The Physiology Of Hypercortisolism

内源性病理性高皮质醇症，或库欣综合征，与生活质量差、发病率和死亡率增加有关。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。当高皮质醇症严重时，它的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这些症状。除了糖皮质激素过量的典型特征，如近端肌肉无力和宽紫色条纹外，患者还可能出现由高皮质血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，内科医生和全科医生必须将库欣综合征视为病因，内分泌学家应该寻找并治疗这些合并症。推荐筛查库欣综合征的试验包括1毫克地塞米松抑制、尿中游离皮质醇和深夜唾液皮质醇。生理性高皮质血症患者可能会轻微升高，应排除外源性糖皮质激素的使用。每一种筛查试验都有注意事项，应根据每位患者的特点和生活方式进行个性化选择。

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.