None listed
Conditions
Brief summary
Heart disease and stroke is accelerated in people with type 2 diabetes. More recently insulin resistance, even in those without diabetes, has been identified as a major driver. People can have insulin resistance, with normal blood glucose levels, for years and be unaware they are at-risk of heart disease and stroke. It is important to identify these people because early intervention can prevent development of type 2 diabetes, heart disease and stroke. The standard clinical assessments are not effective at identifying insulin resistance at its earliest time point. We aim to do a community screen to determine whether the mixed meal challenge (a milk drink with fat, protein and carbohydrate) can identify insulin resistance in the population that would otherwise be undetected using conventional testing. We hypothesise that the mixed meal challenge will be a new low-cost, easy to perform, diagnostic test, forming a necessary and fundamental strategy for the prevention of type 2 diabetes, heart disease and stroke in routine practice.
Interventions
This study is to evaluate whether a mixed meal challenge (milk drink comprising 55 grams carbohydrates, 35 grams protein and 7 grams fat; one dose given orally) is more sensitive at detecting insulin resistance than traditional clinical tests (fasting blood sample or the oral glucose tolerance test containing 75 grams glucose).
Participants at-risk of insulin resistance will have their insulin sensitivity (i.e., level of insulin resistance) measured by a fasting blood sample (control), a mixe
This study is to evaluate whether a mixed meal challenge (milk drink comprising 55 grams carbohydrates, 35 grams protein and 7 grams fat; one dose given orally) is more sensitive at detecting insulin resistance than traditional clinical tests (fasting blood sample or the oral glucose tolerance test containing 75 grams glucose). Participants at-risk of insulin resistance will have their insulin sensitivity (i.e., level of insulin resistance) measured by a fasting blood sample (control), a mixed meal challenge (intervention) and an oral glucose tolerance test (control) compared to the gold standard hyperinsulinemic euglycemic clamp (40 mU/m2/min; control) in a randomised cross-over order. Each test will be conducted 1-4 weeks apart. Participants will have their diet (3-day food diary) and level of physical activity (questionnaire and accelerometer worn for 7 days) assessed once in the 7 day baseline period. Participants will be asked to fast overnight (10-12 hours) before coming in to the laboratory in the morning for each test/challenge. Participants will have their fasting blood biochemistries measured (glucose, HbA1c, total cholesterol, low density lipoprotein, high density lipoprotein, triglyceride and insulin concentrations). Participants will undergo metabolic (blood glucose, plasma insulin and cardiometabolic hormone concentrations) and blood pressure testing before and during a mixed meal challenge, oral glucose tolerance test and hyperinsulinemic euglycemic clamp. Consumption of the glucose or milk drink will occur within 5 minutes and supervised by research staff. Body composition (weight, height and dual x-ray absorptiometry) will assessed in the fasting state at one of the testing visits. Participants also have the 'option' to undergo state-of-the art cardiovascular testing [cardiac function, vascular stiffness, central blood pressure, femoral artery blood flow and skeletal muscle/adipose tissue microvascular blood flow].
Sponsors
Deakin University
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Diagnosis
Masking
Blinded (masking used) (Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
35 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
1. Fasting blood glucose <= 6.0 mM 2. 35-75 years old PLUS at least one of the below risk factors for insulin resistance: i). Overweight/obese (body mass index >=25 kg/m2). ii). Elevated blood pressure (defined as seated blood pressure >130/85 mmHg, or on medication to control blood pressure). iii). Abnormal blood lipids (fasting triglycerides >1.7 mM, total cholesterol >5.5 mM or high density lipoproteins <1.0 mM for males or <1.3 mM for females, or on medication to treat their lipids). iv). Have a parent with type 2 diabetes or a parent with premature onset cardiovascular disease (males <=55 years, females <=65 years). v). Prior history of gestational diabetes (for females).
Exclusion criteria
1. Have type 2 diabetes or elevated fasting blood glucose (> 6.0 mM). 2. <35 or >75 years old. 3. On medication known to alter insulin sensitivity or blood glucose levels (e.g. metformin, glucocorticoids). 4. Have cardiovascular disease (e.g. previous heart attack, stroke, pacemaker etc). 5. Pregnant or lactating. 6. Lactose/dairy intolerance or people abstaining from dairy.
Outcome results
None listed