Glycated albumin (GA) and the GA/HbA1c ratio are higher in diabetic patients positive for insulin antibodies with high binding capacity and low affinity.

Patients with diabetes mellitus having insulin antibodies (InsAb) with properties of high binding capacity and low affinity, which are observed in insulin autoimmune syndrome (IAS), are known to have greater plasma glucose fluctuations. Glycated albumin (GA) and the GA/HbA1c ratio have been demonstrated to reflect plasma glucose fluctuations. Hence, we hypothesized that GA or the GA/HbA1c ratio in diabetic patients having InsAb with properties of high binding capacity and low affinity may be higher than those in InsAb-negative diabetic patients, and we verified this hypothesis. Subjects were 12 diabetic patients who had InsAb noted while being treated with insulin and were subjected to Scatchard analysis and whose InsAb had properties similar to those of patients with IAS (affinity constant K1 < 0.24 × 1/10-8 M, number of binding sites R1 ≥ 11.5 × 10-8 M) [four cases of type 1 diabetes (T1D) and eight cases of type 2 diabetes (T2D)]. The control group consisted of T1D and T2D cases matched to the T1D and T2D cases, respectively, according to sex, age, BMI, and HbA1c. GA and the GA/HbA1c ratio were compared between both groups. GA and the GA/HbA1c ratio in InsAb-positive patients was significantly higher than that in the control group for both T1D and T2D patients. Diabetic patients having InsAb with properties of high binding capacity and low affinity had higher GA and the GA/HbA1c ratio than those of InsAb-negative patients. Greater plasma glucose fluctuations were suggested in InsAb-positive diabetic patients.

Accuracy of a Professional Continuous Glucose Monitoring Device in Individuals with Type 2 Diabetes Mellitus.

Among continuous glucose monitoring (CGM) devices, which continuously measure glucose concentration in subcutaneous interstitial fluid for comprehensive monitoring of blood glucose profile, only FreeStyle Libre Pro® (Abbott Diabetes Care) is currently available in Japan as a professional system. FreeStyle Libre Pro® is easy to use because it does not require calibration by self-monitoring of blood glucose (SMBG), but information on its accuracy has been insufficient. To evaluate the measurement accuracy of FreeStyle Libre Pro®, we have now compared blood glucose levels determined by this device with those measured by SMBG in 40 individuals with type 2 diabetes mellitus. The mean absolute relative difference (MARD) for FreeStyle Libre Pro® measurements compared with SMBG measurements was calculated as an index of CGM accuracy. Overall blood glucose values measured by SMBG were 167.0 ± 60.1 mg/dL, and those determined by FreeStyle Libre Pro® were 155.0 ± 60.7 mg/dL, with this difference being statistically significant. The MARD for FreeStyle Libre Pro® relative to SMBG was 12.7 ± 9.3%. It was substantially higher in 2 of the 40 patients, at 49.2% and 47.5%, than in the other 38 individuals. MARD values did not differ significantly between before and 2 h after meals. However, the MARD was significantly higher for SMBG values of <100 mg/dL than for those of ≥250 mg/dL. Our results thus indicate that the measurement accuracy of FreeStyle Libre Pro® is relatively good, but that some cases in which values determined by the device deviate from SMBG values require caution in interpretation.

Relationship between glycated hemoglobin level and duration of hypoglycemia in type 2 diabetes patients treated with sulfonylureas: A multicenter cross-sectional study.

AIMS/INTRODUCTION: Sulfonylurea-related hypoglycemia increases the risk of cardiovascular sequela, such as cardiac arrhythmia. This study aimed to clarify the relationship between the level of glycated hemoglobin (HbA1c ) and the duration of hypoglycemia in type 2 diabetes patients treated with sulfonylureas. MATERIALS AND METHODS: Glucose levels in the enrolled patients (n = 300) were investigated with a professional continuous glucose monitoring device in the outpatient setting at six diabetes centers in Japan. RESULTS: A total of 269 participants completed the study. The duration of hypoglycemia with glucose values of <54 mg/dL was significantly longer in patients with an HbA1c level of ≤6.4% than in those with an HbA1c level of ≥8.0%, and that of hypoglycemia with glucose values of <70 mg/dL was significantly longer in patients with an HbA1c level of ≤6.4%, 6.5-6.9% or 7.0-7.4% than in those with an HbA1c level of ≥8.0%. Patients with an HbA1c level of ≤6.4% were exposed to glucose values of <70 mg/dL for >10% of the time in daily life (6.8 ± 5.6 min/h). The duration of hypoglycemia with glucose values of <70 mg/dL was longer at night than during the daytime, and the nadir of glucose values occurred between 03.00 and 05.00 hours irrespective of HbA1c level. The duration of hypoglycemia was associated with the duration of diabetes and sulfonylurea dose. CONCLUSIONS: The duration of hypoglycemia was inversely correlated with HbA1c level and was longer during the night-time than daytime in type 2 diabetes patients treated with sulfonylureas.

Clinical characteristics of insulin resistance syndromes: A nationwide survey in Japan.

AIMS/INTRODUCTION: Insulin resistance syndrome (IRS) of type A or B is triggered by gene abnormalities of or autoantibodies to the insulin receptor, respectively. Rabson-Mendenhall/Donohue syndrome is also caused by defects of the insulin receptor gene (INSR), but is more serious than type A IRS. Here, we carried out a nationwide survey of these syndromes in Japan. MATERIALS AND METHODS: We sent questionnaires to a total of 1,957 academic councilors or responsible individuals at certified facilities of the Japan Diabetes Society, as well as at the department pediatrics or neonatology in medical centers with >300 beds. RESULTS: We received 904 responses with information on 23, 30 and 10 cases of type A or B IRS and Rabson-Mendenhall/Donohue syndrome, respectively. Eight cases with type A IRS-like clinical features, but without an abnormality of INSR, were tentatively designated type X IRS, with five of these cases testing positive for PIK3R1 mutations. Fasting serum insulin levels at diagnosis (mean ± standard deviation) were 132.0 ± 112.4, 1122.1 ± 3292.5, 2895.5 ± 3181.5 and 145.0 ± 141.4 µU/mL for type A IRS, type B IRS, Rabson-Mendenhall/Donohue syndrome and type X IRS, respectively. Type A and type X IRS, as well as Rabson-Mendenhall/Donohue syndrome were associated with low birthweight. Type B IRS was diagnosed most frequently in older individuals, and was often associated with concurrent autoimmune conditions and hypoglycemia. CONCLUSIONS: Information yielded by this first nationwide survey should provide epidemiological insight into these rare conditions and inform better healthcare for affected patients.

Acromegaly caused by a somatotroph adenoma in patient with neurofibromatosis type 1.

Although acromegaly has been reported in patients with Neurofibromatosis type 1 (NF1), these cases have not been associated with growth hormone (GH)-producing somatotroph adenoma, but with optic pathway glioma. A 68 year-old Japanese woman, who had been clinically diagnosed with NF1, was referred to our hospital due to a thyroid tumor and hypercalcemia. Acromegaly was suspected due to her facial features, and subsequent examinations revealed the presence of GH excess with a pituitary tumor, leading to the diagnosis of acromegaly. Histological and immunohistochemical analysis demonstrated an eosinophilic pituitary adenoma with diffuse positivity for GH, indicating typical somatotroph adenoma. In addition, her thyroid tumor was diagnosed histologically as follicular thyroid carcinoma (FTC) with primary hyperparathyroidism (PHPT). To investigate the pathogenesis of this untypical multiple endocrine tumor case of NF1, genetic analysis was performed using peripheral leukocytes and tissue of resected tumors. A heterozygous novel germline nonsense mutation (p.Arg1534*) in exon 35 of the NF1 gene was detected from peripheral leukocytes, which results in a truncated protein lacking the critical domain for GTPase activity, strongly suggesting its causal role in NF1. The loss of heterozygosity (LOH) in exon 35 of the NF1 gene was not detected in the somatotroph adenoma, parathyroid adenoma, and FTC. Although any mutations of the following genes; MEN1, CDKN1B, and PAX8-PPARγ were not detected, a heterozygous GNAS R201C mutation was detected in the somatotroph adenoma. To our knowledge, this is the first rare MEN1-like case of genetically diagnosed NF1 complicated with acromegaly caused by a somatotroph adenoma.

The prescription rates of glucagon for hypoglycemia by pediatricians and physicians are low in Japan.

PURPOSE: Hypoglycemia is a common and life-threatening complication in type 1 diabetes mellitus (T1DM) patients. Current guidelines recommend glucagon for treating hypoglycemia in out-of-hospital settings; however, glucagon is reportedly underused in such patients. We conducted a doctor-oriented, questionnaire-based survey of pediatricians and physicians to determine the glucagon prescription rate and identify the reason(s) for its underuse in T1DM patients. METHODS: A questionnaire was mailed to 415 pediatricians and 200 physicians employed at 66 facilities with >100 general wards throughout Hyogo, Japan. The following variables were surveyed: doctor's specialty, glucagon prescription rate, familiarity with glucagon use guidelines, barriers to prescribing glucagon, and attitude changes after education. RESULTS: After 16 doctors were found to have retired, 599 doctors were enrolled; 305 (187 pediatricians and 118 physicians) returned a completed questionnaire. In all, 45 pediatricians and 104 physicians were treating T1DM patients, of whom 24% and 28% reported prescribing glucagon, respectively. The guideline familiarity rate among pediatricians was lower than that among physicians. The major barrier to prescribing glucagon was the complex preparation procedure required by patients/caregivers. More than half of the doctors who did not prescribe glucagon began doing so after being educated about the guidelines. CONCLUSION: The glucagon prescription rate was low among both pediatricians and physicians in Japan.

Treatment of a case of severe insulin resistance as a result of a PIK3R1 mutation with a sodium-glucose cotransporter 2 inhibitor.

A Japanese woman aged in her late 30s with severe insulin resistance and bodily features including a triangular face, prominent forehead, small chin, large and low-set ears, and ocular depression was investigated. A similar phenotype was not observed in other family members with the exception of her son, suggesting that the condition was caused by a de novo mutation that was transmitted from mother to son. Exome analysis showed the presence in the proband and her son of a c.1945C>T mutation in PIK3R1, a common mutation associated with SHORT (short stature, hyperextensibility of joints and/or inguinal hernia, ocular depression, Rieger anomaly, and teething delay) syndrome. Administration of a sodium-glucose cotransporter 2 inhibitor lowered the proband's hemoglobin A1c level and allowed a reduction in her insulin dose without treatment-related adverse events including ketoacidosis, exaggerated loss of body mass or hypoglycemia. Sodium-glucose cotransporter 2 inhibitors might thus offer an additional option for the treatment of genetic syndromes of severe insulin resistance.

Effect of switching from conventional continuous subcutaneous insulin infusion to sensor augmented pump therapy on glycemic profile in Japanese patients with type 1 diabetes.

AIMS: Evidence suggests that sensor augmented pump (SAP) therapy is superior to conventional continuous subcutaneous insulin infusion (CSII) for achieving glycemic control in patients with type 1 diabetes. However, the clinical benefit of SAP therapy in East Asians has not yet been demonstrated. METHODS: The effect of switching from conventional CSII to SAP therapy on glycemic profile was examined in 18 Japanese patients with type 1 diabetes. The glycemic profile of the patients was determined by retrospective continuous glucose monitoring (CGM) within 1 month before the treatment switch, whereas that at 6 and 12 months after the switch was evaluated with the CGM function of the SAP device. Hemoglobin A1c levels were also measured before and after the switch to SAP therapy. RESULTS: The duration of hypoglycemia was significantly decreased at both 6 and 12 months after the change in treatment (6.6 ± 4.5, 3.2 ± 4.1, and 3.0 ± 2.8 min/h for before and 6 and 12 months, respectively), as was the HbA1c level at 12 months (7.8 ± 1.0 and 7.4 ± 0.9%, respectively). The duration of hyperglycemia did not differ between before and after the treatment switch. The decline in HbA1c level at 12 months after the switch to SAP was negatively correlated with age. CONCLUSION: Switching from conventional CSII to SAP therapy was associated with a decrease in both the duration of hypoglycemia and the level of HbA1c in Japanese patients with type 1 diabetes.

D-dimer as a significant marker of deep vein thrombosis in patients with subclinical or overt Cushing's syndrome.

Venous thromboembolism (VTE) is frequently associated with hypercortisolemia. This retrospective single-center study aimed to clarify the significance of plasma D-dimer levels for VTE screening in patients with subclinical or overt Cushing's syndrome (soCS). A total of 72 consecutive treatment-naïve patients with soCS diagnosed at Kobe University Hospital between 2002 and 2014 were enrolled. Patients with both lower extremity ultrasound and D-dimer measurement data (n = 19) were recruited in study 1 and divided into 2 groups, a deep vein thrombosis (DVT) (-) group (n = 12) and DVT (+) group (n = 7) for a comparison of the associated factors. The age and D-dimer levels were higher in the DVT (+) group than in the DVT (-) group (p = 0.04 and 0.02, respectively). A receiver operating characteristic analysis found that D-dimer level ≥2.6 µg/mL correlated with the presence of DVT (sensitivity, 100%; specificity, 91.7%). Next, patients with D-dimer measurement data (n = 36) were recruited in study 2 and divided into 2 groups according to D-dimer level: D-dimer (-), <1 µg/mL group (n = 23) and D-dimer (+), ≥1 µg/mL group (n = 13); the groups were compared with respect to various VTE-related risk factors. A logistic regression analysis revealed that elevated cortisol level after low-dose dexamethasone suppression was a significant risk factor for D-dimer elevation (OR = 1.21, p = 0.02). In conclusion, these data demonstrate that a D-dimer level ≥2.6 µg/mL is an indicator of DVT in treatment naïve patients with soCS and suggests that relatively high autonomous cortisol secretion may be associated with thrombus formation.