原口 卓也

<jats:sec> <jats:title/> <jats:p>Evaluation of insulin secretory capacity is essential to understand the pathophysiologic condition of individuals with diabetes and assess the efficacy of drugs used in the treatment of this disease. The 1-mg i.v. glucagon stimulation test (GST) is widely used to evaluate residual β-cell function; we previously reported that GST assessment of insulin secretory capacity is useful in assessing the efficacy of glucagon-like peptide 1 (GLP-1) receptor agonists (GLP-1RAs). However, recent reports have indicated that pharmacologic concentrations of glucagon stimulate insulin secretion through GLP-1 receptors, confounding the issue. The current studies were undertaken to reassess the reliability of the GST for evaluation of insulin secretory capacity under GLP-1RAs and dipeptidyl peptidase 4 inhibitors (DPP-4is). Our first study included individuals receiving GLP-1RA treatment, evaluated by the GST before and after treatment. Although the fasting C-peptide response (CPR) levels were elevated after treatment, the induction of insulin secretion by glucagon was significantly reduced. Our second study compared glucagon-induced insulin secretion between DPP-4i users and nonusers, assessed by the GST after propensity score matching. Although the fasting CPR levels were similar in the two investigations, glucagon-induced insulin secretion was significantly lower with DPP-4i use. These results suggest that the GST might underestimate insulin secretory capacity under incretin-based therapy.</jats:p> </jats:sec> <jats:sec> <jats:title>Article Highlights</jats:title> </jats:sec>

<h4>Context</h4>Roxadustat, a hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitor, a recently developed class of drugs for treatment of anemia in chronic kidney disease (CKD), is reported to have a structure unlike that of other HIF-PH inhibitors but similar to that of triiodothyronine and bind to the thyroid hormone receptor in vitro. However, reports on the effects of roxadustat on thyroid function are limited and not detailed, and it remains unknown whether other HIF-PH inhibitors also affect thyroid function.<h4>Objective</h4>To compare the effect of roxadustat with daprodustat, another HIF-PH inhibitor, on thyroid function in patients with renal anemia in CKD.<h4>Methods</h4>This retrospective observational study included a total of 26 patients with anemia in CKD who were treated with roxadustat or daprodustat; thyroid-stimulating hormone (TSH) and free thyroxine (FT4) were measured before and after treatment with the drugs.<h4>Results</h4>After initiation of roxadustat, TSH showed a significant decrease (2.4732 [1.7858-4.9016] μIU/mL before treatment and 0.659 [0.112-2.005] μIU/mL after treatment, P < .05); FT4 showed a significant decrease (0.93 [0.84-1.05] ng/dL before treatment and 0.70 [0.53-0.85] ng/dL after treatment, P < .01). After daprodustat initiation, neither TSH nor FT4 showed a significant change (TSH: 3.044 [1.853-4.171] μIU/mL before treatment and 2.893 [1.866-4.894] μIU/mL after treatment, P = .635; FT4 was 0.93 [0.81-1.00] ng/dL before treatment and 0.97 [0.87-1.05] ng/dL after treatment, P = .328).<h4>Conclusion</h4>Roxadustat decreases TSH and FT4 levels while daprodustat does not.

AIMS/INTRODUCTION: This study was designed and carried out to investigate the association of dipeptidyl peptidase-4 inhibitor (DPP-4i) use with pancreatic cancer (PC) in individuals with diabetes in Japan. MATERIALS AND METHODS: The JMDC Claims Database, which contains the medical and prescription information of Japanese employment-based health insurance programs, was used. The primary outcome was duration to the first occurrence of PC (International Classification of Diseases 10th Revision code C25), both all and hospitalized, from prescription of DPP-4is or other oral glucose-lowering agents (GLAs). RESULTS: Individuals with diabetes who received DPP-4is (n = 61,430) or other oral GLAs (n = 83,304) were analyzed. Follow-up periods (median [interquartile range]) were 17 months (8-33) for DPP-4is and 14 months (7-28) for other oral GLAs. Kaplan-Meier curve analysis to determine the duration of first use of DPP4i or other oral GLA to diagnosis of PC disclosed no differences between the two groups in duration to all or hospitalized PC (log-rank test: all, P = 0.7140; hospitalized, P = 0.3446). Cox proportional hazards models showed that use of DPP-4is did not affect the PC risk adjusted for medications, age, sex and risk comorbidities (all, hazard ratio 1.1, 95% confidence interval 0.8-1.3, P = 0.6518; hospitalized, hazard ratio 1.1, 95% confidence interval 0.8-1.4, P = 0.6662). Similar results were obtained when individuals with ≥2 years oral GLA treatment and those with medical checkup data (e.g., smoking or drinking habit) available were analyzed. CONCLUSION: This database study shows that there is not a significant PC risk due to DPP-4i treatment in individuals with diabetes in Japan, but larger studies with longer follow up are required to confirm these findings.

AIMS/INTRODUCTION: The aim of this study was to develop a scale to evaluate disease stigma in patients with lifestyle-related chronic non-communicable diseases (LCNCDs), which we named the Kanden Institute Stigma Scale (KISS), and to consider its possible clinical application for patients with diabetes. MATERIALS AND METHODS: An initial 90 questions were drafted and categorized into six subscales according to the manifestations of stigma. The final version of the KISS was developed as a 24-item questionnaire comprising four items for each subscale. RESULTS: A total of 539 outpatients including 452 patients with diabetes and 87 patients without diabetes were recruited. Construct validity was confirmed by assessing the correlation with previously established measures. Confirmatory factor analysis showed the KISS to have good model fitness (adjusted goodness-of-fit index = 0.856). Test-retest reproducibility analysis showed that the intraclass coefficient of the first and a second KISS was 0.843 (P < 0.001), indicating excellent reproducibility. The KISS showed higher scores for patients with diabetes than for patients without diabetes (12.23 ± 0.49 vs 5.76 ± 0.73, P < 0.05). The KISS score was significantly higher in type 1 and type 2 diabetes patients taking insulin therapy than in type 2 diabetes patients not taking insulin (P < 0.05). CONCLUSION: The KISS is a validated and reliable questionnaire for assessment of stigma among patients with diabetes as well as other lifestyle-related chronic non-communicable diseases, and might contribute to identifying and rectifying diabetes stigma, as well promoting awareness among health care professionals of this very consequential health problem.

AIMS/INTRODUCTION: Differences in the glucose-lowering mechanisms of glucagon-like peptide-1 receptor agonists (GLP-1RAs) have been noted. Clarifying these differences could facilitate the choice of optimal drugs for individuals with type 2 diabetes and requires investigation in a clinical setting. MATERIALS AND METHODS: A single-arm, prospective, observational study was conducted to evaluate the effects of various GLP-1RAs on postprandial glucose excursion, secretions of insulin and glucagon as well as on the gastric emptying rate. Participants were subjected to meal tolerance tests before and 2 weeks and 12 weeks after GLP-1RA initiation. Effects on postprandial secretions of glucose-dependent insulinotropic polypeptide (GIP) and apolipoprotein B48 were also investigated. RESULTS: Eighteen subjects with type 2 diabetes received one of three GLP-1RAs, i.e., lixisenatide, n = 7; liraglutide, n = 6; or dulaglutide, n = 5. While 12-week administration of all of the GLP-1RAs significantly reduced HbA1c, only lixisenatide and liraglutide, but not dulaglutide, significantly reduced body weight. Postprandial glucose elevation was improved by all of the GLP-1RAs. Postprandial insulin levels were suppressed by lixisenatide, while insulin levels were enhanced by liraglutide. Postprandial glucagon levels were suppressed by lixisenatide. The gastric emptying rate was significantly delayed by lixisenatide, while liraglutide and dulaglutide had limited effects on gastric emptying. GIP secretion was suppressed by lixisenatide and liraglutide. Apolipoprotein B48 secretion was suppressed by all of the GLP-1RAs. CONCLUSIONS: All of the GLP-1RAs were found to improve HbA1c in a 12-week prospective observational study in Japanese individuals with type 2 diabetes. However, differences in the mechanisms of the glucose-lowering effects and body weight reduction were observed.

To clarify the association between lifestyle changes as a result of coronavirus disease 2019 containment measures and changes in metabolic and glycemic status in patients with diabetes, a cross-sectional, single-center, observation study was carried out. A self-reported questionnaire was provided to ascertain the frequency of various lifestyle activities before and after the coronavirus disease 2019 containment measures in Japan. Among 463 patients, change in glycated hemoglobin was significantly associated with change in bodyweight. After stratification by age 65 years, binary logistic regression analysis showed that increased frequency of snack eating increased bodyweight (odds ratio 1.709, P = 0.007) and glycated hemoglobin (odds ratio 1.420, P = 0.025) in the younger group, whereas in the older patients, reduced walking activities resulted in weight gain (odds ratio 0.726, P = 0.010). In conclusion, changes in eating behavior and physical activity increased bodyweight and reduced glycemic control among diabetes patients, but by different processes depending on age under the coronavirus disease 2019 containment measures in Japan.

This study investigated the safety and efficacy of the sodium-glucose co-transporter-2 (SGLT2) inhibitor luseogliflozin with differing carbohydrate intakes in Japanese individuals with type 2 diabetes (T2D). Participants were randomly assigned to 3 carbohydrate-adjusted meals for 14 days (days 1-14; a high carbohydrate [HC; 55% total energy carbohydrate] and high glycaemic index [HGI] meal; an HC [55% total energy carbohydrate] and low glycaemic index [LGI] meal; or a low carbohydrate [LC; 40% total energy carbohydrate] and HGI meal). All participants received luseogliflozin for the last 7 days (days 8-14), continuous glucose monitoring (CGM) before and after luseogliflozin treatment (days 5-8 and days 12-15) and blood tests on days 1, 8 and 15. Luseogliflozin significantly decreased the area under the curve and mean of CGM values in all 3 groups similarly. Fasting plasma glucose, insulin and glucagon were similar at all time points. Ketone bodies on day 15 were significantly higher in the LC-HGI group compared with the HC-HGI and HC-LGI groups. In conclusion, luseogliflozin has similar efficacy and safety in Japanese people with T2D when meals contain 40% to 55% total energy carbohydrate, but a strict LC diet on this class of drug should be avoided to prevent SGLT2 inhibitor-associated diabetic ketoacidosis.