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Tohru Funahashi

Publications and source records attributed to Tohru Funahashi.

At least 55 records · Page 3Linked to original sources
PubMed2005

Pioglitazone improves left ventricular diastolic function in patients with essential hypertension.

BACKGROUND: Left ventricular (LV) hypertrophy and diastolic dysfunction, which are common cardiac consequences of hypertension, are modified by insulin resistance. The present study assessed the hypothesis that primary treatment of insulin resistance may reverse such cardiac changes in hypertensive patients. METHODS: A total of 30 patients with essential hypertension were enrolled in this study. In echocardiographic examinations, LV mass index, the peak velocity ratio of early diastolic to atrial filling (E/A), and the E-wave deceleration time (DcT) were determined. Insulin sensitivity test with steady-state plasma glucose (SSPG) method, oral glucose tolerance test, and blood samplings for measurement of adiponectin and matrix metalloproteinase (MMP)-2 were also performed. Six months after treatment with pioglitazone (30 mg/day), an insulin sensitizer, these examinations were repeated. RESULTS: Pioglitazone significantly increased E/A and decreased DcT, without a change in LV mass index. These improvements in diastolic properties were much greater in subjects with a marked (>or==3.3 mmol/L) decrease in SSPG (n=11) than the others (n=19), although the decrease in glucose levels did not differ between the two groups. In addition, the changes in E/A and DcT were closely correlated with the decrease in SSPG. Pioglitazone treatment significantly elevated plasma adiponectin and MMP-2 levels, and the increase in MMP-2 was positively correlated with the increase in adiponectin. CONCLUSIONS: The present findings demonstrate that pioglitazone improves LV diastolic function without LV mass regression in hypertensive patients in proportion to the amelioration of insulin resistance. These findings suggest that increased adiponectin and MMP may be involved in the beneficial effect of pioglitazone on diastolic function.

Adiponectin↗
PubMed2005

Lifestyle modification improves risk factors in type 2 diabetes relatives.

AIMS: To investigate the short-term (16 weeks) effect of lifestyle intervention on insulin sensitivity, anthropometric and metabolic variables in non-diabetic first-degree relatives of type 2 diabetic patients (FDR). METHODS: Seventy-seven (49 male, 28 female) FDR were allocated to one of three groups, diet (D-group; n = 25), diet and exercise (DE-group; n = 30) or control group (C-group; n = 22). Lifestyle counselling was based on current nutrition recommendations, including increased intake of fatty fish and low glycaemic index foods. Group counselling was given on two occasions with follow-up through telephone interviews every 10 days. Assessments included insulin sensitivity index (Si), anthropometry, lipid parameters, circulating leptin and adiponectin levels. RESULTS: The D-group reduced total cholesterol (-0.31 mmol/l, P = 0.024), LDL cholesterol (-0.22 mmol/l, P = 0.021) and apolipoprotein B (-9.5 mg/dl, P = 0.009) levels, whereas the DE-group decreased body weight (-2.1%, P = 0.030) and waist circumference (-3.0 cm, P < 0.001) versus controls. A 13% reduction in fasting insulin was observed in the DE-group, but no significant improvement in Si in D-group or DE-group was observed. A subgroup, adherent to diet and who increased exercise, significantly improved Si and lipid profile. CONCLUSIONS: The improved metabolic risk profile in FDR suggests that lifestyle changes can be effective in individuals at high risk to develop type 2 diabetes and cardiovascular disease.

Adult↗
PubMed2005

Levels of the adipocyte-derived plasma protein, adiponectin, have a close relationship with atheroma.

INTRODUCTION: Inflammation is a key process in atherosclerotic formation. Structural changes in the carotid arterial wall including detection of focal plaques are measured as the intima-media thickness (IMT) providing an index of atheroma. Coronary arterial plaques may be considered as vascular structural changes. Distensibility of the arteries can be assessed by functional changes in pulse wave velocity (PWV) providing an index of sclerosis. Adiponectin has potential antiatherosclerotic properties. We hypothesized that adiponectin was associated with atherosclerotic vascular changes involved in inflammation. MATERIALS AND METHODS: We enrolled 142 patients with coronary artery disease (CAD) and 108 control patients, matched for age, sex, and body mass index (BMI) with CAD patients. We investigated the relationship between adiponectin, C-reactive protein (CRP), and atherosclerotic vascular changes. RESULTS: CRP (p=0.0009), high-density lipoprotein cholesterol (HDL-C; p=0.02), and IMTmax (p=0.02) were determinants of adiponectin independent of glucose intolerance (p=0.0001), BMI (p=0.002), and CAD (p=0.03), all of which have been significantly associated with adiponectin (r=0.38). Adiponectin was not correlated with PWV. CRP, glucose intolerance, and HDL-C that correlated with adiponectin were inversely correlated with IMTmax and CAD. CRP was negatively correlated with HDL-C (r=-0.24, p=0.0002) and positively correlated with glucose intolerance (r=0.15, p=0.01). CONCLUSIONS: Adiponectin has a close relationship with CRP, IMTmax, CAD, HDL-C, and other established risk factors. CRP, glucose intolerance, and HDL-C are common mediators between adiponectin and atheromatous vascular changes, which are contrary to each other. The exacerbation of atherogenesis may be involved in a decrease of adiponectin through abnormal glyco- and lipid-metabolism by promoting inflammation.

Adiponectin↗
PubMed2005

Resting metabolic rate is an important predictor of serum adiponectin concentrations: potential implications for obesity-related disorders.

BACKGROUND: Little is known about the regulation of adiponectin. Animal studies suggest local regulation by adipocytokines or alterations in energy expenditure, and studies in humans suggest regulation by alcohol intake and ethnicity. OBJECTIVE: To identify regulators of adiponectin in humans, we measured resting metabolic rate (RMR), serum adiponectin, glucose, insulin, triacylglycerol, alcohol intake, and anthropometric indexes in 457 white patients with overweight or obesity. DESIGN: A cross-sectional design was used, and multivariate regression analysis was performed with adiponectin as the dependent variable and potential predictors as independent variables. RESULTS: Simple linear analyses showed significant associations between adiponectin and sex, with a standardized coefficient of -0.38 (women compared with men) and an explanation of variation of the model (R(2)) of 14%; age (0.21; 4%); RMR (-0.52; 27%); fat-free mass (-0.40; 16%); fat mass (-0.16; 2%); visceral fat (-0.24; 6%; computed tomography at L4-L5); fasting triacylglycerol (-0.28; 8%); and insulin resistance (-0.38; 14%; homeostasis model assessment). Adiponectin and alcohol were not associated (-0.04; 0%). Multivariate analyses, which allowed adjustment for confounding, showed that RMR is the most important predictor of adiponectin (-0.31; 29%), followed successively by insulin resistance (-0.16; 31%; model containing RMR and insulin resistance), fat mass (0.20; 34%), age (0.34; 35%), visceral fat (-0.34; 40%), and fasting triacylglycerol (-0.12, 41%). CONCLUSIONS: Low resting metabolism (RMR) is associated with high serum adiponectin. We speculate that subjects with low RMR, who are theoretically at greater risk of obesity-related disorders, are especially protected by adiponectin.

Adiponectin↗
PubMed2005

Hypoadiponectinemia is associated with coronary artery spasm in men.

BACKGROUND: The relationship between adiponectin and coronary spastic angina (CSA), both of which are closely involved in coronary endothelial dysfunction, has not been elucidated. METHODS AND RESULTS: Plasma adiponectin concentrations were examined in 55 men with CSA and 55 with chest pain syndrome (CPS). The plasma log-adiponectin levels were significantly lower in patients with CSA than with CPS (0.61+/-0.28 vs 0.80+/-0.21 microg/ml, p < 0.0001). The prevalence of smoking was significantly higher in the CSA patients than in those with CPS (50.9% vs 29.1%, p = 0.0195). In multiple logistic regression analysis, log-adiponectin (p = 0.0008) and smoking (p = 0.0210) were independent determinants of CSA. Conclusions Hypoadiponectinemia is a potential risk factor for CSA in men, independent of smoking.

Adiponectin↗
PubMed2005

Common Polymorphisms in the Adiponectin Gene ACDC Are Not Associated With Diabetes in Pima Indians.

Adiponectin is an abundant adipose tissue-derived protein with important metabolic effects. Plasma adiponectin levels are decreased in obese individuals, and low adiponectin levels predict insulin resistance and type 2 diabetes. Two variants in the adiponectin gene ACDC have been previously associated with plasma adiponectin levels, obesity, insulin resistance, and type 2 diabetes. To determine the role of genetic variation in ACDC in susceptibility to obesity and type 2 diabetes in Pima Indians, we screened the promoter, exons, and exon-intron boundaries of the gene to identify allelic variants. We identified 17 informative polymorphisms that comprised four common (minor allele frequency >15%) linkage disequilibrium clusters consisting of 1-4 variants each. We genotyped one representative polymorphism from each cluster in 1,338 individuals and assessed genotypic association with type 2 diabetes, BMI, serum lipid levels, serum adiponectin levels, and measures of insulin sensitivity and secretion. None of the ACDC variants were associated with type 2 diabetes, BMI, or measures of insulin sensitivity or secretion. One variant, single nucleotide polymorphism (SNP)-12823, was associated with serum adiponectin levels (P = 0.002), but this association explained only 2% of the variance of serum adiponectin levels. Our findings suggest that these common ACDC polymorphisms do not play a major role in susceptibility to obesity or type 2 diabetes in this population.

Adiponectin↗
PubMed2005

[Adiponectin].

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Adiponectin↗
PubMed2005

Inverse relationship between plasminogen activator inhibitor-I activity and adiponectin in overweight and obese women. Interrelationship with visceral adipose tissue, insulin resistance, HDL-chol and inflammation.

Adipose tissue is an active endocrine organ secreting different adipokines such as plasminogen activator inhibitor-1 (PAI-1) and adiponectin, among many others. In this study, we investigated the association between PAI-1 activity and serum adiponectin levels in a group of 444 overweight and obese women and assessed the interrelationship with visceral adipose tissue (VAT; CT-scan L4-L5), insulin resistance (HOMA-IR), HDL cholesterol (HDL-chol) and inflammation (hs-CRP). PAI-1 was inversely related to adiponectin (r = -0.25, p < 0.001; adjusted for age and BMI). After adjustment for age, VAT, HOMA-IR and hs-CRP, the relationship remained significant (r = -0.15; p = 0.001), but disappeared after additional adjustment for HDL-chol (r = -0.09; p = 0.067). Subjects were divided in two groups according to the median levels of adiponectin or PAI-1 levels. PAI-1 activity (19.1 +/- 11.4 vs. 15.8 +/- 8.6 AU/ml; p = 0.003) and adiponectin levels (9.8 +/- 4.6 vs. 8.4 +/- 4.0 microg/ml; p < 0.001) were significantly higher in the low adiponectin/PAI-1 groups. The difference in PAI-1 remained significant after adjustment for age and BMI (p = 0.001), became borderline significant after adjustment for age and VAT (p = 0.052), and disappeared after adjustment for age and HOMA-IR (p = 0.116) or age and HDL-chol (p = 0.443). The difference in adiponectin levels remained significant after adjustment for age, VAT, HOMA-IR and hs-CRP (p = 0.006), but disappeared after additional adjustment for HDL-chol (p = 0.089). Further analyses suggest a contribution of HOMA-IR and/or HDL-chol in the relationship between PAI-1 and adiponectin. HDL-chol was found to be the only factor independently determining both factors. In conclusion, in overweight and obese women, PAI-1 activity was inversely related to serum adiponectin, independent of visceral adipose tissue.

Adiponectin↗
PubMed2004

Visfatin: a protein secreted by visceral fat that mimics the effects of insulin.

Fat tissue produces a variety of secreted proteins (adipocytokines) with important roles in metabolism. We isolated a newly identified adipocytokine, visfatin, that is highly enriched in the visceral fat of both humans and mice and whose expression level in plasma increases during the development of obesity. Visfatin corresponds to a protein identified previously as pre-B cell colony-enhancing factor (PBEF), a 52-kilodalton cytokine expressed in lymphocytes. Visfatin exerted insulin-mimetic effects in cultured cells and lowered plasma glucose levels in mice. Mice heterozygous for a targeted mutation in the visfatin gene had modestly higher levels of plasma glucose relative to wild-type littermates. Surprisingly, visfatin binds to and activates the insulin receptor. Further study of visfatin's physiological role may lead to new insights into glucose homeostasis and/or new therapies for metabolic disorders such as diabetes.

Adipocytes↗
PubMed2004

Adaptation to fasting by glycerol transport through aquaporin 7 in adipose tissue.

Adipocytes hydrolyze triglycerides and secrete free fatty acids and glycerol into the circulation. The molecular mechanism involved in glycerol transport from adipocytes has not been elucidated. Here, we investigated glycerol and glucose metabolism in mice lacking aquaporin 7 (Aqp7), a member of the aquaglyceroporins expressed in adipose tissue, and demonstrated that Aqp7 functions as a glycerol gateway molecule in vivo. Aqp7-knockout (KO) mice had lower plasma glycerol levels compared with WT mice but had normal plasma free fatty acid levels. The increase in plasma glycerol level in response to beta(3)-adrenergic agonist was severely impaired in KO mice. Epinephrine-stimulated glycerol secretion was also impaired in Aqp7 knockdown adipocytes. During prolonged fasting, plasma glycerol was elevated and the plasma glucose level was maintained in WT mice. In contrast, KO mice showed a disrupted increase of plasma glycerol and rapid reduction of plasma glucose during prolonged fasting. Our findings indicate that the lack of effective glycerol transport from adipocytes by glycerol gateway molecule causes defective adaptation to prolonged fasting.

Adaptation, Physiological↗
PubMed2004

Adiponectin in chronic kidney disease is related more to metabolic disturbances than to decline in renal function.

BACKGROUND: Adiponectin, a newly discovered collagen-like protein of the collectin family exclusively produced by adipocytes, possesses anti-inflammatory properties. Plasma adiponectin is associated with a decreased cardiovascular risk in non-renal patients, and is reduced in obesity and insulin-resistant states. Although reports show an increase in the adiponectin level in maintenance haemodialysis, peritoneal dialysis and end-stage renal disease, there is no documentation of adiponectin levels and regulation in the early stages of chronic kidney disease (CKD). METHODS: We prospectively measured glomerular filtration rate (GFR) in 48 patients with CKD using inulin clearance. Fasting blood was drawn to determine insulin, leptin, adiponectin and C-reactive protein (CRP) levels. Body fat mass was calculated using skinfold thickness measurements. RESULTS: The patients' mean GFR was 53.5+/-24.9 (SD) ml/min/1.73 m2. Adiponectin was in the normal range in men (9.8+/-2.9 mg/l) and women (16.6+/-5.0 mg/l) with CKD, being significantly higher in women than men (P<0.001). Serum leptin was above normal (10.4+/-10.7 microg/l), whereas serum insulin and CRP were within their normal ranges (3.5+/-3.3 microU/ml and 2.6+/-5.0 mg/l, respectively). In linear regression analysis, adiponectin was negatively correlated with GFR (P = 0.02), fat mass (P = 0.03) and body mass index (P = 0.002), and strongly positively correlated with serum leptin (P = 0.003). A positive relationship was also found between plasma adiponectin and the urinary albumin/creatinine ratio (P = 0.007). No relationship was found between adiponectin and insulin or adiponectin and CRP. In multiple regression analysis, adiponectin was significantly positively correlated with leptin (P<0.0001), negatively with body mass index (P<0.0001) and only weakly with GFR (P = 0.04). CONCLUSIONS: Despite an adverse metabolic environment in chronic renal insufficiency, serum adiponectin increases in non-obese patients when renal function deteriorates. Adiponectin is only weakly affected by renal function per se, but appears influenced by proteinuria, and more significantly by body mass index and the change in serum leptin that accompanies decline in renal function.

Adiponectin↗
PubMed2004

Adiponectin-mediated modulation of hypertrophic signals in the heart.

Patients with diabetes and other obesity-linked conditions have increased susceptibility to cardiovascular disorders. The adipocytokine adiponectin is decreased in patients with obesity-linked diseases. Here, we found that pressure overload in adiponectin-deficient mice resulted in enhanced concentric cardiac hypertrophy and increased mortality that was associated with increased extracellular signal-regulated kinase (ERK) and diminished AMP-activated protein kinase (AMPK) signaling in the myocardium. Adenovirus-mediated supplemention of adiponectin attenuated cardiac hypertrophy in response to pressure overload in adiponectin-deficient, wild-type and diabetic db/db mice. In cultures of cardiac myocytes, adiponectin activated AMPK and inhibited agonist-stimulated hypertrophy and ERK activation. Transduction with a dominant-negative form of AMPK reversed these effects, suggesting that adiponectin inhibits hypertrophic signaling in the myocardium through activation of AMPK signaling. Adiponectin may have utility for the treatment of hypertrophic cardiomyopathy associated with diabetes and other obesity-related diseases.

AMP-Activated Protein Kinases↗
PubMed2004

Adiponectin down-regulates acyl-coenzyme A:cholesterol acyltransferase-1 in cultured human monocyte-derived macrophages.

Acyl-coenzyme A:cholesterol acyltransferase-1 (ACAT-1) catalyzes the formation of cholesteryl esters (CE) and plays a significant role in formation of macrophage-derived foam cells in atherosclerotic lesions. Adiponectin was reported to play an anti-atherogenic role by inhibiting class A scavenger receptor (SR-A) expression in human macrophages. To further clarify its additional property, we examined its effect on ACAT-1 expression using human macrophages. Immunoblot analyses revealed a significant reduction of ACAT-1 protein by a low concentration (1 microg/ml) of adiponectin. The ACAT activity was also decreased in parallel by adiponectin. Northern blot analyses revealed that all four ACAT-1 mRNA transcripts (2.8, 3.6, 4.3, and 7.0 kb) were decreased almost equally by adiponectin. Furthermore, acetyl-LDL-induced CE-accumulation in these macrophages was reduced significantly by this adipocytokine. These results demonstrate the inhibitory effect of adiponectin on ACAT-1 expression, suggesting that adiponectin may play an anti-atherogenic role by down-regulating the expression of ACAT-1 as well as SR-A in human macrophages.

Adiponectin↗
PubMed2004

Hypoadiponectinemia is an independent risk factor for hypertension.

Adiponectin is one of the key molecules in the metabolic syndrome, and its concentration is decreased in obesity, type-2 diabetes, and coronary artery disease. Genetic investigation has revealed that 2 polymorphisms (I164T and G276T) are related to adiponectin concentration and diabetes. To examine whether adiponectin affects hypertension genetically or biologically, we performed a case-control study. A total of 446 diagnosed cases of hypertension (HT) in men and 312 normotensive (NT) men were enrolled in this study. Plasma adiponectin concentration was measured using an enzyme-linked immunosorbent assay system. Single nucleotide polymorphisms were determined by TaqMan polymerase chain reaction method. After adjustment for confounding factors, adiponectin concentration was significantly lower in HT (HT: 5.2+/-0.2 microg/mL; NT: 6.1+/-0.2 microg/mL; P<0.001). Furthermore, multiple regression analysis indicated that hypoadiponectinemia was an independent risk factor for hypertension (P<0.001). Blood pressure was inversely associated with adiponectin concentration in normotensives regardless of insulin resistance. In subjects carrying the TC genotype of the I164T polymorphism, adiponectin concentration was significantly lower (TC: 2.6+/-0.9 microg/mL; TT: 5.5+/-0.1 microg/mL; P<0.01), and most of them had hypertension. In contrast, the G276T polymorphism was not associated with adiponectin concentration or hypertension. In conclusion, hypoadiponectinemia is a marker for predisposition to hypertension in men.

Adiponectin↗
PubMed2004

Adiponectin stimulates angiogenesis in response to tissue ischemia through stimulation of amp-activated protein kinase signaling.

Obesity is a risk factor for the development of cardiovascular diseases that are associated with impaired angiogenesis. Adiponectin is an adipocyte-specific adipocytokine with anti-atherogenic and anti-diabetic properties, and its plasma levels are reduced in association with obesity-linked diseases. Here, we investigated whether adiponectin regulates angiogenesis in response to tissue ischemia using adiponectin knock-out (KO) mice. Angiogenic repair of ischemic hind limbs was impaired in adiponectin-KO mice compared with wild-type (WT) mice as evaluated by laser Doppler flow method and capillary density analyses. Adenovirus-mediated supplement of adiponectin accelerated angiogenic repair in both adiponectin-KO and WT mice. Intramuscular injection of an adenovirus encoding dominant-negative AMP-activated kinase diminished the improvement in limb perfusion seen in WT mice and abolished the adiponectin-induced enhancement of perfusion. These data indicate that adiponectin can function to stimulate angiogenesis in response to ischemic stress by promoting AMP-activated kinase signaling. Therefore, adiponectin may be useful in the treatment for obesity-related vascular deficiency diseases.

AMP-Activated Protein Kinases↗
PubMed2004

Adiponectin specifically increased tissue inhibitor of metalloproteinase-1 through interleukin-10 expression in human macrophages.

BACKGROUND: Vascular inflammation and subsequent matrix degradation play an important role in the development of atherosclerosis. We previously reported that adiponectin, an adipose-specific plasma protein, accumulated to the injured artery and attenuated vascular inflammatory response. Clinically, high plasma adiponectin level was associated with low cardiovascular event rate in patients with chronic renal failure. The present study was designed to elucidate the effects of adiponectin on matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) in human monocyte-derived macrophages. METHODS AND RESULTS: Human monocyte-derived macrophages were incubated with the physiological concentrations of human recombinant adiponectin for the time indicated. Adiponectin treatment dose-dependently increased TIMP-1 mRNA levels without affecting MMP-9 mRNA levels. Adiponectin also augmented TIMP-1 secretion into the media, whereas MMP-9 secretion and activity were unchanged. Time course experiments indicated that TIMP-1 mRNA levels started to increase at 24 hours of adiponectin treatment and were significantly elevated at 48 hours. Adiponectin significantly increased interleukin-10 (IL-10) mRNA expression at the transcriptional level within 6 hours and significantly increased IL-10 protein secretion within 24 hours. Cotreatment of adiponectin with anti-IL-10 monoclonal antibody completely abolished adiponectin-induced TIMP-1 mRNA expression. CONCLUSIONS: Adiponectin selectively increased TIMP-1 expression in human monocyte-derived macrophages through IL-10 induction. This study identified, for the first time, the adiponectin/IL-10 interaction against vascular inflammation.

Adiponectin↗
PubMed2004

Adiponectin I164T mutation is associated with the metabolic syndrome and coronary artery disease.

OBJECTIVES: This study examined the association of mutations in adiponectin gene with the prevalence of coronary artery disease (CAD). BACKGROUND: Coronary artery disease is a major cause of mortality in the industrial countries. Adiponectin gene locus, chromosome 3q27, is the candidate site for CAD. We have reported that adiponectin has antiatherogenic and antidiabetic properties, and that the plasma levels negatively correlated with body mass index (BMI) are significantly low in patients with CAD or type 2 diabetes. METHODS: The study subjects were 383 consecutive patients with angiographically confirmed CAD and 368 non-CAD subjects adjusted for age and BMI in the Japanese population. Single nucleotide polymorphisms (SNPs) in the adiponectin gene were determined by Taqman polymerase chain reaction (PCR) method or a PCR-based assay for the analysis of restriction fragment length polymorphism. The plasma adiponectin concentration was measured by enzyme-linked immunosorbent assay. RESULTS: Among SNPs, the frequency of I164T mutation was significantly higher in CAD subjects (2.9%) than in the control (0.8%, p < 0.05). The plasma adiponectin levels in subjects carrying the I164T mutation were significantly lower than in those without the mutation, and were independent of BMI. In contrast, SNP94 and SNP276, which are reported to be associated with an increased risk of type 2 diabetes, were associated neither with CAD prevalence nor with plasma adiponectin level. Subjects with I164T mutation exhibited a clinical phenotype of the metabolic syndrome. CONCLUSIONS: The I164T mutation in the adiponectin gene was a common genetic background associated with the metabolic syndrome and CAD in the Japanese population.

Adiponectin↗