Although oxidative stress is the main pathophysiology of the development of diabetic neuropathy, oral administration of antioxidants has given disappointing results. Here, we hypothesized that local delivery of antioxidants would provide protective effects on Schwann cells due to the high concentration of local lesions. We prepared alpha-tocopherol (ATF)-loaded liposomes and tested their skin penetration after sonication. An in vitro study using IMS-32 cells was conducted to determine the level of reactive oxygen species (ROS) scavenging effects of ATF-liposomes. ATF reduced ROS in high-glucose-exposed IMS-32 cells in a dosedependent manner. ATF-liposomes also reduced the ROS level in vitro and ultrasound irradiation enhanced delivery to the dermis in porcine ear skin. This study showed that it is feasible to deliver ATF through the skin and can effectively reduce ROS. This model is worthy of development for clinical use.
Background Serotonin (5-hydroxytryptamine [5-HT]) is a monoamine neurotransmitter that has various functions in central and peripheral tissues. While 5-HT is known to regulate various biological processes in liver, direct role of 5-HT and its receptors, especially 5-HT receptor 2A (HTR2A) and HTR2B, in development and progression of alcoholic liver disease (ALD) in vivo is not well understood.
Methods Blood 5-HT level was measured from both human ALD patients and ethanol (EtOH) diet-fed mouse models. Gut-specific tryptophan hydroxylase 1 (Tph1) knockout mice, liver-specific Htr2a knockout mice, and liver-specific Htr2b knockout mice were fed with EtOH diet. Then we evaluated liver damage, hepatic steatosis, endoplasmic reticulum (ER) stress, and inflammation.
Results Blood 5-HT concentrations are increased in both humans and mice with ALD. Both gut-specific Tph1 knockout and liver- specific Htr2a knockout mice are resistant to steatosis by down-regulating lipogenic pathways in liver of chronic EtOH diet-fed mice. Moreover, genetic inhibition of both gut-derived serotonin (GDS) synthesis and hepatic HTR2A signaling prevents ER stress in liver of chronic EtOH diet-fed mice. Additionally, we found that ablation of HTR2A signaling protects against disease progression by attenuating liver injury and inflammation in chronic plus binge EtOH diet-fed mice. Also, inhibiting HTR2A signaling ameliorates alcohol-induced liver injury and ER stress in an acute EtOH diet-fed mice model.
Conclusion GDS directly regulates lipogenesis and ER stress via signaling through hepatic HTR2A in the context of ALD. Inhibiting HTR2A signaling protects against alcohol-induced steatosis, liver injury and disease progression in various ALD mouse models and may also provide a novel therapeutic strategy for ALD.
Jiaheng Chen, Yu Ting Li, Zimin Niu, Zhanpeng He, Yao Jie Xie, Jose Hernandez, Wenyong Huang, Harry H.X. Wang, on Behalf of the Guangzhou Diabetic Eye Study Group
Received May 10, 2024 Accepted October 23, 2024 Published online February 4, 2025
Background Diabetic macrovascular and microvascular complications often coexist and may share similar risk factors and pathological pathways. We aimed to investigate whether 10-year atherosclerotic cardiovascular disease (ASCVD) risk, which is commonly assessed in diabetes management, can predict incident diabetic nephropathy (DN) and retinopathy (DR) in patients with type 2 diabetes mellitus (T2DM).
Methods This prospective cohort study enrolled 2,891 patients with clinically diagnosed T2DM who were free of ASCVD, nephropathy, or retinopathy at baseline in the Guangzhou (2017–2022) and Shaoguan (2019–2021) Diabetic Eye Study in southern China. The 10-year ASCVD risk was calculated by the Prediction for ASCVD Risk in China (China-PAR) equations. Multivariable- adjusted Cox proportional hazard models were developed to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). The area under the receiver operating characteristic curve (AUC) was used to evaluate predictive capability.
Results During follow-up, a total of 171 cases of DN and 532 cases of DR were documented. Each 1% increment in 10-year ASCVD risk was associated with increased risk of DN (pooled HR, 1.122; 95% CI, 1.094 to 1.150) but not DR (pooled HR, 0.996; 95% CI, 0.979 to 1.013). The model demonstrated acceptable performance in predicting new-onset DN (pooled AUC, 0.670; 95% CI, 0.628 to 0.715). These results were consistent across cohorts and subgroups, with the association appearing to be more pronounced in women.
Conclusion Ten-year ASCVD risk predicts incident DN but not DR in our study population with T2DM. Regular monitoring of ASCVD risk in routine diabetes practice may add to the ability to enhance population-based prevention for both macrovascular and microvascular diseases, particularly among women.
Background Diabetic kidney disease (DKD) is recognized as a significant complication of diabetes mellitus and categorized into glomerular DKDs and tubular DKDs, each governed by distinct pathological mechanisms and biomarkers.
Methods Through the identification of common features observed in glomerular and tubular lesions in DKD, numerous differentially expressed gene were identified by the machine learning, single-cell transcriptome and mendelian randomization.
Results The diagnostic markers versican (VCAN) was identified, offering supplementary options for clinical diagnosis. VCAN significantly highly expressed in glomerular parietal epithelial cell and proximal convoluted tubular cell. It was mainly involved in the up-regulation of immune genes and infiltration of immune cells like mast cell. Mendelian randomization analysis confirmed that serum VCAN protein levels were a risky factor for DKD, while there was no reverse association. It exhibited the good diagnostic potential for estimated glomerular filtration rate and proteinuria in DKD.
Conclusion VCAN showed the prospects into DKD pathology and clinical indicator.
Background In acute and chronic renal inflammatory diseases, the activation of inflammatory cells is involved in the defect of erythropoietin (EPO) production. Ras guanine nucleotide-releasing protein-4 (RasGRP4) promotes renal inflammatory injury in type 2 diabetes mellitus (T2DM). Our study aimed to investigate the role and mechanism of RasGRP4 in the production of renal EPO in diabetes.
Methods The degree of tissue injury was observed by pathological staining. Inflammatory cell infiltration was analyzed by immunohistochemical staining. Serum EPO levels were detected by enzyme-linked immunosorbent assay, and EPO production and renal interstitial fibrosis were analyzed by immunofluorescence. Quantitative real-time polymerase chain reaction and Western blotting were used to detect the expression of key inflammatory factors and the activation of signaling pathways. In vitro, the interaction between peripheral blood mononuclear cells (PBMCs) and C3H10T1/2 cells was investigated via cell coculture experiments.
Results RasGRP4 decreased the expression of hypoxia-inducible factor 2-alpha (HIF2A) via the ubiquitination–proteasome degradation pathway and promoted myofibroblastic transformation by activating critical inflammatory pathways, consequently reducing the production of EPO in T2DM mice.
Conclusion RasGRP4 participates in the production of renal EPO in diabetic mice by affecting the secretion of proinflammatory cytokines in PBMCs, degrading HIF2A, and promoting the myofibroblastic transformation of C3H10T1/2 cells.
Background Normalized creatinine-to-cystatin C ratio (NCCR) was reported to approximate relative skeletal muscle mass and diabetes risk. However, the association between NCCR and cardiometabolic multimorbidity (CMM) remains elusive. This study aimed to explore their relationship in a large-scale prospective cohort.
Methods This study included 5,849 middle-age and older participants from the China Health and Retirement Longitudinal Study (CHARLS) enrolled between 2011 and 2012. The baseline NCCR was determined as creatinine (mg/dL)/cystatin C (mg/L)×10/body mass (kg). CMM was defined as the simultaneous occurrence of two or more of the following conditions: heart disease, stroke, and type 2 diabetes mellitus. Logistic regression analysis and Cox regression analysis were employed to estimate the relationship between NCCR and CMM. The joint effect of body mass index and NCCR on the risk of CMM were further analyzed.
Results During a median 4-year follow-up, 227 (3.9%) participants developed CMM. The risk of CMM was significantly decreased with per standard deviation increase of NCCR (odds ratio, 0.72; 95% confidence interval, 0.62 to 0.85) after adjustment for confounders (P<0.001). Further sex-specific analysis found significant negative associations between NCCR and CMM in female either without or with one CMM component at baseline, which was attenuated in males but remained statistically significant among those with one basal CMM component. Notably, non-obese individuals with high NCCR levels had the lowest CMM risk compared to obese counterparts with low NCCR levels in both genders.
Conclusion High NCCR was independently associated with reduced risk of CMM in middle-aged and older adults in China, particularly females.
Nam Hoon Kim, Soo Lim, In-Kyung Jeong, Eun-Jung Rhee, Jun Sung Moon, Ohk-Hyun Ryu, Hyuk-Sang Kwon, Jong Chul Won, Sang Soo Kim, Sang Yong Kim, Bon Jeong Ku, Heung Yong Jin, Sin Gon Kim, Bong-Soo Cha, on Behalf of Investigators of ENVELOP Study
Received May 9, 2024 Accepted August 14, 2024 Published online January 6, 2025
Background The novel sodium-glucose cotransporter-2 (SGLT2) inhibitor enavogliflozin effectively lowers glycosylated hemoglobin levels and body weights without the increased risk of serious adverse events; however, the long-term clinical benefits of enavogliflozin in terms of cardiovascular and renal outcomes have not been investigated.
Methods This study is an investigator-initiated, multicenter, randomized, pragmatic, open-label, active-controlled, non-inferiority trial. Eligible participants are adults (aged ≥19 years) with type 2 diabetes mellitus (T2DM) who have a history of, or are at risk of, cardiovascular disease. A total of 2,862 participants will be randomly assigned to receive either enavogliflozin or other SGLT2 inhibitors with proven cardiorenal benefits, such as dapagliflozin or empagliflozin. The primary endpoint is the time to the first occurrence of a composite of major adverse cardiovascular or renal events (Clinical Research Information Service registration number: KCT0009243).
Conclusion This trial will determine whether enavogliflozin is non-inferior to dapagliflozin or empagliflozin in terms of cardiorenal outcomes in patients with T2DM and cardiovascular risk factors. This study will elucidate the role of enavogliflozin in preventing vascular complications in patients with T2DM.
Background This study aimed to investigate the prevalence, management, and comorbidities of diabetes mellitus among Korean adults.
Methods Data from the Korea National Health and Nutrition Examination Survey (2019–2022) were analyzed to assess the prevalence, treatment, risk factors, and comorbidities of diabetes. Comparisons between young and older adults with diabetes were emphasized.
Results Among Korean adults aged ≥30 years, the prevalence of diabetes is 15.5% during 2021–2022. Of these, 74.7% were aware of their condition, 70.9% received antidiabetic treatment, and only 32.4% achieved glycosylated hemoglobin (HbA1c) <6.5%. Moreover, 15.9% met the integrated management targets, which included HbA1c <6.5%, blood pressure <140/85 mm Hg, and low-density lipoprotein cholesterol <100 mg/dL. In young adults aged 19 to 39 years, the prevalence of diabetes was 2.2%. Among them, 43.3% were aware of their condition, 34.6% received treatment, and 29.6% achieved HbA1c <6.5%. Obesity affected 87.1%, and 26.9% had both hypertension and hypercholesterolemia. Among adults aged ≥65 years, the prevalence of diabetes was 29.3%, with awareness, treatment, and control rates of 78.8%, 75.7%, and 31.2%, respectively. Integrated management targets (HbA1c <7.5%, hypertension, and lipids) were achieved by 40.1%.
Conclusion Diabetes mellitus remains highly prevalent among Korean adults, with significant gaps in integrated glycemic, blood pressure, and lipid control. Older adults with diabetes show higher awareness and treatment rates but limited integrated management outcomes. Young adults with diabetes bear a significant burden of obesity and comorbidities, alongside low awareness and treatment rates. Therefore, early intervention programs, education, and strategies tailored to younger populations are urgently required.
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Diabetes in Korean Adults: Prevalence, Management, and Comorbidities Sung Hoon Yu Diabetes & Metabolism Journal.2025; 49(1): 22. CrossRef
Type 2 diabetes mellitus (T2DM) is marked by chronic hyperglycemia, gradually worsening β-cell failure, and insulin resistance. Glucotoxicity and oxidative stress cause β-cell failure by increasing reactive oxygen species (ROS) production, impairing insulin secretion, and disrupting transcription factors such as pancreatic and duodenal homeobox 1 (PDX-1) and musculoaponeurotic fibrosarcoma oncogene family A (MafA). Cluster determinant 36 (CD36), an essential glycoprotein responsible for fatty acid uptake, exacerbates oxidative stress and induces the apoptosis of β-cells under hyperglycemic conditions through pathways involving ceramide, thioredoxin-interacting protein (TXNIP), and Rac1-nicotinamide adenine dinucleotide phosphate oxidase (NOX)-mediated redoxosome formation. Targeting CD36 pathways has emerged as a promising therapeutic strategy. Oral hypoglycemic agents, such as metformin, teneligliptin, and pioglitazone, have shown protective effects on β-cells by enhancing antioxidant defenses. These agents reduce glucotoxicity via mechanisms such as suppressing CD36 expression and stabilizing mitochondrial function. Additionally, novel insights into the glutathione antioxidant system and its role in β-cell survival underscore its therapeutic potential. This review focuses on the key contribution of oxidative stress and CD36 to β-cell impairment, the therapeutic promise of antioxidants, and the need for further research to apply these findings in clinical practice. Promising strategies targeting these mechanisms may help preserve β-cell function and slow T2DM progression.
The Korean National Health Information Database (NHID), which contains nationwide real-world claims data including sociodemographic data, health care utilization data, health screening data, and healthcare provider information, is a powerful resource to test various hypotheses. It is also longitudinal in nature due to the recommended health checkup every 2 years and is appropriate for long-term follow-up study as well as evaluating the relationships between health outcomes and changes in parameters such as lifestyle factors, anthropometric measurements, and laboratory results. However, because these data are not collected for research purposes, precise operational definitions of diseases are required to facilitate big data analysis using the Korean NHID. In this review, we describe the characteristics of the Korean NHID, operational definitions of diseases used for research related to diabetes, and introduce representative research for diabetes-related diseases using the Korean NHID.
Background Both sodium-glucose cotransporters (SGLTs) and Na+/H+ exchangers (NHEs) rely on a favorable Na-electrochemical gradient. Gastrin, through the cholecystokinin B receptor (CCKBR), can induce natriuresis and diuresis by inhibiting renal NHEs activity. The present study aims to unveil the role of renal CCKBR in diabetes through SGLT2-mediated glucose reabsorption.
Methods Renal tubule-specific Cckbr-knockout (CckbrCKO) mice and wild-type (WT) mice were utilized to investigate the effect of renal CCKBR on SGLT2 and systemic glucose homeostasis under normal diet, high-fat diet (HFD), and HFD with a subsequent injection of a low dose of streptozotocin. The regulation of SGLT2 expression by gastrin/CCKBR and the underlying mechanism was explored using human kidney (HK)-2 cells.
Results CCKBR was downregulated in kidneys of diabetic mice. Compared with WT mice, CckbrCKO mice exhibited a greater susceptibility to obesity and diabetes when subjected to HFD. In vitro experiments using HK-2 cells revealed an upregulation of glucose transporters after incubation with high glucose, a response that was significantly attenuated following gastrin intervention. The glucose uptake from the culture medium of cells was altered accordingly. Moreover, gastrin administration effectively mitigated hyperglycemia in WT diabetic mice by inhibition of SGLT2 mediated glucose reabsorption, but this effect was compromised in the absence of CCKBR, as seen in CckbrCKO mice. Mechanistically, gastrin/CCKBR substantially reduced SGLT2 expression in HK-2 cells exposed to high glucose, via modulating Erk/nuclear factor-kappa B (NF-κB) pathway.
Conclusion Our study underscores the crucial role of renal gastrin/CCKBR in SGLT2 regulation and glucose reabsorption, and renal gastrin/CCKBR can be a promising therapeutic target for diabetes.
Background Cumulative evidence consistently shows that anthropometric and body composition measurements are strongly linked to the risk of incident diabetes, typically based on baseline measurements. This study aims to assess whether repeated measurements enhance the prediction of diabetes risk beyond baseline assessments alone.
Methods We utilized data from a 16-year population-based follow-up cohort within the Korean Genome and Epidemiology Study, comprising 6,030 individuals aged 40 to 69 years at baseline. We included eight indices: a body shape index (ABSI), body adiposity index (BAI), waist circumference (WC), body mass index (BMI), waist-to-hip ratio (WHR), weight-adjusted skeletal muscle index (SMI), percent body fat, and fat-to-muscle ratio. The effect of these measurements for incident diabetes was estimated using Harrell’s C-indexes and hazard ratios with 95% confidence intervals, employing time-dependent Cox proportional hazard models.
Results Over the 16-year follow-up, 939 new diabetes cases were identified (cumulative incidence, 15.6%). The median number of indicator measurements per participant was eight. The basic model, including 10 features (sex, age, education levels, physical activity, alcohol intake, current smoking, total energy intake, dietary diversity score, and log-transformed C-reactive protein levels, and quartiles of unweighted genetic risk score at baseline), yielded a Harrell’s C-index of 0.610. The highest C-index in repeated measurements was for WC (0.668) across the general population, weight-adjusted SMI in men, and WHR in women. However, except for ABSI and BAI, the diabetes predictive power of the other indicators was comparable. Additionally, repeated measurements of WC, BMI, and WHR in women were found to contribute to improved discrimination compared to baseline measurements, but not in men.
Conclusion Utilizing repeated measurements of general and central adiposity to predict diabetes may be helpful in predicting hidden risks, especially in women.