Defective autophagy in vascular smooth muscle cells enhances the healing of abdominal aortic aneurysm.

Autophagy is an evolutionarily conserved cellular catabolic process essential for cell homeostasis, and thus its failure is associated with several diseases. While autophagy has been reported to play a role in vascular smooth muscle cells (SMCs) in vascular disorders, its precise role in the pathogenesis of abdominal aortic aneurysm (AAA) has not yet been elucidated. In this study, we investigated the role of SMC autophagy in AAA formation. As a mouse model of AAA, we used control apolipoprotein E-deficient (apoeKO) mice and Atg7cKO (SMC-specific Atg7-deficient mice):apoeKO mice administered angiotensin II for 4 weeks. Intriguingly, Kaplan-Meier curves showed that the survival rates of Atg7cKO:apoeKO mice were significantly higher than those of apoeKO mice. The hematoma area in AAA of Atg7cKO:apoeKO mice was smaller than in apoeKO mice despite the lack of a significant difference in AAA incidence between the two groups. Furthermore, the amount of granulomatous tissues was significantly larger and the collagen-positive area within AAA was significantly larger in Atg7cKO:apoeKO mice than in apoeKO mice. In accordance with these findings, SMCs cultured from Atg7cKO mice showed increased expression of collagens, independent of angiotensin II action. Taken together, our data suggest that defective autophagy in SMCs elicits AAA healing that may underlie the better survival rate under dyslipidemia and angiotensin II infusion.

Lower intake of saturated fatty acids is associated with persistently higher arterial stiffness in patients with type 2 diabetes.

AIMS/INTRODUCTION: There are few studies to investigate the relationship between macronutrients and longitudinal changes in arterial stiffness in patients with type 2 diabetes mellitus. This exploratory study sought to determine whether macronutrients were correlated with increased arterial stiffness independently of conventional atherosclerotic risk factors. MATERIALS AND METHODS: The study participants comprised 733 type 2 diabetes outpatients who had no apparent history of cardiovascular diseases. The dietary schedule was assessed with a validated, brief, self-administered diet history questionnaire. At baseline and at years 2 and 5, brachial-ankle pulse wave velocity was measured. A multivariable linear mixed-effects model was used to determine the predictive values of macronutrients and atherosclerotic risk factors for longitudinal changes in brachial-ankle pulse wave velocity. RESULTS: There was a significant increase in brachial-ankle pulse wave velocity values over the 5-year follow-up period. In a multivariable linear mixed-effects model that adjusted for age and sex, lower saturated fatty acid intake was significantly correlated with persistently higher brachial-ankle pulse wave velocity, independently of other atherosclerotic risk factors. Lower intake of dairy products in particular showed this correlation. CONCLUSIONS: Our data showed that lower saturated fatty acids intake was correlated with persistently higher brachial-ankle pulse wave velocity in type 2 diabetes patients. Among food sources of saturated fatty acids, lower dairy products specifically were correlated with elevated brachial-ankle pulse wave velocity. This might be because the consumption of dairy products in Japan is much lower than in Western countries.

Liraglutide Improves Estimated Glomerular Filtration Rate Slopes in Patients with Chronic Kidney Disease and Type 2 Diabetes: A 7-Year Retrospective Analysis.

Background: Liraglutide was administered to patients with type 2 diabetes, and its effects on estimated glomerular filtration rate (eGFR) slopes and albuminuria were retrospectively evaluated. Methods: This study included 568 patients with type 2 diabetes who received liraglutide therapy (up to 0.9 mg/day) >1 year and were followed-up for a maximum of 2 years before and 7 years after treatment. The decline in renal function was estimated as the slope of the individual linear regression line of eGFR over the follow-up time. Spot urine samples were collected to measure albuminuria, which were calculated using creatinine levels. In addition, HbA1c, body weight, blood pressure, and heart rate were monitored. Results: The mean liraglutide treatment period was 3.1 ± 2.0 years. The mean baseline eGFR slope [mL/(min ·1.73 m2·year)] was -2.75 ± 6.04. After liraglutide treatment, the mean eGFR slope significantly improved (-1.42 ± 4.30, P < 0.01). This effect appeared more pronounced for baseline eGFRs <45 mL/(min ·1.73 m2). Albuminuria, HbA1c, body weight, and systolic blood pressure levels were significantly reduced after treatment with liraglutide for 1 year, whereas diastolic blood pressure and heart rates were increased. Conclusions: Patients treated with liraglutide experienced a significantly slower annual decline in kidney function. The benefit appeared more pronounced in patients with the development and progression of diabetic kidney disease. These results suggest that the benefits of liraglutide on kidney function identified in clinical trials appear to be well generalizable to clinical practice.

Breakfast skipping is associated with persistently increased arterial stiffness in patients with type 2 diabetes.

OBJECTIVE: While certain lifestyle habits may be associated with arterial stiffness, there is limited literature investigating the relationship between lifestyle habits and longitudinal changes in arterial stiffness in patients with type 2 diabetes mellitus (T2DM). This is an exploratory study to determine whether lifestyle habits, in addition to conventional atherosclerotic risk factors, are associated with increased arterial stiffness. RESEARCH DESIGN AND METHODS: The study participants comprised 734 Japanese outpatients with T2DM and no history of apparent cardiovascular diseases. Lifestyle habits were analyzed using self-reported questionnaires, and brachial-ankle pulse wave velocity (baPWV) was measured at baseline, and at years 2 and 5. A multivariable linear mixed-effects model was used to determine the predictive value of lifestyle habits and possible atherosclerotic risk factors for longitudinal change in baPWV. RESULTS: Over 5 years of follow-up, baPWV values significantly increased. In a multivariable linear mixed-effects model that adjusted for age and gender, a low frequency of breakfast intake was significantly associated with persistently high baPWV, independently of other lifestyle habits. Furthermore, in a multivariable linear mixed-effects model that included both lifestyle habits and possible atherosclerotic risk factors, a low frequency of breakfast intake remained the only independent predictive factor for persistently high baPWV. Subjects who ate breakfast less frequently tended to have additional unhealthy lifestyle habits and atherosclerotic risk factors. CONCLUSIONS: Our analyses suggest that breakfast skipping is an independent lifestyle habit that is associated with persistently increased arterial stiffness in patients with T2DM. TRIAL REGISTRATION NUMBER: UMIN000010932.

Canagliflozin Increases Postprandial Total Glucagon-Like Peptide 1 Levels in the Absence of α-Glucosidase Inhibitor Therapy in Patients with Type 2 Diabetes: A Single-Arm, Non-randomized, Open-Label Study.

INTRODUCTION: To investigate canagliflozin-induced changes in postprandial total glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) levels in patients with type 2 diabetes mellitus (T2DM). METHODS: Forty-five patients with T2DM who had inadequate glycemic control (glycated hemoglobin ≥ 6.5%) with diet and exercise alone (n = 15, drug naïve) and in combination with either a stable dose of the α-glucosidase inhibitor acarbose (n = 15) or metformin (n = 15) received canagliflozin, a sodium-glucose cotransporter 2 inhibitor, at 100 mg once daily for 12 weeks. The primary endpoint was the change from baseline to week 12 in postprandial glucose and plasma levels of total GLP-1 and GIP during a meal tolerance test (MTT). RESULTS: Canagliflozin significantly reduced postprandial blood glucose (mean difference - 40.2 mg/mL at 60 min) and increased postprandial total GLP-1 (mean difference 1.8 pg/mL at 60 min) during an MTT. A transient reduction in the postprandial GIP level at only 30 min (mean difference - 80.3 pg/mL) during an MTT was observed. No changes in postprandial GLP-1 or GIP levels were seen after canagliflozin treatment as an add-on to acarbose in patients with T2DM. Acarbose treatment significantly decreased postprandial total GIP levels (P < 0.05) and tended to increase postprandial total GLP-1 levels (P = 0.07) compared to the other two treatments prior to canagliflozin. CONCLUSION: Canagliflozin 100 mg increased postprandial total GLP-1 levels in the absence of acarbose, suggesting that it may upregulate GLP-1 secretion through delayed glucose absorption in the upper intestine, as with the α-glucosidase inhibitor. TRIAL REGISTRATION: University Hospital Medical Information Network, UMIN000018345. FUNDING: Mitsubishi Tanabe Pharma Corporation.

Effect of luseogliflozin on hepatic fat content in type 2 diabetes patients with non-alcoholic fatty liver disease: A prospective, single-arm trial (LEAD trial).

AIMS: No pharmacological therapies are approved for non-alcoholic fatty liver disease (NAFLD). Luseogliflozin, a sodium glucose cotransporter 2 inhibitor, has been developed for the treatment of adults with type 2 diabetes (T2DM). The aim of this prospective, single-arm study is to evaluate the efficacy of luseogliflozin on hepatic fat content and glycated hemoglobin (HbA1c) in T2DM patients with NAFLD. METHODS: Forty T2DM patients with NAFLD were treated with luseogliflozin 2.5 mg/day for 24 weeks. Primary end-points were changes in HbA1c and hepatic steatosis evaluated by magnetic resonance imaging-hepatic fat fraction from baseline. Secondary end-points were changes in metabolic and hepatic function-related parameters, including hepatic fibrosis markers (Fibrosis-4 index, NAFLD fibrosis score, type IV collagen 7S. and Wisteria floribunda agglutinin-positive Mac-2 binding protein). RESULTS: Not only HbA1c and transaminase activities but also hepatic fat content were significantly decreased after 24 weeks of therapy with luseogliflozin. The reduction of hepatic fat content was significantly correlated with the reduction of alanine aminotransferase. Although hepatic fibrosis markers were unchanged, serum ferritin levels reduced and serum albumin significantly increased after the treatment. CONCLUSION: Luseogliflozin can be a novel promising agent for the treatment of T2DM patients with NAFLD. Prospective randomized controlled trials are warranted to confirm this impact of luseogliflozin onT2DM with NAFLD.

Defective autophagy in vascular smooth muscle cells enhances atherosclerotic plaque instability.

Autophagy is considered as an evolutionarily conserved cellular catabolic process. Defective autophagy has been implicated in various human diseases, including cardiovascular diseases. Recently, we and others demonstrated that defective autophagy in vascular smooth muscle cells (SMCs) promotes the progression of atherosclerosis. In this study, we investigated the role of autophagy in SMCs on plaque instability in vivo. We generated mice with a defect atg7in which is an essential gene for autophagy, in SMCs by crossing Atg7f/f mice with transgelin (Tagln) Cre+/0 mice (Atg7cKO). Then, Atg7cKO and apolipoprotein E (apoe)-deficient (apoeKO) mice were crossed to generate Atg7cKO:apoeKO mice. To generate a mouse model of plaque instability, we conducted to form a tandem stenosis in the carotid artery of Atg7cKO:apoeKO mice and their controls (apoeKO mice) at the age of 10 weeks. At 5 weeks after surgery, the percentage of cross-sectional stenosis area in the operated common carotid artery of Atg7cKO:apoeKO mice was significantly higher than that in apoeKO mice. In addition, thrombus, which was not observed in apoeKO mice, was frequently found in Atg7cKO:apoeKO mice. Furthermore, the number of Berlin blue staining-positive areas, which indicated intraplaque hemorrhage, was significantly higher in Atg7cKO:apoeKO mice than in control apoeKO mice. Taken together, our data suggest that defective autophagy in SMCs enhances plaque instability and the risk of plaque rupture.

Defective autophagy in vascular smooth muscle cells enhances cell death and atherosclerosis.

Macroautophagy/autophagy is considered as an evolutionarily conserved cellular catabolic process. In this study, we aimed to elucidate the role of autophagy in vascular smooth muscle cells (SMCs) on atherosclerosis. SMCs cultured from mice with SMC-specific deletion of the essential autophagy gene atg7 (Atg7cKO) showed reduced serum-induced cell growth, increased cell death, and decreased cell proliferation rate. Furthermore, 7-ketocholestrerol enhanced apoptosis and the expression of CCL2 (chemokine [C-C motif] ligand 2) with the activation of TRP53, the mouse ortholog of human and rat TP53, in SMCs from Atg7cKO mice. In addition, Atg7cKO mice crossed with Apoe (apolipoprotein E)-deficient mice (apoeKO; Atg7cKO:apoeKO) showed reduced medial cellularity and increased TUNEL-positive cells in the descending aorta at 10 weeks of age. Intriguingly, Atg7cKO: apoeKO mice fed a Western diet containing 1.25% cholesterol for 14 weeks showed a reduced survival rate. Autopsy of the mice demonstrated the presence of aortic rupture. Analysis of the descending aorta in Atg7cKO:apoeKO mice showed increased plaque area, increased TUNEL-positive area, decreased SMC-positive area, accumulation of macrophages in the media, and adventitia and perivascular tissue, increased CCL2 expression in SMCs in the vascular wall, medial disruption, and aneurysm formation. In conclusion, our data suggest that defective autophagy in SMCs enhances atherosclerotic changes with outward arterial remodeling.

Efficacy of ipragliflozin as monotherapy or as add-on therapy with other oral antidiabetic medications for treating type 2 diabetes in Japanese patients with inadequate glycemic control: A subgroup analysis based on patient characteristics.

AIMS/INTRODUCTION: The aim of the present study was to evaluate the efficacy and safety of ipragliflozin in treating Japanese type 2 diabetes patients with inadequate glycemic control by investigating diurnal variations of blood glucose and body composition. MATERIALS AND METHODS: This was an investigator-initiated, multicenter, prospective study with a 6-month treatment period. The primary outcome investigated was change in hemoglobin A1c levels from baseline. Secondary outcomes included changes in fasting plasma glucose, insulin resistance, variations in 24-h glucose levels detected by continuous glucose monitoring, bodyweight, body composition, waist circumference and serum lipids. Adverse events were evaluated throughout the study. RESULTS: A total of 98 patients completed the study. Over the 6-month period, ipragliflozin-treated patients showed reduction in hemoglobin A1c levels by 0.3%, fasting plasma glucose levels by 13.0 mg/dL, bodyweight by 2.1 kg, body fat mass by 1.5 kg and extracellular water by 0.3 kg, as well as a decrease in systolic/diastolic blood pressures. Significant reductions from baseline in mean amplitude of glucose excursions and standard deviation, and the reduced frequency of hyperglycemia were confirmed. High-density lipoprotein cholesterol was also significantly improved. Notably, the subgroup analysis of hemoglobin A1c levels, bodyweight, waist circumference, and body composition based on age, sex and body mass index showed similar reductions within each subgroup. The incidences of adverse events and adverse drug reactions were 20.0% and 1.0%, respectively, over the 6-month period. CONCLUSIONS: Ipragliflozin is a useful oral antidiabetic medication for patients with a wide range of background characteristics.

Safety and efficacy of metformin up-titration in Japanese patients with type 2 diabetes mellitus treated with vildagliptin and low-dose metformin.

BACKGROUND: This study investigated the safety and efficacy of metformin up-titration in Japanese patients with type 2 diabetes mellitus treated with vildagliptin (100 mg/day) and low-dose metformin (500 or 750 mg/day). RESEARCH DESIGN AND METHODS: Fifty patients were randomly allocated to the control group (maintaining the initial low-dose of metformin) and the dose increase group (up-titrating of metformin to 1,500-2,250 mg/day) for 24 weeks. The primary outcome was change in HbA1c from baseline to 24 weeks. RESULTS: Among the 25 patients allocated to the dose increase group, four patients were not able to complete the study protocol because of gastrointestinal symptoms. HbA1c in the dose increase group was significantly but modestly lower than in the control group (change in HbA1c: 0.22 ± 0.57 vs. -0.15 ± 0.58%, group comparison, P < 0.05). The dose increase group did not gain weight during the study period, and no hypoglycemic events were reported in both groups. The rate of gastrointestinal symptoms in the dose increase group was profoundly higher than in the control group (32 vs. 0%, P < 0.01). CONCLUSIONS: In Japanese patients with type 2 diabetes treated with vildagliptin and low-dose metformin, metformin up-titration significantly but modestly improved glycemic control without hypoglycemia and weight gain.

Relationships Among Conventional Cardiovascular Risk Factors and Lifestyle Habits With Arterial Stiffness in Type 2 Diabetic Patients.

BACKGROUND: While conventional cardiovascular risk factors and certain lifestyle habits are associated with arterial stiffness in patients with type 2 diabetes mellitus (T2DM), it is still unknown whether they are actually associated with arterial stiffness even after adjustment for conventional cardiovascular risk factors and lifestyle habits. The aim of this study was to identify variables that are associated with brachial-ankle pulse wave velocity (baPWV). METHODS: The study participants comprised 724 Japanese T2DM outpatients free of history of cardiovascular diseases. Lifestyle habits were analyzed using self-reported questionnaires. The associations among conventional cardiovascular risk factors and lifestyle habits with baPWV were investigated by multivariable linear regression analysis. RESULTS: The mean age of the study subjects was 57.8 ± 8.6 years, and 62.8% of those were males. The mean HbA1c was 7.0±1.0%, and the estimated duration of T2DM was 9.9 ± 7.2 years. Multiple linear regression analysis that included age and gender demonstrated that age and male sex were positively associated with baPWV. In a model adjusted for numerous conventional cardiovascular risk factors and lifestyle habits, age, duration of T2DM, systolic blood pressure, serum uric acid, urinary albumin excretion and poor sleep quality were positively associated with baPWV, while body mass index was negatively associated with baPWV. CONCLUSIONS: In Japanese T2DM, in addition to several conventional cardiovascular risk factors, poor sleep quality was associated with baPWV even after adjustment for numerous conventional cardiovascular risk factors and lifestyle habits.

Relationships between lifestyle patterns and cardio-renal-metabolic parameters in patients with type 2 diabetes mellitus: A cross-sectional study.

INTRODUCTION: While individuals tend to show accumulation of certain lifestyle patterns, the effect of such patterns in real daily life on cardio-renal-metabolic parameters remains largely unknown. This study aimed to assess clustering of lifestyle patterns and investigate the relationships between such patterns and cardio-renal-metabolic parameters. PARTICIPANTS AND METHODS: The study participants were 726 Japanese type 2 diabetes mellitus (T2DM) outpatients free of history of cardiovascular diseases. The relationship between lifestyle patterns and cardio-renal-metabolic parameters was investigated by linear and logistic regression analyses. RESULTS: Factor analysis identified three lifestyle patterns. Subjects characterized by evening type, poor sleep quality and depressive status (type 1 pattern) had high levels of HbA1c, alanine aminotransferase and albuminuria. Subjects characterized by high consumption of food, alcohol and cigarettes (type 2 pattern) had high levels of γ-glutamyl transpeptidase, triglycerides, HDL-cholesterol, blood pressure, and brachial-ankle pulse wave velocity. Subjects characterized by high physical activity (type 3 pattern) had low uric acid and mild elevation of alanine aminotransferase and aspartate aminotransferase. In multivariate regression analysis adjusted by age, gender and BMI, type 1 pattern was associated with higher HbA1c levels, systolic BP and brachial-ankle pulse wave velocity. Type 2 pattern was associated with higher HDL-cholesterol levels, triglycerides, aspartate aminotransferase, ɤ- glutamyl transpeptidase levels, and diastolic BP. CONCLUSIONS: The study identified three lifestyle patterns that were associated with distinct cardio-metabolic-renal parameters in T2DM patients. TRIAL REGISTRATION: UMIN000010932.

Relationship between dietary patterns and risk factors for cardiovascular disease in patients with type 2 diabetes mellitus: a cross-sectional study.

BACKGROUND: While some dietary patterns are associated with the incidence of type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD), the relationship between dietary pattern and risk factors for CVD in patients with T2DM remains to be clarified. The aim of this study was to identify dietary patterns and investigate the relationship between dietary patterns and potential risk factors for CVD in patients with T2DM. METHODS: The study participants comprised 726 Japanese T2DM outpatients free of history of CVD. Life styles were analyzed using self-reported questionnaires. The relationship between dietary patterns, identified by factor analysis, and potential risk factors for CVD was investigated by linear and logistic regression analyses. RESULTS: Six dietary patterns were identified by factor analysis. Especially, three dietary patterns were associated with risk factors for CVD. The "Seaweeds, Vegetables, Soy products and Mushrooms" pattern, characterized by high consumption of seaweeds, soy products and mushrooms, was associated with lower use of diabetes medication and healthier lifestyles. The "Noodle and Soup" pattern, characterized by high consumption of noodle and soup was associated with higher body mass index, alanine aminotransferase, aspartate aminotransferase, γ-glutamyl transpeptidase and triglyceride levels. The "Fruit, Dairy products and Sweets" pattern was associated with lower γ-glutamyl transpeptidase levels, blood pressure, albuminuria and brachial-ankle pulse wave velocity. CONCLUSIONS: The findings suggested that dietary patterns correlated with risk factors for CVD in T2DM patients.

Effect of Repetitive Glucose Spike and Hypoglycaemia on Atherosclerosis and Death Rate in Apo E-Deficient Mice.

Epidemiological data suggest that postprandial hyperglycaemia and hypoglycaemia are potential risk factors for cardiovascular disease. However, the effects of repetitive postprandial glucose spikes, repetitive hypoglycaemia, and their combination on the progression of atherosclerosis remain largely unknown. The present study investigated the effects of rapid rises and falls in glucose, and their combination, on the progression of atherosclerosis in apolipoprotein (apo) E-deficient mice. In this study, apo E-deficient mice with forced oral administration of glucose twice daily for 15 weeks were used as a model of repetitive postprandial glucose spikes, and apo E-deficient mice given an intraperitoneal injection of insulin once a week for 15 weeks were used as a model of repetitive hypoglycaemia. In addition, we established a model of both repetitive postprandial glucose spikes and hypoglycaemia by combining the above interventions. Atherosclerosis was evaluated in all mice by oil red O staining. Administration of ipragliflozin, a selective inhibitor of sodium-glucose cotransporter 2, in the mouse model of repetitive glucose spikes inhibited the progression of atherosclerosis, whereas long-term repetitive glucose spikes, repetitive hypoglycaemia, and their combination had no significant impact on atherosclerosis. However, repetitive hypoglycaemia was associated with poor survival rate. The results showed that repetitive hypoglycaemia reduces the survival rate without associated progression of atherosclerosis in apo E-deficient mice.

Poor sleep quality is associated with increased arterial stiffness in Japanese patients with type 2 diabetes mellitus.

BACKGROUND: While poor sleep quality can worsen cardiovascular risk factors such as glucose and lipid profiles in patients with type 2 diabetes mellitus (T2DM), the relationship between sleep quality and atherosclerosis remains largely unknown. The aim of this study was to examine this relationship. METHODS: The study participants comprised 724 Japanese T2DM outpatients free of history of cardiovascular diseases. The relationships between sleep quality (assessed by the Pittsburgh Sleep Quality Index (PSQI)) and various clinical and laboratory parameters were investigated. RESULTS: The mean PSQI was 5.1 ± 3.0 (±SD). Patients were divided into three groups based on the total PSQI score; subjects with good sleep quality (n = 462), average sleep quality (n = 185), and poor sleep quality (n = 77). In the age/gender-adjusted model, patients with poor sleep quality tended to be obese, evening type and depressed. However, other lifestyles showed no significant trends. Alanine aminotransferase, fasting blood glucose, HbA1c, systolic blood pressure, urinary albumin excretion, and brachial-ankle pulse wave velocity (baPWV) tended to be higher in patients with poor sleep quality. High baPWV was the only parameter that correlated with poor sleep in a model adjusted for several other lifestyle factors. CONCLUSIONS: Our study indicates that poor sleep quality in T2DM patients correlates with increased arterial wall stiffness, a marker of atherosclerosis and a risk factor for cardiovascular diseases.

Morningness-eveningness questionnaire score and metabolic parameters in patients with type 2 diabetes mellitus.

"Morningness" and "Eveningness" represent lifestyle patterns including sleep-wake patterns. Although previous studies described a relationship between the morningness-eveningness trait and glycemic control in patients with type 2 diabetes mellitus (T2DM), the mechanism underlying this association remains unknown. The study participants comprised 725 Japanese T2DM outpatients free of history of cardiovascular diseases. Various lifestyles were analyzed using self-reported questionnaires, including morningness-eveningness questionnaire (MEQ). The relationships between morningness-eveningness trait and various biochemical parameters were investigated by linear regression analysis and logistic regression analysis. We classified the study patients into three groups, morning type (n=117), neither type (n=424) and evening type (n=184). Subjects of the evening type had high levels of alanine aminotransferase, triglyceride, fasting blood glucose and HbA1c and low high-density lipoprotein-cholesterol level in a model adjusted for age and gender. Furthermore, multivariate analysis showed that the evening type was associated with high HbA1c and estimated glomerular filtration rate even after adjustment for other lifestyle factors known to affect metabolic control. The results suggest that T2DM patients with eveningness trait are under inadequate metabolic control independent of other lifestyle factors. Thus, the evening trait of T2DM patients represents an important target for intervention to ensure appropriate metabolic function.

Effects of sitagliptin or mitiglinide as an add-on to acarbose on daily blood glucose fluctuations measured by 72 h subcutaneous continuous glucose monitoring in Japanese patients with type 2 diabetes: a prospective randomized study.

OBJECTIVE: Postprandial hyperglycemia and blood glucose fluctuations increase the risk of macroangiopathy in patients with type 2 diabetes mellitus (T2DM). However, few studies have examined the effects of oral hypoglycemic drugs on blood glucose fluctuations in daily life. METHODS: Twenty-nine T2DM patients treated with acarbose were randomized to receive either sitagliptin (14 patients) or mitiglinide (15 patients) together with acarbose for 4 weeks. Patients were then switched to a combination of 10 mg mitiglinide and 0.2 mg voglibose for 4 weeks. All patients wore a continuous glucose monitoring (CGM) device for 5 - 7 days in week 3 of each treatment period. RESULTS: The percentage of blood glucose levels in the hyperglycemic range, blood glucose indices derived from 24-h CGM profiles and the glycemic parameters (HbA1c, glycated albumin and fasting plasma glucose) were significantly improved by adding sitagliptin or mitiglinide to ongoing acarbose therapy. These parameters also tended to improve in the mitiglinide/voglibose combination period. CONCLUSION: Daily blood glucose fluctuations were significantly improved by adding sitagliptin or mitiglinide to acarbose, and improved after switching to the mitiglinide/voglibose combination. Larger controlled studies are needed to verify the effects of adding sitagliptin or mitiglinide to acarbose on glucose fluctuations.

Repetitive hypoglycemia increases circulating adrenaline level with resultant worsening of intimal thickening after vascular injury in male Goto-Kakizaki rat carotid artery.

Hypoglycemia associated with diabetes management is a potential risk for cardiovascular diseases. However, the effect of hypoglycemic episodes including a surge of sympathetic activity on the progression of neointima formation after vascular injury remains largely unknown. In this study, insulin was injected intraperitoneally into nonobese diabetic Goto-Kakizaki (GK) rats, once every 3 days for 4 weeks after balloon injury of carotid artery to induce hypoglycemia. Then, we evaluated balloon injury-induced neointima formation. Insulin treatment enhanced neointima formation and increased the number of proliferating cell nuclear antigen (PCNA)-positive cells in the carotid artery. Injection of glucose with insulin prevented hypoglycemia and abrogated intimal thickening. Also, bunazosin, an α1 adrenergic receptor antagonist, prevented intimal thickening and accumulation of PCNA-positive cells induced by insulin treatment despite the presence of concomitant hypoglycemia and high adrenaline levels. Incubation of cultured smooth muscle cells with adrenaline resulted in a significant increase in their proliferation and G0/G1 to S phase progression, which was associated with activation of extracellular signal-regulated kinase, enhanced expression of cell cycle regulatory molecules such as cyclin D1, and cyclin E, and phosphorylation of retinoblastoma protein. These adrenaline-induced effects were abrogated by bunazosin. Our data indicated that increased adrenaline induced by repetitive hypoglycemia promotes intimal thickening and smooth muscle cell proliferation after endothelial denudation in GK rats.