Type 2 diabetes susceptibility genes on mouse chromosome 11 under high sucrose environment.

BACKGROUND: Both genetic and environmental factors contribute to type 2 diabetes development. We used consomic mice established from an animal type 2 diabetes model to identify susceptibility genes that contribute to type 2 diabetes development under specific environments. We previously established consomic strains (C3H-Chr 11NSY and C3H-Chr 14NSY) that possess diabetogenic Chr 11 or 14 of the Nagoya-Shibata-Yasuda (NSY) mouse, an animal model of spontaneous type 2 diabetes, in the genetic background of C3H mice. To search genes contribute to type 2 diabetes under specific environment, we first investigated whether sucrose administration deteriorates type 2 diabetes-related traits in the consomic strains. We dissected loci on Chr 11 by establishing congenic strains possessing different segments of NSY-derived Chr 11 under sucrose administration. RESULTS: In C3H-Chr 11NSY mice, sucrose administration for 10 weeks deteriorated hyperglycemia, insulin resistance, and impaired insulin secretion, which is comparable to NSY mice with sucrose. In C3H-Chr 14NSY mice, sucrose administration induced glucose intolerance, but not insulin resistance and impaired insulin secretion. To dissect the gene(s) existing on Chr 11 for sucrose-induced type 2 diabetes, we constructed four novel congenic strains (R1, R2, R3, and R4) with different segments of NSY-derived Chr 11 in C3H mice. R2 mice showed marked glucose intolerance and impaired insulin secretion comparable to C3H-Chr 11NSY mice. R3 and R4 mice also showed impaired insulin secretion. R4 mice showed significant decreases in white adipose tissue, which is in the opposite direction from parental C3H-Chr 11NSY and NSY mice. None of the four congenic strains showed insulin resistance. CONCLUSIONS: Genes on mouse Chr 11 could explain glucose intolerance, impaired insulin secretion, insulin resistance in NSY mice under sucrose administration. Congenic mapping with high sucrose environment localized susceptibility genes for type 2 diabetes associated with impaired insulin secretion in the middle segment (26.0-63.4 Mb) of Chr 11. Gene(s) that decrease white adipose tissue were mapped to the distal segment of Chr 11. The identification of diabetogenic gene on Chr 11 in the future study will facilitate precision medicine in type 2 diabetes by controlling specific environments in targeted subjects with susceptible genotypes.

Fulminant type 1 diabetes associated with Isolated ACTH deficiency induced by anti-programmed cell death 1 antibody-insight into the pathogenesis of autoimmune endocrinopathy.

Therapeutic blocking antibodies against programmed death 1 (PD1) and cytotoxic T-lymphocyte antigen 4 (CTLA4) are applied for advanced cancer therapy, but induce a wide range of immune-related adverse events. In our recent case of a 52-year-old female doctor suffering from breast cancer having metastasized to the lung and liver, it was decided to use nivolumab to prevent the disease progressing after excisional surgeries and multiple chemotherapies. One month after completing the nivolumab course, fatigue, hypoglycemia and hypotension developed and isolated ACTH deficiency (IAD) was diagnosed. A further month later, under steroid supplementation, hyperglycemia emerged alongside thirst and polydipsia, prompting a diagnosis of fulminant type 1 diabetes (FT1D). Her susceptibility to type 1 diabetes was examined by HLA haplotype and CTLA4 gene polymorphism analyses. Polymorphisms CT60G>A and +49G>A in CTLA4 both generated a GG genotype. Our patient manifested one of the rarest combinations of autoimmune disease induced by nivolumab. Whereas the HLA haplotype was unsusceptible to autoimmune type 1 diabetes, polymorphisms of CTLA4, the antibody of which frequently causes hypophysitis, were susceptible to FT1D. Peripheral modulation of activated T cells, mainly by PD-1 antibodies, induced FT1D associated with IAD in patients with CTLA4 polymorphism. This case reveals hints of the T-cell etiology in T1D and evidence of CTLA4 involvement in IAD.

Case report: schwannoma arising from the unilateral adrenal area with bilateral hyperaldosteronism.

BACKGROUND: We report a rare case of a juxta-adrenal schwannoma that could not be discriminated from an adrenal tumor before surgical resection and was complicated by bilateral hyperaldosteronism. To the best of our knowledge, this is first case in which both a juxta-adrenal schwannoma and hyperaldosteronism co-existed. CASE PRESENTATION: A 69-year-old male treated for hypertension was found to have a left supra-renal mass (5.8 × 5.2 cm) by abdominal computed tomography. His laboratory data showed that his plasma aldosterone concentration (PAC) was within the normal range, but his plasma renin activity (PRA) was reduced, resulting in an increased aldosterone/renin ratio (ARR). Load tests of captopril or furosemide in the standing position demonstrated autonomous aldosterone secretion and renin suppression. Adrenal venous sampling (AVS) with ACTH stimulation indicated bilateral hypersecretion of aldosterone. A left supra-renal tumor was resected because of the possibility of malignancy and was found to be a benign schwannoma arising from the juxta-adrenal region together with an adrenal gland. The dissected left adrenal gland was morphologically hyperplastic in the zona glomerulosa, but was immunohistochemically negative for CYP11B2 (aldosterone synthase). Multiple CYP11B2-positive adrenocortical micronodules were detected in the adrenal gland, indicating micronodular hyperplasia. Although bilateral aldosteronism was indicated by AVS before the operation, the PRA, PAC and ARR values were within their respective reference ranges after resection of the unilateral tumor, suggesting that the slight increase in hormone secretion from the remaining right-sided lesion could not be detected after resection. CONCLUSION: A clinical and morphologic diagnosis of juxta-adrenal schwannoma is difficult, particularly in a case of hyperaldosteronism, as shown in this case. These data suggest the complexity and difficulty diagnosing adrenal incidentaloma.

Genetic dissection of susceptibility genes for diabetes and related phenotypes on mouse chromosome 14 by means of congenic strains.

BACKGROUND: A susceptibility locus, Nidd2n, for type 2 diabetes has been mapped to mouse chromosome 14 (Chr 14) and confirmed using the consomic strain (C3H-Chr 14NSY) of the Nagoya-Shibata-Yasuda (NSY) mouse, an animal model of spontaneous type 2 diabetes. The aim of this study was to localize and characterize Nidd2n. RESULTS: We constructed two novel congenic strains homozygous for different segments of NSY-Chr 14 on the control C3H/HeNcrj (C3H) background: R1 (C3H.NSY-(D14Mit206-D14Mit5)) possesses the proximal and middle segment, and R2 (C3H.NSY-(D14Mit206-D14Mit186)) possesses the most proximal segment of NSY-Chr 14. Diabetes-related phenotypes were studied in comparison with those of consomic C3H-Chr 14NSY (R0) and parental NSY and C3H strains. Congenic R1 and R2 showed significantly higher post-challenge glucose than that in C3H mice. Fasting glucose, in contrast, was significantly lower in R1 and R2 than in C3H mice. Insulin sensitivity was significantly impaired in R1 and R2 compared to C3H mice. R2 showed significantly higher body weight and fat-pad weight than those in C3H and R1. Leptin level was significantly higher in R0, R1 and R2 than in C3H mice, with R2 showing the highest level, similar to that in NSY mice. Serum adiponectin level was significantly lower in R0, R1 and R2 than in C3H mice, while it was significantly higher in NSY than in C3H mice. CONCLUSIONS: These data indicate that Chr 14 harbors multiple genes for diabetes-related phenotypes. The original Nidd2n, which is located in the middle region of Chr 14, was divided into two segments; Nidd2.1n in proximal Chr 14 and Nidd2.2n in distal Chr 14. Nidd2.1n contributes to post-challenge hyperglycemia, insulin resistance and adiposity. Nidd2.2n contributes to fasting as well as post-challenge hyperglycemia and insulin resistance. Adp1n, which contributes to decreased adiposity and increased insulin sensitivity, rather than a diabetogenic gene, was mapped in the middle segment.

Glucose values from the same continuous glucose monitoring sensor significantly differ among readers with different generations of algorithm.

Continuous glucose monitoring (CGM) values obtained from CGM systems using the same sensor but with different internal algorithms (the first- and third-generation FreeStyle Libre (1st-gen-libre and 3rd-gen-libre, respectively)) were compared. We used 19,819 paired and simultaneously measured CGM values of 13 patients with diabetes. The average CGM value was significantly higher (P < 0.0001) and the time below range (CGM value < 70 mg/dL) was significantly lower (P < 0.0001) with the 3rd-gen-libre than with the 1st-gen-libre. There was a significant correlation (P < 0.0001) between the CGM values of the 3rd-gen-libre (y-axis, mg/dL) and 1st-gen-libre (x-axis, mg/dL) using the following formula: y = 0.9728x + 10.024. On assessing the association between glycated hemoglobin (HbA1c (%), y-axis) and the average CGM values (x-axis, mg/dL) by applying the obtained equation to previously reported 1st-gen-libre data and converting it to 3rd-gen-libre data, we obtained the equation y = 0.02628x + 3.233, indicating that the glucose management indicator reported in the West may be underestimated compared with the laboratory-measured HbA1c in the Japanese population. Glucose values from the same sensor were found to be significantly different between readers with different algorithms, and the calculation of CGM-related indices may need to be individualized for each device.

High Incidence of Diabetes Mellitus After Distal Pancreatectomy and Its Predictors: A Long-term Follow-up Study.

CONTEXT: Glucose tolerance worsens after distal pancreatectomy (DP); however, the long-term incidence and factors affecting interindividual variation in this worsening are unclear. OBJECTIVE: To investigate the changes in diabetes-related traits before and after DP and to clarify the incidence of diabetes and its predictors. METHODS: Among 493 registered patients, 117 underwent DP. Among these, 56 patients without diabetes before surgery were included in the study. Glucose and endocrine function were prospectively assessed using a 75-g oral glucose tolerance test preoperatively, 1 month after DP, and every 6 months thereafter for up to 36 months. Pancreatic volumetry was performed using multidetector row computed tomography before and after surgery. RESULTS: Insulin secretion decreased and blood glucose levels worsened after DP. Residual pancreatic volume was significantly associated with the reserve capacity of insulin secretion but not with blood glucose levels or the development of diabetes. Among 56 patients, 33 developed diabetes mellitus. The cumulative incidence of diabetes at 36 months after DP was 74.1%. Multivariate Cox regression analysis showed that impaired glucose tolerance as a preoperative factor as well as a decreased insulinogenic index and impaired glucose tolerance at 1 month postoperatively were identified as risk factors for diabetes following DP. CONCLUSION: Impaired glucose tolerance and reduced early-phase insulin response to glucose are involved in the development of new-onset diabetes after DP; the latter is an additional factor in the development of diabetes and becomes apparent when pancreatic beta cell mass is reduced after DP.

New diagnostic criteria (2023) for slowly progressive type 1 diabetes (SPIDDM): Report from Committee on Type 1 Diabetes in Japan Diabetes Society (English version).

The diagnostic criteria for slowly progressive type 1 diabetes (slowly progressive insulin-dependent diabetes mellitus; SPIDDM) have been revised by the Committee on Type 1 Diabetes of the Japan Diabetes Society. All of the following three criteria must be met for "a definitive diagnosis of SPIDDM": (1) presence of anti-islet autoantibodies at some point in time during the disease course; (2) absence of ketosis or ketoacidosis at the diagnosis of diabetes with no requirement of insulin treatment to correct hyperglycemia immediately after diagnosis in principle; and (3) gradual decrease of insulin secretion over time, with insulin treatment required at more than 3 months after diagnosis, and presence of severe endogenous insulin deficiency (fasting serum C-peptide immunoreactivity < 0.6 ng/mL) at the last observed point in time. When a patient fulfills the only (1) and (2), but not (3), he/she is diagnosed with "SPIDDM (probable)" because the diabetes is non-insulin-dependent state.

New diagnostic criteria (2023) for slowly progressive type 1 diabetes (SPIDDM): Report from Committee on Type 1 Diabetes of the Japan Diabetes Society (English version).

The diagnostic criteria for slowly progressive type 1 diabetes (slowly progressive insulin-dependent diabetes mellitus; SPIDDM) have been revised by the Committee on Type 1 Diabetes of the Japan Diabetes Society. All of the following three criteria must be met for 'a definitive diagnosis of SPIDDM': (1) presence of anti-islet autoantibodies at some point in time during the disease course; (2) absence of ketosis or ketoacidosis at the diagnosis of diabetes with no requirement for insulin treatment to correct hyperglycemia immediately after diagnosis in principle; and (3) gradual decrease of insulin secretion over time, with insulin treatment required at more than 3 months after diagnosis, and the presence of severe endogenous insulin deficiency (fasting serum C-peptide immunoreactivity <0.6 ng/mL) at the last observed point in time. When a patient fulfills only (1) and (2), but not (3), he/she is diagnosed with 'SPIDDM (probable)' because the diabetes is non-insulin-dependent type.

Prediction of future insulin-deficiency in glutamic acid decarboxylase autoantibody enzyme-linked immunosorbent assay-positive patients with slowly-progressive type 1 diabetes.

AIMS/INTRODUCTION: This study aimed to identify risk factors that contribute to the progression of slowly-progressive type 1 diabetes by evaluating the positive predictive value (PPV) of factors associated with the progression to an insulin-dependent state. MATERIALS AND METHODS: We selected 60 slowly-progressive type 1 diabetes patients who tested positive for glutamic acid decarboxylase autoantibodies (GADA) at diagnosis from the Japanese Type 1 Diabetes Database Study. GADA levels in these patients were concurrently measured using both radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) techniques. RESULTS: Compared with the non-progressor group (fasting C-peptide [F-CPR] levels maintained ≥0.6 ng/mL), the progressor group showed a younger age at diagnosis, lower body mass index (BMI), lower F-CPR levels and a higher prevalence of insulinoma-associated antigen-2 autoantibodies (IA-2A). The PPV of RIA-GADA increased from 56.3 to 70.0% in the high titer group (≥10 U/mL), and further increased to 76.9, 84.2, 81.0 and 75.0% when combined with specific thresholds for age at diagnosis <47 years, BMI <22.6 kg/m2, F-CPR <1.41 ng/mL and IA-2A positivity, respectively. In contrast, the PPV of ELISA-GADA (71.8%) remained the same at 73.1% in the high titer group (≥180 U/mL), but increased to 81.8, 82.4 and 79.0% when evaluated in conjunction with age at diagnosis, BMI and F-CPR level, respectively. CONCLUSIONS: Our findings show that, unlike RIA-GADA, ELISA-GADA shows no association between GADA titers and the risk of progression to an insulin-dependent state. The PPV improves when age at diagnosis, BMI and F-CPR levels are considered in combination.

Metabolic signatures of ß-cell destruction in type 1 diabetes.

AIMS/INTRODUCTION: In the development of type 1 diabetes, metabolites are significantly altered and might be involved in ß-cell destruction and protection. We aimed to identify new metabolic markers of ß-cell destruction in type 1 diabetes patients. MATERIALS AND METHODS: A total of 33 participants were recruited for this cross-sectional observational study: 23 with type 1 diabetes, seven with type 2 diabetes and three healthy controls. Those with type 1 diabetes were further subdivided into three groups: new-onset, microsecretors and complete lack of endogenous insulin in type 1 diabetes. RESULTS: Metabolomic analysis identified a total of 737 peaks, and partial least square analysis was successful in discriminating between the three groups of type 1 diabetes. Among the factor loadings discriminating type 1 diabetes, 3-phenylpropionic acid (r = 0.80, P = 4.7E-6 ) and hypotaurine (r = -0.484, P = 1.9E-2 ) strongly contributed to identifying new-onset type 1 diabetes, and 5-methylcytosine to identifying complete-lack type 1 diabetes (r = 0.586, P = 6.5E-3 ). Reporter operating characteristics analysis, including all type 1 diabetes, type 2 diabetes and healthy controls, showed that high 3-phenylpropionic acid (Pc <0.0001) and low hypotaurine (Pc <0.0001) were useful for identifying new-onset type 1 diabetes, and high 5-methylcytosine (Pc = 0.002) for the complete-lack type 1 diabetes. CONCLUSIONS: In the present study, metabolic signatures were shown to be useful in identifying type 1 diabetes at different clinical stages, and 3-phenylpropionic acid and hypotaurine are novel biomarkers for identifying new-onset type 1 diabetes, suggesting the involvement of the gut bacterial environment, anti-oxidant mechanisms through the hypotaurine-taurine pathway and methylated deoxyribonucleic acid fragmentation in the process of ß-cell destruction.

Glycemic Excursion and Insulin Action Revealed in a Rare Case of Type 1 Diabetes Complicated with Short Bowel Syndrome.

We herein report a 52-year-old woman with a rare combination of short bowel syndrome due to massive resection of the small intestine and complete loss of endogenous insulin due to type 1 diabetes. To provide nutritional support, she was treated with total parenteral nutrition with co-administration of insulin, requiring careful matching of insulin and glucose levels. This case report provides insights on glycemic excursion and insulin action in type 1 diabetes, even when both insulin and glucose are administered directly into circulation, and the usual obstacles caused by subcutaneous injection of insulin and oral intake of nutrients are eliminated.

Novel loci for hyperglycemia identified by QTL mapping of longitudinal phenotypes and congenic analysis.

We previously reported that four hyperglycemia loci are located on three chromosomes in the Nagoya-Shibata-Yasuda (NSY) mouse model, commonly used to study type 2 diabetes. However, we did not search for hyperglycemia loci across all chromosomes. In this study, we performed quantitative trait loci (QTLs) mapping of longitudinal phenotypes from crosses between NSY (hyperglycemic) and C3H (normoglycemic) mice. We identified four new QTLs for hyperglycemia, namely Nidd5nsy, Nidd6nsy, Nidd1c3h, and Nidd2c3h, on Chromosome 1, 4, 10, and 13, respectively. These QTLs were associated with hyperglycemia in young mice and had attenuated effects in older mice. Nidd5nsy and Nidd6nsy were hyperglycemic with NSY alleles, and Nidd1c3h and Nidd2c3h were hyperglycemic with C3H alleles. We further bred Nidd5nsy congenic mice and demonstrated that Nidd5nsy has a strong effect on hyperglycemia when young, accompanied by insulin resistance and visceral fat accumulation. These results showed that the effects of individual QTLs strengthened or weakened with age, and that the sum of the effects of QTLs captured the age-related deterioration of glucose tolerance in individuals. Our results support the importance of longitudinal phenotypes in the genetic analysis of polygenic traits and have implications for the genetic basis and pathogenesis of type 2 diabetes in humans.

Insulin-dependent diabetes mellitus in older adults: Current status and future prospects.

The recent increase in life expectancy has resulted in an increase in the number of older adults with diabetes mellitus. In addition to type 2 diabetes, in which aging is a well-known risk factor, individuals with type 1 and other types of diabetes are also increasing owing to longevity in the general population and improved prognosis of the disease and comorbidities. Insulin-dependent state in type 1 diabetes and other types of diabetes, such as diabetes after pancreatectomy, inevitably requires insulin treatment for survival; however, daily injection of insulin is often hampered in older adults due to impaired cognitive function or limited activities of daily living. In this review, we aimed to discuss the current situation of insulin-dependent diabetes mellitus in older adults and highlight future prospects. Geriatr Gerontol Int 2022; 22: 549-553.

Poor glycemic control rather than types of diabetes is a risk factor for sarcopenia in diabetes mellitus: The MUSCLES-DM study.

AIMS/INTRODUCTION: Though poor glycemic control and insulin treatment are reported to be associated with sarcopenia in type 2 diabetes, type 1 diabetes may be a stronger risk for sarcopenia. We therefore studied the effect of the type of diabetes, glycemic control, and insulin therapy on the prevalence and characteristics of sarcopenia. MATERIALS AND METHODS: A total of 812 Japanese patients with diabetes (type 1: n = 57; type 2: n = 755) were enrolled in this study. Sarcopenia was defined as low handgrip strength or slow gait speed and low appendicular skeletal muscle mass. RESULTS: Among participants aged ≥65 years, the sarcopenia prevalence rate was higher among patients with type 1 diabetes (20.0%) than among those with type 2 diabetes (8.1%). The prevalence rate of low handgrip strength was higher in type 1 diabetes (50.0%) than in type 2 diabetes (28.7%). In logistic regression analysis, type 1 diabetes was significantly associated with the prevalence of low handgrip strength. In logistic regression analysis, medication with insulin was significantly associated with the prevalence of sarcopenia; this association was not retained after adjusting for HbA1c. CONCLUSIONS: The prevalence of sarcopenia in older adult patients was higher in those with type 1 diabetes than in those with type 2 diabetes. Among the components of sarcopenia, the difference was most prominent in the frequency of low handgrip strength. Poor glycemic control rather than type of diabetes or insulin treatment was revealed to be a primary risk factor for sarcopenia in diabetes mellitus.

Three-Year Observation of Glucose Metabolism After Pancreaticoduodenectomy: A Single-Center Prospective Study in Japan.

CONTEXT: The glucose tolerance of patients changes considerably from before to after pancreaticoduodenectomy wherein approximately half of the pancreas is resected. OBJECTIVE: The aim of this prospective study was to investigate the incidence of and risk factors for diabetes after pancreaticoduodenectomy. METHODS: This study is a part of an ongoing prospective study, the Kindai Prospective Study on Metabolism and Endocrinology after Pancreatectomy (KIP-MEP) study. Of the 457 patients enrolled to date, 96 patients without diabetes who underwent pancreaticoduodenectomy were investigated in this study. Preoperatively, 1 month post-pancreaticoduodenectomy, and every 6 months thereafter, the glucose metabolism and endocrine function were evaluated using the 75 g oral glucose tolerance test. Various other metabolic, endocrine, and exocrine indices were also examined over a period of up to 36 months. RESULTS: Of the 96 patients analyzed in this study, 33 were newly diagnosed with diabetes. The cumulative diabetes incidence at 36 months following pancreaticoduodenectomy was 53.8%. The preoperative insulinogenic index and ΔC-peptide in the glucagon stimulation test were significantly lower in the progressors to diabetes than in the nonprogressors. Multivariate Cox regression analysis demonstrated that the insulinogenic index was the only significant risk factor for new-onset diabetes. CONCLUSION: The majority of patients developed new-onset diabetes after pancreaticoduodenectomy, and a low value of the insulinogenic index was suggested to be a risk factor for diabetes. Preoperative assessment for the prediction of the onset of diabetes serves as useful information for patients and is important for postoperative glycemic control and diabetes management in patients who require pancreaticoduodenectomy.

ß-Cell failure in diabetes: Common susceptibility and mechanisms shared between type 1 and type 2 diabetes.

Diabetes mellitus is etiologically classified into type 1, type 2 and other types of diabetes. Despite distinct etiologies and pathogenesis of these subtypes, many studies have suggested the presence of shared susceptibilities and underlying mechanisms in ß-cell failure among different types of diabetes. Understanding these susceptibilities and mechanisms can help in the development of therapeutic strategies regardless of the diabetes subtype. In this review, we discuss recent evidence indicating the shared genetic susceptibilities and common molecular mechanisms between type 1, type 2 and other types of diabetes, and highlight the future prospects as well.

Glucose Metabolism After Pancreatectomy: Opposite Extremes Between Pancreaticoduodenectomy and Distal Pancreatectomy.

CONTEXT: The rate of glucose metabolism changes drastically after partial pancreatectomy. OBJECTIVE: This work aims to analyze changes in patients' glucose metabolism and endocrine and exocrine function before and after partial pancreatectomy relative to different resection types (Kindai Prospective Study on Metabolism and Endocrinology after Pancreatectomy: KIP-MEP study). METHODS: A series of 278 consecutive patients with scheduled pancreatectomy were enrolled into our prospective study. Of them, 109 individuals without diabetes, who underwent partial pancreatectomy, were investigated. Data were compared between patients with pancreaticoduodenectomy (PD, n = 73) and those with distal pancreatectomy (DP, n = 36). RESULTS: Blood glucose levels during the 75-g oral glucose tolerance test (75gOGTT) significantly decreased after pancreatectomy in the PD group (area under the curve [AUC] -9.3%, P < .01), and significantly increased in the DP population (AUC + 16.8%, P < .01). Insulin secretion rate during the 75gOGTT and glucagon stimulation test significantly decreased after pancreatectomy both in the PD and DP groups (P < .001). Both groups showed similar homeostasis model assessment of insulin resistance (HOMA-IR) values after pancreatectomy. Decrease in exocrine function quality after pancreatectomy was more marked in association with PD than DP (P < .01). Multiple regression analysis indicated that resection type and preoperative HOMA-IR independently influenced glucose tolerance-related postoperative outcomes. CONCLUSIONS: Blood glucose levels after the OGTT differed markedly between PD and DP populations. The observed differences between PD and DP suggest the importance of individualization in the management of metabolism and nutrition after partial pancreatectomy.

Relationship of continuous glucose monitoring-related metrics with HbA1c and residual ß-cell function in Japanese patients with type 1 diabetes.

The targets for continuous glucose monitoring (CGM)-derived metrics were recently set; however, studies on CGM data over a long period with stable glycemic control are limited. We analyzed 194,279 CGM values obtained from 19 adult Japanese patients with type 1 diabetes. CGM data obtained during stable glycemic control over four months were analyzed. CGM-related metrics of different durations "within 120, 90, 60, 30, and 7 days" were calculated from baseline. Time in range (TIR; glucose 70-180 mg/dL), time above range (TAR; glucose ≥ 181 mg/dL), and average glucose levels, but not time below range (TBR; glucose ≤ 69 mg/dL), strongly correlated with glycated hemoglobin (HbA1c) values (P < 0.0001). TBR correlated with glucose coefficient of variation (CV) (P < 0.01). Fasting serum C-peptide levels negatively correlated with glucose CV (P < 0.01). HbA1c of approximately 7% corresponded to TIR of 74% and TAR of 20%. The shorter the CGM period, the weaker was the relationship between HbA1c and CGM-related metrics. TIR, TAR, and average glucose levels accurately reflected HbA1c values in Japanese patients with type 1 diabetes with stable glycemic control. Glucose CV and TBR complemented the limitation of HbA1c to detect glucose variability and hypoglycemia. Stable glycemic control with minimal hypoglycemia depended on residual ß-cell function.

Associations between genetic loci related to lean mass and body composition in type 2 diabetes.

AIM: Several genetic loci related to lean mass have been identified in healthy individuals by genome-wide association studies; however, the contribution of these loci to body composition in type 2 diabetes remains to be investigated. Here, we aimed to clarify the genetic determinants of body composition in individuals with type 2 diabetes. METHODS: A total of 176 Japanese outpatients (70 women and 106 men) with type 2 diabetes were studied using a cross-sectional design. Body composition was measured using bioimpedance analysis with a commercially available device (InBody770). Single-nucleotide polymorphisms in IRS1 (rs2943656), HSD17B11 (rs9991501), VCAN (rs2287926), ADAMTSL3 (rs4842924) and FTO (rs9936385) were evaluated by genotyping. The contributions of single-nucleotide polymorphisms to body composition were examined, considering known clinical determinants. RESULTS: Sex, body composition and age were identified as clinical predictors. IRS1 rs2934656 was identified as an independent predictor of skeletal muscle mass (ß = 0.11, P = 0.026), and ADAMTSL3 rs4842924 was an independent predictor of body fat mass (ß = 0.15, P = 0.0095) and appendicular lean mass (ß = -0.13, P = 0.017). CONCLUSIONS: The findings clarified the contribution of genetic factors - IRS1 and ADAMTSL3 - to interindividual variation in body composition, independent of clinical factors, in type 2 diabetes patients. These data will contribute to the establishment of effective methods for the prediction, prevention, and intervention of sarcopenia and frailty in diabetes patients. Geriatr Gerontol Int 2021; 21: 932-938.

Oncocytic Adrenocortical Carcinoma With Low 18F-FDG Uptake and the Absence of Glucose Transporter 1 Expression.

Adrenocortical carcinoma (ACC) is a rare tumor, and some histological variants (oncocytic, myxoid, and sarcomatoid ACCs) have been reported in addition to the conventional ACC. Among these subtypes, oncocytic ACC is histologically characterized by the presence of abundant eosinophilic granular cytoplasm in the carcinoma cells owing to the accumulation of mitochondria, which generally yields high 18F-fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET). Herein, we report the case of a 21-year-old woman with oncocytic ACC with low FDG uptake on PET scan. Her circulating levels of androgens were high, and androgen-synthesis enzymes were detected in carcinoma cells. The patient also had hypocholesterolemia. However, glucose transporter 1 (GLUT1) was not detected in the tumor, which was considered to account for the low FDG uptake by the tumor. To the best of our knowledge, this is the first case of low FDG uptake by oncocytic ACC without GLUT1 expression. Additionally, since hypocholesterolemia was reported in 3 previous reports of androgen-producing tumors, a possible correlation between androgenicity in adrenal tumors and the development of hypocholesterolemia could be postulated; however, further investigations are needed for clarification. This case highlights important information regarding the diversity of ACC and its impact on hypocholesterolemia.