Increased BMP-Smad signaling does not affect net bone mass in long bones

Bone morphogenetic proteins (BMPs) have been used for orthopedic and dental application due to their osteoinductive properties; however, substantial numbers of adverse reactions such as heterotopic bone formation, increased bone resorption and greater cancer risk have been reported. Since bone morphogenetic proteins signaling exerts pleiotropic effects on various tissues, it is crucial to understand tissue-specific and context-dependent functions of bone morphogenetic proteins. We previously reported that loss-of-function of bone morphogenetic proteins receptor type IA (BMPR1A) in osteoblasts leads to more bone mass in mice partly due to inhibition of bone resorption, indicating that bone morphogenetic protein signaling in osteoblasts promotes osteoclast function. On the other hand, hemizygous constitutively active (ca) mutations for BMPR1A (caBmpr1awt/+) in osteoblasts result in higher bone morphogenetic protein signaling activity and no overt skeletal changes in adult mice. Here, we further bred mice for heterozygous null for Bmpr1a (Bmpr1a+/−) and homozygous mutations of caBmpr1a (caBmpr1a+/+) crossed with Osterix-Cre transgenic mice to understand how differences in the levels of bone morphogenetic protein signaling activity specifically in osteoblasts contribute to bone phenotype. We found that Bmpr1a+/−, caBmpr1awt/+ and caBmpr1a+/+ mice at 3 months of age showed no overt bone phenotypes in tibiae compared to controls by micro-CT and histological analysis although BMP-Smad signaling is increased in both caBmpr1awt/+ and caBmpr1a+/+ tibiae and decreased in the Bmpr1a+/− mice compared to controls. Gene expression analysis demonstrated that slightly higher levels of bone formation markers and resorption markers along with levels of bone morphogenetic protein-Smad signaling, however, there was no significant changes in TRAP positive cells in tibiae. These findings suggest that changes in bone morphogenetic protein signaling activity within differentiating osteoblasts does not affect net bone mass in the adult stage, providing insights into the concerns in the clinical setting such as high-dose and unexpected side effects of bone morphogenetic protein application.

Pilot Trial on the Effect of 5-Aminolevulinic Acid on Glucose Tolerance in Patients with Maternally Inherited Diabetes and Deafness

INTRODUCTION

The amino acid 5-aminolevulinic acid (5-ALA) is the first heme biosynthetic precursor. The combination of 5-ALA with sodium ferrous citrate (SFC) enhances heme production, leading to increased adenosine triphosphate (ATP) production in mitochondria. We investigated whether administering 5-ALA/SFC improves glucose tolerance with an increase in insulin secretion in patients with maternally inherited diabetes and deafness (MIDD), which is characterized by an insulin secretory disorder due to impaired mitochondrial ATP production.

METHODS

This was a single-arm, open-label, interventional study. We prospectively administered the oral glucose tolerance test (OGTT) twice in five patients with MIDD who had received intensive insulin therapy: before and 24 weeks after an administration of 5-ALA/SFC (200/232 mg per day). We measured the concentrations of glucose, insulin, C-peptide, and proinsulin at fasting, and 30, 60, and 120 min after glucose load in each OGTT. The primary endpoint was the changes in the area under the curve (AUC) of serum insulin from 0 to 120 min during OGTT from baseline to 24 weeks.

RESULTS

The serum insulin AUC (µU/mL) during the 120-min OGTT tended to increase from baseline to 24 weeks but not significantly (17.1 ± 13.7 versus 22.3 ± 13.4, p = 0.077). The plasma glucose AUC (mg/dL) during the 120-min OGTT at 24 weeks was not significantly decreased; the late phase of glucose excursion from 60 to 120 min was significantly decreased compared with baseline (357 ± 42 versus 391 ± 50, p = 0.041). The mean level of glycated hemoglobin (HbA1c) decreased from 8.3 ± 1.2% at baseline to 7.9 ± 0.3% at 24 weeks (p = 0.36) without increasing the daily dose of insulin injections.

CONCLUSION

The 24-week administration of 5-ALA/SFC did not demonstrate a significant improvement in insulin secretion in patients with MIDD. Further investigations with a larger number of patients and a placebo control group are required to clarify the potential efficacy of 5-ALA/SFC for ameliorating mitochondrial dysfunctions in MIDD.

TRIAL REGISTRATION

UMIN-CTR000040581 and jRCT071200025.

ODP158 A Pilot Trial on the Efficacy of 5-Aminolevulinic Acid on Glucose Tolerance in Patients with Maternally Inherited Diabetes and Deafness

Objective

Maternally inherited diabetes and deafness (MIDD) is characterized by progressive insulin secretory disorder caused by impairment of mitochondrial adenosine triphosphate (ATP) production in pancreatic beta-cells. The amino acid 5-aminolevulinic acid (5-ALA) is the first heme biosynthetic precursor and the administration of 5-ALA combined with sodium ferrous citrate (SFC) enhance heme production, leading to improvement of mitochondrial function and ATP production. Several studies showed that the treatment with 5-ALA/SFC improved glycemic tolerance in both patients with prediabetes and those with type 2 diabetes. However, no previous studies investigated the efficacy of 5-ALA in patients with MIDD. We carried out the pilot trial to investigate whether the administration of 5-ALA/SFC can improve insulin secretion and glucose tolerance in patients with MIDD.

Methods

We enrolled five patients with MIDD receiving multiple daily injections of insulin. The patients were administered 5-ALA/SFC 100 mg twice a day (200 mg per day) for 24 weeks as adjunctive to insulin treatment. The patients underwent a 75-g oral glucose tolerance test (OGTT) twice before (1 st -OGTT) and 24 weeks after the initiation of 5-ALA/SFC (2 nd -OGTT). We measured levels of plasma glucose, insulin, and glucagon at fasting (0 min), and 30, 60 and 120 min after glucose load (Study protocol: Nakamura Y et al. Medicine (Baltimore). 2021; 100: e25100).

Results

The mean levels of HbA1c tended to decrease from 8.3% to 7.9% (p = 0.36) even though total insulin doses had not changed during the 24 weeks of 5-ALA/SFC administration. In the 2nd -OGTT comparing to the 1 st -OGTT, four of the five patients showed a tendency of improvement in glucose levels with a certain degree of insulin increase, but one patient did not show any improvement. The means of area under the curve (AUC) of serum insulin from fasting to 120 min during 2nd -OGTT was 30% larger but not significant compared to that during 1st -OGTT (p = 0. 077). The late phase of glucose excursion during OGTT determined by AUC of plasma glucose from 60 to120 min during 2nd -OGTT showed 10% reduction compared to that during 1st -OGTT (p = 0. 041). The glucagon levels during OGTT were comparable between before and after 5-ALA/SFC administration. The indexes of insulin sensitivity calculated by the homeostasis model assessment of insulin resistance or Matsuda index were not significantly changed between before and after 5-ALA/SFC administration. None of the patients experienced any adverse events during the study.

Conclusions

The administration of 5-ALA/SFC as adjunctive to insulin therapy might be a novel effective treatment for MIDD that improves insulin secretion via amelioration of mitochondrial function.

Presentation: No date and time listed

Bihormonal dysregulation of insulin and glucagon contributes to glucose intolerance development at one year post-delivery in women with gestational diabetes: a prospective cohort study using an early postpartum 75-g glucose tolerance test

Gestational diabetes mellitus (GDM) is known to be a significant risk factor for the future development of type 2 diabetes. Here, we investigated whether a precise evaluation of β- and α-cell functions helps to identify women at high risk of developing glucose intolerance after GDM. Fifty-six women with GDM underwent a 75-g oral glucose tolerance test (OGTT) at early (6-12 weeks) postpartum. We measured their concentrations of glucose, insulin, proinsulin and glucagon at fasting and 30, 60 and 120 min. At 1-year post-delivery, we classified the women into a normal glucose tolerance (NGT) group or an impaired glucose tolerance (IGT)/diabetes mellitus (DM) group. Forty-three of the 56 women completed the study. At 1-year post-delivery, 17 women had developed IGT/DM and 26 women showed NGT. In the early-postpartum OGTTs, the IGT/DM group showed a lower insulinogenic index, a less glucagon suppression evaluated by the change from fasting to 30 min (ΔGlucagon 30 min), and a higher glucagon-to-insulin ratio at 30 min compared to the NGT group. There were no significant between-group differences in proinsulin levels or proinsulin-to-insulin ratios. Insulinogenic index <0.6 and ΔGlucagon 30 min >0 pg/mL were identified as predictors for the development of IGT/DM after GDM, independent of age, body mass index, and lactation intensity. These results suggest that the bihormonal disorder of insulin and glucagon causes the postpartum development of glucose intolerance. The measurement of plasma insulin and glucagon during the initial OGTT at early postpartum period can help to make optimal decisions regarding the postpartum management of women with GDM.

A single-arm, open-label, intervention study to investigate the improvement of glucose tolerance after administration of the 5-aminolevulinic acid (5-ALA) in the patients with mitochondrial diabetes mellitus

BACKGROUND

Mitochondrial diabetes mellitus (MDM) is characterized by maternal inheritance, progressive neurosensory deafness, insulin secretory disorder, and progressive microvascular complications. Mitochondria are critical organelles that provide energy in the form of adenosine triphosphate (ATP). An impairment of ATP production in pancreatic β cells is regarded as the main cause of the insulin secretory disorder in patients with MDM, and these patients require insulin replacement therapy early after the diagnosis. The amino acid 5-aminolevulinic acid (5-ALA), a precursor of heme metabolites, is a non-proteinogenic δ amino acid synthesized in mitochondria. An addition of ferrous iron to 5-ALA enhances heme biosynthesis and increases ATP production through an upregulation of the respiratory complex. Several studies have reported that the administration of 5-ALA and ferrous iron to existing treatment improved the glycemic control in both patients with prediabetes and those with type 2 diabetes mellitus. The additional administration of 5-ALA and ferrous iron to MDM patients on insulin therapy may improve their insulin secretory capacity and glycemic control by improving their mitochondrial function. The findings of this study are expected to provide new treatment options for MDM and improve the patients' glycemic control and prognosis.

METHODS/DESIGN

This study is a single-arm, open-label pilot intervention study using clinical endpoints to investigate the effects of treatment with 5-ALA plus sodium ferrous citrate (SFC) to patients with MDM on their glucose tolerance. A total of 5 patients with MDM will be administered 5-ALA/SFC (200 mg/d) for 24 weeks. We will perform a 75-g oral glucose tolerance test before and at 24 weeks after the start of this 5-ALA/SFC treatment to evaluate glucose-dependent insulin responses.

DISCUSSION

To the best of our knowledge, this study will be the first assessment of the effects of 5-ALA/SFC in patients with MDM. This study will obtain an evidence regarding the effectiveness and safety of 5-ALA/SFC for patients with MDM.

TRIAL REGISTRATION

This study was registered with the University Hospital Medical Information Network (UMIN000040581) on July 1, 2020 and with the Japan Registry of Clinical Trials (jRCTs071200025) on August 3, 2020.

Impact of glucagon response on early postprandial glucose excursions irrespective of residual β-cell function in type 1 diabetes: A cross-sectional study using a mixed meal tolerance test

Aims/Introduction

Controlling postprandial glucose levels in patients with type 1 diabetes is challenging even under the adequate treatment of insulin injection. Recent studies showed that dysregulated glucagon secretion exacerbates hyperglycemia in type 2 diabetes patients, but little is known in type 1 diabetes patients. We investigated whether the glucagon response to a meal ingestion could influence the postprandial glucose excursion in patients with type 1 diabetes.

Materials and Methods

We enrolled 34 patients with type 1 diabetes and 23 patients with type 2 diabetes as controls. All patients underwent a liquid mixed meal tolerance test. We measured levels of plasma glucose, C‐peptide and glucagon at fasting (0 min), and 30, 60 and 120 min after meal ingestion. All type 1 diabetes patients received their usual basal insulin and two‐thirds of the necessary dose of the premeal bolus insulin.

Results

The levels of plasma glucagon were elevated and peaked 30 min after the mixed meal ingestion in both type 1 diabetes and type 2 diabetes patients. The glucagon increments from fasting to each time point (30, 60 and 120 min) in type 1 diabetes patients were comparable to those in type 2 diabetes patients. Among the type 1 diabetes patients, the glucagon response showed no differences between the subgroups based on diabetes duration (<5 vs ≥5 years) and fasting C‐peptide levels (<0.10 vs ≥0.10 nmol/L). The changes in plasma glucose from fasting to 30 min were positively correlated with those in glucagon, but not C‐peptide, irrespective of diabetes duration and fasting C‐peptide levels in patients with type 1 diabetes.

Conclusions

The dysregulated glucagon likely contributes to postprandial hyperglycemia independent of the residual β‐cell functions during the progression of type 1 diabetes.

The effect of luseogliflozin on bone microarchitecture in older patients with type 2 diabetes: study protocol for a randomized controlled pilot trial using second-generation, high-resolution, peripheral quantitative computed tomography (HR-pQCT)

BACKGROUND

Older patients with type 2 diabetes mellitus (T2DM) have an increased risk of bone fracture independent of their bone mineral density (BMD), which is explained mainly by the deteriorated bone quality in T2DM compared to that in non-diabetic adults. Sodium-glucose co-transporter (SGLT) 2 inhibitors have been studied in several trials in T2DM, and the Canagliflozin Cardiovascular Assessment Study showed an increased fracture risk related to treatment with the SGLT2 inhibitor canagliflozin, although no evidence of increased fracture risk with treatment with other SGLT2 inhibitors has been reported. The mechanism of the difference in the fracture risk between the SGLT2 inhibitors is unknown, but the differences among the SGLT2 inhibitors in the selectivity of SGLT2 against SGLT1 may affect bone metabolism, since among the SGLT2 inhibitors the selectivity of canagliflozin is lowest. We will investigate whether the SGLT2 inhibitor luseogliflozin, which has the higher SGLT2 selectivity, affects bone metabolism by using high-resolution, peripheral quantitative computed tomography (HR-pQCT) which provides direct in vivo morphometric information about the bone microarchitecture.

METHODS/DESIGN

This is a single-center, randomized, open-label, active-controlled, parallel pilot trial. Eligible participants are older (age ≥ 60 years) individuals with T2DM with HbA1c levels at 7.0-8.9%. A total of 24 participants will be allocated to either the luseogliflozin group (taking luseogliflozin) or the control group (taking metformin) in a 1:1 ratio to compare the groups' changes in bone microarchitecture of the radius and tibia which are analyzed by HR-pQCT before and at 48 weeks after the administration of each medication. The laboratory data associated with glycemic control and bone metabolism will be collected every 12 weeks during the study. Recruitment began in June 2019.

DISCUSSION

The reason that we use metformin as an active control is to avoid yielding differences in glycemic control between the luseogliflozin and control groups. Besides, metformin is considered to have a neutral effect on bone. This trial should reveal the effect of luseogliflozin on bone metabolism in older patients with T2DM.

TRIAL REGISTRATION

The study was registered with the University Hospital Medical Information Network (UMIN000036202) on 1 April 2019 and with the Japan Registry of Clinicla Trials (jRCTs071180061) on 14 March 2019.

RENAL FUNCTION AND PLASMA RENIN ACTIVITY AS POTENTIAL FACTORS CAUSING HYPERKALEMIA IN PATIENTS WITH THYROID CARCINOMA UNDERGOING THYROID HORMONE WITHDRAWAL FOR RADIOACTIVE IODINE THERAPY

Objective: Hypothyroidism is not commonly considered a cause of hyperkalemia. We previously reported that hyperkalemia was observed mainly in elderly patients treated with renin-angiotensin-aldosterone system (RAS) inhibitors when levothyroxine treatment was withdrawn for the thyroidectomized patients with thyroid carcinoma to undergo radioactive iodine treatment. Here, we investigated whether acute hypothyroidism causes hyperkalemia in patients who were not treated with RAS inhibitors. We also investigated factors influencing potassium metabolism in hypothyroid patients. Methods: We conducted a single-center, prospective cohort study of 46 Japanese patients with thyroid carcinoma undergoing levothyroxine withdrawal prior to radioiodine therapy. All patients were normokalemic before levothyroxine withdrawal. Blood samples were analyzed 3 times: before, and at 3 and 4 weeks after levothyroxine withdrawal. We investigated factors that may be associated with the elevation of serum potassium levels from a euthyroid state to a hypothyroid state. Results: None of the patients developed symptomatic hyperkalemia. The mean serum potassium level was significantly higher at 4 weeks after levothyroxine withdrawal compared to baseline. The serum sodium levels, the estimated glomerular filtration rate (eGFR), and the plasma renin activity (PRA) decreased significantly as hypothyroidism advanced. In contrast, the plasma levels of adrenocorticotropic hormone, cortisol, aldosterone, and antidiuretic hormone were not changed, while serum thyroid hormone decreased. At 4 weeks after their levothyroxine withdrawal, the patients' serum potassium values were significantly correlated with the eGFR and the PRA. Conclusion: Acute hypothyroidism can cause a significant increase in the serum potassium level, which may be associated with a decreased eGFR and decreased circulating RAS. Abbreviations: ACTH = adrenocorticotropic hormone; ADH = antidiuretic hormone; ATPase = adenosine triphosphatase; eGFR = estimated glomerular filtration rate; HbA1c = glycated hemoglobin; K⁺ = potassium; Na⁺ = sodium; PRA = plasma renin activity; RAS = renin-angiotensin-aldosterone system; T4 = thyroxine; TSH = thyroid-stimulating hormone.

VISCERAL AND SUBCUTANEOUS FAT INCREASED AFTER TREATMENT OF GRAVES DISEASE

Objective: Patients with Graves disease (GD) tend to gain weight after treatment, but it remains unknown if weight gain is associated with an increase in the visceral and/or subcutaneous fat areas (VFA, SFA). Methods: We enrolled 25 newly diagnosed GD patients (22 females, median age 33.0 years) and studied their clinical parameters, and VFA and SFA measured by a dual bioelectric impedance analysis. We divided them into 2 groups based on the rates of change in the VFA and SFA, and we compared clinical parameters at the baseline between the groups to evaluate factors that influence increases in the VFA and/or SFA with treatment. Results: The patients' body weight (BW), VFA, and SFA were significantly increased after a 6-month treatment (BW: from 54.3 ± 10.3 kg to 58.0 ± 11.2 kg; P<.001; VFA: from 47.1 ± 21.3 cm² to 54.7 ± 23.4 cm²; P = .004; SFA: from 159.8 ± 85.9 cm² to 182.2 ± 82.9 cm²; P = .008). The percent changes of BW correlated with the SFA (ρ = .591, P = .002), but not with the VFA. The patients with larger VFA increases had significantly less VFA at the baseline compared to those with smaller increases, expressed as median and interquartile range (33.9 cm² [22.7 to 47.5 cm²] versus 54.5 cm² [45.2 to 64.0], respectively; P = .011). A larger increase in the SFA was negatively associated with serum alkaline phosphatase. An increase in the SFA was associated with free triiodothyronine (T3) in a multivariate logistic analysis (odds ratio: 0.80 [0.59 to 0.97]; P = .013). Conclusion: The patients' BW, VFA, and SFA were increased after GD treatment. The increase in SFA seemed to contribute to weight gain and was associated with a low baseline level of free T3. Abbreviations: ALP = alkaline phosphatase; BMI = body mass index; BW = body weight; GD = Graves disease; SFA = subcutaneous fat area; T3 = triiodothyronine; T4 = thyroxine; TG = triglycerides; VFA = visceral fat areas.

Impaired early-phase suppression of glucagon secretion after glucose load is associated with insulin requirement during pregnancy in gestational diabetes

AIMS/INTRODUCTION

The role of glucagon abnormality has recently been reported in type 2 diabetes; however, its role in gestational diabetes mellitus (GDM) is still unknown. The glucose intolerance in GDM is heterogeneous, and not all patients require insulin treatment during pregnancy. Here, we investigated whether glucagon abnormality is associated with the requirement for insulin treatment during pregnancy.

MATERIALS AND METHODS

A total of 49 pregnant women diagnosed with GDM were enrolled. They underwent a 75-g oral glucose tolerance test during mid-gestation, and we measured their plasma glucagon levels (by a new sandwich enzyme-linked immunosorbent assay) at fasting (0 min), and at 30, 60 and 120 min after glucose load in addition to the levels of plasma glucose and serum insulin. All participants underwent another oral glucose tolerance test at postpartum.

RESULTS

Of the 49 patients, 15 required insulin treatment (Insulin group) and 34 were treated with diet therapy alone until delivery (Diet group). The early-phase glucagon secretion after glucose load, as determined by the changes in glucagon from the baseline to 30 min, was paradoxically augmented during mid-gestation in the Insulin group, but not in the Diet group. The impaired glucagon suppression during mid-gestation in the Insulin group was not associated with insulin secretory/sensitivity indexes studied, and was ameliorated postpartum, although the plasma glucose levels remained higher in the Insulin group versus the Diet group.

CONCLUSIONS

Impaired early-phase suppression of glucagon could be associated with the requirement for insulin treatment during pregnancy in patients with GDM.

Predictive factors of efficacy of combination therapy with basal insulin and liraglutide in type 2 diabetes when switched from longstanding basal-bolus insulin: Association between the responses of β- and α-cells to GLP-1 stimulation and the glycaemic control at 6 months after switching therapy

AIMS

To evaluate the glycaemic control of combination therapy with basal insulin and liraglutide, and to explore the factors predictive of efficacy in patients with type 2 diabetes when switched from longstanding basal-bolus insulin therapy.

METHODS

We studied 41 patients who switched from basal-bolus insulin therapy of more than 3 years to basal insulin/liraglutide combination therapy. Glycaemic control was evaluated at 6 months after switching therapy and used to subdivide the patients into good-responders (HbA1c <7.0% or 1.0% decrease) and poor-responders (the rest of participants). To evaluate the glucose-dependent insulin/glucagon responses without/with liraglutide, a 75-g oral glucose tolerance test (OGTT) was performed twice, before (1st-OGTT) and 2-days after (2nd-OGTT) liraglutide administration.

RESULTS

Twenty-eight patients (68.3%) were identified as good-responders. No differences were found in baseline characteristics including insulin/glucagon responses during 1st-OGTT between the groups. 2nd-OGTT revealed that paradoxical hyperglucagonemia were significantly improved in both groups, but significant increases in insulin secretory response were observed only in good-responders. Logistic regression analyses revealed that the improvement of the insulin-response during 2nd-OGTT compared to that during 1st-OGTT is associated with the good-responder.

CONCLUSIONS

Enhancement of glucose-dependent insulin-response under liraglutide administration is a potential predictor of long-term glycaemic control after switching the therapies.

Late-onset Cerebrotendinous Xanthomatosis with a Novel Mutation in the CYP27A1 Gene

Cerebrotendinous xanthomatosis (CTX) is a rare, autosomal recessive, inborn disruption in bile acid synthesis characterized by severe systemic xanthomas, cataracts and neurological injuries occurring before adolescence without elevation of the serum cholesterol or triglyceride levels. CTX is caused by a deficiency of the mitochondrial enzyme sterol 27-hydroxylase, which is encoded by the CYP27A1 gene. We herein report a 50-year-old Japanese woman with late-onset CTX who had no relevant symptoms before the development of bilateral Achilles tendon xanthomas in middle age. A genetic analysis revealed a compound heterozygous mutation in the CYP27A1 gene with a previously known missense mutation (NM_000784.3:c.1421 G>A) and a novel frame shift mutation of NM_000784.3:c.1342_1343insCACC.

Late-onset Cerebrotendinous Xanthomatosis with a Novel Mutation in the CYP27A1 Gene

Cerebrotendinous xanthomatosis (CTX) is a rare, autosomal recessive, inborn disruption in bile acid synthesis characterized by severe systemic xanthomas, cataracts and neurological injuries occurring before adolescence without elevation of the serum cholesterol or triglyceride levels. CTX is caused by a deficiency of the mitochondrial enzyme sterol 27-hydroxylase, which is encoded by the CYP27A1 gene. We herein report a 50-year-old Japanese woman with late-onset CTX who had no relevant symptoms before the development of bilateral Achilles tendon xanthomas in middle age. A genetic analysis revealed a compound heterozygous mutation in the CYP27A1 gene with a previously known missense mutation (NM_000784.3:c.1421 G>A) and a novel frame shift mutation of NM_000784.3:c.1342_1343insCACC.

Sex differences in insulin and glucagon responses for glucose homeostasis in young healthy Japanese adults

It has been reported that glucose responses during the oral glucose tolerance test differ between healthy women and men. However, it remains unknown what factors contribute to these differences between the sexes. The present study analyzed the insulin and glucagon responses during the oral glucose tolerance test in 25 female and 38 male healthy young adults aged 22–30 years. The plasma glucose levels at 120 min were significantly higher in women than men. Insulin secretion was significantly greater at 30, 90 and 120 min from baseline in women than men. Glucagon suppression was greater at 30 and 120 min from baseline in men than women when determined by a sandwich enzyme‐linked immunosorbent assay glucagon kit. These results suggest that the differences in glucose responses during the oral glucose tolerance test are mediated by the difference between the sexes in bi‐hormonal responses in healthy individuals.

Increased sugar intake as a form of compensatory hyperphagia in patients with type 2 diabetes under dapagliflozin treatment

AIMS

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) cause substantially less weight loss than would be expected based on their caloric deficits, probably due to enhanced appetite regulation known as "compensatory hyperphagia," which occurs to offset the negative energy balance caused by increased glycosuria. We examined whether any specific nutrients contributed to the compensatory hyperphagia in diabetic patients taking SGLT2i.

METHODS

Sixteen patients with type 2 diabetes were newly administered dapagliflozin 5 mg daily as the experimental SGLT2i group. Sixteen age-, sex- and BMI-matched type 2 diabetes patients not receiving dapagliflozin served as controls. A brief-type self-administered diet history questionnaire (BDHQ) was undertaken just before and 3 months after study initiation to evaluate changes of energy and nutrient intakes in each group.

RESULTS

At 3 months, daily intakes of total calories and the proportions of the three major nutrients were not significantly increased in either group. However, daily sucrose intake was significantly increased after treatment versus the baseline value in the SGLT2i group (p = .003), but not in controls. The calculated intakes of all other nutrients were not significantly changed in either group.

CONCLUSIONS

Dapagliflozin treatment specifically increased sucrose intake, which might be an ideal target for nutritional approaches to attenuate compensatory hyperphagia.

Multiple drug combination of anti-diabetic agents as a predictor for poor clinical response to liraglutide

AIM

Aim of the study was to retrospectively analyze the clinical parameters that contribute to the therapeutic outcome of GLP-1 analogues.

METHODS

We enrolled 106 patients with type 2 diabetes mellitus (T2DM), treated with liraglutide (N.=69) or exenatide (N.=37) for longer than three months. The patients were divided into two groups: good responders and poor responders to GLP-1 analogues, based on pretreatment and post-treatment HbA1c levels. Good responders were those whose HbA1c level had decreased by 1% or more, or maintained at less than 7%. All other patients were categorized as poor responders. We used univariate and multivariate analyses to assess pretreatment parameters between the two groups.

RESULTS

Approximately 35% of the patients were poor responders. Our analysis of the pretreatment clinical parameters revealed that number of anti-diabetic agents and use of sulfonylurea were significantly associated with poor response to liraglutide (P=0.02 and P=0.03, respectively) in a multivariate analysis. We were not able to find any candidate related to clinical response to exenatide.

CONCLUSION

Our study showed that the therapeutic effects of GLP-1 analogues on T2DM patients were heterogeneous. T2DM patients who require multiple anti-diabetic agents, especially sulfonylurea, do not benefit from liraglutide treatment.

Uptake of aortic 18F-FDG is correlated with low-density lipoprotein cholesterol and leptin in a general population

Objective

This study investigated the relationship between aortic ¹⁸F-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) uptake and clinical and laboratory findings related to atherosclerosis in a general population.

Methods

¹⁸F-FDG uptake in the ascending aorta was measured on the positron emission tomography/computed tomography (PET/CT) scans of 211 Japanese adults. The maximum target-to-background ratio (TBR) was compared with clinical and laboratory atherosclerosis findings.

Results

By multivariate regression analysis adjusted for age and sex, TBR-ascending aorta (TBR-A) was significantly correlated with various clinical and laboratory parameters, such as body mass index, log visceral fat area, low-density lipoprotein cholesterol (LDL-C), log fasting immunoreactive insulin, log homeostasis model assessment of insulin resistance, log total adiponectin and log-leptin, in all subjects. Furthermore, by multivariate linear regression analysis adjusted for confounding factors, TBR-A was significantly correlated with LDL-C (β = 0.001, p = 0.03) and log-leptin (β = 0.336, p<0.01) in all subjects.

Conclusion

TBR-A was significantly correlated with LDL-C and log-leptin independent from confounding factors. Our results suggest that aortic ¹⁸F-FDG uptake is a good marker of atherosclerosis, even in a general population.

Porphyromonas gingivalis gingipain is involved in the detachment and aggregation of Aggregatibacter actinomycetemcomitans biofilm

Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans are major periodontal pathogens that cause several types of periodontal disease. Our previous study suggested that P. gingivalis gingipains secreted in the subgingival environment are related to the detachment of A.actinomycetemcomitans biofilms. However, it remains unclear whether arginine-specific cysteine proteinase (Rgp) and lysine-specific proteinase (Kgp) play different roles in the detachment of A. actinomycetemcomitans biofilm. The aim of this study was to investigate possible disruptive roles of Kgp and Rgp in the aggregation and attachment of A. actinomycetemcomitans. While P. gingivalis ATCC33277 culture supernatant has an ability to decrease autoaggregation and coaggregation of A. actinomycetemcomitans cells, neither the boiled culture supernatant of ATCC33277 nor the culture supernatant of KDP136 showed this ability. The addition of KYT-1 and KYT-36, specific inhibitors of Rgp and Kgp, respectively, showed no influence on the ability of P. gingivalis culture supernatant. The result of gelatin zymography suggested that other proteases processed by gingipains mediated the decrease of A. actinomycetemcomitans aggregations. We also examined the biofilm-destructive effect of gingipains by assessing the detachment of A. actinomycetemcomitans from polystyrene surfaces. Scanning electron microscope analysis indicated that A. actinomycetemcomitans cells were detached by P. gingivalis Kgp. The quantity of A. actinomycetemcomitans in biofilm was decreased in co-culture with P. gingivalis. However, this was not found after the addition of KYT-36. These findings suggest that Kgp is a critical component for the detachment and decrease of A. actinomycetemcomitans biofilms.

Liraglutide as a potentially useful agent for regulating appetite in diabetic patients with hypothalamic hyperphagia and obesity

Hypothalamic hyperphagia and obesity are characterized by a lack of satiety and an abnormally high appetite that is difficult to control. We herein report the cases of two patients with hypothalamic hyperphagia and obesity with MRI-detectable hypothalamic lesions. These patients suffered from diabetes mellitus associated with an abnormal eating behavior and weight gain. Liraglutide was successfully used to treat their diabetes mellitus and suppress their abnormal appetites. Glucagon-like peptide-1 analogues, including liraglutide, are promising treatment options in patients with hypothalamic hyperphagia and obesity, as these agents enhance the hypothalamic input of the satiety signal, which is lacking in such patients.

Graves' disease complicated by ventricular fibrillation in three men who were smokers

BACKGROUND

Thyrotoxicosis is known to be associated with sinus tachycardia and supraventricular tachyarrhythmias, but rarely with ventricular fibrillation (Vf), which has only occurred in some patients with hypokalemic periodic paralysis or ischemic heart disease.

PATIENT FINDINGS

We present three men who were transferred to our hospital with Graves' disease who developed idiopathic Vf. None of them had hypokalemic periodic paralysis or ischemic heart disease but all were smokers. None of other patients with thyrotoxicosis (587 females and 155 males) who were seen at our hospital, in the period during which the three men were seen, had idiopathic Vf. In our three men with thyrotoxicosis and idiopathic Vf, there was no identifiable underlying heart disease. One of the three patients died of hypoxic encephalopathy. The other two men did not have recurrent Vf after their thyroid function normalized.

SUMMARY

These cases and a review of similar cases in the literature imply that improving thyrotoxicosis seems to be effective for treating idiopathic Vf in some patients.

CONCLUSIONS

Our findings suggest that thyroid hormone excess might play a direct role in the development of Vf in susceptible individuals. Our experience with these three patients suggests that smoking men with thyrotoxicosis likely have an increased risk for Vf, even if they do not have other predisposing factors.

A case of mixed medullary and follicular cell carcinoma of the thyroid

A medullary thyroid carcinoma is a malignant tumor derived from the C-cells of the thyroid. Despite their distinct embryological origin, medullary thyroid carcinomas are exceptionally accompanied by a tumor derived from the follicular cells; this is defined as mixed medullary and follicular cell carcinoma. There have been controversies regarding the origin of this rare mixed thyroid carcinoma questioning whether or not a mixed carcinoma originates from a common cancer stem cell. We present a case of mixed medullary and follicular cell carcinoma in which two thyroid carcinomas were found intermingled in the thyroid as well as in the metastatic cervical lymph nodes. We examined the tumor by immunostaining with thyroglobulin, calcitonin, and thyroid transcription factor-1, and also reviewed the literature and discuss the origin of this rare mixed thyroid carcinoma.

Serological survey of Encephalitozoon cuniculi infection in Japanese dogs

Antibodies to Encephalitozoon cuniculi were examined by enzyme-linked immunosorbent assay using E. cuniculi PTP2 recombinant protein and by Western blot analysis on a total of 472 dog serum samples that had been collected in Japan. Of these samples, 21.8% (103/472) had antibodies against E. cuniculi. Each of 5 serum samples that showed high (>1.0) or low (<0.1) OD value was selected randomly and further examined by Western blot using E. cuniculi-native antigens. All samples with high OD values reacted with specific E. cuniculi proteins, including an antigen of approximately 35 kDa corresponding with PTP2; sera with low OD values did not recognize this E. cuniculi band. This study is the first to demonstrate the prevalence of E. cuniculi infection in dogs in Japan.

Putative IgG4-related pituitary disease with hypopituitarism and/or diabetes insipidus accompanied with elevated serum levels of IgG4

IgG4-positive plasma cell infiltration into multiple organs or tissues, such as the pancreas and salivary glands, associated with increased serum levels of IgG4 is a characteristic finding seen in IgG4-related disease. Affected organs may appear tumorous as a result of chronic inflammatory processes accompanied with progressive fibrosis. Recent cases of this disorder in which the pituitary gland was affected include cases of diffuse enlargement of the pituitary and/or its stalk associated with central diabetes insipidus and/or impaired anterior hormone production. Here we report two such cases, as well as two additional previously undiagnosed cases found in our database. In order to make a correct diagnosis of pituitary lesion involvement with IgG4-related disease, the clinical background and concomitant disorders should be carefully taken into consideration and the measurement of serum levels of IgG4 seems to be useful.

Measuring organic carbon, nutrients and heavy metals in rivers receiving leachate from controlled and uncontrolled municipal solid waste (MSW) landfills

Since landfilling is the common method of waste disposal in Malaysia, river water is greatly exposed to the risk of contamination from leachate unless proper leachate management is carried out. In this study, leachates from three different types of landfills, namely active uncontrolled, active controlled and closed controlled, were characterized, and their relationships with river water chemistry were examined monthly for a year. The influence of leachate on river water chemistry from each type of landfill depended on many factors, including the presence of a leachate control mechanism, leachate characteristics, precipitation, surface runoff and the applied treatment. The impact of leachate from an active uncontrolled landfill was the highest, as the organic content, NH(4)(+)-N, Cd and Mn levels appeared high in the river. At the same time, influences of leachate were also observed from both types of controlled landfills in the form of inorganic nitrogen (NH(4)(+)-N, NO(3)(-)-N and NO(2)(-)-N) and heavy metals (Fe, Cr, Ni and Mn). Improper treatment practice led to high levels of some contaminants in the stream near the closed controlled landfill. Meanwhile, the active controlled landfill, which was located near the coastline, was exposed to the risk of contamination resulting from the pyrite oxidation of the surrounding area.

[A case of solitary sternal metastasis from unknown primary hepatocellular carcinoma]

We report a 61-year-old male patient who was admitted to our hospital for treatment of a rapidly growing tumor on the anterior chest. Chest roentgenography and chest CT scan showed a mass lesion extending to the subcutaneous tissue over the sternum. Although no primary lesion was revealed by subsequent examination and needle biopsy, en-bloc resection of the chest wall tumor was performed because the patient complained of chest pain and the tumor was growing rapidly. Reconstruction of the chest wall was performed using Marlex mesh and bonecement, and the skin defect was repaired with a rectus abdominis musculocutaneous flap. No complications were observed. The pathological diagnosis of the resected specimen was a metastatic sternal tumor from a primary hepatocellular carcinoma. However, postoperative evaluation failed to detect the primary lesion in the liver. Nine months after the operation, the patient remains alive and well without evidence of hepatocellular carcinoma or recurrence. To our knowledge, reports of solitary sternal metastasis from unknown primary hepatocellular carcinoma seem to be rare.