PrediabetesCLOCK-PRIMENCT07618663
Personalized Meal Timing and Walking Based on Glucose Patterns in Adults With Prediabetes
A study testing Phenotype-Guided Meal Timing and Postprandial Walking and Sleep Hygiene and Step-Count Advice in people with Prediabetes and Prediabetes (Insulin Resistance, Impaired Glucose Tolerance), run by Shifa International Hospital at 1 site in Pakistan.
Trial summary
This study will test whether glucose sensor data can be used to identify the time of day when adults with prediabetes are most likely to have high blood sugar after meals. Participants will first wear a continuous glucose monitor and wrist activity monitor and record meal times for 10 days. Read more about this study
- Who is it for?
- Ages 30 to 70 years
- Conditions the study is for
- Prediabetes, Prediabetes (Insulin Resistance, Impaired Glucose Tolerance), Prediabetes or Diabetes
- What is being tested?
- Phenotype-Guided Meal Timing and Postprandial Walking and Sleep Hygiene and Step-Count Advice
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 105 participants
- Where
- 1 sitePakistan
- Study dates
- 1 Jun 2026to 26 Jul 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 30 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age 30 to 70 years
- Prediabetes, defined as either:
- HbA1c 5.7% to 6.4% within 3 months of screening, or
- Fasting plasma glucose 100 to 125 mg/dL on two separate occasions
- Body mass index 23 to 40 kg/m²
- Owns a smartphone compatible with study applications
Show all 9Show fewer
- Willing to wear a continuous glucose monitor and wrist activity monitor during the study period
- Willing to record meals using timestamped meal-photo logging
- Able to provide written informed consent
Who cannot join
- Current or prior diagnosis of type 1 diabetes or type 2 diabetes
- Use of glucose-lowering medication within the past 3 months
- Use of systemic corticosteroid medication within the past 3 months
- Use of prescription weight-loss medication within the past 3 months
- Current shift work
- Transmeridian travel across more than 2 time zones within 4 weeks before enrollment
Show all 12Show fewer
- Known untreated or unstable sleep disorder, including obstructive sleep apnea, narcolepsy, or insomnia disorder
- Pregnancy, planned pregnancy, or breastfeeding
- Gastrointestinal disease or surgery likely to affect nutrient absorption
- Current participation in a structured dietary or exercise intervention program
- Estimated glomerular filtration rate less than 60 mL/min/1.73 m²
- Inability or unwillingness to comply with continuous glucose monitoring, wrist actigraphy, meal logging, or study visits
Trial locations and contacts
1 site in 1 country.
About this study
Official title: CGM-Phenotyped Circadian Glycemic Vulnerability Windows to Personalize Meal Timing and Postprandial Activity in Prediabetes : A Randomized Controlled Trial
This study will test whether glucose sensor data can be used to identify the time of day when adults with prediabetes are most likely to have high blood sugar after meals. Participants will first wear a continuous glucose monitor and wrist activity monitor and record meal times for 10 days. These data will be used to classify each participant's personal "glycemic vulnerability window," such as morning, evening, or generally variable patterns.
Participants will then be randomly assigned to either personalized meal timing plus a short walk after their most vulnerable meal, or to an attention-matched control group receiving sleep hygiene and general step-count advice. The main outcome will be the change in post-meal glucose exposure during each participant's vulnerable window after 4 weeks.
Read the detailed description
Prediabetes is a high-risk metabolic state in which postprandial glucose excursions and glycemic variability may contribute to progression toward type 2 diabetes. Although lifestyle modification can reduce diabetes risk, conventional advice is usually generic and does not account for individual differences in the timing of glucose intolerance across the day. Emerging evidence suggests that circadian biology, meal timing, sleep timing, and postprandial activity may influence glucose regulation, but it remains unclear whether continuous glucose monitoring can be used to personalize the timing of meals and brief activity in adults with prediabetes.
CLOCK-PRIME is a single-center, two-arm, randomized controlled trial in adults with prediabetes. Participants will undergo a 10-day blinded observational run-in period using continuous glucose monitoring, wrist actigraphy, and timestamped meal-photo logging. Run-in data will be used to classify participants into pre-specified circadian glycemic phenotypes based on postprandial glucose incremental area under the curve during morning and evening windows. Participants will be categorized as morning-vulnerable, evening-vulnerable, or globally variable.
After phenotype classification, participants will be randomized to either a phenotype-guided intervention or an attention-matched active control group. The intervention group will receive personalized guidance to shift the highest glycemic-load meal away from the participant's highest-vulnerability window and toward the lowest-vulnerability window. Participants will also be advised to perform a 10-minute brisk walk within 30 minutes after the meal occurring in their highest-vulnerability window. The control group will receive standardized sleep hygiene advice and a general step-count goal, without meal-timing or postprandial walking instructions.
The primary endpoint is the change from baseline to week 4 in vulnerable-window postprandial glucose incremental area under the curve measured by continuous glucose monitoring. Secondary endpoints include time in range, time above range, glucose coefficient of variation, mean postprandial peak glucose, nocturnal mean glucose, sleep regularity, social jetlag, and actigraphy-derived activity patterns. Exploratory mechanistic outcomes include fasting dried-blood-spot measures of cortisol:insulin ratio and selected primary bile acids to assess whether changes in neuroendocrine or enterohepatic metabolic pathways accompany improvement in glycemic vulnerability.
The study is designed to determine whether CGM-derived circadian glycemic vulnerability windows can support a feasible precision lifestyle strategy for reducing postprandial glycemic burden in adults with prediabetes.
- Conditions
- Prediabetes, Prediabetes (Insulin Resistance, Impaired Glucose Tolerance), Prediabetes or Diabetes
- Being tested
- Phenotype-Guided Meal Timing and Postprandial Walking, Sleep Hygiene and Step-Count Advice
- Keywords
- Prediabetes, Continuous Glucose Monitoring, Precision Lifestyle Medicine, Meal Timing, Glycemic Variability
- Medical subject headings
- Prediabetic State, Insulin Resistance, Glucose Intolerance, Diabetes Mellitus
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Phenotype-Guided Meal Timing and Postprandial WalkingBehavioural
Also called Phenotype-Guided Meal Timing, Postprandial Walking
Participants randomized to this arm will receive personalized lifestyle guidance based on their CGM-derived circadian glycemic vulnerability phenotype. During the 10-day run-in period, continuous glucose monitoring, wrist actigraphy, and timestamped meal-photo logs will be used to identify the time window in which each participant has the greatest postprandial glucose exposure. Participants will be advised to shift their highest glycemic-load meal away from their highest-vulnerability window and toward their lowest-vulnerability window where feasible. They will also be instructed to perform a 10-minute brisk walk within 30 minutes after the meal occurring in their highest-vulnerability window on at least 5 days per week. The intervention will be delivered through structured dietitian counseling sessions and brief weekly check-in calls. No calorie restriction, prescribed macronutrient diet, or weight-loss target will be imposed.
Sleep Hygiene and Step-Count AdviceBehavioural
Also called Sleep Hygiene, Step-Count Advice
Participants randomized to the active comparator arm will receive standardized sleep hygiene and general physical activity guidance matched for contact time with the intervention arm. Sleep hygiene advice will include maintaining regular sleep and wake times, aiming for adequate sleep duration, and reducing screen exposure before bedtime. Participants will also be advised to increase their average daily step count by approximately 10% above their run-in baseline, with steps distributed freely throughout the day. This arm will not include any advice on meal timing, carbohydrate timing, glycemic vulnerability windows, or postprandial walking. The intervention will be delivered through structured dietitian counseling sessions and brief weekly check-in calls.
| Study group | Role | What they receive |
|---|---|---|
| Phenotype-Guided Meal Timing and Postprandial Walking | Experimental | Participants will receive personalized lifestyle guidance based on their CGM-derived circadian glycemic vulnerability phenotype. They will be advised to shift their highest glycemic-load meal away from their highest-vulnerability window and toward their lowest-vulnerability window, and to perform a 10-minute brisk walk within 30 minutes after the meal occurring in their highest-vulnerability window. Receives: Behavioral: Phenotype-Guided Meal Timing and Postprandial Walking |
| Attention-Matched Sleep Hygiene and Step-Count Advice | Active comparator | Participants will receive standardized sleep hygiene advice and general step-count guidance matched for contact time with the intervention group. They will not receive meal-timing advice, carbohydrate-timing advice, or postprandial walking instructions. Receives: Behavioral: Sleep Hygiene and Step-Count Advice |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Vulnerable-Window Postprandial Glucose Incremental Area Under the Curve
Change from baseline run-in period to week 4 in mean postprandial glucose incremental area under the curve during each participant's pre-specified highest glycemic vulnerability window. Postprandial glucose incremental area under the curve will be calculated from continuous glucose monitoring data over 120 minutes after logged meals using the trapezoidal rule. Unit of measure: mg/dL·min
Measured: Baseline run-in period to Week 4
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Jun 2026
- Study start1 Jun 2026
- Primary completion30 Jun 2026
- Study completion26 Jul 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for PrediabetesStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Participants with prediabetes will undergo a 10-day blinded run-in period with continuous glucose monitoring, wrist actigraphy, and meal-photo logging to identify individual circadian glycemic vulnerability patterns. After phenotype classification, participants will be randomized in a 1:1 ratio to either phenotype-guided personalized meal timing plus targeted postprandial walking, or to an attention-matched active control group receiving sleep hygiene and general step-count advice.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 105 participants (actual)
Sponsor and investigators
- Lead sponsor
- Shifa International Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Saima Abass Tahammal, Shifa International Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07618663
- Sponsor's protocol ID
- SH-34988909
- Other IDs
- SIAC-02392
- Acronym
- CLOCK-PRIME
- Status last verified
- May 2026
- First submitted
- 24 May 2026
- Last updated
- 28 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: De-identified individual participant data underlying the published results may be shared upon reasonable request after publication, subject to institutional approval, data-use agreement, and protection of participant confidentiality.
Study at a glance
From the registry record, last updated by the sponsor on 28 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- CGM-Phenotyped Circadian Glycemic Vulnerability Windows to Personalize Meal Timing and Postprandial Activity in Prediabetes : A Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07618663
- Acronym / sponsor ID
- CLOCK-PRIME / SH-34988909
- Conditions
- Prediabetes, Prediabetes (Insulin Resistance, Impaired Glucose Tolerance), Prediabetes or Diabetes
- Keywords
- Prediabetes, Continuous Glucose Monitoring, Precision Lifestyle Medicine, Meal Timing, Glycemic Variability
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 105 participants (actual)
- Lead sponsor
- Shifa International HospitalUniversity, hospital or other
- Study start
- 1 Jun 2026 (actual)
- Primary completion
- 30 Jun 2026 (actual)
- Study completion
- 26 Jul 2026 (actual)
- First posted
- 1 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study will test whether glucose sensor data can be used to identify the time of day when adults with prediabetes are most likely to have high blood sugar after meals. Participants will first wear a continuous glucose monitor and wrist activity monitor and record meal times for 10 days. These data will be used to classify each participant's personal "glycemic vulnerability window," such as morning, evening, or generally variable patterns.
Participants will then be randomly assigned to either personalized meal timing plus a short walk after their most vulnerable meal, or to an attention-matched control group receiving sleep hygiene and general step-count advice. The main outcome will be the change in post-meal glucose exposure during each participant's vulnerable window after 4 weeks.
Detailed description
Prediabetes is a high-risk metabolic state in which postprandial glucose excursions and glycemic variability may contribute to progression toward type 2 diabetes. Although lifestyle modification can reduce diabetes risk, conventional advice is usually generic and does not account for individual differences in the timing of glucose intolerance across the day. Emerging evidence suggests that circadian biology, meal timing, sleep timing, and postprandial activity may influence glucose regulation, but it remains unclear whether continuous glucose monitoring can be used to personalize the timing of meals and brief activity in adults with prediabetes.
CLOCK-PRIME is a single-center, two-arm, randomized controlled trial in adults with prediabetes. Participants will undergo a 10-day blinded observational run-in period using continuous glucose monitoring, wrist actigraphy, and timestamped meal-photo logging. Run-in data will be used to classify participants into pre-specified circadian glycemic phenotypes based on postprandial glucose incremental area under the curve during morning and evening windows. Participants will be categorized as morning-vulnerable, evening-vulnerable, or globally variable.
After phenotype classification, participants will be randomized to either a phenotype-guided intervention or an attention-matched active control group. The intervention group will receive personalized guidance to shift the highest glycemic-load meal away from the participant's highest-vulnerability window and toward the lowest-vulnerability window. Participants will also be advised to perform a 10-minute brisk walk within 30 minutes after the meal occurring in their highest-vulnerability window. The control group will receive standardized sleep hygiene advice and a general step-count goal, without meal-timing or postprandial walking instructions.
The primary endpoint is the change from baseline to week 4 in vulnerable-window postprandial glucose incremental area under the curve measured by continuous glucose monitoring. Secondary endpoints include time in range, time above range, glucose coefficient of variation, mean postprandial peak glucose, nocturnal mean glucose, sleep regularity, social jetlag, and actigraphy-derived activity patterns. Exploratory mechanistic outcomes include fasting dried-blood-spot measures of cortisol:insulin ratio and selected primary bile acids to assess whether changes in neuroendocrine or enterohepatic metabolic pathways accompany improvement in glycemic vulnerability.
The study is designed to determine whether CGM-derived circadian glycemic vulnerability windows can support a feasible precision lifestyle strategy for reducing postprandial glycemic burden in adults with prediabetes.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- Participants with prediabetes will undergo a 10-day blinded run-in period with continuous glucose monitoring, wrist actigraphy, and meal-photo logging to identify individual circadian glycemic vulnerability patterns. After phenotype classification, participants will be randomized in a 1:1 ratio to either phenotype-guided personalized meal timing plus targeted postprandial walking, or to an attention-matched active control group receiving sleep hygiene and general step-count advice.
| Arm | Type | Receives |
|---|---|---|
| Phenotype-Guided Meal Timing and Postprandial Walking | Experimental | Behavioral: Phenotype-Guided Meal Timing and Postprandial WalkingParticipants will receive personalized lifestyle guidance based on their CGM-derived circadian glycemic vulnerability phenotype. They will be advised to shift their highest glycemic-load meal away from their highest-vulnerability window and toward their lowest-vulnerability window, and to perform a 10-minute brisk walk within 30 minutes after the meal occurring in their highest-vulnerability window. |
| Attention-Matched Sleep Hygiene and Step-Count Advice | Active comparator | Behavioral: Sleep Hygiene and Step-Count AdviceParticipants will receive standardized sleep hygiene advice and general step-count guidance matched for contact time with the intervention group. They will not receive meal-timing advice, carbohydrate-timing advice, or postprandial walking instructions. |
Who may qualify
- Ages
- 30 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (9 listed)
- Age 30 to 70 years
- Prediabetes, defined as either:
- HbA1c 5.7% to 6.4% within 3 months of screening, or
- Fasting plasma glucose 100 to 125 mg/dL on two separate occasions
- Body mass index 23 to 40 kg/m²
Key exclusion criteria (12 listed)
- Current or prior diagnosis of type 1 diabetes or type 2 diabetes
- Use of glucose-lowering medication within the past 3 months
- Use of systemic corticosteroid medication within the past 3 months
- Use of prescription weight-loss medication within the past 3 months
- Current shift work
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Phenotype-Guided Meal Timing and Postprandial WalkingAlso: Phenotype-Guided Meal Timing, Postprandial WalkingParticipants randomized to this arm will receive personalized lifestyle guidance based on their CGM-derived circadian glycemic vulnerability phenotype. During the 10-day run-in period, continuous glucose monitoring, wrist actigraphy, and timestamped meal-photo logs will be used to identify the time window in which each participant has the greatest postprandial glucose exposure. Participants will be advised to shift their highest glycemic-load meal away from their highest-vulnerability window and toward their lowest-vulnerability window where feasible. They will also be instructed to perform a 10-minute brisk walk within 30 minutes after the meal occurring in their highest-vulnerability window on at least 5 days per week. The intervention will be delivered through structured dietitian counseling sessions and brief weekly check-in calls. No calorie restriction, prescribed macronutrient diet, or weight-loss target will be imposed. | Behavioural | Phenotype-Guided Meal Timing and Postprandial Walking |
| Sleep Hygiene and Step-Count AdviceAlso: Sleep Hygiene, Step-Count AdviceParticipants randomized to the active comparator arm will receive standardized sleep hygiene and general physical activity guidance matched for contact time with the intervention arm. Sleep hygiene advice will include maintaining regular sleep and wake times, aiming for adequate sleep duration, and reducing screen exposure before bedtime. Participants will also be advised to increase their average daily step count by approximately 10% above their run-in baseline, with steps distributed freely throughout the day. This arm will not include any advice on meal timing, carbohydrate timing, glycemic vulnerability windows, or postprandial walking. The intervention will be delivered through structured dietitian counseling sessions and brief weekly check-in calls. | Behavioural | Attention-Matched Sleep Hygiene and Step-Count Advice |
Primary outcome
Change in Vulnerable-Window Postprandial Glucose Incremental Area Under the Curve
Time frame: Baseline run-in period to Week 4
Change from baseline run-in period to week 4 in mean postprandial glucose incremental area under the curve during each participant's pre-specified highest glycemic vulnerability window. Postprandial glucose incremental area under the curve will be calculated from continuous glucose monitoring data over 120 minutes after logged meals using the trapezoidal rule. Unit of measure: mg/dL·min
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Jul 2026.
- Individual participant dataSharing planned: No. De-identified individual participant data underlying the published results may be shared upon reasonable request after publication, subject to institutional approval, data-use agreement, and protection of participant confidentiality.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Phenotype-Guided Meal Timing and Postprandial Walking and Sleep Hygiene and Step-Count Advice in people with Prediabetes and Prediabetes (Insulin Resistance, Impaired Glucose Tolerance), run by Shifa International Hospital at 1 site in Pakistan.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 9 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 28 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Pakistan. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Vulnerable-Window Postprandial Glucose Incremental Area Under the Curve (time frame: Baseline run-in period to Week 4). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Jul 2026.