MTNR1B SNP*Food Timing Interaction on Glucose Control in a Late Eater Mediterranean Population
Phase: NA
Conditions: Non-Diabetic Disorder of Endocrine Pancreas
Sponsor: Universidad de Murcia

INTERVENTION STUDY PROTOCOL 
Impact of melatonin, food timing and receptor gene variant on type 2 diabetes risk 
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“Impact of melatonin, food timing and receptor 
gene variant on type 2 diabetes risk” 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Main researcher: Marta Garaulet Aza 
 
 
 
Identifier: NCT03036592 
 
 
 
Date: 09/01/2016 
 

INTERVENTION STUDY PROTOCOL 
Impact of melatonin, food timing and receptor gene variant on type 2 diabetes risk 
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INCLUSION/EXCLUSION CRITERIA 
• 18-65 years 
• BMI >18,5 kg/m2 and <40 kg/m2 
• No diabetics, no cancer 
• No pregnant 
• European race 
• If your work is outside of the range between 7:00 a.m. and 11:00 p.m. In the case that the patients 
have been shift worker, they will can participate if they leave the shift during 2 years. 
• Not take melatonin in the last two weeks, and the two weeks of the study 
• Not eat the following drugs: 
I. Those that affect blood sugar values: a) insulin; b) medications for type 2 diabetes such as 
Metformin or other oral antidiabetics such as sulfonylureas, meglitinides, or glitazones; c) 
Corticosteroids / steroids; d) growth hormone 
II. Those that affect blood clotting: e) anticoagulant drugs, or anticoagulants such as heparin, 
warfarin (Coumadin) or copylores (Plavix) 
III. Those that affect the values of melatonin or sleep and circadian rhythms: f) beta-blockers for 
hypertension (high blood pressure), such as metoprolol (Lopressor), mexiletine, propranolol or 
verapamil; g) medications for sleep disorders (circadian rhythms) such as lithium, ramelteon, 
hypnotics (such as Ambien, Sonata or Lunesta) or other stimulants such as Provigil 
Name if you take medicines such as nonsteroidal, anti-inflammatory drugs such as ibuprofen or 
aspirin 
• History (family history questions) to non-patients Garaulet 
Level of studies: school / institute / university 
If you are a smoker, how many cigarettes / day 
 
MEASUREMENTS 
 
1. Food timing and dietary record: 
• 7 consecutive days dietary food intake (mobile app and foods pictures) 
 
2. Light exposure: HOBO pendant sensor (7 consecutive days included those days of the study). 
The day of the study, be sure that during OGTT (Oral Glucose Tolerance Test) in the late 
condition (1 hour before their habitual bedtime) the light not be more than 10 luxes and that this 
situation star 30 minutes before the time of the OGTT. In the early condition (4 hour before their 
habitual bedtime) the light would be more than 500 luxes. 
 
3. Anthropometric and biochemistry measurements: 
• 
BMI 
• 
Waist and Hip (cm). 
• 
Impedance data: % Fatty Mass, Kg Fatty Weight, Kg Lean Mass, Kg Muscle Mass, Kg Total 
Water, % Total Water, Kg Bone Mass, Basal Metabolism (KJ), Basal Metabolism (Kcal), 
Metabolic Age, Visceral Fat Level, Degree of Obesity (%) 
• 
Sex, age 
• 
Menopause (Yes/No) and the date of the last menstruation. The patient should be pipi before 
the impedance, all of the impedances would be at the same time (19:00-20:00h). 
 
4. Questionnaires: 
1) Demographics and Health Survey: socioeconomic status, habitual alcohol intake, smoking, sleep 
apnea, insomnia 
2) Inform consent 
3) Anthropometric characteristics and OGTT conditions 
4) International Physical Activity Questionnaire (IPAQ) 
5) Morningness Eveningness Questionnaire (MEQ) 

INTERVENTION STUDY PROTOCOL 
Impact of melatonin, food timing and receptor gene variant on type 2 diabetes risk 
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6) Emotional Eating Questionnaire (EEQ) 
7) Food and Sleep log (food and timing) 
8) Pittsburgh Sleep Quality Index 
9) Day of the experiment menu 
10) Control sheet 
11) Insomnia Severity Index (ISI) 
12) Patient Health Questionnaire-9 (PHQ-9) 
 
5. Actigraphy 
Actigraphy (sensor). For 7 consecutive days to record the activity rhythm the week before the  
OGTT. It should be the week before the study to know how is melatonin (although if you cannot it 
could be two weeks before) 
 
6. OGTTs 
We will administer 75 grams of glucose to the subject after the basal measurement in both 
conditions. Fisher Scientific; Fisher brand Glucose Tolerance Test Beverage, 75 g (75 Sun-dex); 
Orange flavored, caffeine free, non-carbonated; 10 oz fluid / 296 ml. 
Link: https://www.fishersci.com/shop/products/fisherbrand-glucose-tolerance-test-beverages- 
9/401223fb 
 
Write the time of each extraction 
No more than 2 minutes in drink the glucose 
8-h fasting 
2 measures or conditions: 
• 4 h before their habitual bedtime. 
• 1 h before their habitual bedtime (should come 1h before of the T0 and keep in the dark). The 
samples will be just before the glucose T0 and at T30´, T60´, T 90´y T120´ minutes after the 
glucose. 
• Serum insulin and glucose. 
 
7. Determinations 
- Glucose and insulin in the 5 times (T0, T30´, T60´, T 90´y T120´) 
- Melatonin in T0´ and T120´ 
 
8. Subjects report 
1) Demographics and Health Survey: socioeconomic status, habitual alcohol intake, smoking, sleep 
apnea, insomnia 
2) Inform consent 
3) Anthropometric characteristics and OGTT conditions 
4) International Physical Activity Questionnaire (IPAQ) 
5) Morningness Eveningness Questionnaire (MEQ) 
6) Emotional Eating Questionnaire (EEQ) 
7) Food and Sleep log (food and timing) 
8) Pittsburgh Sleep Quality Index 
9) Day of the experiment menu 
10) Control sheet 
11) Insomnia Severity Index (ISI) 
12) Patient Health Questionnaire-9 (PHQ-9) 
11. Store aliquots: 
 
-Glucose: 30-400 µl 
-Insulin: 30-400 µl 
-Melatonin: 30-400 µl 

INTERVENTION STUDY PROTOCOL 
Impact of melatonin, food timing and receptor gene variant on type 2 diabetes risk 
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-Serum: 400 µl 
-DNA: 200 µl 
 
200-300 µl: 1 for insulin, 1 for melatonin 1for glucose, and the rest for store in the freezer.