The Physiology Of Hypercortisolism

内源性病理性皮质醇增多症或库欣综合征与生活质量差、发病率和死亡率增加相关。早期诊断可以减轻这种疾病的自然史。库欣综合征的临床表现各不相同，部分与皮质醇过量的程度和持续时间有关。当皮质醇增多症严重时，其体征和症状是明确无误的。然而，库欣综合征的大多数体征和症状在一般人群中是常见的（例如，高血压和体重增加），并不是所有患者都存在。除了糖皮质激素过量的典型特征，如近端肌无力和宽紫色条纹，患者可能存在由皮质醇增多症引起的相关合并症。这些疾病包括心血管疾病、血栓栓塞性疾病、精神和认知缺陷以及感染。因此，内科医生和通才必须将库欣综合征视为病因之一，内分泌学家应寻找并治疗这些合并症。推荐的库欣综合征筛查试验包括1 mg地塞米松抑制、尿游离皮质醇和深夜唾液皮质醇。在生理性皮质醇增多症患者中，这些可能会轻微升高，应排除，沿着外源性糖皮质激素的使用。每个筛查测试都有警告，测试的选择应该根据每个患者的特征和生活方式进行个性化。我们还发现库欣氏综合征患者的甲状腺功能可能异常，在使用外源性糖皮质激素的患者中必须谨慎解释。

Endogenous pathologic hypercortisolism, or Cushing's syndrome, is associated with poor quality of life, morbidity, and increased mortality. Early diagnosis may mitigate against this natural history of the disorder. The clinical presentation of Cushing's syndrome varies, in part related to the extent and duration of cortisol excess. When hypercortisolism is severe, its signs and symptoms are unmistakable. However, most of the signs and symptoms of Cushing's syndrome are common in the general population (e.g., hypertension and weight gain) and not all are present in every patient. In addition to classical features of glucocorticoid excess, such as proximal muscle weakness and wide purple striae, patients may present with the associated comorbidities that are caused by hypercortisolism. These include cardiovascular disease, thromboembolic disease, psychiatric and cognitive deficits, and infections. As a result, internists and generalists must consider Cushing's syndrome as a cause, and endocrinologists should search for and treat these comorbidities. Recommended tests to screen for Cushing's syndrome include 1 mg dexamethasone suppression, urine free cortisol, and late night salivary cortisol. These may be slightly elevated in patients with physiologic hypercortisolism, which should be excluded, along with exogenous glucocorticoid use. Each screening test has caveats and the choice of tests should be individualized based on each patient's characteristics and lifestyle. We have also found that thyroid functions may be abnormal in Cushing's syndrome and must be interpreted with care in patients taking exogenous glucocorticoids.