Yujiro Nakano

Impact of increased visceral adiposity with normal weight on the progression of arterial stiffness in Japanese patients with type 2 diabetes

Objective Normal-weight abdominal obesity has been reported to be associated with poor mortality. We aimed to investigate the impact of increased visceral adiposity with normal weight (OB(−)VA(+)) on the progression of arterial stiffness in patients with type 2 diabetes. Methods This was a cross-sectional study of 414 patients with type 2 diabetes (mean age 64±12 years; 40.3% female). Visceral fat area (VFA, cm2) was measured by a dual bioelectrical impedance analyzer. Arterial stiffness was assessed by brachial-ankle pulse wave velocity (baPWV, cm/s). Patients were divided into four groups by VFA and body mass index (BMI, kg/m2) as the following: BMI<25 kg/m2 and VFA<100 cm2 (obesity (OB)(−)visceral adiposity (VA)(−)), BMI≥25 kg/m2 and VFA<100 cm2 (OB(+)VA(−)), BMI<25 kg/m2 and VFA≥100 cm2 (OB(−)VA(+)), and BMI≥25 kg/m2 and VFA≥100 cm2 (OB(+)VA(+)). Multivariate linear regression analysis was done to determine the impact of OB(−)VA(+) on arterial stiffness. Results Among the patients, 7.2% were OB(−)VA(+) with higher baPWV levels (1956±444 cm/s) than those with OB(+)VA(−) (1671±416 cm/s, p=0.014), those with OB(+)VA(+) (1744±317 cm/s, p=0.048), and those with OB(−)VA(−) (1620±397 cm/s, p=0.024). In multivariate linear regression analysis, OB(−)VA(+) remained independently associated with baPWV (standardized β 0.184, p=0.001). Conclusions This study provides evidence for the burden of arterial stiffness in OB(−)VA(+) patients with type 2 diabetes; therefore, evaluation of visceral adiposity is of clinical relevance for the better management of non-obese individuals as well as obese populations.

Reduction of visceral fat by liraglutide is associated with ameliorations of hepatic steatosis, albuminuria, and micro-inflammation in type 2 diabetic patients with insulin treatment: a randomized control trial

Liraglutide, an analogue of human glucagon-like peptide 1, reduces cardiovascular events in patients with type 2 diabetes; however, it has still been unknown by which mechanisms liraglutide could reduce cardiovascular events. Type 2 diabetic patients with insulin treatment were enrolled in this randomized, open-label, comparative study. Participants were randomly assigned to liraglutide plus insulin (liraglutide group) and insulin treatment (control group) at 1:1 allocation. Primary endpoint was the change in viscera fat are (VFA, cm2) at 24 weeks. Liver attenuation index (LAI) measured by abdominal computed tomography, urinary albumin-to-creatinine ratio (ACR, mg/g), and C-reactive protein (CRP) levels, skeletal muscle index (SMI), and quality of life (QOL) related to diabetes treatment were also determined. Seventeen patients (8; liraglutide group, 9; control group, mean age 59 ± 13 years; 53% female) completed this study. Liraglutide treatment significantly reduced VFA at 24 weeks; whereas, SFA was unchanged. ACR, LAI, and CRP levels were significantly reduced by liraglutide at 24 weeks and there was no difference in SMI between the two groups. Changes in VFA from baseline to 24 weeks were significantly associated with those in LAI, albuminuria, and HbA1c. Liraglutide treatment significantly improved QOL scores associated with anxiety and dissatisfaction with treatment and satisfaction with treatment. No severe adverse events were observed in both groups. Our data suggest that liraglutide could reduce visceral adiposity in parallel with attenuation of hepatic fat accumulation, albuminuria and micro-inflammation and improve QOL related to diabetes care in insulin-treated patients with type 2 diabetes.

Indirect measure of visceral adiposity ‘A Body Shape Index’ (ABSI) is associated with arterial stiffness in patients with type 2 diabetes

Objective Among indirect measures of visceral adiposity, A Body Shape Index (ABSI), which is defined as waist circumference (WC)/(body mass index (BMI)2/3×height1/2), is unique in that ABSI is positively correlated with visceral adiposity and is supposed to be independent of BMI. ABSI has been also shown to be linearly and positively associated with visceral fat mass and all-cause and cardiovascular disease (CVD) in the general population. It is, however, uncertain whether ABSI could be associated with arterial stiffness in patients with diabetes. Methods This is a cross-sectional study of 607 patients with type 2 diabetes (mean age 64±12 years; 40.0% female). Visceral fat area (VFA, cm2) and subcutaneous fat area (SFA, cm2) were assessed with a dual-impedance analyzer. In order to estimate the risk for CVD, brachial-ankle pulse wave velocity (baPWV, cm) was used for the assessment of arterial stiffness. Results ABSI was significantly and positively correlated with VFA (r=0.138, p=0.001) and negatively associated with BMI (r=−0.085, p=0.037). The correlation of z-score for ABSI with VFA remained significant (r=0.170, p<0.001) but not with BMI (r=0.009, p=0.820). ABSI (standardized β 0.095, p=0.043) but not WC (standardized β −0.060, p=0.200) was significantly and positively correlated with baPWV in the multivariate model including BMI as a covariate. Conclusions ABSI appears to reflect visceral adiposity independently of BMI and to be a substantial marker of arterial stiffening in patients with type 2 diabetes.

Increased visceral adiposity with normal weight is associated with the prevalence of non-alcoholic fatty liver disease in Japanese patients with type 2 diabetes

To investigate the impact of increased visceral adiposity with normal weight (OB[−]VA[+]) on the prevalence of non‐alcoholic fatty liver disease in patients with type 2 diabetes.

Ratio of visceral-to-subcutaneous fat area predicts cardiovascular events in patients with type 2 diabetes

To investigate whether the ratio of visceral fat area (VFA) to subcutaneous fat area (SFA; V/S ratio) could be predictive of cardiovascular disease (CVD) as compared with VFA or SFA in patients with diabetes.

Association of sarcopenia with both latent autoimmune diabetes in adults and type 2 diabetes: a cross-sectional study

BACKGROUND To investigate the association of both latent autoimmune diabetes in adults (LADA) and type 2 diabetes (T2DM) with muscle mass and function (sarcopenia). METHODS Japanese patients with LADA (N=20), T2DM (N=208), and control subjects (N=41) were included in this cross-sectional study. The definition of LADA was based on age of onset (≥30), positive glutamic acid decarboxylase autoantibodies, and insulin requirement within the first 6months after diagnosis. Sarcopenia was diagnosed by the criteria for Asians, using skeletal muscle index (male <7.0 and female <5.4) and grip strength (male <26.0kg and female <18.0kg). The odds ratio (OR) with a 95% confidence interval (CI) was estimated using logistic regression. RESULTS The prevalence of sarcopenia was higher in LADA (35.0%) than in either T2DM (13.3%) or control subjects (9.8%). LADA was significantly associated with an increased risk for sarcopenia in a multivariate model in which age and body mass index were incorporated (OR: 9.57, 95% CI: 1.86-49.27). In contrast, T2DM tended to be associated with an increased risk for sarcopenia (OR: 2.99, 95% CI: 0.83-10.80). CONCLUSIONS This study provides evidence that patients with LADA are at a high risk for sarcopenia compared to those with T2DM or to control subjects.

Molecular characteristics of the KCNJ5 mutated aldosterone-producing adenomas

The pathophysiology of aldosterone-producing adenomas (APAs) has been investigated via genetic approaches and the pathogenic significance of a series of somatic mutations, including KCNJ5, has been uncovered. However, how the mutational status of an APA is associated with its molecular characteristics, including its transcriptome and methylome, has not been fully understood. This study was undertaken to explore the molecular characteristics of APAs, specifically focusing on APAs with KCNJ5 mutations as opposed to those without KCNJ5 mutations, by comparing their transcriptome and methylome status. Cortisol-producing adenomas (CPAs) were used as reference. We conducted transcriptome and methylome analyses of 29 APAs with KCNJ5 mutations, 8 APAs without KCNJ5 mutations and 5 CPAs. Genome-wide gene expression and CpG methylation profiles were obtained from RNA and DNA samples extracted from these 42 adrenal tumors. Cluster analysis of the transcriptome and methylome revealed molecular heterogeneity in APAs depending on their mutational status. DNA hypomethylation and gene expression changes in Wnt signaling and inflammatory response pathways were characteristic of APAs with KCNJ5 mutations. Comparisons between transcriptome data from our APAs and that from normal adrenal cortex obtained from the Gene Expression Omnibus suggested similarities between APAs with KCNJ5 mutations and zona glomerulosa. The present study, which is based on transcriptome and methylome analyses, indicates the molecular heterogeneity of APAs depends on their mutational status. Here, we report the unique characteristics of APAs with KCNJ5 mutations.

Association of diabetic retinopathy with both sarcopenia and muscle quality in patients with type 2 diabetes: a cross-sectional study

Objective To examine whether the existence and severity of diabetic retinopathy (DR) could be associated with the prevalent sarcopenia and muscle quality in patients with type 2 diabetes. Research design and methods This is a cross-sectional study of 316 patients with type 2 diabetes (mean age 65±12 years; 38% female). Body compositions were measured by the dual-energy X-ray absorptiometry. Patients were divided into three groups: patients without DR (NDR), with non-proliferative DR (NPDR) and proliferative DR (PDR). Sarcopenia was diagnosed according to the criteria for Asians, using both skeletal muscle index (SMI) and grip strength (kg). Muscle quality was also determined by the grip strength divided by SMI. Logistic regression analyses were carried out to assess the cross-sectional association of the severity of DR with sarcopenia. In addition, linear regression analyses were performed to determine the associations between DR and muscle quality. Selection of covariates in the multivariate logistic and linear regression analyses was done by a stepwise procedure. Results Among the patients examined, NDR, NPDR and PDR were diagnosed in 261, 38 and 17 patients, respectively. The prevalence of sarcopenia significantly increased along with the progression of DR. Multivariate logistic regression analysis showed that PDR is significantly associated with sarcopenia (OR 7.78, 95% CI 1.52 to 39.81, p=0.014) and low muscle strength (OR 6.25, 95% CI 1.15 to 33.96, p=0.034). Multivariate linear regression analysis additionally showed that the existence of DR was significantly associated with the muscle quality (standardized β −0.136, p=0.005 for NPDR, standardized β −0.146, p=0.003 for PDR). Conclusions This study provides evidence that PDR is significantly associated with sarcopenia, and the existence of DR increases the risk for low muscle quality in patients with type 2 diabetes.

Dipeptidyl peptidase 4 inhibitors attenuates the decline of skeletal muscle mass in patients with type 2 diabetes

Activation of dipeptidyl peptidase 4 has been reported to be associated with impairment of insulin signalling in skeletal muscle, presumably leading to loss of muscle function. This study was aimed to investigate whether the use of dipeptidyl peptidase 4 inhibitors (DPP4i) could attenuate the progressive loss of muscle mass in patients with type 2 diabetes.

Expression of inflammation-related genes in aldosterone-producing adenomas with KCNJ5 mutation.

BACKGROUND The adrenocortical cells have been shown to produce various inflammatory cytokines such as TNFα and IL-6, which could modulate steroidogenesis. However, the role of inflammatory cytokines in aldosterone-producing adenomas (APAs) is not fully understood. In the present study, we examined the relationships between mRNA expression levels of the inflammation-related genes and somatic mutations in APA tissues. METHODS We evaluated mRNA expression levels of TNFA, IL6, and NFKB1 in APA tissues obtained from 44 Japanese APA patients. RESULTS We revealed that mRNA expression patterns of the inflammation-related genes depended on a KCNJ5 somatic mutation. In addition, we showed that mRNA expression levels of the inflammation-related genes correlated with those of the steroidogenic enzyme CYP11B1 in the patients with APAs. CONCLUSION The present study documented for the first time the expression of inflammation-related genes in APAs and the correlation of their expression levels with the KCNJ5 mutation status and mRNA expression levels of steroidogenic enzymes, indicating the pathophysiological relevance of inflammation-related genes in APAs.