Reid Tirissa J, Jin Zhezhen, Shen Wei, Reyes-Vidal Carlos M, Fernandez Jean Carlos, Bruce Jeffrey N, Kostadinov Jane, Post Kalmon D, Freda Pamela U
Department of Medicine, Columbia University, College of Physicians and Surgeons, 650 West 168th Street, 9-905, New York, NY, 10032, USA.
Department of Biostatistics, Columbia University, College of Physicians and Surgeons, New York, NY, 10032, USA.
Pituitary. 2015 Dec;18(6):808-19. doi: 10.1007/s11102-015-0657-2.
Activity of acromegaly is gauged by levels of GH and IGF-1 and epidemiological studies demonstrate that their normalization reduces acromegaly's excess mortality rate. However, few data are available linking IGF-1 levels to features of the disease that may relate to cardiovascular (CV) risk. Therefore, we tested the hypothesis that serum IGF-1 levels relative to the upper normal limit relate to insulin sensitivity, serum CV risk markers and body composition in acromegaly.
In this prospective, cross-sectional study conducted at a pituitary tumor referral center we studied 138 adult acromegaly patients, newly diagnosed and previously treated surgically, with fasting and post-oral glucose levels of endocrine and CV risk markers and body composition assessed by DXA.
Active acromegaly is associated with lower insulin sensitivity, body fat and CRP levels than acromegaly in remission. %ULN IGF-1 strongly predicts insulin sensitivity, better than GH and this persists after adjustment for body fat and lean tissue mass. %ULN IGF-1 also relates inversely to CRP levels and fat mass, positively to lean tissue and skeletal muscle estimated (SM(E)) by DXA, but not to blood pressure, lipids, BMI or waist circumference. Gender interacts with the IGF-1-lean tissue mass relationship.
Active acromegaly presents a unique combination of features associated with CV risk, reduced insulin sensitivity yet lower body fat and lower levels of some serum CV risk markers, a pattern that is reversed in remission. %ULN IGF-1 levels strongly predict these features. Given the known increased CV risk of active acromegaly, these findings suggest that of these factors insulin resistance is most strongly related to disease activity and potentially to the increased CV risk of active acromegaly.
肢端肥大症的活动情况通过生长激素（GH）和胰岛素样生长因子-1（IGF-1）水平来衡量，流行病学研究表明，这些指标恢复正常可降低肢端肥大症的过高死亡率。然而，关于IGF-1水平与可能与心血管（CV）风险相关的疾病特征之间的联系，现有数据较少。因此，我们检验了以下假设：相对于正常上限的血清IGF-1水平与肢端肥大症患者的胰岛素敏感性、血清CV风险标志物及身体组成有关。
在一家垂体肿瘤转诊中心进行的这项前瞻性横断面研究中，我们研究了138例成年肢端肥大症患者，这些患者均为新诊断或曾接受过手术治疗，通过双能X线吸收法（DXA）评估其空腹及口服葡萄糖后内分泌和CV风险标志物水平以及身体组成。
与缓解期的肢端肥大症相比，活动期肢端肥大症患者的胰岛素敏感性、体脂和C反应蛋白（CRP）水平较低。相对于正常上限的IGF-1百分比（%ULN IGF-1）比GH更能强烈预测胰岛素敏感性，在调整体脂和瘦组织质量后，这种关系依然存在。%ULN IGF-1还与CRP水平和脂肪量呈负相关，与DXA估计的瘦组织和骨骼肌（SM(E)）呈正相关，但与血压、血脂、体重指数（BMI）或腰围无关。性别与IGF-1-瘦组织质量关系存在相互作用。
活动期肢端肥大症呈现出与CV风险相关的独特特征组合，胰岛素敏感性降低，但体脂较低且某些血清CV风险标志物水平较低，缓解期则相反。%ULN IGF-1水平能强烈预测这些特征。鉴于已知活动期肢端肥大症的CV风险增加，这些发现表明，在这些因素中，胰岛素抵抗与疾病活动度以及活动期肢端肥大症增加的CV风险最密切相关。
