Abstract:

Objective     To explore the alterations and their implications of first-phase secretion function of islet alpha and beta cell in subjects with normal glucose tolerance, and, family history of diabetes. Methods     40 relatives, with normal glucose tolerant and family history of type 2 diabetes, were enrolled in the observation group (FH+), while 55 healthy volunteers were in the control group (FH-). Fasting blood-glucose(FBG) and 2-hour postprandial sugar(P2hBG) were determined by enzyme technique. Free fatty acid(FAA) was detected by improved colorimetry. Insulin was detected by chemoiluminesence immunoassay, while the ABC-ELISA technique was applied to determine glucagon on an empty stomach and at 2, 4, 6min after L-ARG stimulation. Results     ① The peak value of insulin and glucagon secretion were at 2 minutes, and began to decrease at 4 minutes in the two groups. ② Compared with the FH- group,P2hBG, FINS, HOMAIR and FFA were significantly higher (all P<0.05) , and the peak factor of insulin was obviously lower in the  FH+ group (P<0.05). There were no differernces of FGC and the peak factor of glucagon (P>0.05) between the two groups. ③Correlation analysis showed the peak factor of insulin had positives collinearity with P2hBG and FFA due to that correlation coefficient r  were 0.274 and 0.356, respectively(P<0.05). Conclusions    In genetics, type 2 diabetes mellitus results from the exhaustion of function of beta cells′ firstphase secretion. The peak factor of insulin may be an important predictor for the occurrence and development of type 2 diabetes.

Key words: Family history of diabetes; Firstphase secretion; Islet alpha cell; Islet beta cell