The use of sugar and starch-like foods for energy (carbohydrate metabolism) changes when people sleep. However, it is still not known if differences in the amount of nighttime sleep have an effect on the carbohydrate metabolism of people who have a relative with type 2 diabetes (parent, sibling, or grandparent). This study is being done to test the hypothesis that individual differences in habitual sleep duration may be related to differences in the carbohydrate metabolism of people who have a history of type 2 diabetes in their family.

On two consecutive inpatient days, the participants in this study will undergo two different tests. The first test will determine how much insulin can their body produce in response to an intravenous glucose infusion over a period of several hours. The second test will determine how effective is the action of the sugar-processing hormone, insulin, in their body when it is infused intravenously together with glucose over a period of several hours.

Inclusion Criteria:

• regular sleep habits
• BMI 20 to 27 kg/m2
• at least one parent, sibling or grandparent with type 2 diabetes
• no regular exercise habits

Exclusion Criteria:

• active smoker
• night or shift work
• have highly variable sleep habits
• have a hormonal disorder
• have a sleep disorder
• have an active medical problem
• women only: use of birth control pills
• women only: irregular menstrual periods or pregnancy
• use of medications/compounds that can disrupt sleep

Healthy non-obese community-living men and women with a parent, sibling or grandparent who has type 2 diabetes