Department of Medicine I, St Josef-Hospital, Ruhr-University Bochum, Gudrunstrasse 56, Bochum, Germany.
Eur J Endocrinol. 2010 Oct;163(4):551-8. doi: 10.1530/EJE-10-0330. Epub 2010 Aug 2.
Hyperproinsulinaemia has been reported in patients with type 2 diabetes. It is unclear whether this is due to an intrinsic defect in β-cell function or secondary to the increased demand on the β-cells. We investigated whether hyperproinsulinaemia is also present in patients with secondary diabetes, and whether proinsulin levels are associated with impaired β-cell area or function.
Thirty-three patients with and without diabetes secondary to pancreatic diseases were studied prior to pancreatic surgery. Intact and total proinsulin levels were compared with the pancreatic β-cell area and measures of insulin secretion and action.
Fasting concentrations of total and intact proinsulin were similar in patients with normal, impaired (including two cases of impaired fasting glucose) and diabetic glucose tolerance (P=0.58 and P=0.98 respectively). There were no differences in the total proinsulin/insulin or intact proinsulin/insulin ratio between the groups (P=0.23 and P=0.71 respectively). There was a weak inverse association between the total proinsulin/insulin ratio and pancreatic β-cell area (r(2)=0.14, P=0.032), whereas the intact proinsulin/insulin ratio and the intact and total proinsulin levels were unrelated to β-cell area. However, a strong inverse relationship between homeostasis model assessment index of β-cell function and both the total and the intact proinsulin/insulin ratio was found (r(2)=0.55 and r(2)=0.48 respectively). The association of insulin resistance (IR) with intact proinsulin was much weaker than the correlation with fasting insulin.
Hyperproinsulinaemia is associated with defects in insulin secretion rather than a reduction in β-cell area. The weak association between intact proinsulin and IR argues against the usefulness of this parameter in clinical practice.
已有研究报告称，2 型糖尿病患者存在高胰岛素原血症。目前尚不清楚这是由于β细胞功能的内在缺陷，还是由于β细胞的需求增加所致。我们研究了继发糖尿病患者是否也存在高胰岛素原血症，以及胰岛素原水平是否与β细胞面积或功能受损相关。
在胰腺手术前，研究了 33 例胰腺疾病继发糖尿病患者和非糖尿病患者。比较了空腹时的胰岛素原水平与β细胞面积及胰岛素分泌和作用的各项指标。
空腹时，正常糖耐量、糖耐量受损（包括 2 例空腹血糖受损）和糖尿病患者的总胰岛素原和完整胰岛素原浓度相似（P=0.58 和 P=0.98）。各组间的总胰岛素原/胰岛素或完整胰岛素原/胰岛素比值均无差异（P=0.23 和 P=0.71）。总胰岛素原/胰岛素比值与β细胞面积呈弱负相关（r²=0.14，P=0.032），而完整胰岛素原/胰岛素比值以及完整和总胰岛素原水平与β细胞面积无关。然而，我们发现，β细胞功能的稳态模型评估指数与总胰岛素原/胰岛素和完整胰岛素原/胰岛素比值均呈强负相关（r²=0.55 和 r²=0.48）。与空腹胰岛素相比，胰岛素抵抗（IR）与完整胰岛素原的相关性要弱得多。
高胰岛素原血症与胰岛素分泌缺陷有关，而与β细胞面积减少无关。完整胰岛素原与 IR 的弱相关性表明，该参数在临床实践中可能用处不大。
