Polymorphism, Restriction Fragment LengthNCT05750732
Weight Loss and CLOCK 3111T/C Polymorphism
An observational study of Polymorphism, Restriction Fragment Length and Obesity, run by Hacettepe University at 1 site in Turkey (Türkiye).
Trial summary
The goal of this observational study is to investigate the relationship of CLOCK 3111T/C (rs1801260) gene variant with nutritional habits, nutritional status, chronotype, sleep quality, some biochemical parameters in overweight or obese individuals and to observe its effect on weight loss diet intervention. Read more about this study
- Who is it for?
- Ages 20 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Polymorphism, Restriction Fragment Length, Obesity
- What is being tested?
- Weight loss diet
- Type of treatment
- Lifestyle or therapy programme
- How many people
- 400 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 20 Feb 2023to 1 Feb 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 20 to 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: The population of the study consists of overweight or obese individuals who applied to Hacettepe University Adult Hospital Endocrinology outpatient clinic. Individuals will be included in the study after being evaluated by the responsible physician and dietitian in Hacettepe University Adult Hospital Endocrinology outpatient clinic in terms of inclusion and exclusion criteria.
Who may be able to join
- Be in the 20-50 age range
- BMI in the range of 25-40 kg/m2 for the study group
- BMI of 18.5-24.9 kg/m2 for the control group
Who cannot join
- Those with type 1 diabetes
- Those with Type 2 diabetes who take insulin therapy or use oral diabetes medication
- Those who use drugs for weight loss
- Those with unstable cardiovascular disease
- Those with kidney or liver failure
- Presence of diagnosed malabsorption (celiac disease, Crohn's, ulcerative colitis)
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- Those who have undergone bariatric surgery
- Those who are pregnant or breastfeeding
- Menopausal women
- Those who use corticosteroids
- Those with severe endocrine disorders (hypothyroidism, hyperthyroidism, hypopituitarism)
- Those with psychiatric or neurological disease
- Weight change of >5% in the last 6 months
- Those with malignant tumors
- Those with eating disorders
- Shift workers
- Relatives
- People from different ethnic backgrounds
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site, 1 recruiting
- Recruiting
Hacettepe University
Ankara, 06050
Hande Gül Ulusoy Gezer, MSc, +905357314604, handegululusoy@gmail.com
About this study
Official title: Investigation of the Relationship Between Weight Loss Diet and Circadian Gene CLOCK 3111T/C Polymorphism
The goal of this observational study is to investigate the relationship of CLOCK 3111T/C (rs1801260) gene variant with nutritional habits, nutritional status, chronotype, sleep quality, some biochemical parameters in overweight or obese individuals and to observe its effect on weight loss diet intervention. The main questions it aims to answer are:
- Is the frequency of carrying the CLOCK 3111T/C (rs1801260) gene risk allele different between individuals with normal body weight and those who are overweight or obese?
- Do those with the CLOCK 3111T/C (rs1801260) risk allele have a higher frequency of evening chronotype and a shorter sleep duration?
- Is the effect of CLOCK 3111T/C (rs1801260) gene alleles different on weight loss diet response in overweight or obese individuals? A questionnaire will be applied to the individuals in both groups (normal body weight and overweight/obese individuals) to evaluate their general characteristics, eating habits, adherence to Mediterranean diet, DASH and MIND. In addition, anthropometric measurements, 3-day food consumption record and 3-day physical activity record will be taken from individuals. CLOCK 3111T/C (rs1801260) gene variant analysis in whole blood, adiponectin and leptin hormones in serum samples will be studied. Participants those who are overweight/obese will be asked to follow a weight loss diet for 3 months.
Researchers will compare participants with normal body weight and those who are overweight or obese to see if there is a difference between the frequency of carrying the CLOCK 3111T/C (rs1801260) gene risk allele.
- Conditions
- Polymorphism, Restriction Fragment Length, Obesity
- Being tested
- Weight loss diet
- Keywords
- obesity, circadian rhythm, polymorphism, CLOCK gene, weight loss diet
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Weight loss dietBehavioural
Participants in the study group will be given training on the weight loss diet, which is a routine part of their treatment.
| Study group | Role | What they receive |
|---|---|---|
| Study group | Age range 20-50, BMI range of 25-40 kg/m2 Receives: Behavioral: Weight loss diet | |
| Control group | Age range 20-50, BMI range18.5-24.9 kg/m2 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in body weight
Body weight (kg) at 12 weeks minus weight at baseline (kg)
Measured: Baseline to 12 weeks
Change in dietary energy and nutrient intakes
Energy and nutrients intakes will be assessed using a dietary recall method at baseline, 4th week, 8th week and at end of the intervention
Measured: Baseline to 12 weeks
Circadian CLOCK gene polymorphism
Comparative analysis of the frequency distributions of genotypes and alleles of 3111T/C CLOCK gene polymorphism will be carried out both in study and control group
Measured: 1 day
Secondary outcomes (8)
Change in sleep quality
Using 19-item Pittsburg Sleep Quality Index (PSQI)
Measured: Baseline to 12 weeks
Change in adherence to Mediterranean diet
Using the 14-item Mediterranean Diet Adherence Screener (MEDAS)
Measured: Baseline to 12 weeks
Change in adherence to DASH
Using the 11-item Dietary Approaches to Stop Hypertension-Quality (DASH-Q)
Measured: Baseline to 12 weeks
Change in adherence to MIND
Using the 14-item The Mediterranean-DASH Diet Intervention for Neurodegenerative Delay (MIND) score
Measured: Baseline to 12 weeks
Change in chronotype
Using the 19-item The Morningness-Eveningness Questionnaire (MEQ)
Measured: Baseline to 12 weeks
Change in eating behaviors
Using the 18-item The Three-Factor Eating Questionnaire (TFEQ-18)
Measured: Baseline to 12 weeks
Change in night eating behaviors
Using the 16-item The Night Eating Questionnaire (NEQ)
Measured: Baseline to 12 weeks
Change in serum adiponectin and leptin level
Using ELISA kits
Measured: Baseline to 12 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Mar 2023
- Study start20 Feb 2023
- Primary completion1 Jun 2025 (estimated)
- Study completion1 Feb 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Polymorphism, Restriction Fragment LengthStudies 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
- Observational
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Enrolment
- 400 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hacettepe University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Hande Gül Ulusoy Gezer, Hacettepe University
- Investigators
- Hanife Seda Oğuz Baykal, Dr, Study chair, Hacettepe UniversityErdem Karabulut, Prof, Study chair, Hacettepe UniversityNeslişah Rakıcıoğlu, Prof, Study director, Hacettepe UniversityHande Gül Ulusoy Gezer, MSc, Principal investigator, Hacettepe University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05750732
- Sponsor's protocol ID
- GO 22/1321
- Status last verified
- Oct 2024
- First submitted
- 20 Feb 2023
- Last updated
- 27 Apr 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 27 Apr 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Investigation of the Relationship Between Weight Loss Diet and Circadian Gene CLOCK 3111T/C Polymorphism
- ClinicalTrials.gov ID
- NCT05750732
- Acronym / sponsor ID
- GO 22/1321
- Conditions
- Polymorphism, Restriction Fragment Length, Obesity
- Keywords
- obesity, circadian rhythm, polymorphism, CLOCK gene, weight loss diet
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 400 participants (estimated)
- Lead sponsor
- Hacettepe UniversityUniversity, hospital or other
- Study start
- 20 Feb 2023 (actual)
- Primary completion
- 1 Jun 2025 (estimated)
- Study completion
- 1 Feb 2026 (estimated)
- First posted
- 2 Mar 2023 (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.
The goal of this observational study is to investigate the relationship of CLOCK 3111T/C (rs1801260) gene variant with nutritional habits, nutritional status, chronotype, sleep quality, some biochemical parameters in overweight or obese individuals and to observe its effect on weight loss diet intervention. The main questions it aims to answer are:
- Is the frequency of carrying the CLOCK 3111T/C (rs1801260) gene risk allele different between individuals with normal body weight and those who are overweight or obese?
- Do those with the CLOCK 3111T/C (rs1801260) risk allele have a higher frequency of evening chronotype and a shorter sleep duration?
- Is the effect of CLOCK 3111T/C (rs1801260) gene alleles different on weight loss diet response in overweight or obese individuals? A questionnaire will be applied to the individuals in both groups (normal body weight and overweight/obese individuals) to evaluate their general characteristics, eating habits, adherence to Mediterranean diet, DASH and MIND. In addition, anthropometric measurements, 3-day food consumption record and 3-day physical activity record will be taken from individuals. CLOCK 3111T/C (rs1801260) gene variant analysis in whole blood, adiponectin and leptin hormones in serum samples will be studied. Participants those who are overweight/obese will be asked to follow a weight loss diet for 3 months.
Researchers will compare participants with normal body weight and those who are overweight or obese to see if there is a difference between the frequency of carrying the CLOCK 3111T/C (rs1801260) gene risk allele.
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Study group | – | Behavioral: Weight loss dietAge range 20-50, BMI range of 25-40 kg/m2 |
| Control group | – | –Age range 20-50, BMI range18.5-24.9 kg/m2 |
Who may qualify
- Ages
- 20 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- The population of the study consists of overweight or obese individuals who applied to Hacettepe University Adult Hospital Endocrinology outpatient clinic. Individuals will be included in the study after being evaluated by the responsible physician and dietitian in Hacettepe University Adult Hospital Endocrinology outpatient clinic in terms of inclusion and exclusion criteria.
Key inclusion criteria (3 listed)
- Be in the 20-50 age range
- BMI in the range of 25-40 kg/m2 for the study group
- BMI of 18.5-24.9 kg/m2 for the control group
Key exclusion criteria (18 listed)
- Those with type 1 diabetes
- Those with Type 2 diabetes who take insulin therapy or use oral diabetes medication
- Those who use drugs for weight loss
- Those with unstable cardiovascular disease
- Those with kidney or liver failure
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 |
|---|---|---|
| Weight loss dietParticipants in the study group will be given training on the weight loss diet, which is a routine part of their treatment. | Behavioural | Study group |
Primary outcome
Change in body weight
Time frame: Baseline to 12 weeks
Body weight (kg) at 12 weeks minus weight at baseline (kg)
Change in dietary energy and nutrient intakes
Time frame: Baseline to 12 weeks
Energy and nutrients intakes will be assessed using a dietary recall method at baseline, 4th week, 8th week and at end of the intervention
Circadian CLOCK gene polymorphism
Time frame: 1 day
Comparative analysis of the frequency distributions of genotypes and alleles of 3111T/C CLOCK gene polymorphism will be carried out both in study and control group
8 secondary outcomes
Change in sleep quality
Time frame: Baseline to 12 weeks
Change in adherence to Mediterranean diet
Time frame: Baseline to 12 weeks
Change in adherence to DASH
Time frame: Baseline to 12 weeks
Change in adherence to MIND
Time frame: Baseline to 12 weeks
Change in chronotype
Time frame: Baseline to 12 weeks
Change in eating behaviors
Time frame: Baseline to 12 weeks
Change in night eating behaviors
Time frame: Baseline to 12 weeks
Change in serum adiponectin and leptin level
Time frame: Baseline to 12 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Apr 2025.
- Individual participant dataSharing planned: Undecided
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.
Hanife Seda Oğuz Baykal, Dr study chair
Hacettepe University
Erdem Karabulut, Prof study chair
Hacettepe University
Neslişah Rakıcıoğlu, Prof study director
Hacettepe University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Polymorphism, Restriction Fragment Length and Obesity, run by Hacettepe University at 1 site in Turkey (Türkiye).
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 3 inclusion and 18 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: looking for participants now, as of the sponsor's last update on 27 Apr 2025. 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 Turkey (Türkiye). 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Hande Gül Ulusoy Gezer, MSc (+905357314604, handegululusoy@hacettepe.edu.tr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in body weight (time frame: Baseline to 12 weeks). The study lists 3 primary outcomes in all. 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 27 Apr 2025.