Assessment of daily food and nutrient intake in Japanese type 2 diabetes mellitus patients using dietary reference intakes

Medical nutrition therapy for the management of diabetes plays an important role in preventing diabetes complications and managing metabolic control. However, little is known about actual eating habits of individuals with type 2 diabetic mellitus (T2DM), especially in Japan. Therefore, we sought to (1) assess the dietary intake of individuals with T2DM, and (2) characterize their intake relative to national recommendations. This cross-sectional study involved 149 patients (77 males and 72 females) aged 40-79 years with T2DM recruited at a Kyoto hospital. Dietary intake was assessed using a validated self-administered diet history questionnaire. Under-consumption, adequacy, and over-consumption, of nutrients were compared to the age- and sex-based standards of the Japanese Dietary Reference Intakes. Among the results, most notable are (1) the inadequacy of diets in men with respect to intake of vitamins and minerals, likely owing to low intake of vegetables and fruits; (2) excess contributions of fat intake to total energy in both sexes; and (3) excess consumption of sweets and beverages relative to the national average. The prevalence of diabetes complications may be increasing because of a major gap between the typical dietary intake of individuals with T2DM and dietary recommendation.

Lepr(db/db) Mice with senescence marker protein-30 knockout (Lepr(db/db)Smp30(Y/-)) exhibit increases in small dense-LDL and severe fatty liver despite being fed a standard diet

Background/Aims

The senescence marker protein-30 (SMP30) is a 34 kDa protein originally identified in rat liver that shows decreased levels with age. Several functional studies using SMP30 knockout (Smp30^Y/−) mice established that SMP30 functions as an antioxidant and protects against apoptosis. To address the potential role of SMP30 in nonalcoholic fatty liver disease (NAFLD) pathogenesis, we established Smp30^Y/− mice on a Lepr^db/db background (Lepr^db/dbSmp30^Y/− mice).

Research Design/Principal Findings

Male Lepr^db/dbSmp30^Y/− mice were fed a standard diet (340 kcal/100 g, fat 5.6%) for 16 weeks whereupon the lipid/lipoprotein profiles, hepatic expression of genes related to lipid metabolism and endoplasmic reticulum stress markers were analyzed by HPLC, quantitative RT-PCR and western blotting, respectively. Changes in the liver at a histological level were also investigated. The amount of SMP30 mRNA and protein in livers was decreased in Lepr^db/dbSmp30^Y/+ mice compared with Lepr^db/+Smp30^Y/+ mice. Compared with Lepr^db/dbSmp30^Y/+ mice, 24 week old Lepr^db/dbSmp30^Y/− mice showed: i) increased small dense LDL-cho and decreased HDL-cho levels; ii) fatty liver accompanied by numerous inflammatory cells and increased oxidative stress; iii) decreased mRNA expression of genes involved in fatty acid oxidation (PPARα) and lipoprotein uptake (LDLR and VLDLR) but increased CD36 levels; and iv) increased endoplasmic reticulum stress.

Conclusion

Our data strongly suggest that SMP30 is closely associated with NAFLD pathogenesis, and might be a possible therapeutic target for NAFLD.

Testosterone deficiency induces markedly decreased serum triglycerides, increased small dense LDL, and hepatic steatosis mediated by dysregulation of lipid assembly and secretion in mice fed a high-fat diet

OBJECTIVE

Although low serum testosterone (T) is associated with metabolic disorders, the mechanism of this association is unclear. The objective of the present study was to investigate the combined effects of T deficiency and a high-fat diet (HFD) on hepatic lipid homeostasis in mice.

MATERIALS/METHODS

Orchiectomized (ORX) mice and sham-operated (SHAM) mice were randomly divided into five groups: SHAM mice fed a standard diet (SD), SHAM mice fed HFD, ORX mice fed SD, ORX mice fed HFD, and ORX mice fed HFD with T supplementation. After 4weeks of treatment, we investigated the synthesis and secretion of lipids in the liver and detailed serum lipoprotein profiles in each group.

RESULTS

ORX mice fed HFD showed increased hepatic steatosis, markedly decreased serum triglyceride (TG) and TG-VLDL content, and increased serum very small-LDL content. Gene expression analysis revealed that ORX mice fed HFD showed significantly decreased expression of microsomal triglyceride transfer protein, lipin-1, peroxisome proliferator-activated receptor (PPAR)-α and PPAR-γ coactivator 1-α, and significantly increased sterol regulatory element-binding protein-1, diacylglycerol acyltransferase-2 and fatty acid synthase. Reduction of hepatic AMPK phosphorylation was observed in ORX mice fed HFD. These perturbations in ORX mice fed HFD were normalized to the levels of SHAM mice fed HFD by T supplementation.

CONCLUSION

T deficiency is associated with failure of lipid homeostasis mediated by altered expression of genes involved in hepatic assembly and secretion of lipids.

Effects of liraglutide on postprandial insulin and glucagon responses in Japanese patients with type 2 diabetes

This study assessed the endocrine pancreatic responses to liraglutide (0.9 mg once a day) during normal living conditions in Japanese patients with type 2 diabetes. The study included 14 hospitalized patients with type 2 diabetes. Meal tests were performed after improvement of glycemic control achieved by two weeks of multiple insulin injection therapy and after approximately two weeks of liraglutide treatment. Continuous glucose monitoring was performed to compare daily variation in glycemic control between multiple insulin injection therapy and liraglutide treatment. Liraglutide reduced plasma glucose levels after the test meals (60-180 min; p<0.05), as a result of significant increases in insulin secretion (0-180 min; p<0.05) and decreases in the incremental ratio of plasma glucagon (15-60 min; p<0.05). Continuous glucose monitoring showed that liraglutide treatment was also associated with a decrease in glucose variability. We also demonstrated that optimal glycemic control seen as a reduction in 24-h mean glucose levels and variability was obtained only with liraglutide monotherapy. In conclusion, liraglutide treatment increases insulin secretion and suppresses glucagon secretion in Japanese patients with type 2 diabetes under normal living conditions. The main therapeutic advantages of liraglutide are its use as monotherapy and its ability to decrease glucose variability.

Beneficial effect of calcium channel blockers on home blood pressure variability in the morning in patients with type 2 diabetes

Aims/Introduction

Recent studies have shown the association between blood pressure variability and cardiovascular events. The present study was designed to investigate the relationship between antihypertensive drug class and home blood pressure variability in patients with type 2 diabetes.

Materials and Methods

We compared home blood pressure variability among patients treated with calcium channel blockers (n = 44), with angiotensin II receptor blockers and/or angiotensin‐converting enzyme inhibitors (n = 159), and with calcium channel blockers combined with angiotensin II receptor blockers and/or angiotensin‐converting enzyme inhibitors (n = 183). Next, we analyzed the effect of calcium channel blockers on morning blood pressure variability using multiple linear regression analysis.

Results

Coefficient variation of morning systolic blood pressure in patients treated with calcium channel blockers was significantly lower than that in patients treated with angiotensin II receptor blockers and/or angiotensin‐converting enzyme inhibitors (P = 0.036). Multivariate linear regression analyses showed that treatment with calcium channel blockers was significantly correlated with coefficient variation of morning systolic blood pressure (β = −0.264, P = 0.001).

Conclusions

The present study implies a possibility for validity on selecting calcium channel blockers in hypertensive patients with type 2 diabetes to reduce home blood pressure variability.

Could home arterial stiffness index be a novel marker for arterial stiffness in patients with type 2 diabetes?

Recent studies suggested that home arterial stiffness index (HASI) may be a new measure of arterial stiffness. The aim of this study was to investigate whether HASI is more strongly associated with arterial stiffness than is pulse pressure (PP) and thus a more suitable tool than PP for evaluating arterial stiffness in patients with type 2 diabetes. We evaluated the relationship of HASI or PP with pulse wave velocity (PWV) as well as with major cardiovascular risk factors in 332 patients with type 2 diabetes. Furthermore, we compared the area under the receiver-operator characteristic curve (AUC) of HASI or PP for PWV. Morning PP was positively associated with PWV (r=0.303, P<0.0001), while morning HASI was not (r=-0.006, P=0.9063). Multiple regression analysis demonstrated that morning PP (β=0.179, P=0.0210), but not morning HASI (β=-0.040, P=0.5036), was independently associated with PWV. The AUCs (95% confidence interval (CI)) of morning HASI and morning PP for arterial stiffness were 0.510 (0.448-0.573) (P=0.745) and 0.638 (0.578-0.698) (P<0.0001), respectively. The AUC (95% CI) of morning HASI for arterial stiffness was significantly less than that of morning PP (P=0.0005). In conclusion, morning HASI is less correlated with PWV than is morning PP in patients with type 2 diabetes.

Serum pepsinogen I/II ratio is correlated with albuminuria in patients with type 2 diabetes

Helicobacter pylori infection, which is a common cause of atrophic gastritis, has been reported to represent a causal factor increasing the vascular damage and consequent albuminuria. On the other hand, decreased serum pepsinogen (PG) I/II ratio can be used to assess gastric mucosal atrophy. To the best of our knowledge, there are no studies investigating the correlation between PG I/II ratio and diabetic nephropathy. Therefore, we investigated a relationship between PG I/II ratio and degree of urinary albumin excretion (UAE) in patients with type 2 diabetes. We evaluated relationships between PG I/II ratio and degree of UAE or estimated glomerular filtration rate as well as various factors, including age, body mass index, blood pressure, hemoglobin A1c, serum lipid concentrations, uric acid or C-reactive protein in 333 consecutive patients with type 2 diabetes. PG I/II ratio correlated positively with logarithm of UAE in all patients (r = 0.174, P = 0.0016) and in patients without Helicobacter pylori infection (r = 0.352, P < 0.0001). Multiple regression analysis identified that PG I/II ratio correlated independently with logarithm of UAE in all patients (β = 0.264, P = 0.0005) and in patients without Helicobacter pylori infection (β = 0.295, P = 0.0022). These data suggest that serum PG I/II ratio is correlated with diabetic nephropathy.

Home blood pressure variability on one occasion is a novel factor associated with arterial stiffness in patients with type 2 diabetes

Recent studies have suggested that not only mean blood pressure but also variability in blood pressure might be related to cardiovascular disease. The aim of this study was to investigate the association between home blood pressure variability on one occasion and markers of arterial stiffness in patients with type 2 diabetes. We investigated the relationship between the s.d. of clinic- or home-measured systolic blood pressure on one occasion and pulse wave velocity (PWV) in 332 patients with type 2 diabetes, and we evaluated whether the SD of clinic- or home-measured systolic blood pressure on one occasion was an independent determinant of PWV by multivariate linear regression analysis, after adjustment for known risk factors for arterial stiffness, including sex, age, duration of diabetes, body mass index, hemoglobin A1c, serum total cholesterol, triglycerides, smoking status, drinking alcohol, presence of antihypertensive medication, average systolic blood pressure and heart rate. Age, average morning home-measured systolic blood pressure, heart rate and PWV (r=0.259, P<0.0001) were positively correlated with the s.d. of morning home blood pressure on one occasion. Multiple regression analysis demonstrated that age, average morning home-measured systolic blood pressure (P=0.0019), heart rate and the s.d. of morning home-measured systolic blood pressure on one occasion (P=0.0159) were independently associated with PWV. In conclusion, home blood pressure variability on one occasion was correlated with PWV, independent of other known risk factors, in Japanese patients with type 2 diabetes.

Andropausal symptoms in men with Type 2 diabetes

AIMS

Serum androgen concentration is reported to be low in patients with Type 2 diabetes. There have been no studies comparing andropausal symptoms such as sleep disturbance, depression, erectile dysfunction and lower urinary tract symptoms simultaneously between men with Type 2 diabetes and subjects without diabetes.

METHODS

We compared andropausal symptom scores such as the Pittsburgh Sleep Quality Index, the Self-Rating Depression Scale, the International Index of Erectile Function and the International Prostate Symptom Score in 296 men with Type 2 diabetes and in 267 subjects without diabetes. Furthermore, we evaluated relationships of andropausal symptom scores to various anthropometric factors and compared andropausal symptom scores according to diabetic complications in men with Type 2 diabetes.

RESULTS

Andropausal symptom scores such as the Pittsburgh Sleep Quality Index, the Self-Rating Depression Scale, the International Index of Erectile Function and the International Prostate Symptom Score were 4.2 ± 2.6 vs. 5.0 ± 3.3, P<0.01 by unpaired Student's t-test, 34.8 ± 8.2 vs. 38.4 ± 9.3, P<0.0001, 11.5 ± 6.4 vs. 9.9 ± 6.9, P<0.01 and 7.3 ± 6.7 vs. 9.0 ± 7.1, P<0.01 in subjects without diabetes and in patients with diabetes, respectively. The Pittsburgh Sleep Quality Index was higher in patients with neuropathy than without. The Self-Rating Depression Scale was higher in patients with advanced retinopathy. The International Index of Erectile Function was lower in patients with advanced retinopathy and nephropathy. The International Index of Erectile Function was lower and the International Prostate Symptom Score was higher in patients with cardiovascular disease than without.

CONCLUSIONS

Our data demonstrated that men with Type 2 diabetes have higher prevalence of andropausal symptoms, especially those with diabetic complications.

Serum allograft inflammatory factor-1 is a novel marker for diabetic nephropathy

AIMS

Recent studies have identified macrophage-mediated injury as an important component in the development of diabetic nephropathy. The aim of this study was to investigate the correlations between serum allograft inflammatory factor-1 (AIF-1) concentration, which is a marker of activated macrophages, and diabetic nephropathy.

METHODS

Serum AIF-1 concentrations were measured in 284 patients with type 2 diabetes. We evaluated relationships of serum AIF-1 concentrations to degree of urinary albumin excretion (UAE) or estimated glomerular filtration rate (eGFR) in univariate and multivariate linear regression analyses.

RESULTS

Serum AIF-1 concentrations positively correlated with logarithm of UAE (r=0.260, P<0.0001), whereas serum AIF-1 concentrations inversely correlated with eGFR (r=-0.312, P<0.0001). Mean serum AIF-1 concentration was higher in patients with macroalbuminuria than that in patients with normoalbuminuria (P=0.0001) or that in patients with microalbuminuria (P=0.0093). In multivariate linear regression analyses, serum AIF-1 concentrations were independently correlated with logarithm of UAE (β=0.213, P=0.0120) and with eGFR (β=-0.286, P=0.0011).

CONCLUSIONS

Serum AIF-1 concentration correlated with albuminuria and eGFR in patients with type 2 diabetes and it could be a marker of diabetic nephropathy as well as activated macrophages.

The serum concentration of allograft inflammatory factor-1 is correlated with metabolic parameters in healthy subjects

Obesity is associated with low-grade chronic inflammation characterized by inflamed adipose tissue with increased infiltration of macrophages. The aim of this study was to investigate the correlations between the serum concentration of allograft inflammatory factor-1 (AIF-1), which is a marker of activated macrophages, and metabolic parameters. The serum AIF-1 concentrations were measured in 303 healthy subjects (163 men and 140 women). We then evaluated the relationships between the serum AIF-1 concentrations and metabolic parameters, including fasting plasma glucose levels, serum lipid concentration, uric acid concentration, and waist circumference. The serum AIF-1 concentrations positively correlated with levels of fasting plasma glucose (r = 0.159, P =.0056), hemoglobin A(1c) (r = 0.169, P = .0032), triglycerides (r = 0.137, P = .0172), and uric acid (r = 0.146, P = .0108) and with waist circumference (r = 0.221, P = .0001) and body mass index (r = 0.185, P = .0012), whereas the serum AIF-1 concentrations inversely correlated with high-density lipoprotein cholesterol level (r = -0.178, P = .0019). Stepwise multiple regression analysis demonstrated that hemoglobin A(1c) level (β = .133, F = 5.490, P < .05) and waist circumference (β = .197, F = 11.954, P < .05) were independent predictors of the serum AIF-1 concentrations. The serum AIF-1 concentrations correlated with clinical and biochemical metabolic parameters. Allograft inflammatory factor-1 may be a significant predictor of activated macrophages as well as cardiovascular disease in humans.

Atrophic gastritis is associated with coronary artery disease

Atrophic gastritis is characterized by chronic inflammation of gastric mucosa by Helicobacter pylori infection and other factors. Helicobacter pylori infection has been linked to coronary artery disease. To our knowledge, however, no reports are available on the relationship between atrophic gastritis and coronary artery disease. In this study, we investigated the relationship between atrophic gastritis, which is diagnosed based on serum pepsinogen levels (pepsinogen I ≤ 70 ng/mL and pepsinogen I/II ratio ≤ 3.0), and the prevalence of coronary artery disease in general Japanese population. Among 2,633 study subjects, 531 subjects (20.2%) were diagnosed as atrophic gastritis. The prevalence of coronary artery disease was higher in the atrophic gastritis-positive group than that in the atrophic gastritis-negative group (5.8% vs 2.8%, p = 0.0005). Multiple logistic regression analysis demonstrated that atrophic gastritis was independently associated with coronary artery disease (odds ratio, 1.67; 95% confidence interval, 1.03–2.72), after adjustment for age, sex, obesity, hypertension, diabetes mellitus, dyslipidemia, hyperuricemia, and habits of smoking and drinking. These results suggest that atrophic gastritis is an independent risk factor for coronary artery disease. Chronic inflammation of gastric mucosa may be associated with the prevalence of coronary artery disease.

Toe-brachial index is associated more strongly with albuminuria or glomerular filtration rate than ankle-brachial index in patients with type 2 diabetes

The aim of this study was to investigate whether toe-brachial index (TBI) is more strongly associated with albuminuria or estimated glomerular filtration rate (eGFR) than ankle-brachial index (ABI), and thus is a more suitable tool for evaluating the association between peripheral artery disease (PAD) and diabetic nephropathy than ABI in patients with type 2 diabetes. We evaluated the relationships between ABI or TBI and the degree of urinary albumin excretion or eGFR, as well as the major cardiovascular risk factors, in 390 patients with type 2 diabetes. Furthermore, we compared the area under the receiver-operator characteristic curve (AUC) of TBI or ABI for albuminuria or chronic kidney disease (CKD). Low-density lipoprotein cholesterol was negatively associated with ABI. Age and duration of diabetes were negatively associated with TBI, and diastolic blood pressure and high-density lipoprotein cholesterol were positively associated with TBI. Log (urinary albumin excretion) was associated more strongly with TBI (r=-0.265, P<0.0001) than with ABI (r=-0.132, P=0.0111), and eGFR was positively associated with TBI (r=0.195, P=0.0002) but not with ABI (r=0.023, P=0.6571). The AUCs of TBI for albuminuria (P=0.0002) and CKD (P=0.0322) were significantly greater than those of ABI. In conclusion, TBI is associated more strongly with albuminuria and eGFR than ABI in patients with type 2 diabetes. Our study suggests that TBI may be a more suitable tool for evaluating the association between PAD and diabetic nephropathy than ABI in patients with type 2 diabetes.

Pepsinogen I/II ratio is related to glucose, triacylglycerol, and uric acid levels

OBJECTIVE

Under- and overnutrition are associated with a worse prognosis and constitute independent risk factors for morbidity and mortality. It is increasingly important to understand the factors that affect nutritional and metabolic statuses. The purpose of this study was to assess the relation between the pepsinogen I/II ratio and several biochemical markers.

METHODS

A cross-sectional study was performed in 1985 subjects who underwent a health screening test. Subjects had no medications for hyperuricemia, dyslipidemia, diabetes mellitus, or hypertension. All subjects were classified into two groups. Subjects with a pepsinogen I/II ratio below 3 were defined as having atrophic gastritis. The relations between the pepsinogen I/II ratio and several biochemical markers, including total cholesterol, triacylglycerol, uric acid, cholinesterase, and glucose levels, were evaluated.

RESULTS

The presence of atrophic gastritis was significantly associated with age, smoking status, alcohol consumption, body mass index, and triacylglycerol, uric acid, cholinesterase, and hemoglobin levels. Multiple linear regression analysis demonstrated that the pepsinogen I/II ratio was an independent determinant of glucose level (β = 0.104, P < 0.0001), triacylglycerol level (β = 0.072, P = 0.0014), uric acid level (β = 0.048, P = 0.0138), and hemoglobin (β = 0.037, P = 0.0429) after adjustments for age, sex, smoking status, alcohol consumption, and body mass index.

CONCLUSION

The pepsinogen I/II ratio was related to glucose, triacylglycerol, and uric acid levels. Such an association fosters the idea that a decreased pepsinogen I/II ratio seems favorable for the prevention of overnutrition.

High plasma 5-hydroxyindole-3-acetic acid concentrations in subjects with metabolic syndrome

OBJECTIVE

Serotonin mediates vasoconstriction and induces the activation of platelets, which may promote atherosclerosis. The aim of this study was to investigate whether plasma 5-hydroxyindole-3-acetic acid (5-HIAA; a derivative end product of serotonin) concentrations are high in subjects with metabolic syndrome (MetS) and to investigate the relationship between plasma 5-HIAA concentrations and clinical and biochemical metabolic parameters.

RESEARCH DESIGN AND METHODS

Plasma 5-HIAA concentrations were measured in 311 subjects (152 men and 159 women) recruited from the Oike Clinic, which provides regular health check-ups for employees. We evaluated the relationship between plasma 5-HIAA concentrations and clinical and biochemical metabolic parameters, including waist circumference, serum lipid concentrations, fasting plasma glucose, or blood pressure.

RESULTS

Plasma 5-HIAA concentrations were higher in subjects with MetS than in those without, in both men (6.5 ± 4.4 vs. 4.9 ± 1.3 ng/mL, P < 0.005) and women (7.9 ± 6.5 vs. 5.2 ± 1.6 ng/mL, P < 0.005). In men, fasting plasma glucose (r = 0.197, P = 0.0146) was positively correlated, whereas HDL cholesterol (r = -0.217, P = 0.0071) was negatively correlated, with logarithmic (log) (plasma 5-HIAA concentrations). In women, triglycerides (r = 0.252, P = 0.0013) and fasting plasma glucose (r = 0.344, P < 0.0001) were positively correlated, whereas HDL cholesterol (r = -0.328, P < 0.0001) was negatively correlated, with log (5-HIAA concentrations). Furthermore, log (plasma 5-HIAA concentrations) were higher in subjects with more components of MetS.

CONCLUSIONS

Plasma 5-HIAA concentrations are high in subjects with MetS, suggesting the potential importance of serotonin in the development of cardiovascular disease in MetS.

Eosinophil count is positively correlated with coronary artery calcification

Recent studies suggested that allergic disorders and increased eosinophil count were associated with atherosclerosis. The purpose of this study was to assess the relationship between eosinophil count and coronary artery calcification (CAC). We performed a cross-sectional study in 1363 consecutive participants with clinical suspicion of coronary heart disease (CHD). We evaluated the relationships between CAC score determined by multislice CT and peripheral eosinophil count as well as major cardiovascular risk factors, including age, body mass index, smoking status, hypertension, dyslipidemia, diabetes mellitus (DM), high-sensitivity C-reactive protein and estimated glomerular filtration rate (eGFR). Sex (P=0.0004), hypertension (P=0.0002), dyslipidemia (P=0.0004) and DM (P=0.0061) were associated with log(CAC+1), respectively. Positive correlations were found between log(CAC+1), and age (r=0.325, P<0.0001) and eosinophil count (r=0.165, P<0.0001). Negative correlations were found between log(CAC+1) and eGFR (r=-0.166, P<0.0001). Multivariate linear regression analysis demonstrated that age (β=0.314, P<0.0001), sex (β=0.124, P<0.0001), hypertension (β=0.084, P=0.0008), DM (β=0.108, P<0.0001), eGFR (β=-0.079, P=0.0021) and eosinophil count (β=0.147, P<0.0001) were independent determinants of log(CAC+1). In conclusion, eosinophil count correlated positively with CAC in participants with clinical suspicion of CHD.

Visit-to-visit variability in systolic blood pressure is correlated with diabetic nephropathy and atherosclerosis in patients with type 2 diabetes

OBJECTIVE

Recent studies make remarks on the effect of variability in systolic blood pressure (SBP) on the development of cardiovascular disease. The aim of this study was to investigate the relationship between the variability in SBP and the degree of diabetic nephropathy and atherosclerosis in patients with type 2 diabetes.

METHODS

We measured SBP in 422 consecutive patients with type 2 diabetes at every visit during a year, and we calculated the coefficient of variation (CV) of SBP. Then, we evaluated relationships of variability of SBP to degree of urinary albumin excretion (UAE), which is a useful marker for cardiovascular disease as well as diabetic nephropathy, ankle-brachial index (ABI) and pulse wave velocity (PWV).

RESULTS

CV of SBP positively correlated with logUAE (r=0.210, P<0.0001) or PWV (r=0.409, P<0.0001), whereas CV of SBP inversely correlated with ABI (r=-0.098, P=0.0463). Multiple regression analysis demonstrated that CV of SBP independently correlated with logUAE (β=0.149, P=0.0072), PWV (β=0.337, P<0.0001) or ABI (β=-0.162, P=0.0101).

CONCLUSIONS

Not only average SBP but also variability in SBP is correlated with diabetic nephropathy and atherosclerosis in patients with type 2 diabetes.

Pancreatic insulin release in vitamin C-deficient senescence marker protein-30/gluconolactonase knockout mice

We recently identified senescence marker protein-30 as the lactone-hydrolyzing enzyme gluconolactonase, which is involved in vitamin C biosynthesis. In this study, we investigated the effects of vitamin C on insulin secretion from pancreatic β-cells using senescence marker protein-30/gluconolactonase knockout mice. In intraperitoneal glucose tolerance tests, vitamin C-deficient senescence marker protein-30/gluconolactonase knockout mice demonstrated impaired glucose tolerance with significantly lower blood insulin levels at 30 and 120 min post-challenge than in wild type mice (p<0.01-0.05). In contrast, vitamin C-sufficient senescence marker protein-30/gluconolactonase knockout mice demonstrated significantly higher blood glucose and lower insulin only at the 30 min post-challenge time point (p<0.05). Senescence marker protein-30/gluconolactonase knockout mice showed enhanced insulin sensitivity regardless of vitamin C status. Static incubation of islets revealed that 20 mM glucose-stimulated insulin secretion and islet ATP production were significantly decreased at 60 min only in vitamin C-deficient SMP30/GNL knockout mice relative to wild type mice (p<0.05). These results indicate that the site of vitamin C action lies between glycolysis and mitochondrial oxidative phosphorylation, while SMP30 deficiency itself impairs the distal portion of insulin secretion pathway.

Risk factors for development of diabetes mellitus, hypertension and dyslipidemia

We investigated the risk factors for the development of diabetes mellitus, hypertension and dyslipidemia simultaneously in a community-based observational cohort study (n=4304). When hypertension or dyslipidemia was present at baseline, hazard ratio (95% CI) of developing diabetes mellitus at year 5 is 3.014 (2.131-4.264) or 2.112 (1.520-2.936), respectively.

Intervention with delivery of diabetic meals improves glycemic control in patients with type 2 diabetes mellitus

The aim of this study was to investigate the effects of a diabetic meal delivery system on glycemic control over a 12 month period in patients with type 2 diabetes. A total of 77 patients with type 2 diabetes were assigned randomly into three dietary intervention groups: group M, diabetic meal delivery; group D, individual dietary counseling; and group C, conventional dietary education. In group M, HbA_1c levels decreased significantly from 8.2 ± 1.2% to 7.4 ± 0.8% after 12 months (p<0.05), while in group D, HbA_1c levels decreased significantly throughout the entire 12 month period, from 8.5 ± 1.7% at baseline to 7.4 ± 1.1% at the endpoint. Similarly, fasting blood glucose (FBG) levels decreased significantly between 1 and 12 months in group M (p<0.05), and decreased significantly during the entire 12 month period in group D (p<0.01). There were no significant changes in either HbA_1c or FBG levels in group C. This study provides evidence that intervention with delivery of diabetic meals to patients with type 2 diabetes can be equally effective for achieving glycemic control as individual dietary counselling by a dietitian. Diabetic meal delivery can therefore be used successfully to provide diabetes education to outpatients.

Randomized controlled trial of two forms of self-management group education in Japanese people with impaired glucose tolerance

The aim of this study was to determine the effectiveness of education on diabetes prevention in subjects with impaired glucose tolerance. A total of 100 subjects of impaired glucose tolerance with hemoglobin A1c (HbA1c) levels ≥5.5 to <6.1% were assigned randomly to either support or control groups. All subjects received education in 8 sessions over a 6-month period. The support group consisted of 10 members collaborating with a dietitian or a nurse who learned coping skills by employing a participant-centered approach. Participants in the support group were required to keep a diary that monitored weight, food intake and blood glucose levels, while the control group attended several lectures. Subjects assigned to the support group had a reduction in mean HbA1c levels from 5.77 ± 0.36% at baseline to 5.39 ± 0.24% at the endpoint (p<0.01). Weight, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) levels also decreased (p<0.01) in the support group, whereas subjects in the control group had no observable reduction in these indices. After intervention, participants of the support group had improvements in their 2-h post-meal blood glucose levels. Support group education can be effective for improving glycemic control in participants when carried out in collaboration with educators and other team members.

Relationship between cardio-ankle vascular index (CAVI) and coronary artery calcification (CAC) in patients with type 2 diabetes mellitus

Early detection of atherosclerosis is important for patients with type 2 diabetes mellitus because cardiovascular disease (CVD) is a main cause of death in these people. In this study, we investigated the relationship between an arterial stiffness parameter called cardio-ankle vascular index (CAVI) and coronary artery calcification (CAC). We performed a cross-sectional study in 371 type 2 diabetic patients with clinical suspicion of coronary heart disease (CHD). We evaluated the relationships between CAVI and CAC score determined by multislice computed tomography as well as major cardiovascular risk factors, including age, body mass index, hemoglobinA1c and the Framingham CHD risk score. CAVI was correlated with age (r = 0.301, p < 0.0001), uric acid (r = 0.236, p < 0.0001), estimated glomerular filtration rate (r = -0.145, p = 0.0166), CHD risk score (r = 0.327, p < 0.0001) and log (CAC + 1) (r = 0.303, p < 0.0001). The area under the receiver operating characteristic curve for CAVI was higher than that of CHD risk score in predicting CAC >0, CAC >100, CAC >400, or CAC >1000. CAVI is positively correlated with CAC, and is considered to be a useful method to detect CAC.

Uncontrolled home blood pressure in the morning is associated with nephropathy in Japanese type 2 diabetes

The purposes of this study were to investigate the state of blood pressure control level and to investigate the relationship between blood pressure control level and nephropathy in Japanese type 2 diabetes. We measured clinic and home blood pressure in 923 type 2 diabetic patients. According to the criteria for hypertension in the Japanese Society of Hypertension Guidelines 2009, patients were classified into four groups by clinic systolic blood pressure (130 mmHg) and morning systolic blood pressure (125 mmHg), as follows: controlled hypertension (CH), white-coat hypertension (WCH), masked hypertension (MH), and sustained hypertension (SH). Of all patients, 13.9, 12.6, 13.3, and 60.2% were identified as having CH, WCH, MH, and SH, respectively. The average number of drugs prescribed was 1.8. We assessed the association between blood pressure control level and nephropathy in diabetic patients. The degree of urinary albumin excretion and the prevalence of nephropathy in diabetic patients were higher in MH and SH groups than those in the CH group. The majority of patients had poor blood pressure control, regardless of ongoing conventional antihypertensive therapy, and diabetic patients with MH and SH were associated with nephropathy. It is suggested that more aggressive antihypertensive treatment is recommended to prevent nephropathy in diabetic patients.