Endocrinology Unit, Department of Medicine, Padova University Hospital, Padua, Italy.
Internal Medicine Unit, Department of Medicine, University of Padova, Padua, Italy.
J Clin Endocrinol Metab. 2019 Mar 1;104(3):856-862. doi: 10.1210/jc.2018-01360.
The oral glucose tolerance test (OGTT) is considered the most useful method for diagnosing active acromegaly and for patient follow-up after neurosurgery. Despite its widespread use, only a few small studies have so far focused on patients' clinical features associated with different GH responsiveness to OGTT.
We aimed to investigate the association between glucose-induced GH response and endocrine profiles, clinical manifestations, and response to therapy in a large cohort of patients with acromegaly.
According to GH response to OGTT, patients were grouped as paradoxical (GH-Par) or nonparadoxical (GH-NPar), and their clinical and pathological features were compared in terms of pituitary tumor size, invasiveness, biochemical profiles, and response to therapy.
The study concerned 496 patients with acromegaly. At diagnosis, those with GH-Par (n = 184) were older than those with GH-NPar (n = 312) (mean ± SD, 44.1 ± 13.7 years vs 40.5 ± 12.7 years; P < 0.01) and had smaller tumors (0.82 vs 1.57 cm3; P < 0.01) that less frequently invaded the cavernous sinus (15% vs 27%; P < 0.01). The GH-Par group also had a higher basal GH per volume ratio (14.3 vs 10.5 μg/L ⋅ cm3; P < 0.05) and a lower incidence of hyperprolactinemia (17% vs 30%; P < 0.01) than the GH-NPar group. Importantly, the GH-Par group had a higher rate of remission in response to somatostatin analogues (52% vs 26%; P < 0.01) and a more marked drop in IGF-1 and GH after 6 months of therapy.
Our data strongly suggest that serum GH responsiveness to oral glucose challenge reflects some important biological features of pituitary tumors and that the OGTT may have some prognostic value.
口服葡萄糖耐量试验（OGTT）被认为是诊断活跃性肢端肥大症和神经外科手术后患者随访的最有用方法。尽管它被广泛应用，但到目前为止，只有少数小型研究关注了患者的临床特征与 OGTT 下不同的 GH 反应之间的关系。
我们旨在调查 OGTT 下 GH 反应与大样本肢端肥大症患者的内分泌特征、临床表现和治疗反应之间的关系。
根据 OGTT 下 GH 的反应，将患者分为反常性（GH-Par）或非反常性（GH-NPar），并比较肿瘤大小、侵袭性、生化特征和治疗反应方面的临床和病理特征。
本研究涉及 496 例肢端肥大症患者。在诊断时，GH-Par 组（n=184）患者的年龄大于 GH-NPar 组（n=312）（均值±标准差，44.1±13.7 岁比 40.5±12.7 岁；P＜0.01），肿瘤较小（0.82cm³比 1.57cm³；P＜0.01），较少侵犯海绵窦（15%比 27%；P＜0.01）。GH-Par 组的基础 GH 与容积比（14.3μg/L ⋅ cm³比 10.5μg/L ⋅ cm³；P＜0.05）更高，催乳素升高的发生率（17%比 30%；P＜0.01）更低。重要的是，GH-Par 组对生长抑素类似物的缓解率更高（52%比 26%；P＜0.01），治疗 6 个月后 IGF-1 和 GH 下降更明显。
我们的数据强烈表明，口服葡萄糖刺激下血清 GH 的反应性反映了垂体瘤的一些重要生物学特征，OGTT 可能具有一定的预后价值。
