Type-2 Diabetes
Conditions
Keywords
glucose variability, glycemia, type-2 diabetes
Brief summary
Persons with type 2 diabetes mellitus (T2DM) have swings in their blood sugar levels that may lead to a higher risk of developing heart disease. An important part of diabetes management involves eating a diet to prevent large swings in blood sugar levels. Walnuts contain fat, protein and fiber that may reduce the swings in blood sugar. The purpose of this study is to compare the effects of a walnut-free American Diabetes Association (ADA) diet versus 2 levels of walnut-enriched ADA diets on blood sugar swings. Eighteen male and female adults with T2DM will participate in the study. Subjects will be randomized to consume an ADA diet with or without walnuts for 3 consecutive days every other week. Subjects must test their blood sugar twice daily and wear a continuous glucose monitor during the three 72-hour study periods. Subjects will be between 40 and 70 years of age and will be recruited from the surrounding community using flyers and public service announcements. Consent will take place in the Department of Nutrition at Loma Linda University by the study investigators. In total, subject participation will last 5 weeks and all meals will be provided during the 3 study periods.
Interventions
DIETARY_SUPPLEMENTFull dose
20% of daily energy needs supplied by walnuts
DIETARY_SUPPLEMENTHalf dose
10% of daily energy needs supplied by walnuts
DIETARY_SUPPLEMENTControl
Walnut free meals
Sponsors
California Walnut Commission
Loma Linda University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
40 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
* adults between age 40 and 70 years with type 2 diabetes * duration of type 2 diabetes more than 6 months but less than 10 years * HbA1c 6.0-8.0% * BMI 25-40 kg/m2 * diet controlled or stable dose of metformin for at least 3 months * willing to test blood glucose with personal meter twice a day during study test days
Exclusion criteria
* using oral hypoglycemic agents or insulin * history of ischemic heart disease or congestive heart failure * history of severe diabetic complication (neuropathy, renal failure, stroke) * taking medication affecting glucose levels (i.e. corticosteroids) * active infectious disease * active malignancy * pregnant or breast feeding woman * smoker * history of daily caffeine or alcohol intake * known allergy to nuts * lactose or gluten intolerance
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Within-day glucose variability | 3 days | The primary objective is to evaluate the effect of two isocaloric walnut-enriched meal plans versus a walnut-free ADA meal plan on within-day glucose variability in adults with diabetes by assessing: a) the overall standard deviation (SD) around the sensor glucose calculated for each day and then averaged over the 3-day study periods; b) the mean amplitude of glycemic excursions (MAGE) over the 3-day study periods. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Dose response to between-day glycemic variability | 3 days | The effect of the three isocaloric ADA meal plans (full-dose, half-dose, walnut free) on the mean of the daily differences(MODD) will be recorded as a measure of between-day glycemic variability |
| Glucose levels by meal | 3 days | Glucose levels will be measured before and after breakfast, lunch and dinner for each of the three isocaloric ADA meal plans (full-dose, half-dose, walnut free) |
| Mean glucose of sensor range | 3 days | The mean of the glucose for the range captured on each sensor (sensor maximal glucose level minus minimal glucose level will be recorded |
| Glucose variability dose response | 3 days | A secondary objective will be to test for a dose-response effect, i.e. the more walnuts (full-dose versus half-dose) the lower the glucose variability. |
| Duration of hyperglycemia | 3 days | The duration of hyperglycemia will be measured as hours per day for each of the three isocaloric ADA meal plans (full-dose, half-dose, walnut free) |
| Net glycemia at 2 hours | 3 days | The continuous overall net glycemic action will be measured at 2 hour intervals |
| Net glycemia at 4 hours | 3 days | The continuous overall net glycemic action will be measured at 4 hour intervals |
| Duration of hypoglycemia | 3 days | The duration of hypoglycemia will be measured as hours per day for each of the three isocaloric ADA meal plans (full-dose, half-dose, walnut free) |
Countries
United States
Outcome results
None listed