Association between four adipokines and insulin sensitivity in patients with obesity, type 1 or type 2 diabetes mellitus, and in the general Chinese population / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Hyperinsulinemic euglycemic clamp is the gold standard to evaluate the insulin sensitivity, but it is too complicated and expensive to use in clinic. We tried to find an alternative indicator to reflect insulin sensitivity. To evaluate the association between the four adipokines, adiponectin, leptin, resistin and tumor necrosis factor-alpha (TNF-alpha) with insulin sensitivity, we used a hyperinsulinemic euglycemic clamp to test insulin sensitivity in Chinese patients with obesity and type 1 or type 2 diabetes mellitus versus controls.</p><p><b>METHODS</b>In this parallel control study, we tested insulin sensitivity using a hyperinsulinemic euglycemic clamp in different groups, then examined levels of adiponectin, leptin, resistin and TNF-alpha in serum, and the relationship between the different adipokines and glucose disposal rate (M value), as well as insulin sensitivity index (M value/insulin, M/I), which are the "gold standard" indices of insulin sensitivity.</p><p><b>RESULTS</b>There were significant differences in mean leptin values in the four adipokines from the four different groups (P < 0.001; comparison of the variation between different groups was analyzed by variance analysis). Compared to controls (using multiple comparison two-way Dunnett t test), only the leptin level showed significant differences in the four adipokines from the four different groups at the same time (P < 0.001). The association analysis between the different adipokines and M or M/I values also showed that only leptin negatively correlated with M (r = -0.64, P < 0.001) or M/I values (r = -0.56, P < 0.001); there was no relationship between the other three adipokines and M or M/I values.</p><p><b>CONCLUSION</b>Only leptin was associated with M or M/I values. Therefore, leptin might be one of the predictive factors of the degree of insulin resistance and risk of the accompanying disease.</p>

Investigation on pharmacokinetics and bioavailabiUty of insulin dry powder inhalation / 中华内分泌代谢杂志

Objective To study the characteristics of pharmacokinetics and pharmacodynamics of insulin dry powder inhalation and its relative bioavailability as compared with subcutaneous injection of regular insulin. Methods In this open,single-center,randomized,two-period,cross-over,euglycemic glucose clamp study,18 healthy volunteers(14 men and 4 women),aged(24.9?1.7)years,with body mass index(20.6?1.2)kg/m~2, received the insulin dry powder inhalatin(80 U)or regular insulin(15 U)subcutaneous administration.The blood samples of this study at 0,20,30,40,50,60,70,80,90,100,110,120,135,150,165,180,195, 210,225,240,270,300,330,360,390,420,450 and 480 rain were taken for serum insulin measurement, meanwhile,glucose infusion rates(GIR)were determined per 5 minutes over a period of 8 hours.Results The C_(max)were(57.9?17.8 vs 114.5?29.7)mU/L(tested vs reference preparation),T_(max)were(46.7?45.6 vs 107.8?33.7)min,GIR_(max)were(3.35?0.98 vs 5.17?1.75)mg?kg~(-1)?min~(-1)and T_(GIRmax)were(88.3?17.0 vs 151.9?34.6)min.The relative bioavailability was(10.26?2.25)%,and the relative bioefficacy was(14.33?7.26)%.Conclusion The study shows that insulin dry powder inhalation is absorbed via lungs and its action sets in earlier than that of the regular insulin injected subcutaneously.These pharmacokinetie and pharmacodynamic data may provide a reliabe guide for further clinical trial.