Almond Effects on Glucose Intolerance Study (AEGIS)

The study will be conducted at Physicians at Sugar Creek (PSC)-the model family practice center for the Memorial Family Medicine Residency Program. The ethnicity of PSC patients is approximately 30% non-Hispanic white, 30% Hispanic, 30% African-American, and 10% Asian.

Potential participants will be identified by searching PSC electronic medical records (Centricity) to find adults aged 18-75 with impaired glucose tolerance, without diabetes (one-hour oral glucose tolerance test result >160 md/dl and two-hour OGTT result <200 mg/dl), without hypoglycemic medications and corticosteroids on their active medications list, and without almond allergy on their allergy list.

Recruitment flyers will be posted in the clinic to encourage interested individuals to contact the investigators about their potential study eligibility. The investigators will also approach previously identified potentially eligible patients during routine clinical visits in the clinic, to elicit their interest in participating in the study. Those expressing interest will be scheduled for an intake visit with an investigator, to further ascertain their eligibility and invite eligible individuals to take part in the study. Interested eligible individuals who render verbal and written informed consent will then be instructed in the study protocol and scheduled for their first data gathering visit.

Each participant will be scheduled to undergo two 2-hour oral glucose tolerance tests (OGTT), starting between 7:00 and 9:30 a.m., one to four weeks apart. Test A will be a standard 75-gram OGTT. Test B will be an OGTT that will begin 30 minutes after ingestion of a low-carbohydrate pre-load "snack" consisting of 1/2 oz (14 grams) of unsalted, dry-roasted almonds (12 average size almonds). Each participant will be given an 8-ounce glass of water to drink with the almonds. Participants will be randomized to one of two test sequences (A-B or B-A), to control for sequence effects on results.

To minimize variability of OGTT results, participants will be asked to eat as they usually do throughout the study. Participants will be asked to refrain from vigorous physical activity for 8 hours prior to each OGTT and to minimize their physical activity during each OGTT. Participants will complete a Perceived Stress Scale and a 24-hour food, alcohol, and activity recall for the day before each OGTT to analyze potential confounding effects of stress, diet, alcohol, and physical activity on the results.