Division of Endocrinology and School of Medicine of Ribeirão Preto, University of São Paulo, 14049-900 Ribeirão Preto, Brazil.
Horm Metab Res. 2010 Jan;42(1):50-5. doi: 10.1055/s-0029-1239522. Epub 2009 Oct 1.
Biochemical markers for remission on acromegaly activity are controversial. We studied a subset of treated acromegalic patients with discordant nadir GH levels after oral glucose tolerance test (oGTT) and IGF-I values to refine the current consensus on acromegaly remission. We also compared GH results by two GH immunoassays. From a cohort of 75 treated acromegalic patients, we studied 13 patients who presented an elevated IGF-I despite post-oGTT nadir GH of < or =1 microg/l. The 12-h daytime GH profile (GH-12 h), nadir GH after oGTT, and basal IGF-I levels were studied in patients and controls. Bland-Altman method showed high concordance between GH assays. Acromegalic patients showed higher mean GH-12 h values (0.71+/-0.36 vs. 0.31+/-0.28 microg/l; p<0.05) and nadir GH after oGTT (0.48+/-0.32 vs. 0.097+/-0.002 microg/l; p<0.05) as compared to controls. Nadir GH correlated with mean GH-12 h (r=0.92, p<0.05). The mean GH-12 h value from upper 95% CI of controls (0.54 microg/l) would correspond to a theoretical normal nadir GH of < or =0.27 microg/l. Patients with GH nadir < or =0.3 microg/l had IGF-I between 100-130% ULNR (percentage of upper limit of normal range) and mean GH-12 h of 0.35+/-0.15, and patients with GH nadir >0.3 and < or =1 microg/l had IGF-I >130% ULNR and mean GH-12 h of 0.93+/-0.24 microg/l. Our data integrate daytime GH secretion, nadir GH after oGTT, and plasma IGF-I concentrations showing a continuum of mild residual activity in a subgroup of treated acromegaly with nadir GH values < or =1 microg/l. The degree of increased IGF-I levels and nadir GH after oGTT are correlated with the subtle abnormalities of daytime GH secretion.
在肢端肥大症活性的缓解方面，生化标志物存在争议。我们研究了一组接受治疗的肢端肥大症患者，他们在口服葡萄糖耐量试验（oGTT）后 GH 水平和 IGF-I 值存在差异，以完善当前关于肢端肥大症缓解的共识。我们还比较了两种 GH 免疫测定法的 GH 结果。从 75 例接受治疗的肢端肥大症患者中，我们研究了 13 例患者，尽管 oGTT 后 GH 最低值 < 或 =1μg/l，但 IGF-I 仍升高。对患者和对照组进行了 12 小时日间 GH 谱（GH-12 h）、oGTT 后 GH 最低值和基础 IGF-I 水平的研究。Bland-Altman 法显示两种 GH 检测方法具有高度一致性。肢端肥大症患者的平均 GH-12 h 值（0.71+/-0.36 vs. 0.31+/-0.28μg/l；p<0.05）和 oGTT 后 GH 最低值（0.48+/-0.32 vs. 0.097+/-0.002μg/l；p<0.05）均高于对照组。GH 最低值与平均 GH-12 h 相关（r=0.92，p<0.05）。对照组上 95%CI 的平均 GH-12 h 值（0.54μg/l）相当于理论上正常的 GH 最低值 < 或 =0.27μg/l。GH 最低值 < 或 =0.3μg/l 的患者 IGF-I 为 100-130%ULNR（正常值上限百分比），平均 GH-12 h 为 0.35+/-0.15，而 GH 最低值 >0.3 和 < 或 =1μg/l 的患者 IGF-I >130%ULNR，平均 GH-12 h 为 0.93+/-0.24μg/l。我们的数据整合了日间 GH 分泌、oGTT 后 GH 最低值和血浆 IGF-I 浓度，显示在一组 GH 最低值 < 或 =1μg/l 的接受治疗的肢端肥大症患者中存在轻微残留活性的连续体。IGF-I 水平和 oGTT 后 GH 最低值的升高程度与日间 GH 分泌的轻微异常相关。
