An interventional study of Timing of OGTT and Timing of Standardized Meal in PreDiabetes, Overweight and Impaired Glucose Tolerance, sponsored by Johns Hopkins University. Recruiting at 1 site in United States. Open to participants aged 18 Years to 23 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-05-11.
Sponsored by Johns Hopkins University · Not applicable, Interventional, and Prevention
The proposed study uses a novel and rigorous randomized cross-over study design in youth (18-23y) with late and non-late chronotype (n=35 per group) to assess the glycemic effect of "aligning" an oral glucose tolerance test (OGTT) or first-meal of day to a subject's chronotype. Both groups will undergo 2 OGTTs (aligned and mis-aligned with chronotype) to compare glucose tolerance and insulin sensitivity within-subject (primary outcome) and between groups (Aim 1). Then, youth will also undergo two standardized meals (aligned and mis-aligned with chronotype) while wearing continuous glucose monitoring to compare post-prandial glucose excursions within-subject and between groups (Aim 2). A pilot Exploratory Aim 3 (n=12 per group) will investigate delayed melatonin patterns under dim-light as a potential pathophysiologic mechanism behind abnormal glucose tolerance in youth with late chronotype on morning OGTTs.
918 studies on the registry are indexed under Prediabetic State; 232 are open to participants now.
This study's planned enrollment of 70 is above the median of 62 across 762 interventional studies indexed under Prediabetic State.
Browse Prediabetic State studies →Johns Hopkins University is the lead sponsor of 1,815 studies on the registry; 315 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Sleep onset after 2am
Diagnostic Test: Timing of OGTT · Behavioral: Timing of Standardized Meal
Sleep onset before 11pm
Diagnostic Test: Timing of OGTT · Behavioral: Timing of Standardized Meal
In Aim 1, timing of oral glucose tolerance test will be altered.
In Aim 2, timing of a standardized meal will be altered.
2-Hour Difference in Glucose
Within-subject difference in 2-hour glucose after glucose ingestion on OGTT between early and late OGTT (primary analysis) in the late chronotype group and secondary analysis will be between group differences between early and late OGTT.
Time frame: Day 4 and Day 11 of Aim 1 derived from OGTT
Insulin Sensitivity (by Oral Minimal Model)
Within-subject difference in insulin sensitivity (derived from oral Minimal Model) between early and late OGTT (primary analysis) in the late chronotype group and secondary analysis will be between group differences between early and late OGTT.
Time frame: Day 4 and Day 11 of Aim 1 derived from OGTT
2-hour Incremental Area Under the Curve (iAUC) for glucose
Within-subject difference in iAUC for glucose from continuous glucose monitor between early and late Meal (primary analysis) in the late chronotype group and secondary analysis will be between group differences between early and late Meal.
Time frame: Day 1 and Day 8 of Aim 2 during post-prandial period following each standardized meal
Difference in Fasting Glucose
Within-subject difference in fasting glucose at start of OGTT between early and late OGTT (primary analysis) in the late chronotype group and secondary analysis will be between group differences between early and late OGTT.
Time frame: Day 4 and Day 11 of Aim 1 obtained before OGTT
Insulin secretion indices
Within-subject difference in insulin secretion (dynamic phase, static phase, total and insulin secretory rate) from c-peptide minimal model between early and late OGTT (primary analysis) in the late chronotype group and secondary analysis will be between group differences between early and late OGTT.
Time frame: Day 4 and Day 11 of Aim 1 derived from OGTT
Incremental Area Under the Curve (iAUC) for Insulin
Within-subject difference in iAUC for insulin after glucose ingestion between early and late OGTT (primary analysis) in the late chronotype group and secondary analysis will be between group differences between early and late OGTT.
Time frame: Day 4 and Day 11 of Aim 1 derived from OGTT
Hemoglobin A1c levels
Analysis of between group differences in hemoglobin A1c levels
Time frame: Day 4 of Aim 1 during first OGTT Visit
Difference in Disposition Index
Within-subject difference in disposition index (derived from insulin sensitivity and insulin secretion metrics) between early and late OGTT (primary analysis) in the late chronotype group and secondary analysis will be between group differences between early and late OGTT.
Time frame: Day 4 and Day 11 of Aim 1 derived from OGTT
Difference in Insulin Clearance
Within-subject difference in insulin clearance (derived from Watanabe et al. model) between early and late OGTT (primary analysis) in the late chronotype group and secondary analysis will be between group differences between early and late OGTT.
Time frame: Day 4 and Day 11 of Aim 1 derived from OGTT
Mean Glucose
Analysis of between group differences in mean glucose derived from continuous glucose monitor
Time frame: Up to 8 days
Percent Time Spent Above 120 mg/dL
Analysis of between group differences in time spent above 120 mg/dL derived from continuous glucose monitor. Over course of wearing continuous glucose monitor for Aim 2 (8 days)\]
Time frame: Up to 8 days
Percent Time Spent Above 140 mg/dL
Analysis of between group differences in time spent above 140 mg/dL derived from continuous glucose monitor. Over course of wearing continuous glucose monitor for Aim 2 (8 days).
Time frame: Up to 8 days
Number of Excursions greater than 140mg/dL
Analysis of between group differences in the number of excursions above 140 mg/dL derived from continuous glucose monitor. Over course of wearing continuous glucose monitor for Aim 2 (8 days).
Time frame: Up to 8 days
Difference in Post-prandial peak
Within-subject difference in post-prandial peak from continuous glucose monitor between early and late Meal (primary analysis) in the late chronotype group and secondary analysis will be between group differences between early and late Meal
Time frame: Day 1 and Day 8 of Aim 2 during post-prandial period following each standardized meal
Standard Deviation of Glucose
Analysis of between group differences in standard deviation of glucose derived from continuous glucose monitor. Over course of wearing continuous glucose monitor for Aim 2 (8 days).
Time frame: Up to 8 days
Coefficient of Variation of Glucose
Analysis of between group differences in coefficient of variation of glucose derived from continuous glucose monitor. Over course of wearing continuous glucose monitor for Aim 2 (8 days).
Time frame: Up to 8 days
PDFs hosted by the registry, ClinicalTrials.gov.
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