Acute Insulin Response

Insulin secretion, in response to a glucose challenge, occurs in 2 phases. The first phase, or acute insulin response (AIR), is characterized by rapid increase in plasma insulin levels over 3 to 5 minutes followed by a decline. A second phase of insulin secretion begins at around 10 minutes and is maintained until circulating glucose levels return to normal. Thompson et al. (1995) used the AIR as a measure of insulin secretory function in linkage analyses in Pima Indians and localized a genetic element on chromosome 1p31 near the short tandem repeat marker (STRP) D1S198. This element may account for a maximum of 80% of the genetic variants in AIR. As a first step in the isolation of the gene responsible for the phenotypic variation in AIR, Thompson et al. (1997) constructed a YAC contig and physical map of the 1p31 region, which includes the leptin receptor locus (601007).