Shift-work Disorder, Type 2 Diabetes
Conditions
Brief summary
This study will compare the effects of a whey protein supplement or a placebo consumed before the evening meal on health outcomes in night shift workers.
Detailed description
Participants are assigned in random order to two conditions, for 12 days each. The interventions are 1) a 30g whey protein preload consumed 1-1.5 hr prior to their main evening meal every day for 12 days. No other advice will be given. 2) an identical mixed-nutrient drink matched for caloric content, taste and palatability consumed 1-1.5 hr prior to their main evening meal every day for 12 days(placebo). Conditions are separated by a 2-week washout period, during which participants will be encouraged to maintain their habitual diet and physical activity levels. Metabolic testing will be performed at baseline, and at the end of both conditions.
Interventions
DIETARY_SUPPLEMENTwhey protein
Protein drink containing 30g whey protein isolate powder (dissolved in water) consumed 1-1.5 hr prior to their main evening meal every day for 12 days, No other advice will be given.
DIETARY_SUPPLEMENTPlacebo
Energy-matched mixed-nutrient placebo drink consumed 1-1.5 hr prior to their main evening meal every day for 12 days. No other advice will be given.
Sponsors
University of Adelaide
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
FEMALE
Age
35 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* Female * Night shift workers (with a minimum of 6 months in their current shift work schedule) * 35-65 years * BMI 28.0-35.0 kg/m2; waist circumference \> 80cm * Weight stable in the past 6 months
Exclusion criteria
* Those working standard day time hours only, or those who work less than three to four night shifts per fortnight on average * Personal history and/or diagnosis of: diabetes, cancer, major psychiatric disorders, liver disease, gastro-intestinal surgery or disease (including malabsorption), eating disorders, anaemia, insomnia or cardiovascular disease, and/or any other condition deemed unstable by the study physician * Taking medications known to alter body composition or metabolism, including (but not limited to): any medication used to lower blood glucose or antidiabetic medications (metformin, sulfonylureas, Glucagon-like peptide-1 (GLP-1) analogues \[i.e. exenatide\], thiazolidinediones or DPP-IV inhibitors \[i.e. 'gliptins'\]), medications affecting weight, appetite or gut motility (i.e. diuretics, domperidone, cisapride, orlistat, phentermine, topiramate) * Participants who are taking stable doses (i.e. \> 12 months) of androgenic medications (i.e. testosterone) or SSRI's will not be excluded. Personal history/diagnosis (self-reported) of diabetes (type 1 or 2), major psychiatric disorders (schizophrenia, major depressive disorder, bipolar disorder, eating disorders), gastrointestinal disorders, haematological disorders (i.e. thalassemia, iron-deficiency anaemia) insomnia, or any other medical condition, deemed unstable by the study physician * Pregnant, planning a pregnancy or breastfeeding * Those who have lost or gained \>5% of body weight in the last 6 months * Those who consume four or more standard drinks on a single occasion at a 'daily or almost daily' occurrence * current smokers of cigarettes/marijuana/e-cigarettes/vaporisers * unable to comprehend the study protocol (i.e. due to English language or cognitive difficulties)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Glycaemic response | 12 days (3 hours meal test) | Change in glucose (AUC) following a standard breakfast |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Resting metabolic rate | 12 days | Changes in resting metabolic rate |
| respiratory quotient | 12 days | Changes in respiratory quotient |
| 24-hour glucose profiles | 12 days | Change in 24-hour glucose profiles assessed by continuous glucose monitoring |
| Glucose variability | 12 days | Change in 24-hour glucose variability (as SD, standard deviation) assessed by continuous glucose monitoring |
| GLP-1 | 12 days (3 hours meal test) | Change in GLP-1 (AUC) following a standard breakfast |
| GIP | 12 days (3 hours meal test) | Change in GIP (AUC) following a standard breakfast |
| Blood pressure | 12 days | Changes in systolic blood pressure and diastolic blood pressure |
| Insulin | 12 days | Change in fasting and postprandial insulin following a standard breakfast |
| Ghrelin | 12 days (3 hours meal test) | Change in ghrelin (AUC) following a standard breakfast |
| PYY | 12 days | Change in YY (AUC) following a standard breakfast |
| Adiponectin | 12 days | Change in fasting adiponectin |
| C-Reactive Protein (CRP) | 12 days | Change in fasting CRP |
| Blood lipids | 12 days | Changes in blood lipid profile (total cholesterol, HDL-, LDL-cholesterol and triglycerides) |
| glucagon | 12 days (3 hours meal test) | Change in glucagon (AUC) following a standard breakfast |
Countries
Australia
Contacts
Primary ContactAmy Hutchison, PhD
Backup ContactLeonie Heilbronn, PhD
Outcome results
None listed