Pituitary incidentalomas (PIs) are tumors of the pituitary gland discovered unexpectedly upon imaging that are not due to symptoms related specifically to the lesion (e.g., visual loss) or a clinical manifestation of hormonal disorders (1). Vernooij and colleagues reported analysis of patient with magnetic resonance imagings of the brain showed PIs were present in 1.6% persons (2). The previous autopsy investigations also showed the prevalence of PIs were 2.7-24.0 % (3-5). Whereas, adrenal incidentalomas, the same endocrine incidental tumors as PIs, have been investigated in several studies (6-9), even though their prevalence investigated by autopsy were reported to be lower than that of PIs (1.1-5.0 %) (10-12). However, few studies have focused on PIs (2,13,14). Summary Recent advances in imaging technology resulted in an increase in pituitary incidentalomas (PIs) detection. PIs were reported to be present in 1.6% persons with magnetic resonance imaging of the brain. Whereas, there were few studies about PIs with detailed investigation. We aimed to investigate the clinical and endocrinological characteristics of PIs. We evaluated 65 patients diagnosed with PIs who underwent detailed clinical and endocrinological evaluations. Of the 65 patients, 33 (50.8%) had non-functional pituitary adenomas (NFPAs), 11 (16.9%) had Rathke's cleft cysts (RCCs), 7 (10.8%) had functional pituitary adenomas (FPAs), 6 (9.2%) had benign extra-pituitary tumors (BEPTs), and 8 (12.3%) had malignant tumors (MTs). Compared with patients with NFPAs, those with MTs were significantly younger and had a significantly lower body mass index, lower prevalence of hypertension, and lower prevalence of dyslipidemia. Patients with MTs had significantly higher prevalence of central diabetes insipidus than those with NFPAs. In addition, patients with NFPAs had significantly higher prevalence of pituitary apoplexy than those with FPAs, BEPTs, and MTs. In conclusion, our study demonstrated clinical and endocrinological characteristics of PIs. Highly detailed clinical and endocrinological investigations should be performed for PIs. In addition, MTs should be considered in the differential diagnosis for young and lean patients with central diabetes insipidus.

Osteoporosis is a complication of type 2 diabetes mellitus (T2DM). Blockade of receptor activator of nuclear factor kappa-B ligand (RANKL) improves osteoporosis, but might also improve glucose tolerance through reduction of hepatic insulin resistance. However, the effect of denosumab (a human monoclonal antibody of RANKL) upon glycemic and metabolic parameters is controversial. We revealed the effect of denosumab upon glycemic and metabolic parameters for 52 weeks. We evaluated 20 individuals diagnosed with both osteoporosis (male and female: postmenopausal) and T2DM. We measured glycemic and metabolic parameters before and 26/52 weeks after administration of denosumab (60 mg per 26 weeks) without changing any other medication each patient was taking. All patients completed the study without complications and the T-score (lumbar spine and femoral neck) improved significantly from baseline to 52 weeks after denosumab administration (P < .001, .001, respectively). None of the glycemic parameters changed significantly from baseline to 26 weeks after denosumab administration, but levels of glycated hemoglobin and homeostasis model assessment of insulin resistance improved significantly from baseline to 52 weeks after administration (P = .019, .008, respectively). The levels of liver enzymes did not change significantly from baseline to 26 weeks after denosumab administration, but levels of aspartate transaminase and alanine aminotransferase improved significantly from baseline to 52 weeks after administration (P = .014, .004, respectively). None of the markers of lipid metabolism and body mass index changed significantly from baseline to 26/52 weeks after denosumab administration. These data demonstrated that denosumab is useful for T2DM patients with osteoporosis for glycemic control via improvement of insulin resistance. Also, the effect of denosumab might be due to improvement of hepatic function.

Glucose intolerance is often observed in patients with pheochromocytoma. However, it remains controversial issue that glucose intolerance on pheochromocytoma is caused by impaired insulin secretion and/or by increased insulin resistance. We aimed to reveal the mechanism of glucose intolerance on pheochromocytoma with regard to the type and amount of catecholamines released. We evaluated 12 individuals diagnosed with pheochromocytoma and who underwent surgery to remove it. We examined glycemic parameters before and after surgery and investigated the association between the change of parameters of insulin secretion (homeostasis model assessment of β-cell function (HOMA-β)), insulin resistance (homeostasis model assessment of insulin resistance (HOMA-IR)) and that of urinary levels of metanephrine/normetanephrine before and after surgery. Overall, fasting plasma glucose, glycated hemoglobin (HbA1c), HOMA-β, and HOMA-IR were improved significantly after surgery. Regression analysis showed that the improvement in HOMA-β from before to after surgery was significantly positively associated with an improvement in urinary levels of metanephrine from before to after surgery and showed a significantly negative association with improvement in urinary levels of normetanephrine from before to after surgery. The improvement in HOMA-IR from before to after surgery was significantly positively associated with an improvement in urinary levels of normetanephrine from before to after surgery. Our results showed that pheochromocytoma extirpation improved glycemic parameters. Furthermore, the different effects elicited by excess amounts of adrenaline and noradrenaline on glucose intolerance were demonstrated.

Objectives We retrospectively investigated the clinical and endocrinological characteristics of adrenal incidentalomas. Methods We studied 61 patients who had been diagnosed with adrenal incidentalomas and had undergone detailed clinical and endocrinological evaluations while hospitalized. We used common criteria to diagnose the functional tumors, but for sub-clinical Cushing's syndrome, we used an updated set of diagnosis criteria: serum cortisol ≥1.8 μg/dL after a positive response to a 1-mg dexamethasone suppression test if the patient has a low morning adrenocorticotropic hormone (ACTH) level (<10 pg/mL) and a loss of the diurnal serum cortisol rhythm. Results Of the 61 patients, none (0%) had malignant tumors, 8 (13.1%) had pheochromocytoma, and 15 (24.6%) had primary aldosteronism; when diagnosed by our revised criteria, 13 (21.3%) had cortisol-secreting adenomas (Cushing's syndrome and sub-clinical Cushing's syndrome), and 25 (41.0%) had non-functional tumors. Compared with the non-functional tumor group, the primary aldosteronism group and the cortisol-secreting adenoma group were significantly younger and had significantly higher rates of hypokalemia, whereas the pheochromocytoma group had significantly larger tumors and a significantly lower body mass index. Conclusion Our study found a larger percentage of functional tumors among adrenal incidentalomas than past reports, partly because we used a lower serum cortisol level after a dexamethasone suppression test to diagnose sub-clinical Cushing's syndrome and because all of the patients were hospitalized and could therefore receive more detailed examinations. Young patients with hypokalemia or lean patients with large adrenal tumors warrant particularly careful investigation.

Background: Few studies have focused on the "glucose-normalizing effects" of high and standard doses of dipeptidyl peptidase-4 (DPP-4) inhibitors evaluated using continuous glucose monitoring (CGM). Teneligliptin is a DPP-4 inhibitor licensed in Japan for administration at standard (20 mg/day) and high (40 mg/day) doses to treat type 2 diabetes mellitus. However, little is known about its effects on the "quality" of glucose control or plasma glucose fluctuation, including factors such as postprandial glucose levels and frequency of hypoglycemia. We used CGM to study the efficacy of high-dose teneligliptin for the treatment of diabetic patients. Materials and methods:Mean amplitude of glycemic excursions (MAGE), and mean, minimum, maximum, and standard deviation (SD) of glucose concentrations were measured by CGM in ten hospitalized individuals with type 2 diabetes mellitus. Results:Compared with effects of standard-dose teneligliptin, MAGE, SD, and maximum glucose concentrations were significantly reduced by high-dose teneligliptin (P < 0.01). There was no significant difference in mean glucose concentrations, whereas minimum glucose concentrations were significantly increased by high-dose teneligliptin (P = 0.0314). Conclusion:High-dose teneligliptin decreases hypoglycemia and may provide good "quality" of glucose control, thereby reducing the risk of diabetic complications and improving the patients' quality of life.