Insulin secretion and sensitivity in Bangladeshi prediabetic subjects.
OBJECTIVE
There are still considerable controversies regarding the basic pathophysiological mechanisms of impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT). The present study was undertaken to explore the beta-cell function and insulin sensitivity in a Bangladeshi prediabetic population.


METHODS
Twenty-four IFG and 112 IGT subjects, along with 40 healthy controls, were selected purposively following 2003 ADA cut-off values and 2006 WHO/IDF grouping. IGT subjects were subcategorized into 53 isolated IGT (I-IGT) and 59 combined IFG-IGT subjects. Plasma glucose and insulin (by chemiluminescent immunoassay) were measured at fasting and 2 h after 75 g of oral glucose load. Insulin sensitivity was assessed by homeostasis model assessment (HOMA-S%) and insulin sensitivity index for glycemia (ISI(gly)) and insulin secretion by HOMA-B%.


RESULTS
Compared to control, fasting and 2-h plasma insulin were higher in I-IGT and IFG-IGT subjects; similarly, HOMA-S% [median (range)] was lower in I-IGT and IFG-IGT subjects [116 (54-227) vs. 93 (23-187) and 79 (32-197)%, P<.05 and P<.001]; ISI(gly) was also lower in I-IGT and IFG-IGT subjects [0.95 (0.54-1.64) vs. 0.64 (0.26-1.24) and 0.65 (0.29-1.20), P<.001]. But HOMA-B% was compromised in IFG and IFG-IGT groups [88 (59-182) vs. 68 (37-107) and 74 (36-141)%, P<.001 and P<.05]. The IGT group (combination of I-IGT and IFG-IGT) showed higher fasting and 2-h insulin, and lower HOMA-S% as well as ISI(gly), but compromised HOMA-B% was not evident.


CONCLUSIONS
The pathophysiological mechanisms differ in IFG (having B-cell dysfunction) and I-IGT (an insulin-resistant condition). The pathophysiology of IFG-IGT (having both B-cell dysfunction and insulin resistance) indicates that it may be a different entity and not be included in IGT.
Rahman
Muhammad Hafizur
MH
Department of Pharmacology, Faridpur Medical College, Faridpur, Bangladesh. hafizdrendo@yahoo.com
Hafizur
Rahman Muhammad
RM
Nahar
Qamrun
Q
Khan
Abdur Rahman
AR
Ali
Liaquat
L
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001459:Bangladesh; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D003937:Diagnosis, Differential; D042241:Early Diagnosis; D005260:Female; D018149:Glucose Intolerance / Q000175:diagnosis* / Q000503:physiopathology; D005951:Glucose Tolerance Test / Q000706:statistics & numerical data; D006706:Homeostasis; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D007333:Insulin Resistance; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011236:Prediabetic State / Q000145:classification / Q000503:physiopathology*; D055815:Young Adult
D001786:Blood Glucose; D007328:Insulin