Lifestyle Patterns and Glycemic Control

Department of Health and Human Services, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

The goal of the proposed study is to evaluate the feasibility and initial efficacy of stabilizing lifestyle behaviors to improve glucose control and body composition in patients with pre-diabetes. The investigator proposes that following stable lifestyle behaviors will improve patients' glucose control, body composition, and liver fat. The results from this study has the potential to impact clinical practice and patient care.

Variability in lifestyle behaviors has been associated with adverse health, specifically poor glucose control. The project proposes to test whether reducing this variability improves glycemia in patients with pre-diabetes. If successful, this simple positive lifestyle message to keep stable behaviors has the potential to improve the health of millions of adults worldwide. This project will enroll participants with pre-diabetes who have erratic lifestyle behaviors and randomize them to either maintain their usual habits (control group) or stabilize their behaviors (stability group). Both groups will be followed for 12 weeks. Before the start of the 12-week period, all participants will track their sleep for 2 weeks and will wear a glucose monitor to measure their glucose levels. At the start and end of the 12-week period, they will come to the research lab to undergo a glucose tolerance test. This test will measure how their body reacts to a glucose load. They will also undergo magnetic resonance imaging and spectroscopy scanning. This scan will provide information on body composition and liver fat content.

A randomized, parallel-arm clinical intervention study to assess the role of variability in lifestyle behaviors on glucose control and body composition in adults with pre-diabetes. The goal is to test whether following a fixed schedule improves glucose control and insulin sensitivity and reduces adiposity compared to those who maintain a variable schedule.

Participants will not be blinded to the intervention or purpose of the study but will be told that rest-activity patterns will be examined in the context of well-being and that we will test the influence of these lifestyle patterns on glucose control and body composition. Although the investigators and research assistant directly involved in the conduct of the study cannot be blinded to participant assignment to the intervention or control group, the technicians involved in sample processing and the biostatistician (Dr. Cheng) will be blinded to this information to reduce the risk of bias.

Participants randomized to Variable Schedule (VS) will be asked to maintain their usual habits for 12 weeks.

Participants randomized to Fixed Schedule (FS) will be asked to stabilize their lifestyle behaviors for 12 weeks.

Testing glycemic control.The primary outcome variable is glucose under the curve during the oral glucose tolerance test.

Testing glucose variability. The primary outcome variables are mean amplitude of glucose excursion and standard deviation of average glucose.

This is to assess disposition index, measured using HOMA-IR. The disposition index is the product of the insulogenic index and homeostatic model of assessment for insulin resistance.

NF-κB nuclear fluorescence area for pilot study. This component of the study is completed and measures are no longer collected as of 08/15/2023.

Assessing whether long-term glycemia is changed by measuring hemoglobin A1c using two-sample t-tests.

redox sensitive fluorogenic probe fluorescence intensity for pilot study. This component of the study is completed and measures are no longer collected as of 08/15/2023.

Inclusion Criteria: Pre-diabetic kg/m2 (hemoglobin A1c 5.7-6.4%) 35 years or older BMI between 25-39.9 kg/m2 Sleep duration ≥6 hours a night assessed with wrist actigraphy (for 14 nights) Variable bedtime, SD≥45 minutes. Exclusion Criteria: Chronic Kidney Disease (GFR<60) Uncontrolled hypertension (≥160/100 mmHg) Obstructive Sleep Apnea Psychiatric or neurological disorder Prevalent cardiovascular disease Dyslipidemia (triglycerides≥200 mg/dL) Medications that affect insulin sensitivity, glucose concentrations, and body weight Non-day or rotating shift workers Travel across time zones Active participation in weight loss program or within past 3 months Current or past alcohol/drug abuse