Bolinder J, Fernlund P, Borg H, Arnqvist H J, Björk E, Blohmé G, Eriksson J W, Nyström L, Ostman J, Sundkvist G
Department of Medicine, Karolinska University Hospital Huddinge.
Scand J Clin Lab Invest. 2005;65(7):585-94. doi: 10.1080/00365510500261869.
To investigate whether measurements of proinsulin and/or intermediate proinsulin degradation products could be used to differentiate between autoimmune (type 1) and non-autoimmune (type 2) diabetes in young adults.
Total proinsulin, intact proinsulin and 32,33 split proinsulin concentrations were measured in 25 patients aged 15-34 years with type 1 diabetes, as defined by the presence of at least two positive islet autoantibodies, and in 23 antibody-negative patients of similar age with type 2 diabetes, at the time of clinical onset of diabetes and at 3-4 months thereafter. Comparisons were made with data from 25 healthy subjects matched for gender and age.
Plasma levels of total proinsulin, intact proinsulin and 32,33 split proinsulin were significantly increased 2-3-fold in the patients with newly diagnosed type 2 diabetes as compared with the controls, both in absolute terms (p<0.0001) and when related to circulating insulin (p<0.01-0.0002). In contrast, absolute proinsulin and 32,33 split proinsulin concentrations were significantly lower in patients with onset of type 1 diabetes than in controls. When proinsulin and split proinsulin release were related to plasma insulin, however, similar ratios were found in the type 1 diabetes patients and in controls. Using the 90th percentile for total proinsulin in the control group as the cut-off, the sensitivity and specificity for differentiation between autoimmune and non-autoimmune diabetes were 87% and 92%, respectively. At 3-4 months after clinical onset of diabetes, proinsulin secretion was still 2-3 times higher in type 2 than in type 1 diabetes patients (p<0.001).
Young adult patients with newly diagnosed type 2 diabetes display disproportionate hyperproinsulinemia, whereas proinsulin secretion appears to be normal in patients with clinical onset of type 1 diabetes. Evaluation of proinsulin and 32,33 split proinsulin concentrations may be useful as a diagnostic tool in differentiating between autoimmune and non-autoimmune diabetes in young adults, particularly in those lacking islet autoantibodies at diagnosis.
研究胰岛素原和/或胰岛素原中间降解产物的检测是否可用于区分年轻成人中的自身免疫性（1型）糖尿病和非自身免疫性（2型）糖尿病。
测定了25例年龄在15 - 34岁、存在至少两种阳性胰岛自身抗体的1型糖尿病患者以及23例年龄相仿、临床诊断为2型糖尿病且抗体阴性患者在糖尿病临床发病时及之后3 - 4个月时的总胰岛素原、完整胰岛素原和32,33 - 分裂胰岛素原浓度。将这些数据与25名年龄和性别匹配的健康受试者的数据进行比较。
与对照组相比，新诊断的2型糖尿病患者的总胰岛素原、完整胰岛素原和32,33 - 分裂胰岛素原的血浆水平显著升高2 - 3倍，无论是绝对值（p<0.0001）还是与循环胰岛素相关时（p<0.01 - 0.0002）。相比之下，1型糖尿病发病患者的胰岛素原和32,33 - 分裂胰岛素原的绝对浓度显著低于对照组。然而，当胰岛素原和分裂胰岛素原释放与血浆胰岛素相关时，1型糖尿病患者和对照组的比例相似。以对照组总胰岛素原的第90百分位数作为临界值，区分自身免疫性和非自身免疫性糖尿病的敏感性和特异性分别为87%和92%。在糖尿病临床发病后3 - 4个月，2型糖尿病患者的胰岛素原分泌仍比1型糖尿病患者高2 - 3倍（p<0.001）。结论：新诊断的年轻2型糖尿病患者存在不成比例的高胰岛素原血症，而1型糖尿病临床发病患者的胰岛素原分泌似乎正常。评估胰岛素原和32,33 - 分裂胰岛素原浓度可能有助于作为区分年轻成人自身免疫性和非自身免疫性糖尿病的诊断工具，特别是在诊断时缺乏胰岛自身抗体的患者中。
