Impact of Bedtime Snacks on Glucose Control in Type 2 Diabetes

Study Overview
=================
Brief Summary
-----------------
Approximately 3 million Canadians have type 2 diabetes, a condition where the blood sugar levels are too high, uncontrolled blood sugars lead to cardiovascular disease and other complications. Patients with type 2 diabetes are often advised to consume a snack before bed in order to help control morning blood sugar levels. However, scientific evidence for this dietary approach is limited and there is no data to help elucidate what the ideal bedtime snack is. We hypothesize that a high protein, high fat snack with very little carbohydrate, will be an effective bedtime snack for lowering morning glucose without spiking glucose levels in the night. In this study we will determine if a bedtime snack that is high in protein and fat but low in carbohydrate can help improve morning glucose control in people with type 2 diabetes. This information will provide scientific evidence for the potential health benefits of strategically-timed high protein, high fat snack consumption in people with type 2 diabetes.

Detailed Description
-----------------
Fifteen patients with physician diagnosed type 2 diabetes (HbA1c 6.5-9%), between the ages of 30-80 years, and not on exogenous insulin therapy, will complete three, 3-day intervention periods (proof-of-concept randomized trial). Participants will consume a standardized diet for three days with either i) two hard-boiled eggs, ii) fruit yogurt; or iii) control no-bedtime snack, thirty minutes prior to bedtime. Fasting blood samples will be obtained on Day 4 in the morning after following each 3-day dietary intervention. Blood glucose will be monitored continuously across the intervention period using continuous glucose monitoring (CGM). CGM allows for the moment-to-moment changes in blood glucose to be examined for several days, allowing the unique opportunity to examine the glucose responses at different points of the day, including fasting hyperglycemia in the morning, nocturnal glucose, and postprandial glucose in response to meals. To our knowledge, CGM technology has never been used in a bedtime snacking study in type 2 diabetes.

Official Title
-----------------
A High-protein Bedtime Snack to Control Morning Blood Glucose

Conditions
-----------------
Type 2 Diabetes Mellitus

Intervention / Treatment
-----------------
* Other: Dietary


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Diagnosed Type 2 Diabetes HbA1c between 6.5 - 9.0% No dietary restraints (lactose intolerance, dislike eggs, celiac disease) Exclusion Criteria: Heart attack or stroke within last year Exogenous insulin

Ages Eligible for Study
-----------------
Minimum Age: 30 Years
Maximum Age: 80 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High protein no carbohydrate<br>Dietary. Two eggs will be consumed 30 minutes prior to bedtime. Energy content of dinner will be reduced to account for the calories in the bedtime snack. | Other: Dietary<br>* Diet will be manipulated by providing different bedtime snacks within an otherwise isocaloric diet.<br>|
| Active Comparator: High protein carbohydrate containing<br>Dietary. A low-fat yogurt will be consumed 30 minutes prior to bedtime. Protein will be matched to the high protein bedtime snack condition. Energy content of dinner will be reduced to account for the calories in the bedtime snack. | Other: Dietary<br>* Diet will be manipulated by providing different bedtime snacks within an otherwise isocaloric diet.<br>|
| No Intervention: Control no snack<br>No snack will be consumed prior to bed. | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fasting Plasma glucose | Fasting Plasma glucose | Day 4 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 24 h mean blood glucose | continuous blood glucose monitoring | Average of three days during each intervention | 
| postprandial glucose | breakfast AUC | Average of three days during each intervention | 
| Fasting insulin | Fasting plasma insulin | Average of three days during each intervention | 
| Fasting homeostasis model assessment of insulin resistance (HOMA-IR) | Calculated by fasting plasma glucose and insulin | Day 4 | 
| Overnight blood glucose | Glucose assessed during sleep by continuous glucose monitoring | Average of three days during each intervention | 
| Fasting continuous glucose monitoring glucose | 15-minute average glucose assessed by CGM in the fasted state upon awakening | Average of the three days during each intervention |