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Correlation of the incretin effect with first‐ and second‐phase insulin secretions in Koreans with various glucose tolerance statuses
Author(s) -
Oh Tae Jung,
Park Kyong Soo,
Cho Young Min
Publication year - 2015
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1111/cen.12623
Subject(s) - medicine , endocrinology , incretin , insulin , glucose clamp technique , diabetes mellitus , type 2 diabetes , clamp , insulin resistance , impaired glucose tolerance , pancreatic hormone , mechanical engineering , clamping , engineering
Summary Objective To examine the relationship between beta‐cell function and the incretin effect. Design We performed a 180‐min hyperglycaemic clamp study with oral glucose administration at 60 min in Korean subjects with normal glucose tolerance ( NGT , n = 9), impaired fasting glucose ( IFG , n = 6) and type 2 diabetes mellitus (T2 DM , n = 6). Measurements First‐ and second‐phase insulin secretions were measured during the first 60 min. The insulin response to intravenous glucose during the 60‐ to 120‐min interval (Ins iv ) was calculated using a prediction method. The insulin response to oral glucose (Ins oral ) was calculated by subtracting the Ins iv from the overall insulin response during the 60‐ to 120‐min interval (Ins overall ). The incretin effect under the hyperglycaemic clamp condition ( IE clamp ) was calculated by the equation: 100 × [(Ins overall − Ins iv )/Ins overall ]. Results The IE clamp was comparable among the three groups (46·3 ± 6·4%, 35·7 ± 8·8% and 51·4 ± 7·4% for the NGT, IFG and T2DM group, respectively, P = 0·327) and was not correlated with the first‐ and second‐phase insulin secretions. However, the Ins oral ( mU /l 60 min) was significantly different between the NGT, IFG and T2DM groups (5199 ± 1185, 2164 ± 956 and 1034 ± 355, respectively; P = 0·010) and was well correlated with the first‐ and second‐phase insulin secretions. Conclusions The incretin effect measured by the hyperglycaemic clamp with oral glucose loading was neither correlated with beta‐cell function nor different between NGT , IFG and T2 DM groups in Koreans.