Kronborg J, Johnsen S H, Njølstad I, Toft I, Eriksen B O, Jenssen T
Institute of Clinical Medicine, University of Tromsø, Tromsø, Norway.
Diabetologia. 2007 Aug;50(8):1607-14. doi: 10.1007/s00125-007-0715-z. Epub 2007 Jun 9.
AIMS/HYPOTHESIS: Proinsulin is increased in persons at cardiovascular risk. Increased secretion of proinsulin relative to insulin has been suggested as a sign of defective conversion of proinsulin to insulin and C-peptide and is associated with beta cell dysfunction. It has also been suggested that proinsulin has more of a pro-atherogenic effect than insulin, the levels of which are also increased in the insulin resistance state. In this prospective population-based study, we examined whether the proinsulin:insulin ratio (PIR) or insulin:glucose ratio (IGR, an insulin resistance surrogate) predicted carotid plaque size in nondiabetic participants.
The study included 1,859 men and 1,998 women aged 25-82 years from the Tromsø Study, who were examined with B-mode high resolution ultrasound at baseline in 1994-1995 and at follow-up in 2001-2002. All images were computer processed to yield mm(2) measures of plaque. Proinsulin and insulin were measured at baseline. All analyses were stratified for sex.
After adjusting for age, baseline plaque area, BMI, cholesterol, HDL-cholesterol, HbA(1c), IGR, albumin:creatinine ratio, fibrinogen, BP and lifestyle factors (tobacco smoking, alcohol consumption, physical activity), PIR was significantly associated with plaque size at follow-up in women but not men. For each SD in the PIR in women, the mean plaque area increased by 0.97 mm(2) (95% CI 0.44-1.50). IGR was not associated with carotid plaque size.
CONCLUSIONS/INTERPRETATION: The PIR is associated with progressive carotid artery plaque size in women.
目的/假设：心血管疾病风险人群的胰岛素原水平升高。相对于胰岛素而言，胰岛素原分泌增加被认为是胰岛素原向胰岛素和C肽转化缺陷的标志，且与β细胞功能障碍有关。也有观点认为，胰岛素原比胰岛素具有更强的促动脉粥样硬化作用，在胰岛素抵抗状态下，胰岛素水平也会升高。在这项基于人群的前瞻性研究中，我们探讨了胰岛素原：胰岛素比值（PIR）或胰岛素：葡萄糖比值（IGR，胰岛素抵抗替代指标）能否预测非糖尿病参与者的颈动脉斑块大小。
该研究纳入了来自特罗姆瑟研究的1859名男性和1998名女性，年龄在25 - 82岁之间，于1994 - 1995年基线时和2001 - 2002年随访时接受了B型高分辨率超声检查。所有图像均经过计算机处理，以得出斑块面积的平方毫米测量值。在基线时测量胰岛素原和胰岛素水平。所有分析均按性别分层。
在调整年龄、基线斑块面积、体重指数、胆固醇、高密度脂蛋白胆固醇、糖化血红蛋白、IGR、白蛋白：肌酐比值、纤维蛋白原、血压和生活方式因素（吸烟、饮酒、体育活动）后，PIR在女性中与随访时的斑块大小显著相关，而在男性中则不然。女性PIR每增加一个标准差，平均斑块面积增加0.97平方毫米（95%置信区间0.44 - 1.50）。IGR与颈动脉斑块大小无关。
结论/解读：PIR与女性颈动脉斑块的进展大小相关。
