title: Impact of one-hour postchallenge glucose on the relationship between insulin sensitivity and secretion.
abstract: The impact of postchallenge glucose on the relationship between insulin sensitivity (SI) and secretion (β) is unknown. We analyzed data from 2,264 health examinees (male/female 1,524/740, median age 54 yrs) with normal glucose tolerance (NGT, n = 1,623), non-diabetic hyperglycemia (NDH, n = 555), or diabetes (DM, n = 86) using OGTT-derived indices of SI (insulin sensitivity index [ISI]-Matsuda, 1/HOMA-IR, and 1/fasting IRI) and β (δIRI0-30/δPG0-30, and Stumvoll 1st [Stumvoll-1] and 2nd [Stumvoll-2] phases). The combination of 1/HOMA-IR and Stumvoll-1 recapitulated the hyperbolic SI-β relationship with the slope of the fitted line -1.000 in NGT subjects, and therefore it was utilized in the following analysis of the SI-β correlation. In multiple regression analysis of the relationship between SI and β, an independent correlation was found for 1 h-plasma glucose (PG; PG60) but not for 2 h-PG. When the NGT subjects were grouped by PG60 quartile (Q), the fitted line was flat in Q1 but progressively steeper from Q2 to Q4, with a slope (95%CI) of -0.663 (-0.726~-0.605), -0.680 (-0.745~-0.622), -0.847 (-0.922~-0.779), and -1.259 (-1.370~-1.158) (P for trend < 0.05). The fitted line steepened further in the NDH and DM groups, with a slope of -1.545 and -1.915, respectively (P < 0.01 for the difference). The intercept of the fitted line for SI-β correlation was also progressively lower across the PG60 Q for NGT, NDH, and DM. In conclusion, using the 1/HOMA-IR-Stumvoll-1 pair for an analysis of the SI-β relationship, elevated PG60 was associated with steepening and downward shifting of the fitted line for the SI-β correlation. The finding suggests impaired beta cell function.
authors.affiliation: Diabetes Center, Aizawa Hospital, Matsumoto 390-8510, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Sato
authors.forename: Rie
authors.initials: R
authors.lastname: Oka
authors.forename: Yasuto
authors.initials: Y
authors.lastname: Nakasone
authors.forename: Masafumi
authors.initials: M
authors.lastname: Katakura
authors.forename: Keishi
authors.initials: K
authors.lastname: Yamauchi
authors.forename: Toru
authors.initials: T
authors.lastname: Aizawa
mesh_terms: D001786:Blood Glucose / Q000032:analysis; D003920:Diabetes Mellitus / Q000097:blood* / Q000503:physiopathology; D005260:Female; D005947:Glucose / Q000008:administration & dosage*; D018149:Glucose Intolerance / Q000097:blood* / Q000503:physiopathology; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance / Q000502:physiology*; D000078790:Insulin Secretion; D008297:Male; D008875:Middle Aged
chemical_list: D001786:Blood Glucose; D007328:Insulin; D005947:Glucose