Usefulness of cortisol/ACTH ratio (CAR) for diagnosis of cushing's syndrome: comparison of CAR with findings in dexamethasone suppression test.

Cushing's syndrome and subclinical Cushing's syndrome (SCS) are conditions of increased cortisol secretion from the adrenal glands. Cushing's syndrome includes adrenocorticotropic hormone (ACTH)-dependent Cushing's syndrome (Cushing's disease) and ACTH-independent Cushing's syndrome (AICS). The purpose of this study was to investigate the diagnostic potential of the cortisol / adrenocorticotropic hormone (ACTH) ratio (CAR) for diagnosis of Cushing's syndrome or SCS in adult subjects. This was a single-center, retrospective, observational study. This study enrolled 44 subjects with SCS, 14 AICS, 10 CD, and 248 non-Cushing's syndrome subjects who had undergone a 1 mg dexamethasone suppression test (1 mg DST). Definition of SCS was as follows: no physical signs characteristic of Cushing syndrome and cortisol was ≥ 83 nmol/L in 1 mg DST. The diagnostic potential of CAR for diagnosis of Cushing's syndrome was evaluated by comparing the correlation between CAR and after-load cortisol level in 1 mg DST. As the results, there was a strong positive correlation between CAR and after-load cortisol level in subjects with AICS (r = 0.800, p < 0.005). CAR was 10,040 ± 4170 nmol/pmol in subjects with NCS, 17,535 ± 10,246 nmol/pmol in SCS, 101,221 ± 18,009 nmol/pmol in AICS, and 4324 ± 2051 nmol/pmol in CD, all of which were significantly higher compared to those with AICS (p < 0.0005). The cutoff values of CAR for screening at our institution were 11,849.6 nmol/pmol for AICS (AUC 0.935, p < 0.005, sensitivity 92.3%, specificity 83.5%) and 7006.1 nmol/pmol for CD (AUC 0.714, p < 0.05, sensitivity 100.0%, specificity 46.8%). There was a positive correlation between CAR and adrenal adenoma diameter in subjects with AICS (r = 0.508, p < 0.05), but there was no correlation between tumor diameter and CAR in subjects with SCS and CD. In conclusion, high CAR indicates increased cortisol secretion from the adrenal glands. Since CAR is a simple indicator that can be easily evaluated by general practitioners as well as endocrinologists, we think CAR would be useful for the early detection of Cushing's syndrome.

Central Diabetes Insipidus Due to IgG4-related Hypophysitis That Required over One Year to Reach the Final Diagnosis Due to Symptoms Being Masked by Sialadenitis.

Pituitary inflammation due to IgG4-related disease is a rare condition and is sometimes accompanied by central diabetes insipidus. Central diabetes insipidus produces a strong thirst sensation, which may be difficult to distinguish when complicated by salivary insufficiency. A 45-year-old man was admitted to our department for a thorough examination of his thirst and polyuria. He had suddenly developed these symptoms more than one year earlier and visited an oral surgeon. Swelling of the left submandibular gland, right parotid gland, and cervical lymph nodes had been observed. Since his IgG4 level was relatively high at 792 mg/dL and a lip biopsy showed high plasmacytoid infiltration around the gland ducts, he had been diagnosed with IgG4-related disease. He had started taking 0.4 mg/kg/day of prednisolone, and his chief complaint temporarily improved. However, since the symptom recurred, he was referred to our institution. After admission, to examine the cause of his thirst and polyuria, we performed a water restriction test, vasopressin loading test, hypertonic saline loading test and pituitary magnetic resonance imaging. Based on the findings, we diagnosed him with central diabetes insipidus due to IgG4-related hypophysitis. We increased the dose of prednisolone to 0.6 mg/kg/day and started 10 µg/day of intranasal desmopressin. His symptoms were subsequently alleviated, and his serum IgG4 level finally normalized. We should remember that IgG4-related disease can be accompanied by hypophysitis and that central diabetes insipidus is brought about by IgG4-related hypophysitis. This case report should remind physicians of the fact that pituitary inflammation due to IgG4-related disease is very rare and can be masked by symptoms due to salivary gland inflammation, which can lead to pitfalls in the diagnosis in clinical practice.

Long-term effect of submucous turbinectomy in patients with perennial allergic rhinitis.

OBJECTIVES: The long-term effect of submucous turbinectomy for patients with perennial allergic rhinitis was assessed. STUDY DESIGN: A cohort study of 45 patients with severe perennial allergic rhinitis who underwent submucous turbinectomy and were followed up after surgery for more than 3 years was performed. We investigated quality of life in 30 of 45 patients who had passed over 5 years after the surgery. METHODS: Nasal symptoms were assessed with a standard symptom score by diary cards. Nasal congestion was evaluated by rhinometry. Nasal challenge tests in vivo were performed to evaluate allergic reactions. These examinations were performed before surgery and at 1 year, more than 3 years, and more than 5 years after submucous turbinectomy. We determined the symptom scores and the quality of life using card questionnaires in 30 patients at the time point of more than 5 years after surgery. RESULTS: The mean [+/- SD] total nasal symptom score (maximum 9) was significantly lower at 1 year after surgery (7.5+/-1.6 vs. 1.8+/-1.8, P <.0001) compared with before surgery. A significant improvement in nasal symptoms was noted at the 3-year (2.8+/-2.3, P <.0001) and 5-year (3.3+/-1.6, P <.0001) time points. A significant increase in total nasal airflow value was noted at each time point after surgery, with a gradual reduction in the total nasal symptom score as well (before surgery, 269.4+/-249.5 cm3/s; 1 y after surgery, 450.1+/-197.7 cm3/s; more than 3 y after surgery, 385.1+/-182.3 cm3/s). The nasal challenge test score was also reduced 1 year after surgery (2.1+/-1.0 vs. 0.6+/-0.7, P <.0001). However, there was no further significant increase at the 3-year time point (0.4+/-0.7, P <.0001) after surgery. In regard to postoperative quality of life, according to the results of the card questionnaire, 50% of the patients had not been receiving antiallergic treatments in the postoperative period. CONCLUSION: Our results suggest that submucous turbinectomy is a useful strategy for the longterm management of nasal allergic reaction and contributes to the improvement in quality of life.