Insulin resistance and ß-cell function influence postprandial blood glucose levels in Japanese patients with gestational diabetes mellitus.

AIMS/INTRODUCTION: The aim of this study in patients with gestational diabetes mellitus (GDM) was to evaluate the relationship of insulin resistance and secretion to area-under-the-sensor glucose concentration-time curve from before to 120 min postmeal (CGM-AUC(0-120 min)) as determined with continuous glucose monitoring (CGM). MATERIALS AND METHODS: Immunoreactive insulin and HbA1c were determined in 22 Japanese patients with GDM undergoing a 75 g oral glucose tolerance test. Patients underwent CGM within 3 weeks of receiving a diagnosis of GDM. RESULTS: HbA1c (NGSP) was 5.5 ± 0.4%, BMI was 24.8 ± 5.3 kg/m(2), mean sensor glucose by CGM was 94.2 ± 10.3 mg/dL, standard deviation was 17.5 ± 4.4 mg/dL, and CGM-AUC(0-120 min) was 204.2 ± 23.8 h mg/dL. The insulin resistance indices the homeostasis model assessment ratio (HOMA-R), quantitative insulin sensitivity check index (QUICKI), and the Matsuda Index were correlated with CGM-AUC(0-120 min). The disposition index (DI), which was used to evaluate insulin secretion, was negatively correlated with CGM-AUC(0-120 min). CONCLUSIONS: Not only insulin resistance but also beta cell dysfunction contributes to postprandial hyperglycemia in Japanese patients with GDM.

Mechanical stretch induced interleukin-18 (IL-18) expression through Angiotensin subtype 1 receptor (AT1R) and endothelin-1 in cardiomyocytes.

Interleukin-18 (IL-18) is a proinflammatory cytokine with multiple biological functions. We and others have demonstrated that an increased level of circulating IL-18 is one of the risk factors for cardiovascular diseases. Endothelin-1 (ET-1) has been reported to be a potent hypertrophy-promoting factor through RhoA and Rho-Kinase. Mechanical stretch induces a hypertrophic response, partly through the production of ET-1 through Endothelin A receptor (ETAR). Moreover, it has also been reported that mechanical stretch induces cardiac hypertrophy through Angiotensin subtype 1 receptor (AT1R). However, the mechanism by which the IL-18 gene expression is regulated in cardiomyocytes has not yet been fully understood. This study was designed to elucidate the functional significance of IL-18 gene expression in response to mechanical stretch. Neonatal rat cardiomyocytes cultured on silicone dishes were subjected to stretch. The moderate 20% mechanical stretch resulted in the elevation of IL-18 expression in a time-dependent manner with the maximal level achieved 36 hours after the stretch. Olmesartan, AT1R antagonist inhibited stretch-induced IL-18 expression. ETAR blockade BQ123 inhibited stretch-induced IL-18 expression. However, the Endothelin B receptor (ETBR) receptor blockade BQ788 did not inhibit this reaction. ET-1 induced IL-18 expression, with a peak induction after 4 hours of incubation. These results might suggest that stretch stimulation of cardiomyocytes induced ET-1 and, subsequently, ET-1 up-regulated the IL-18 expression. Furthermore, Fasudil, a Rho-Kinase inhibitor, and Simvastatin, a HMG-CoA reductase inhibitor, led to a significant reduction in mechanical stretch-induced IL-18 expression. These results indicated, for the first time, that IL-18 expression is induced by mechanical stretch in cardiomyocytes via the ETAR, AT1R, and the Rho/Rho-K pathways. The induction of IL-18 from cardiomyocytes by mechanical stress might cause the deterioration of cardiac functions in autocrine and paracrine fashion. The inhibition of IL-18 expression induced by mechanical stress might be one of the mechanisms that account for the beneficial cardiovascular effects of AT1R antagonist, ETAR blockade, Statin, and Rho-Kinase inhibitor.

Postabsorptive hyperglucagonemia in patients with type 2 diabetes mellitus analyzed with a novel enzyme-linked immunosorbent assay.

AIMS/INTRODUCTION: The aims of the present study were to investigate the performance of a novel sandwich enzyme-linked immunosorbent assay (ELISA) for measuring glucagon (1-29) with monoclonal antibodies against both the C- and N-terminal regions of glucagon (1-29), and to analyze the differences in plasma levels and responses of glucagon (1-29) to oral glucose loading in normal glucose tolerance (NGT) subjects and patients with type 2 diabetes mellitus. MATERIALS AND METHODS: The cross-reactivity against proglucagon fragments using the ELISA kit and two types of conventional radioimmunoassay (RIA) kits was evaluated. A 75-g oral glucose tolerance test was carried out with NGT subjects and patients with type 2 diabetes mellitus, and the glucagon (1-29) concentration was measured using three types of kit. RESULTS: The ELISA kit clearly had the lowest cross-reactivity against miniglucagon (19-29) and glicentin (1-61). The oral glucose tolerance test was carried out with 30 NGT and 17 patients with type 2 diabetes mellitus. The glucagon (1-29) levels measured by the ELISA kit after glucose loading were significantly higher at all time-points in the type 2 diabetes mellitus group than in the NGT group. However, the glucagon (1-29) levels measured by one RIA kit were significantly higher in the NGT group, and those measured with the other RIA kit were approximately the same among the groups. CONCLUSIONS: The novel sandwich ELISA accurately determines plasma glucagon (1-29) concentrations with much less cross-reactivity against other proglucagon fragments than conventional RIA kits.

Evaluation of blood glucose fluctuation in Japanese patients with type 1 diabetes mellitus by self-monitoring of blood glucose and continuous glucose monitoring.

AIMS: Accurate assessment of blood glucose fluctuation is essential for managing blood glucose control while avoiding hypoglycemia in patients with diabetes mellitus. In this study, blood glucose was measured by continuous glucose monitoring (CGM) in patients with type 1 diabetes mellitus (T1DM) whom self-monitoring of blood glucose (SMBG) was carried out three or more times per day, and evaluation was performed using blood glucose fluctuation parameters obtained by CGM and SMBG. METHODS: Twenty-nine insulin-depleted patients with T1DM were enrolled. Their blood glucose fluctuations were measured at the same time by SMBG and CGM, and the correlations were evaluated. RESULTS: Correlations were found between the following values obtained by SMBG and CGM: mean and standard deviation of blood glucose levels, average daily risk range, Morbus value and high-blood-glucose index. The hypoglycemia duration and the nocturnal hypoglycemia duration showed no correlation with any of the blood glucose fluctuation parameters obtained by SMBG. CONCLUSIONS: The findings suggest that routine SMBG and glycated hemoglobin (HbA1c) measurement are sufficient for evaluation of hyperglycemia in T1DM. On the other hand, blood glucose fluctuation parameters obtained by SMBG and HbA1c have been shown to have no correlations with either hypoglycemia duration or nocturnal hypoglycemia duration.

Response of incretins (GIP and GLP-1) to an oral glucose load in female and male subjects with normal glucose tolerance.

The aim of this study was to analyze the blood glucose profile and the response of incretins in healthy young subjects by the 75 g oral glucose tolerance test (OGTT). We first reported that plasma glucose and GIP levels were higher in males during the early phase of the OGTT.

Medium-term effects of insulin degludec on patients with type 1 diabetes mellitus.

OBJECTIVE: The aim of this study was to analyze the changes in daily blood glucose fluctuation and insulin dose in patients with type 1 diabetes mellitus (T1DM) undergoing basal-bolus therapy following a switching of basal insulin used from insulin glargine or detemir to insulin degludec. METHODS: Seven patients with T1DM were enrolled. All patients treated with insulin glargine or detemir twice daily were switched to insulin degludec with 80-90 % of the prior insulin dose. During the study period, the basal insulin doses were adjusted by the attending physician. The patients underwent continuous glucose monitoring before, 3 days after, and 24 weeks after switching to insulin degludec. The daily insulin dose was analyzed before, 3 days after, and 24 weeks after switching. Glycated hemoglobin levels were measured before and 24 weeks after switching. RESULTS: The blood glucose profile did not change significantly before and after switching. On the other hand, the total daily insulin dose and total daily basal insulin dose decreased significantly 24 weeks after switching. DISCUSSION: In patients with T1DM undergoing insulin glargine or detemir treatment, it is possible to achieve similar glycemic control in the medium term with a once daily, lower dose of insulin degludec.

Effects of switching from insulin glargine or detemir to insulin degludec in patients with type 1 diabetes mellitus.

INTRODUCTION: Insulin degludec is a new, ultra-long-acting basal insulin. The aim of this study was to analyze the changes of basal insulin dose and blood glucose profile in basal-bolus therapy of type 1 diabetes mellitus (T1DM) at the switching of basal insulin from insulin glargine or detemir to insulin degludec. METHODS: Sixteen patients with T1DM were enrolled. The patients underwent continuous glucose monitoring before and after the switching of insulin glargine or detemir to degludec. Ten patients treated with insulin glargine or detemir twice daily, were switched to insulin degludec with 80-90% of the prior insulin dose. The remaining six patients treated with insulin glargine once daily, were switched to insulin degludec without down titration. The changes of daily insulin dose and glycated hemoglobin (HbA1c) were also examined for 12 weeks after switching to insulin degludec. RESULTS: In the patients switched from twice-daily basal insulin, no significant difference was found between before and after switching in the blood glucose profile. In the once-daily group, blood glucose levels showed a tendency to decrease after switching to the degludec treatment. During the study period, total daily insulin dose (TDD) and total daily basal insulin dose (TBD) decreased significantly in the twice-daily group, and TDD and TBD showed a tendency to decrease after switching to degludec in the once-daily group. In both groups, the changes of HbA1c were not significantly different. CONCLUSION: It is possible to achieve similar glycemic control with once-daily injection and lower doses of insulin degludec in patients with T1DM who have been treated with insulin glargine or detemir.

OCT assessment of thin-cap fibroatheroma distribution in native coronary arteries.

OBJECTIVES: We evaluated the geographic distribution of thin-cap fibroatheromas (TCFAs) in the coronary arteries using optical coherence tomography (OCT), a high-resolution imaging modality. BACKGROUND: Plaque rupture is the most frequent cause of acute myocardial infarction (AMI). It has been recognized that TCFA is the primary plaque type at the site of plaque rupture. METHODS: We performed 3-vessel OCT examinations in 55 patients: 35 AMI and 20 stable angina pectoris patients. The criteria for TCFA in an OCT image was a lipid-rich plaque with fibrotic cap thickness <65 microm. The distance between each TCFA location and the respective coronary artery ostium was measured with motorized OCT imaging pullback. The total length of all 3 coronary arteries imaged by OCT pullbacks was 82 +/- 21 mm in the left anterior descending coronary artery (LAD), 67 +/- 26 mm in the left circumflex coronary artery (LCx), and 104 +/- 32 mm in the right coronary artery (RCA). RESULTS: OCT detected 94 TCFAs in 165 coronary arteries. The minimum fibrous-cap thickness of TCFAs was 57.4 +/- 5.4 microm in AMI patients, and 55.9 +/- 7.3 microm in stable angina pectoris patients (p = 0.4). Of the total of 94 TCFAs, 28 were detected in the LAD, 18 in the LCx, and 48 in the RCA. Most LAD TCFAs were located between 0 and 30 mm from the LAD ostium (76%). Conversely, LCx and RCA TCFAs were evenly distributed throughout the entire coronary length. The clustering of the TCFAs was similar in culprit segments as compared with nonculprit segments. In AMI patients, most LAD TCFAs were distributed near side branches, mainly positioned opposite the side branch bifurcation. CONCLUSIONS: Three-vessel OCT imaging showed that TCFAs tend to cluster in predictable spots within the proximal segment of the LAD, but develop relatively evenly in the LCx and RCA arteries.

A disappearing left atrial thrombus.

The authors report a case of a migrating left atrial thrombus identified under direct visualization using transthoracic echocardiography in an elderly patient with atrial fibrillation. The left atrial-ventricular-aortic course of the thrombus was observed in real time, and prompt diagnosis and treatment of an acute cardioembolic cerebral infarction were performed. This case provides an example of the importance of transthoracic echocardiography in the diagnosis of stroke.

Aldosterone induces interleukin-18 through endothelin-1, angiotensin II, Rho/Rho-kinase, and PPARs in cardiomyocytes.

Aldosterone (Aldo) is recognized as an important risk factor for cardiovascular diseases. IL-18 induces myocardial hypertrophy, loss of contractility of cardiomyocytes, and apoptosis leading myocardial dysfunction. However, so far, there have been few reports concerning the interaction between Aldo and IL-18. The present study examined the effects and mechanisms of Aldo on IL-18 expression and the roles of peroxisome proliferator-activated receptor (PPAR) agonists in rat cardiomyocytes. We used cultured rat neonatal cardiomyocytes stimulated with Aldo to measure IL-18 mRNA and protein expression, Rho-kinase, and NF-kappaB activity. We also investigated the effects of PPAR agonists on these actions. Aldo, endothelin-1 (ET-1), and angiotensin II (ANG II) increased IL-18 mRNA and protein expression. Mineralocorticoid receptor antagonists, endothelin A receptor antagonist, and ANG II receptor antagonist inhibited Aldo-induced IL-18 expression. Aldo induced ET-1 and ANG II production in cultured media. Moreover, Rho/Rho-kinase inhibitor and statin inhibited Aldo-induced IL-18 expression. On the other hand, Aldo upregulated the activities of Rho-kinase and NF-kappaB. PPAR agonists attenuated the Aldo-induced IL-18 expression and NF-kappaB activity but not the Rho-kinase activity. Our findings indicate that Aldo induces IL-18 expression through a mechanism that involves, at a minimum, ET-1 and ANG II acting via the Rho/Rho-kinase and PPAR/NF-kappaB pathway. The induction of IL-18 in cardiomyocytes by Aldo, ET-1, and ANG II might, therefore, cause a deterioration of the cardiac function in an autocrine and paracrine fashion. The inhibition of the IL-18 expression by PPAR agonists might be one of the mechanisms whereby the beneficial cardiovascular effects are exerted.

[Postgastrectomy beriberi exaggerated by diuretic use: a case report].

A 66-year-old male was referred to our hospital because of severe pitting edema in the lower extremities in April 2003. He had undergone a partial gastrectomy for gastric cancer 17 years before and radiotherapy for oropharyngeal cancer 1 year before. He had suffered from the edema for 4 years. Loop diuretics prescribed by his family doctor were effective for relieving the edema at first, but the edema was not resolved. He was hospitalized with evidence of hypothyroidism from blood analysis. Administration of levothyroxin partially relieved the edema, but loop diuretics were continued because the edema was not completely diminished. He was admitted to our hospital again in October 2003, because of unsteady gait and worsened edema. Neurological examination revealed the stocking-and-glove pattern of sensory disturbance and distal muscle weakness in the lower extremities. Plasma vitamin B1 (thiamine)concentration was low, and the diagnosis was beriberi. After vitamin B, supplementation was initiated, the patient's edema completely disappeared in a few days, and his gait disturbance gradually subsided. Diuretics lead to increased urinary vitamin B1 excretion, so we should be watchful for thiamine deficiency in patients treated with diuretics who underwent gastrectomy and potentially have latent vitamin B1 deficiency.

Accuracy of nonstenotic coronary atherosclerosis assessment by multi-detector computed tomography.

BACKGROUND: The ability to evaluate coronary stenosis using multi-detector computed tomography (MDCT) has been well discussed. In contrast, several studies demonstrated that the plaque burden measured by intravascular ultrasound (IVUS) has a relationship to the risk of cardiovascular events. the accuracy of MDCT was studied to determine plaque and vessel size compared with IVUS. METHODS AND RESULTS: Fifty-six proximal lesions (American College of Cardiology/American Heart Association classification: segment 1, 5, 6) from 33 patients were assessed using MDCT and IVUS. The plaque and vessel area were measured from the cross-sectional image using both MDCT and IVUS. Eight coronary artery lesions with motion artifacts and heavily calcified plaques were excluded from the analysis. The vessel and lumen size evaluated using MDCT were closely correlated with those evaluated by IVUS (R(2)=0.614, 0.750 respectively). Furthermore, there was a strong correlation between percentage plaque area assessed by MDCT and IVUS (R(2)=0.824). CONCLUSION: MDCT can noninvasively quantify coronary atherosclerotic plaque with good correlation compared with IVUS in patients with atherosclerosis.

Cardiac wall motion abnormalities observed in a patient with transient hyperthyroidism.

A 74-year-old woman, with a history of hypertension and hyperlipidemia, was admitted to our hospital. She was found to have a sinus tachycardia with ST-segment elevations in leads II, III, (a)V(F), and V(3) through V(6) in electrocardiography, hypokinesis of the left ventricular apex by echocardiography, and normal findings on coronary angiography. Blood analysis revealed an increase in the creatine kinase MB fraction, a significant positive detection in troponin T, and transient elevations in the concentrations of free triiodothyronine, free thyroxine, thyroid globulin antibody, and thyroid peroxidase antibody. Defects in myocardial perfusion and fatty acid metabolism in the apical area were also demonstrated by myocardial scintigraphy. These data suggest that tako-tsubo syndrome or myocardial infarction may be induced in patients with mild and transient hyperthyroidism.