Correlation between postprandial bile acids and body fat mass in healthy normal-weight subjects.

BACKGROUND: Bile acids (BAs) play important roles in glucose regulation and energy homeostasis via G protein-coupled receptors, such as enteroendocrine L cell TGR5. The aim of the present study was to investigate the relationship between postprandial BA levels and body composition after ingestion of a standard test meal. METHODS: Eleven healthy subjects of normal weight (body-mass index, 22.0 ± 1.6 kg/m(2) [mean ± SD]), ingested a 400-kcal test meal, and blood samples were obtained from them before ingestion and every 30 min for 120 min after ingestion. The BA fractions were measured with high-performance liquid chromatography. To evaluate body composition, body impedance analysis was performed 1h before ingestion of the test meal. RESULTS: Concentrations of both total BA and total glycine-conjugated BA (GCBA) at 30, 60, 90, and 120 min after test-meal ingestion were significantly higher than those at baseline. The body-mass index was correlated with total GCBA at baseline. Moreover, body fat mass was correlated with total GCBA at 30 min (r=-0.688, P=0.019) and 60 min (r=-0.642, P=0.033) and with total BA at 30 min (r=-0.688, P=0.019) and 60 min (r=-0.642, P=0.033). CONCLUSION: The postprandial BA response is inversely related with body fat mass in healthy subjects of normal weight.

Change in urinary N-acetyl-ß-d-glucosaminidase levels relevant to postprandial glycemic control conditions in subjects without diabetes mellitus.

BACKGROUND: To assess the relationship between the serum level of 1,5-anhydroglucitol (1,5-AG), a marker of postprandial hyperglycemia, and the ratio of the urinary activity of N-acetyl-ß-d-glucosaminidase to creatinine (NAG index) in subjects without diabetes mellitus (DM). METHODS: This was a cross-sectional study with 495 subjects without DM who had an estimated glomerular filtration rate≥30ml/min/1.73m(2). Subjects were divided into tertiles based on serum 1,5-AG levels: high (>21.0µg/ml), middle (14.0-21.0µg/ml), and low (<14.0µg/ml). Adjusted odds ratios for an elevated urinary NAG index (>5.8U/g creatinine) according to the HbA1c (≤5.4%, 5.5%-5.9%, and 6.0%-6.4%) and 1,5-AG tertiles were calculated. RESULTS: The NAG index was negatively correlated with the serum 1,5-AG level in all subjects. The slopes of the regression lines for these variables did not differ significantly between elderly (≥65y) and nonelderly subjects. As compared with high 1,5-AG and HbA1c≤5.4%, the odds ratios for an elevated urinary NAG index increased progressively to 7.71 across the categories of low 1,5-AG and HbA1c of 6.0% to 6.4%. CONCLUSION: Poor control of postprandial glucose is related to an elevated urinary NAG index in persons without DM.

What characteristics at baseline are associated with the glucose-lowering effect of colestimide in patients with type 2 diabetes and hypercholesterolemia according to response to treatment?

Colestimide, an anion exchange resin, reportedly improves glycemic control in patients with type 2 diabetes. However, no studies of the glucose-lowering effect of colestimide have identified responders and nonresponders. In the present study, we compared glycemic control, lipids, and body-mass index (BMI) among patients with type 2 diabetes receiving colestimide (n=59) until 24 weeks after the start of treatment. Subjects were classified as responders to treatment (n=40), who showed a 15% or greater decrease in glycated hemoglobin (HbA1c) or a 20% or greater decrease in plasma glucose level or both after 24 weeks of colestimide treatment as compared with baseline; nonresponders showed HbA1c>11.5% or fasting plasma glucose (FPG)>250 mg/dL during the course of the study and <15% decrease in HbA1c levels or <20% decrease in FPG levels or both after 24 weeks of colestimide treatment as compared with baseline. In responders, FPG decreased significantly from 196 ± 91 mg/dL to 125 ± 47 mg/dL after 24 weeks (P<0.001), and HbA1c decreased from 9.1% ± 2.0% to 7.0% ± 0.9% (P<0.001). In nonresponders, HbA1c decreased significantly from 7.7% ± 2.9% to 7.6% ± 1.2% (P<0.05). Multiple logistic regression analysis revealed that baseline HbA1c and the presence of cholelithiasis were significant determinants of the response to colestimide treatment when corrected for sex, age, triglyceride levels, and BMI at baseline and the presence of fatty liver. In conclusion, baseline HbA1c and the presence of cholelithiasis have strong and independent influences on the glucose-lowering effect of colestimide.

Low-molecular-weight lipoprotein (a) and low relative lymphocyte concentration are significant and independent risk factors for coronary heart disease in patients with type 2 diabetes mellitus: Lp(a) phenotype, lymphocyte, and coronary heart disease.

BACKGROUND: The aim of the present prospective study was to examine whether lipoprotein (a) [Lp(a)] phenotypes and/or low relative lymphocyte concentration (LRLC) are independently associated with coronary heart disease (CHD) in patients with type 2 diabetes mellitus (T2DM). METHODS: Serum Lp(a) concentration, Lp(a) phenotypes, and RLC were analyzed in 214 subjects. Lp(a) phenotypes were classified into 7 subtypes according to sodium dodecyl sulfate-agarose gel electrophoresis by Western blotting. Subjects were assigned to the low-molecular-weight (LMW (number of KIV repeats: 11-22) ) and high-molecular-weight (HMW( number of KIV repeats: >22 )) Lp(a) groups according to Lp(a) phenotype and to the LRLC (RLC: <20.3%) and normal RLC (NRLC; RLC: ≥20.3%) groups according to RLC. A CHD event was defined as the occurrence of angina pectoris or myocardial infarction during the follow-up period. RESULTS: During the follow-up period, 30 cases of CHD events were verified. Neutrophil count showed no correlation with CHD, while relative neutrophil concentration and RLC showed positive and negative correlations, respectively, with CHD. The Cox proportional hazard model analysis revealed the following hazard ratios adjusted for LMW Lp(a), LRLC, and LMW Lp(a) + LRLC: (4.31; 95% confidence interval [CI], 1.99-9.32; P < 0.01, 3.621; 95% CI, 1.50-8.75; P < 0.05, and 7.15; 95% CI, 2.17-23.56; P < 0.01, respectively). CONCLUSIONS: Our results suggest that both LMW Lp(a) and LRLC are significant and independent risk factors for CHD and that the combination thereof more strongly predicts CHD in patients with T2DM.

The effects of postprandial glucose and insulin levels on postprandial endothelial function in subjects with normal glucose tolerance.

BACKGROUND: Previous studies have demonstrated that postprandial hyperglycemia attenuates brachial artery flow-mediated dilation (FMD) in prediabetic patients, in diabetic patients, and even in normal subjects. We have previously reported that postprandial hyperinsulinemia also attenuates FMD. In the present study we evaluated the relationship between different degrees of postprandial attenuation of FMD induced by postprandial hyperglycemia and hyperinsulinemia and differences in ingested carbohydrate content in non-diabetic individuals. METHODS: Thirty-seven healthy subjects with no family history of diabetes were divided into 3 groups: a 75-g oral glucose loading group (OG group) (n = 14), a test meal group (TM group) (n = 12; 400 kcal, carbohydrate content 40.7 g), and a control group (n = 11). The FMD was measured at preload (FMD0) and at 60 minutes (FMD60) and 120 (FMD120) minutes after loading. Plasma glucose (PG) and immunoreactive insulin (IRI) levels were determined at preload (PG0, IRI0) and at 30 (PG30, IRI30), 60 (PG60, IRI60), and 120 (PG120, IRI120) minutes after loading. RESULT: Percentage decreases from FMD0 to FMD60 were significantly greater in the TM group (-21.19% ± 17.90%; P < 0.001) and the OG group (-17.59% ± 26.64%) than in the control group (6.46% ± 9.17%; P < 0.01), whereas no significant difference was observed between the TM and OG groups. In contrast, the percentage decrease from FMD0 to FMD120 was significantly greater in the OG group (-18.91% ± 16.58%) than in the control group (6.78% ± 11.43%; P < 0.001) or the TM group (5.22% ± 37.22%; P < 0.05), but no significant difference was observed between the control and TM groups. The FMD60 was significantly correlated with HOMA-IR (r = -0.389; P < 0.05). In contrast, FMD120 was significantly correlated with IRI60 (r = -0.462; P < 0.05) and the AUC of IRI (r = -0.468; P < 0.05). Furthermore, the percentage change from FMD0 to FMD120 was significantly correlated with the CV of PG (r = 0.404; P < 0.05), IRI60 (r = 0.401; p < 0.05) and the AUC of IRI (r = 0.427; P < 0.05). No significant correlation was observed between any other FMDs and glucose metabolic variables. CONCLUSION: Differences in the attenuation of postprandial FMD induced by different postprandial insulin levels may occur a long time postprandially but not shortly after a meal.

Effects of bile-acid-binding resin (colestimide) on blood glucose and visceral fat in Japanese patients with type 2 diabetes mellitus and hypercholesterolemia: an open-label, randomized, case-control, crossover study.

OBJECTIVE: The objective was to examine the effects of colestimide on blood glucose, visceral fat, adipocytokines, and bile acid conjugate fractions in Japanese patients. METHODS: This study was an open-label, randomized, case-control, crossover study of colestimide 3 g/day in 40 Japanese patients with type 2 diabetes mellitus (T2D) and hypercholesterolemia. Patients were assigned to the colestimide group in which pravastatin and colestimide were administered orally and to the statin group in which pravastatin alone was administered orally. The principal outcome measures were serum lipid levels, fasting plasma glucose level in the early morning, hemoglobin A1c (HbA(1c)), visceral fat area (VFA), and serum 1,5-anhydroglucitol (1,5-AG) level. RESULTS: Serum low-density lipoprotein cholesterol levels significantly decreased from 113±38 mg/dl at baseline to 90±20 mg/dl (P=.009) at week 12 of colestimide administration. HbA(1c) significantly decreased from 7.4%±0.9% at baseline to 6.9%±0.9% (P=.001) at week 12 of colestimide administration. Serum 1,5-AG levels increased from 9.4±10.1 µg/ml to 12.4±9.5 µg/ml (P=.05) at week 12 of colestimide administration. The statin group showed no significant changes in lipids and 1,5-AG. However, ΔVFA was inversely correlated with Δcholic acid, and multivariate analysis revealed that ΔVFA was a significant explanatory variable. CONCLUSIONS: Colestimide holds promise not only for the treatment of hypercholesterolemia but also for the possible improvement of T2D and visceral fat obesity.

Oral glucose loading attenuates endothelial function in normal individual.

BACKGROUND: We evaluated the relationship between glucose fluctuation and vascular endothelial function. MATERIAL AND METHODS: We recruited 25 healthy individuals with no family history of diabetes (14 subjects and 11 controls). Brachial artery flow-mediated dilation (FMD) and elapsed time when the after-hyperaemia maximum brachial artery diameter is reached; the peak times (PT) of each study subject were measured before and at 60, 120, and 180 min after 75-g oral glucose loading. FMD and PT of controls were measured for four consecutive hours in the fasting state from morning. Also, brachial-ankle pulse wave velocity (baPWV) of each subject was measured at 180 min after 75-g oral glucose loading. RESULTS: Flow-mediated dilation of the study subjects was significantly lower at 60, 120 and 180 min than at pre-load, and significantly lower than that of the controls at 60 and 120 min, but not significantly different at 0 and 180 min. There was no significant difference between the PT of the subjects and the controls during 75-g oral glucose loading. In contrast, the PT of the subjects was significantly shorter than that of the controls at 120 and 180 min, but showed no significant difference at 0 and 60 min. Moreover, baPWV had no significant relationship with FMD. CONCLUSIONS: Our study showed that oral glucose loading attenuates FMD and shortens elapsed time at the maximum after-hyperaemia diameter, and the effect of glucose fluctuation on atherosclerosis in individuals with normal glucose tolerance remains despite only the attenuation of endothelial function.

Daily blood glucose profiles of glibenclamide and gliclazide taken once or twice daily in elderly type 2 diabetic patients.

AIM: The aim of this study was to evaluate the difference in daily blood glucose profiles between once- and twice-daily regimens of a moderate daily dose of glibenclamide or gliclazide in elderly patients with type 2 diabetes. METHODS: Daily blood glucose profile data were evaluated in 18 elderly type 2 diabetic patients treated with 80 mg/day gliclazide or 5 mg/day glibenclamide as monotherapy. The first daily blood glucose profile of the twice-daily regimen was performed approximately 1 week before hospital discharge, and the second was performed after taking a once-daily regimen for 4-7 days. Plasma glucose and plasma immunoreactive insulin (IRI) concentrations were measured daily at 12 time points: 08.00 (before breakfast); 10.00; 12.00 (before lunch); 14.00; 18.00 (before dinner); 20.00; 0.00; 02.00; 03.00; 04.00; 06.00; and 08.00 hours the next morning. RESULTS: Daily blood glucose profiles and plasma IRI profiles did not differ between the once- and twice-daily regimen groups in either the gliclazide group or the glibenclamide group. Plasma glucose values between midnight and early morning tended to be lower than the 08.00 hours plasma glucose value in the glibenclamide group, but not in the gliclazide group. CONCLUSION: These results suggest that the blood glucose-lowering effects of a once- and twice-daily moderate daily dose of glibenclamide or gliclazide do not differ in elderly type 2 diabetic patients. However, glibenclamide, regardless of the dosage schedule, tends to lower the plasma glucose values between midnight and early morning.

Lack of relationship between blood glucose-lowering activity of colestimide and serum cholecystokinin (CCK) concentrations in patients with type 2 diabetes.

Colestimide has been reported to lower blood glucose levels in patients with type 2 diabetes and hypercholesterolemia. We investigated the mechanism of the hypoglycemic activity of colestimide by examining changes in serum cholecystokinin (CCK) and insulin concentrations before and after its 2-week oral administration. A total of seven type 2 diabetes inpatients with hypercholesterolemia received colestimide after their blood glucose levels had stabilized. We daily measured plasma glucose levels and serum lipid concentrations, calculated Body Mass Index (BMI), and determined whole-day changes in serum immunoreactive insulin (IRI) and CCK concentrations in all study subjects. We daily measured plasma glucose levels, as well as serum IRI and CCK concentrations at 10 time points for measurement. Plasma glucose levels, as well as serum IRI and CCK concentrations before and after the 2-week oral administration of colestimide were compared. The means of total cholesterol levels and BMI decreased significantly after administration. At time points for measurement (10 : 00 and 12 : 00), plasma glucose levels decreased significantly after administration (P=0.026 and P=0.009, respectively). Diurnal changes in serum IRI and CCK concentrations were not observed after administration, except for the IRI concentration at 20: 00. The effect of colestimide on CCK may not explain the mechanism of its blood glucose-lowering activity in patients with type 2 diabetes and hypercholesterolemia.

Colestimide lowers plasma glucose levels and increases plasma glucagon-like PEPTIDE-1 (7-36) levels in patients with type 2 diabetes mellitus complicated by hypercholesterolemia.

BACKGROUND: Colestimide has been reported to lower blood glucose levels in patients with type 2 diabetes complicated by hypercholesterolemia. AIM: To examine the mechanism by which colestimide decreases plasma glucose levels in the above patients. METHODS: A total of 16 inpatients with type 2 diabetes complicated by hypercholesterolemia received colestimide for 1 week after their plasma glucose levels stabilized. We measured plasma glucose, serum immunoreactive insulin (IRI), serum lipid, plasma glucagon, and plasma glucagon-like peptide-1 (GLP-1) levels. These variables at baseline and 1 week of colestimide administration were compared. RESULTS: Preprandial plasma glucose levels (baseline: 132 +/- 33 mg/dL vs. completion: 118 +/- 43 mg/dL, P=0.073) tended to decrease after colestimide administration, while 1-hr postprandial plasma glucose levels (baseline: 208 +/- 49 mg/dL vs. completion: 166 +/- 30 mg/dL, P<0.001) and 2-hr postprandial plasma glucose levels (baseline: 209 +/- 56 mg/dL vs. completion: 178 +/- 39 mg/dL, P=0.015) decreased significantly at 1 week of colestimide administration. The 2-hr postprandial plasma GLP-1 level was significantly (P=0.015) higher at 1 week of colestimide administration as compared with the baseline level, while there were no significant changes in preprandial and 1-hr postprandial plasma GLP-1 levels. CONCLUSIONS: The GLP-1-increasing activity of colestimide may explain, at least in part, the mechanism of its blood glucose-lowering activity in patients with type 2 diabetes complicated by hypercholesterolemia.