support a meaningful contrast.

The record also illustrates why analysis populations matter. Enrollment is listed as 27, while the primary endpoint note reports 10 metabolic syndrome and 13 control samples and explains that some samples were lost during tissue processing. Those details make clear that enrollment and the number of usable primary samples are not interchangeable. Transparent reporting of sample disposition and the reasons for missing measurements helps readers judge how well an endpoint result represents the enrolled groups.

A further statistical issue is the distinction between group comparison and causal inference. The record explicitly describes the comparison as nonrandomized and not like-for-like. That warning matters because differences between groups can reflect factors beyond the group label. Statistical estimates can describe an observed association, but a causal interpretation depends on design and analysis assumptions that are not reported.

Finally, the record lists primary and secondary outcomes but reports zero analyses. This makes the case for reporting estimates, uncertainty, analysis populations, and methods alongside outcome names. A registry entry can communicate what was measured, yet a reader needs results and methods to judge precision, missing-data effects, multiplicity, and robustness. The record is therefore statistically informative about study intent and limitations, while leaving the central quantitative question unresolved.

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 primary outcome is that no group-level PC:PE results or direct comparison are reported in the registry record. The means and standard errors are specified as the intended summary, but their values are absent. There is no reported confidence interval or p-value for the comparison. Consequently, the direction, magnitude, and precision of the primary result cannot be assessed from this record.

The primary analysis population excludes samples lost during tissue processing. The record identifies the reason as processing loss, but does not explain the number lost by group or whether the loss could be related to participant characteristics or the underlying measurement. The endpoint counts are 10 for Metabolic Syndrome and 13 for Control, whereas overall enrollment is 27. No further participant flow is reported, so the relationship between enrollment and each analysis population is unclear.

The comparison is explicitly nonrandomized, with allocation not stated, and the record cautions that the arms are not a like-for-like control comparison. It does not report participant characteristics, matching, covariate adjustment, or an approach to confounding. Any group contrast, if available elsewhere, would therefore need cautious descriptive interpretation.

The registry identifies secondary outcomes but does not report their analyses. It also does not report detailed statistical methods, a protocol, a sample-size justification, interim analyses, or multiplicity procedures. Without these details, readers cannot evaluate whether analyses were prespecified, how assumptions were assessed, or how missing observations beyond the primary sample loss were handled. The safety record gives event counts but no detailed ascertainment methods or follow-up duration. Together, these omissions limit both reproducibility and the scope of conclusions that can be drawn from the registry entry.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Composition & Function of Sarcoplasmic Reticulum in Persons With the Metabolic Syndrome — NCT02122666.
• Registry record last updated 2024-10-26; status last verified 2024-08.
• Results first posted 2024-10-26.
• 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

NCT02122666 is a completed study sponsored by Washington University School of Medicine, with enrollment listed as 27 and primary completion on 2024-02-15. It compares a Metabolic Syndrome group with a Control group in a study of sarcoplasmic reticulum composition and function. Both groups are described as undergoing muscle biopsy, oral glucose tolerance testing with insulin measurements, and DEXA scanning.

The primary outcome is the mean PC:PE ratio in thigh muscle at Study Visit Week 4. Samples lost during tissue processing were excluded; the primary population description gives 10 participants with metabolic syndrome and 13 controls. Insulin Sensitivity and Lean and Fat Body Mass are listed as secondary outcomes. The registry reports zero analyses, and the primary numerical results are not reported in the registry record. Its design note states that the comparison is nonrandomized and the arms are not a like-for-like control comparison. Serious adverse events and deaths are recorded as zero in both groups.