Objective: To examine the clinical characteristics and metabolic features of subclinical Cushing's syndrome (SCS), and determine the effects of surgical or conservative approaches on the hormone levels and metabolic comorbidities in patients with SCS, thereby providing the evidence for decision-making in SCS management. Methods: A total of 56 consecutive SCS patients were selected in Drum Tower Hospital Affiliated to Nanjing University Medical School between 2010 and 2018, with 41 patients undergoing surgical treatment and 15 patients receiving conservative therapy. Meanwhile, 56 and 68 cases of sex-and age-matched patients diagnosed as nonfunctional adrenal adenoma (NFA) and adrenal Cushing's syndrome (CS) were included respectively. Clinical characteristics of patients in different groups were compared. Hormone levels and metabolic comorbidities were also observed during follow-up. Results: There were 56 SCS patients, including 15 males and 41 females, with an age of (52.0±12.6) years. The circadian rhythms of adrenocorticotropic hormone (ACTH) and cortisol disappeared in CS and SCS groups. Compared to NFA group, patients with SCS were characterized by suppressed plasma ACTH level [2.40 (1.11, 4.33) pmol/L vs 4.23 (2.74, 6.26) pmol/L], elevated midnight cortisol level [(240±121) nmol/L vs (59±8) nmol/L] and increased cortisol level after 1 mg overnight dexamethasone suppression test [(241±130) nmol/L vs (34±12) nmol/L] (all P<0.01). The derangement of ACTH-cortisol axis was more obvious in CS patients compared to SCS patients. The prevalence of hypertension, glucose intolerance, dyslipidemia and osteopenia/osteoporosis were higher in SCS patients compared to NFA patients (75.0% vs 41.1%, 33.9% vs 12.5%, 62.5% vs 28.6%, 35.7% vs 8.9%, all P<0.05). The 24-hour urine free cortisol correlated positively with systolic blood pressure, glycated hemoglobin A1c (HbA1c) and fasting blood glucose in SCS patients (r=0.335, 0.562 and 0.463, respectively, all P<0.05). In the surgical group, body weight, body mass index (BMI) and blood pressure decreased significantly after surgery (all P<0.05). Glucose intolerance/diabetes mellitus improved in 6 of 9 patients, BMI of 4 of 11 overweight/obesity patients normalized, and hypertension in 54.5% of patients (12/22) showed improvement after surgery. However, no alterations of hormone levels and metabolic parameters were observed in conservatively-managed patients. Conclusions: Patients with SCS are characterized by mild autonomous cortisol secretion and increased risk of metabolic comorbidities. Compared with conservative management, hormone abnormalities were corrected and metabolic abnormalities were improved in some SCS patients after surgery.
目的： 提高对亚临床库欣综合征（SCS）临床及代谢特征的认识，明确手术或保守治疗的SCS患者激素及代谢合并症变化，为治疗决策提供借鉴。 方法： 纳入2010至2018年在南京大学医学院附属鼓楼医院明确诊断的SCS患者56例（41例接受手术治疗，15例随访观察）。同时选择与SCS性别、年龄匹配的肾上腺无功能瘤（NFA）患者56例，肾上腺腺瘤型临床库欣综合征（CS）患者68例。比较各组临床特征及SCS手术或保守治疗或随访观察的激素水平及代谢异常状态变化。 结果： 纳入SCS患者56例，男15例，女41例，就诊年龄（52.0±12.6）岁。CS和SCS组促肾上腺皮质激素（ACTH）及皮质醇昼夜节律消失。与NFA患者相比，SCS患者血浆ACTH水平较低[8∶00 ACTH：2.40（1.11，4.33）pmol/L比4.23（2.74，6.26）pmol/L]，夜间皮质醇水平[（240±121）nmol/L比（59±8）nmol/L]和1 mg地塞米松抑制后皮质醇水平[（241±130）nmol/L比（34±12）nmol/L]更高（均P<0.01）。CS组ACTH及皮质醇轴功能紊乱较SCS组更明显。SCS患者高血压、糖代谢异常、脂代谢异常和骨量减少/骨质疏松症的发生率高于NAF组（75.0%比41.1%，33.9%比12.5%，62.5%比28.6%，35.7%比8.9%，均P<0.05）。SCS患者24 h尿游离皮质醇与收缩压、糖化血红蛋白及空腹血糖呈正相关（r值分别为0.335、0.562、0.463，均P<0.05）。手术治疗后SCS患者体重、体质指数及血压较术前下降（均P<0.05）。其中手术组9例糖代谢异常患者6例缓解，11例超重/肥胖患者4例BMI恢复正常，22例高血压患者12例（54.5%）缓解。未手术组激素水平及代谢异常状态较基线无明显变化。 结论： SCS患者存在轻度自主性皮质醇分泌，其合并代谢合并症风险增加。相对于保守治疗，手术治疗后SCS患者激素异常纠正且部分患者代谢异常得到改善。.
Keywords: Adrenal incidentaloma; Conservative management; Cushing syndrome; Subclinical Cushing′s syndrome; Surgical procedures, operative.