Prevalence and determinants of diabetic nephropathy in Korea: Korea national health and nutrition examination survey

2023 Diabetic Kidney Disease Fact Sheet in Korea

BACKGRUOUND

To investigate the prevalence, incidence, comorbidities, and management status of diabetic kidney disease (DKD) and diabetes-related end-stage kidney disease (ESKD) in South Korea.

METHODS

We used the Korea National Health and Nutrition Examination Survey data (2019 to 2021, n=2,665) for the evaluation of prevalence, comorbidities, control rate of glycemia and comorbidities in DKD, and the Korean Health Insurance Service-customized database (2008 to 2019, n=3,950,857) for the evaluation of trends in the incidence and prevalence rate of diabetes-related ESKD, renin-angiotensin system (RAS) blockers and sodium glucose cotransporter 2 (SGLT2) inhibitors use for DKD, and the risk of atherosclerotic cardiovascular disease (ASCVD) and mortality according to DKD stages. DKD was defined as albuminuria or low estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 in patients with diabetes mellitus.

RESULTS

The prevalence of DKD was 25.4% (albuminuria, 22.0%; low eGFR, 6.73%) in patients with diabetes mellitus aged ≥30 years. Patients with DKD had a higher rate of comorbidities, including hypertension, dyslipidemia, and central obesity; however, their control rates were lower than those without DKD. Prescription rate of SGLT2 inhibitors with reduced eGFR increased steadily, reaching 5.94% in 2019. Approximately 70% of DKD patients were treated with RAS blockers. The prevalence rate of diabetesrelated ESKD has been steadily increasing, with a higher rate in older adults. ASCVD and mortality were significantly associated with an in increase in DKD stage.

CONCLUSION

DKD is prevalent among Korean patients with diabetes and is an independent risk factor for cardiovascular morbidity and mortality, which requiring intensive management of diabetes and comorbidities. The prevalence of diabetes-related ESKD has been increasing, especially in the older adults, during past decade.

Associations between dietary patterns and renal impairment in individuals with diabetes: a cross-sectional study

BACKGROUND

A variety of chronic diseases are affected by diet. To our knowledge, few studies have investigated the relationship between dietary patterns and renal impairment in individuals with diabetes within an Asian population. This study aimed to assess the relationship between renal impairment and dietary patterns in individuals with diabetes within a Chinese population.

METHODS

In this cross-sectional survey, we analysed data on 1522 participants with diabetes aged 18 years or older who took part in the China National Diabetic Chronic Complications Study. We utilised the Chinese Diabetes Complications Questionnaire, including the semiquantitative food frequency questionnaire (SQFFQ). We identified three dietary patterns using factor analysis: Chinese traditional, healthy and plant-based dietary patterns, and these dietary patterns were used to classify participants into four groups based on the quartiles of their scores. A decrease in the estimated glomerular filtration rate (eGFR; <60 mL/min/1.73 m2 ) and an increase in the albumin-to-creatinine ratio (ACR; ≥3 mg/mmol) were used as indicators of renal impairment. Binary logistic regression models were used to estimate the odds ratio (OR) of the highest quartile (Q4: high intake levels of each dietary pattern) for renal impairment compared to the lowest quartile (Q1: low intake levels of each dietary pattern).

RESULTS

Among the 1522 participants, there was a 5.5% prevalence of low eGFR, with prevalence rates of 5.2% in men and 5.9% in women, yet the prevalence of albuminuria was as high as 47.9%. After adjusting for confounders, participants in Q4 of the plant-based dietary pattern had a smaller OR for renal impairment than those in Q1.

CONCLUSIONS

Our findings demonstrated that a plant-based dietary pattern is associated with a reduced risk of renal impairment in a population with diabetes.

Determinants of diabetic nephropathy among adult diabetic patients on follow-up at public hospitals in Addis Ababa, Ethiopia: A case-control study

Background

Diabetic nephropathy is defined as patients with diabetes mellitus who have persistent proteinuria for at least three consecutive measurements per year, a high blood creatinine level (>130 mol/l), or a decrease in glomerular filtration rate (<60 ml/min). Limited studies were done in Ethiopia on determinants of diabetic nephropathy among diabetic patients. Therefore, this study aimed to identify determinants of nephropathy among adult diabetic patients on follow-up at public hospitals in Addis Ababa, Ethiopia, 2022.

Methods

A hospital-based unmatched case-control study design was conducted from 6 September to 9 November 2022, among diabetic patients on follow-up at public health hospitals in Addis Ababa. Using consecutive sampling techniques, a total of 442 (353 controls and 89 cases) were recruited, with a control-to-case ratio of 4:1. The data were collected using a structured and interview-administered questionnaire and variables like high-density lipoprotein, low-density lipoprotein, Glycated hemoglobin, and type of diabetes were extracted from the medical records of the patients using a checklist. The collected data were entered into Epidata 3.1 and analyzed by STATA version 15.0. Variables with a p-value < 0.25 in the bivariable logistic regression were selected for the final model. In multivariable logistic regression model fitting, variables with a p-value < 0.05 with 95% CI adjusted odds ratio have declared statistically significant risk factors of diabetic nephropathy.

Results

In this study, out of 442 study participants, 334 controls and 89 cases were included in the analysis, with a response rate of 94.6% and 100%, respectively. The majority of the study participants were 92.13% of cases and 84.13% of controls; 7.87% of cases, and 15.87% of controls were type 2 diabetes mellitus. Age 65 and above years old (AOR: 2.42; 95% CI: 1.28, 4.57); Smoking cigarette (AOR: 2.22; 95% CI: 1.18, 4.16); Non-adherent to diet (AOR: 2.11; 95% CI: 1.15, 3.84); Drinking alcohols (AOR: 1.95; 95% CI: 1.07, 3.52); Duration with diabetes more than 10 years (AOR: 3.39; 95% CI: 1.76, 6.54); Poor glycemic control (AOR: 2.19; 95% CI: 1.23, 4.28); and Low-density lipoprotein (AOR: 2.97; 95% CI: 1.69, 5.28) were found to be statistically significant risk factors of nephropathy among diabetic patients.

Conclusion

This study found that old age, smoking cigarettes, non-adherence to diet, duration of diabetes, alcohol drinking, Glycated hemoglobin A1C, and high low-density lipoprotein were risk factors for nephropathy. Hence, continuous health education on lifestyle modifications and diabetic-related complications in each follow-up visit via front-line health professionals are very essential to avert the problem.

Kidney Health Plan 2033 in Korea: bridging the gap between the present and the future

In response to the increase in the prevalence of chronic kidney disease (CKD) in Korea, the growth of patients requiring renal replacement therapy and the subsequent increase in medical costs, the rapid expansion of patients with end-stage kidney disease (ESKD), and the decrease in patients receiving home therapy, including peritoneal dialysis, the Korean Society of Nephrology has proclaimed the new policy, Kidney Health Plan 2033 (KHP 2033). KHP 2033 would serve as a milestone to bridge the current issues to a future solution by directing the prevention and progression of CKD and ESKD, particularly diabetic kidney disease, and increasing the proportion of home therapy, thereby reducing the socioeconomic burden of kidney disease and improving the quality of life. Here, we provide the background for the necessity of KHP 2033, as well as the contents of KHP 2033, and enlighten the Korean Society of Nephrology's future goals. Together with patients, healthcare providers, academic societies, and national policymakers, we need to move forward with goal-oriented drive and leadership to achieve these goals.

Risk Factors of Microalbuminuria among Patients with Type 2 Diabetes Mellitus in Korea: A Cross-Sectional Study Based on 2019-2020 Korea National Health and Nutrition Examination Survey Data

Diabetes mellitus is a chronic disease with high economic and social burdens. This study aimed to determine the risk factors of microalbuminuria among patients with type 2 diabetes mellitus. Microalbuminuria is predictive of early-stage renal complications and subsequent progression to renal dysfunction. We collected data on type 2 diabetes patients who participated in the 2019-2020 Korea National Health and Nutrition Examination Survey. The risk factors for microalbuminuria among patients with type 2 diabetes were analyzed using logistic regression. As a result, the odds ratios were 1.036 (95% confidence interval (CI) = 1.019-1.053, p < 0.001) for systolic blood pressure, 0.966 (95% CI = 0.941-0.989, p = 0.007) for high-density lipoprotein cholesterol level, 1.008 (95% CI = 1.002-1.014, p = 0.015) for fasting blood sugar level, and 0.855 (95% CI = 0.729-0.998, p = 0.043) for hemoglobin level. A significant strength of this study is the identification of low hemoglobin level (i.e., anemia) as a risk factor for microalbuminuria in patients with type 2 diabetes. This finding implies that the early detection and management of microalbuminuria can prevent the development of diabetic nephropathy.

Neutrophil-lymphocyte ratio as an inflammatory biomarker of diabetic nephropathy among type 2 diabetes mellitus patients: A comparative cross-sectional study

Objective

This study aimed to determine the neutrophil-lymphocyte ratio (NLR) as an inflammatory biomarker among type 2 diabetes mellitus (T2DM) patients with diabetic nephropathy (DN).

Methods

A comparative cross-sectional study design was conducted on 199 T2DM patients attending Bole 17 Health Center, Addis Ababa, Ethiopia. The urine albumin test was done by the MICRAL-II test strip. Fasting blood sugar was measured by a glucometer. Complete blood count was analyzed using an automated hematology analyzer (HUMAN GmbH, Wiesbaden, Hesse, Germany). The student's t-test, a chi-square test, and Pearson correlation were applied to analyze the data.

Results

Out of the 199 diabetes mellitus patients, 45 (22.6%) and 154 (77.4%) were found with DN and without DN, respectively. Interestingly, the mean NLR value (2.66 ± 0.49) was found significantly higher in diabetic patients with DN compared to the mean NLR (1.65 ± 0.20) in diabetes patients without DN (p < 0.0001). The NLR showed positive significant correlation with variables such as age (r = 0.162, p = 0.023), duration of disease (r = 0.52, p < 0.0001), absolute neutrophil count (r = 0.712, p < 0.0001), total white blood cell count (r = 0.162, p = 0.022), systolic blood pressure (r = 0.338, p < 0.0001), and diastolic blood pressure (r = 0.731, p < 0.0001). On the other hand, negatively significant correlation was found between NLR and absolute lymphocyte count (r = -0.770, p < 0.000).

Conclusion

The NLR was significantly increased in T2DM patients with DN, suggesting that inflammation and endothelial dysfunction could be an integral part of the pathogenesis of DN, and therefore, this ratio may be considered as a predictor and a prognostic biomarker of DN.

Development and assessment of diabetic nephropathy prediction model using hub genes identified by weighted correlation network analysis

Diabetic nephropathy (DN) is one microvascular complication of diabetes. About 30% of diabetic patients can develop DN, which is closely related to the high incidence and mortality of heart diseases, and then develop end-stage renal diseases. Therefore, early detection and screening of high-risk patients with DN is important. Herein, we explored the differences of serum transcriptomics between DN and non-DN in type II diabetes mellitus (T2DM) patients. We obtained 110 target genes using weighted correlation network analysis. Gene Ontology enrichment analysis indicates these target genes are mainly related to membrane adhesion, alpha-amino acid biosynthesis, metabolism, and binding, terminus, inhibitory synapse, clathrinid-sculpted vesicle, kinase activity, hormone binding, receptor activity, and transporter activity. Kyoto Encyclopedia of Genes and Genomes analysis indicates the process of DN in diabetic patients can involve synaptic vesicle cycle, cysteine and methionine metabolism, N-Glycan biosynthesis, osteoclast differentiation, and cAMP signaling pathway. Next, we detected the expression levels of hub genes in a retrospective cohort. Then, we developed a risk score tool included in the prediction model for early DN in T2DM patients. The prediction model was well applied into clinical practice, as confirmed by internal validation and several other methods. A novel DN risk model with relatively high prediction accuracy was established based on clinical characteristics and hub genes of serum detection. The estimated risk score can help clinicians develop individualized intervention programs for DN in T2DM. External validation data are required before individualized intervention measures.

Renoprotective Mechanism of Sodium-Glucose Cotransporter 2 Inhibitors: Focusing on Renal Hemodynamics

Diabetic kidney disease (DKD) is a prevalent renal complication of diabetes mellitus that ultimately develops into end-stage kidney disease (ESKD) when not managed appropriately. Substantial risk of ESKD remains even with intensive management of hyperglycemia and risk factors of DKD and timely use of renin-angiotensin-aldosterone inhibitors. Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce hyperglycemia primarily by inhibiting glucose and sodium reabsorption in the renal proximal tubule. Currently, their effects expand to prevent or delay cardiovascular and renal adverse events, even in those without diabetes. In dedicated renal outcome trials, SGLT2 inhibitors significantly reduced the risk of composite renal adverse events, including the development of ESKD or renal replacement therapy, which led to the positioning of SGLT2 inhibitors as the mainstay of chronic kidney disease management. Multiple mechanisms of action of SGLT2 inhibitors, including hemodynamic, metabolic, and anti-inflammatory effects, have been proposed. Restoration of tubuloglomerular feedback is a plausible explanation for the alteration in renal hemodynamics induced by SGLT2 inhibition and for the associated renal benefit. This review discusses the clinical rationale and mechanism related to the protection SGLT2 inhibitors exert on the kidney, focusing on renal hemodynamic effects.

Development and Validation of a Model That Predicts the Risk of Diabetic Nephropathy in Type 2 Diabetes Mellitus Patients: A Cross-Sectional Study

Purpose

To develop a nomogram model that predicts the risk of diabetic nephropathy (DN) incidence in type 2 diabetes mellitus (T2DM) patients.

Methods

We collect information from electronic medical record systems. The data were split into a training set (n=521) containing 73.8% of patients and a validation set (n=185) holding the remaining 26.2% of patients based on the date of data collection. Stepwise and multivariable logistic regression analyses were used to screen out DN risk factors. A predictive model including selected risk factors was developed by logistic regression analysis. The results of binary logistic regression are presented through forest plots and nomogram. Lastly, the c-index, calibration plots, and receiver operating characteristic (ROC) curves were used to assess the accuracy of the nomogram in internal and external validation. The clinical benefit of the model was evaluated by decision curve analysis.

Results

Predictors included serum creatinine (Scr), hypertension, glycosylated hemoglobin A1c (HbA1c), blood urea nitrogen (BUN), body mass index (BMI), triglycerides (TG), and Diabetic peripheral neuropathy (DPN). Harrell’s C-indexes were 0.773 (95% CI:0.726–0.821) and 0.758 (95% CI:0.679–0.837) in the training and validation sets, respectively. Decision curve analysis (DCA) demonstrated that the novel nomogram was clinically valuable.

Conclusion

Our simple nomogram with seven factors may help clinicians predict the risk of DN incidence in patients with T2DM.

3-Hydroxybutyrate Ameliorates the Progression of Diabetic Nephropathy

Studies report beneficial effects of 3-hydroxybutyrate (3-OHB) on the treatment of type 2 diabetes and obesity, but the effects of 3-OHB on diabetic nephropathy have not been elucidated. This study was designed to investigate the efficacy and mechanism of 3-OHB against progression of diabetic nephropathy (DN). Mice (db/db) were fed normal chow, high-fat, or ketogenic diets (KD) containing precursors of 3-OHB. Hyperglycemia was determined based on random glucose level (≥250 mg/dL). Fasting blood glucose and body weights were measured once a week. Twenty four-hour urine albumin to creatinine ratio was determined 5 weeks after the differential diet. Energy expenditure was measured 9 weeks after the differential diet. Body weights were significantly lower in the KD group than those in other groups, but no significant differences in fasting blood glucose levels among three groups were observed. Urine albumin to creatinine ratio and serum blood urea nitrogen (BUN) to creatinine ratio in the KD group were significantly lower than in other groups. Histologic and quantitative analysis of mesangial area suggested that KD delayed the progression of DN phenotype in db/db mice. Metabolic cage analysis also revealed that KD increased energy expenditure in db/db mice. In vitro studies with proximal tubular cells revealed that 3-OHB stimulated autophagic flux. 3-OHB increased LC3 I to LC3 II ratio, phosphorylation of AMPK, beclin, p62 degradation, and NRF2 expression. Moreover, we found that 3-OHB attenuated high glucose-induced reactive oxygen species (ROS) levels in proximal tubular cells. In vivo study also confirmed increased LC3 and decreased ROS levels in the kidney of KD mice. In summary, this study shows in both in vivo and in vitro models that 3-OHB delays the progression of DN by augmenting autophagy and inhibiting oxidative stress.

Protective effects of klotho on palmitate-induced podocyte injury in diabetic nephropathy

The anti-aging gene, klotho, has been identified as a multi-functional humoral factor and is implicated in multiple biological processes. However, the effects of klotho on podocyte injury in diabetic nephropathy are poorly understood. Thus, the current study aims to investigate the renoprotective effects of klotho against podocyte injury in diabetic nephropathy. We examined lipid accumulation and klotho expression in the kidneys of diabetic patients and animals. We stimulated cultured mouse podocytes with palmitate to induce lipotoxicity-mediated podocyte injury with or without recombinant klotho. Klotho level was decreased in podocytes of lipid-accumulated obese diabetic kidneys and palmitate-treated mouse podocytes. Palmitate-treated podocytes showed increased apoptosis, intracellular ROS, ER stress, inflammation, and fibrosis, and these were significantly attenuated by klotho administration. Klotho treatment restored palmitate-induced downregulation of the antioxidant molecules, Nrf2, Keap1, and SOD1. Klotho inhibited the phosphorylation of FOXO3a, promoted its nuclear translocation, and then upregulated MnSOD expression. In addition, klotho administration attenuated palmitate-induced cytoskeleton changes, decreased nephrin expression, and increased TRPC6 expression, eventually improving podocyte albumin permeability. These results suggest that klotho administration prevents palmitate-induced functional and morphological podocyte injuries, and this may indicate that klotho is a potential therapeutic agent for the treatment of podocyte injury in obese diabetic nephropathy.

Limitations of Deep Learning Attention Mechanisms in Clinical Research: Empirical Case Study Based on the Korean Diabetic Disease Setting

Background

Despite excellent prediction performance, noninterpretability has undermined the value of applying deep-learning algorithms in clinical practice. To overcome this limitation, attention mechanism has been introduced to clinical research as an explanatory modeling method. However, potential limitations of using this attractive method have not been clarified to clinical researchers. Furthermore, there has been a lack of introductory information explaining attention mechanisms to clinical researchers.

Objective

The aim of this study was to introduce the basic concepts and design approaches of attention mechanisms. In addition, we aimed to empirically assess the potential limitations of current attention mechanisms in terms of prediction and interpretability performance.

Methods

First, the basic concepts and several key considerations regarding attention mechanisms were identified. Second, four approaches to attention mechanisms were suggested according to a two-dimensional framework based on the degrees of freedom and uncertainty awareness. Third, the prediction performance, probability reliability, concentration of variable importance, consistency of attention results, and generalizability of attention results to conventional statistics were assessed in the diabetic classification modeling setting. Fourth, the potential limitations of attention mechanisms were considered.

Results

Prediction performance was very high for all models. Probability reliability was high in models with uncertainty awareness. Variable importance was concentrated in several variables when uncertainty awareness was not considered. The consistency of attention results was high when uncertainty awareness was considered. The generalizability of attention results to conventional statistics was poor regardless of the modeling approach.

Conclusions

The attention mechanism is an attractive technique with potential to be very promising in the future. However, it may not yet be desirable to rely on this method to assess variable importance in clinical settings. Therefore, along with theoretical studies enhancing attention mechanisms, more empirical studies investigating potential limitations should be encouraged.

Study of serum pentraxin 3 level in patients with diabetic nephropathy

Background

Pentraxin 3 (PTX3), a member of a superfamily of conserved proteins called pentraxins. PTX3 and C-reactive protein (CRP) are members of this family and play an important role in the innate immune system. PTX3 is classified as a long pentraxin, while CRP is a short pentraxin. PTX3 is reported to be a vascular inflammatory marker providing prognostic information of vasculopathy, such as diabetic nephropathy (DN). The purpose of this study is to evaluate the association between serum PTX3 concentrations and the development and/or progression of DN. A total number of 66 patients with type 2 diabetes mellitus (T2DM) and 22 healthy subjects were enrolled in this study. Patients with T2DM were divided, according to the levels of urinary albumin/creatinine ratio (UACR), into three groups: normoalbuminuric, microalbuminuric, and macroalbuminuric groups. Serum PTX3 and high-sensitivity C-reactive protein (hs-CRP) concentrations were determined using ELISA kits.

Results

Serum PTX3 and hs-CRP concentrations were significantly higher in patients with T2DM compared with the controls. Furthermore, serum PTX3 concentrations were significantly higher in macroalbuminuric patients than in microalbuminuric patients (P < 0.001) and also were significantly higher in microalbuminuric patients than in normoalbuminuric patients (P < 0.001). However, there were no significant differences between controls and T2DM patients with normoalbuminuria regarding serum PTX3 concentrations (P > 0.05). Moreover, like PTX3, hs-CRP concentrations were higher in microalbuminuric patients than in normoalbuminuric patients (P < 0.05), and also, there were no significant differences between controls and T2DM patients with normoalbuminuria regarding hs-CRP concentrations (P > 0.05). But, unlike PTX3, there were no significant differences between macroalbuminuric and microalbuminuric patients regarding hs-CRP concentrations (P > 0.05).

Conclusions

Serum PTX3 is positively associated with DN development and progression, and may be a more accurate predictor of DN development than hs-CRP as it can discriminate between macroalbuminuric and microalbuminuric DN patients, while hs-CRP cannot.

Did Sejong the Great have ankylosing spondylitis? The oldest documented case of ankylosing spondylitis

AIM

Sejong the Great (May 7, 1397-March 30, 1450), a king during Korea's Choson Dynasty, is the most respected historical figure in South Korean society, and consequently, many studies have been conducted on his achievements and the disease he suffered. The dominant trend of scholarship claims that Sejong suffered from diabetic retinopathy. However, this interpretation has not been medically verified. The present analysis aimed to demonstrate that Sejong's is the oldest documented case of ankylosing spondylitis.

METHODS

The Annals of the Choson Dynasty (hereafter, The Annals) are daily records of the king. The Annals were recorded for 472 years (1392-1865) and contain 49 646 667 Chinese characters. Records in The Annals on Sejong span 1418-1450; the present study author reviewed these records.

RESULTS

Sejong's medical records are mentioned 40 times in the source text. The king first experienced musculoskeletal pain in his knee at the age of 22 years. Sejong's knee pain is mentioned 3 times, and his back pain, which he described as "stiff and immobile", is mentioned 6 times. He complained most frequently of ocular symptoms described as "prickly or tingling," which are mentioned 12 times.

CONCLUSIONS

Based on the analysis of official documentation, the author argues that there is a high probability that Sejong suffered from ankylosing spondylitis, making this the oldest officially documented case of the disease.

Differential Urinary Proteome Analysis for Predicting Prognosis in Type 2 Diabetes Patients with and without Renal Dysfunction

Renal dysfunction, a major complication of type 2 diabetes, can be predicted from estimated glomerular filtration rate (eGFR) and protein markers such as albumin concentration. Urinary protein biomarkers may be used to monitor or predict patient status. Urine samples were selected from patients enrolled in the retrospective diabetic kidney disease (DKD) study, including 35 with good and 19 with poor prognosis. After removal of albumin and immunoglobulin, the remaining proteins were reduced, alkylated, digested, and analyzed qualitatively and quantitatively with a nano LC-MS platform. Each protein was identified, and its concentration normalized to that of creatinine. A prognostic model of DKD was formulated based on the adjusted quantities of each protein in the two groups. Of 1296 proteins identified in the 54 urine samples, 66 were differentially abundant in the two groups (area under the curve (AUC): p-value < 0.05), but none showed significantly better performance than albumin. To improve the predictive power by multivariate analysis, five proteins (ACP2, CTSA, GM2A, MUC1, and SPARCL1) were selected as significant by an AUC-based random forest method. The application of two classifiers—support vector machine and random forest—showed that the multivariate model performed better than univariate analysis of mucin-1 (AUC: 0.935 vs. 0.791) and albumin (AUC: 1.0 vs. 0.722). The urinary proteome can reflect kidney function directly and can predict the prognosis of patients with chronic kidney dysfunction. Classification based on five urinary proteins may better predict the prognosis of DKD patients than urinary albumin concentration or eGFR.

Nomogram for the prediction of diabetic nephropathy risk among patients with type 2 diabetes mellitus based on a questionnaire and biochemical indicators: a retrospective study

Purpose: Develop a diabetic nephropathy incidence risk nomogram in a Chinese population with type 2 diabetes mellitus.

Results: Predictors included systolic blood pressure, diastolic blood pressure, fasting blood glucose, glycosylated hemoglobin A1c, total triglycerides, serum creatinine, blood urea nitrogen and body mass index. The model displayed medium predictive power with a C-index of 0.744 and an area under curve of 0.744. Internal verification of C-index reached 0.737. The decision curve analysis showed the risk threshold was 20%. The value of net reclassification improvement and integrated discrimination improvement were 0.131, 0.05, and that the nomogram could be applied in clinical practice.

Conclusion: Diabetic nephropathy incidence risk nomogram incorporating 8 features is useful to predict diabetic nephropathy incidence risk in type 2 diabetes mellitus patients.

Methods: Questionnaires, physical examinations and biochemical tests were performed on 3489 T2DM patients in six communities in Shanghai. LASSO regression was used to optimize feature selection by running cyclic coordinate descent. Logistic regression analysis was applied to build a prediction model incorporating the selected features. The C-index, calibration plot, curve analysis, forest plot, net reclassification improvement, integrated discrimination improvement and internal validation were used to validate the discrimination, calibration and clinical usefulness of the model.

Urine E-cadherin: A Marker for Early Detection of Kidney Injury in Diabetic Patients

Diabetic nephropathy (DN) is the main reason for end-stage renal disease. Microalbuminuria as the non-invasive available diagnosis marker lacks specificity and gives high false positive rates. To identify and validate biomarkers for DN, we used in the present study urine samples from four patient groups: diabetes without nephropathy, diabetes with microalbuminuria, diabetes with macroalbuminuria and proteinuria without diabetes. For the longitudinal validation, we recruited 563 diabetic patients and collected 1363 urine samples with the clinical data during a follow-up of 6 years. Comparative urinary proteomics identified four proteins Apolipoprotein A-I (APOA1), Beta-2-microglobulin (B2M), E-cadherin (CDH1) and Lithostathine-1-alpha (REG1A), which differentiated with high statistical strength (p < 0.05) between DN patients and the other groups. Label-free mass spectrometric quantification of the candidates confirmed the discriminatory value of E-cadherin and Lithostathine-1-alpha (p < 0.05). Immunological validation highlighted E-cadherin as the only marker able to differentiate significantly between the different DN stages with an area under the curve (AUC) of 0.85 (95%-CI: [0.72, 0.97]). The analysis of the samples from the longitudinal study confirmed the prognostic value of E-cadherin, the critical increase in urinary E-cadherin level was measured 20 ± 12.5 months before the onset of microalbuminuria and correlated significantly (p < 0.05) with the glomerular filtration rate measured by estimated glomerular filtration rate (eGFR).

Risk factors for diabetic nephropathy complications in community patients with type 2 diabetes mellitus in Shanghai: Logistic regression and classification tree model analysis

BACKGROUND

The prevalence of type 2 diabetes mellitus (T2DM) in China was 11.6% in 2010. Chronic complications are the main diabetes-related cause of death and disability, accounting for more than 80% of the cost of diabetes treatment. Diabetic nephropathy (DN) is a common microvascular complication and is the second leading cause of end-stage renal failure in China.

OBJECTIVE

We aimed to analyse the DN status among community-based T2DM patients and to explore risk factors for T2DM with DN.

METHODS

This study was conducted in six communities of Shanghai. We administered a questionnaire, physical examination, and biochemical tests to 5078 patients with T2DM. Logistic regression and the classification tree model were used to analyse risk factors for T2DM with DN.

RESULTS

In total, 1937 patients were diagnosed with DN (prevalence 38.4%). The logistic regression model indicated that course of disease more than 15 years, body mass index (BMI) greater than 24 kg/m² , haemoglobin A1c (HbA1c) greater than 7.5%, fasting blood glucose (FBG) greater than 11.0 mmol/L, total cholesterol (TC), and high-density lipoprotein (HDL)-C control failure, hypertension, and diabetic retinopathy were risk factors for T2DM with DN (P < .05). The classification tree model identified seven risk factors (HbA1c, FBG, hypertension, postprandial blood glucose, BMI, triacylglycerol, and HDL), of which, HbA1c (cut-off point 7.45%), hypertension, and FBG showed the strongest association.

CONCLUSION

This suggests that screening for DN based on HbA1c, FBG, and hypertension should be more extensively promoted by the government on a community level, more attention should be focused on patients' health management, and that patients should be educated on self-management.

Predictive Factors for Efficacy of AST-120 Treatment in Diabetic Nephropathy: a Prospective Single-Arm, Open-Label, Multi-Center Study

BACKGROUND

Removal of uremic toxins such as indoxyl sulfate by AST-120 is known to improve renal function and delay the initiation of dialysis in patients with advanced chronic kidney disease. However, it is unclear whether the addition of AST-120 to conventional treatments is effective in delaying the progression of renal dysfunction in patients with diabetic nephropathy.

METHODS

A total of 100 patients with type 2 diabetes and renal dysfunction (serum creatinine levels ranging from 1.5 to 3.0 mg/dL) were recruited from eight centers in Korea and treated with AST-120 (6 g/day) for 24 weeks. The primary endpoint was improvement in renal function measured as the gradient of the reciprocal serum creatinine level (1/sCr) over time (i.e., the ratio of 1/sCr time slope for post- to pre-AST-120 therapy). A response was defined as a ratio change of the regression coefficient of 1/sCr ≤ 0.90.

RESULTS

Renal function improved in 80.3% of patients (61/76) after 24 weeks of AST-120 treatment. There were no differences between responder and non-responder groups in baseline characteristics except for diastolic blood pressure (73.5 ± 9.5 mmHg in the responder group vs. 79.3 ± 11.1 mmHg in the non-responder group; P = 0.046). Serum lipid peroxidation level decreased significantly in the responder group (from 2.25 ± 0.56 μol/L to 1.91 ± 0.72 μol/L; P = 0.002) but not in the non-responder group.

CONCLUSION

The addition of AST-120 to conventional treatments may delay the progression of renal dysfunction in diabetic nephropathy. The antioxidant effect of AST-120 might contribute to improvement in renal function.

MicroRNA-326-3p ameliorates high glucose and ox-LDL-IC- induced fibrotic injury in renal mesangial cells by targeting FcγRIII

AIM

The aim of the present study was to identify the regulatory relationship between miR-326-3p and FcγRIII, and to explore the involvement of miR-326-3p/FcγRIII/TGF-β/Smad signalling pathway in fibrotic injury, which was induced by the high glucose (HG) and oxidized low density lipoprotein immune complex (ox-LDL-IC) in mouse glomerular mesangial cells (GMCs).

METHODS

Dual-luciferase reporter system and real time PCR (RT-PCR) were used to identify FcγRIII as a target gene of miR-326-3p. Lentiviral transduction was used to construct different expression of miR-326-3p in GMCs, which were divided into three groups: miR-326-3p mimics group (miR-326-3p group), miR-326-3p inhibitor group (miR-326-3p-inhibit group) and scramble control group (control group). Then, each group was stimulated by normal glucose (NG), HG, ox-LDL-IC and HG + ox-LDL-IC, respectively. RT-PCR and western blot were used to measure the expressions of Col-I, CTGF, α-SMA, TGF-β, Smad2/3 and pSmad2/3.

RESULTS

FcγRIII was regulated negatively by miR-326-3p in GMCs under the condition of HG and ox-LDL-IC, which implied FcγRIII as a target gene of miR-326-3p. Furthermore, compared with normal glucose group, the expressions of Col-I, CTGF, α-SMA, TGF-β and pSmad2/3 were higher under the condition of HG, ox-LDL-IC and HG + ox-LDL-IC (P < 0.05). In particular, miR-326-3p-inhibit groups exhibited the most significant increase (P < 0.05), while miR-326-3p could attenuate the increase (P < 0.05).

CONCLUSION

FcγRIII was identified as a target gene of miR-326-3p. MiR-326-3p/FcγRIII/TGF-β/Smad signaling pathway was investigated to be involved in the pathophysiology of renal fibrosis of DKD.

Cigarette smoking as a risk factor for diabetic nephropathy: A systematic review and meta-analysis of prospective cohort studies

Background

Observational studies suggested that tobacco smoking was associated with diabetic nephropathy (DN). However, the results were conflicting and inconsistent. In the study, we performed a meta-analysis to assess the relationship between tobacco smoking and the development of DN.

Materials and methods

We searched in PubMed, Embase, Web of Science and the Cochrane Library (CENTRAL) from database inception until Mar 8, 2018, and updated our search on May 1, 2018. We screened the reference lists of the retrieved articles. Only original prospective cohort studies which have investigated the association between smoking and DN incidence or its progression were included. Pooled HRs and 95% confidence intervals (CIs) were calculated using a random effects model.

Results

A total of 9 prospective cohort studies were identified, including more than 203337 participants. Compared with those of no smoking, smoking participants increased the risk of developing DN (HR = 1.07, 95% CI: 1.01–1.13, P = 0.01). The subgroup analysis showed that the current and total smoking may increase the risk of DN, but these results did not reach statistical significance (current: HR = 1.69, 95% CI = 0.79–3.64, p = 0.17; total: HR = 1.17, 95% CI = 0.97–1.41, p = 0.10), whereas former smoking significantly increased the risk of DN (HR = 1.04, 95% CI = 1.03–1.05, p<0.001). Compared with no-smokers, smokers showed an elevated risk of developing DN (HR = 1.05; 95% CI, 1.00–1.11, P = 0.05). In patients with T2DM, those who smoked were at an increased risk of developing DN, as compared to those who had never smoked (HR = 1.05; 95% CI, 1.00–1.11, P = 0.05). However, compared to no smoking, smoking did not increase the risk of DN development in patients with T2DM (HR = 1.15; 95% CI, 0.9–1.47, P = 0.25). Univariate and multivariate meta-regression did not find any confounding factors. No publication bias was found in the meta-analysis.

Conclusions

The present study highlighted that smoking was an independent risk factor for DN, especially in patients with T1DM. This is the first meta-analysis of prospective cohort studies to discuss the relationship between smoking and DN.

Plasma endoglin in Type2 diabetic patients with nephropathy

BACKGROUND

Diabetic nephropathy may be a common complication of diabetes mellitus. Endoglin is glycoprotein located on cell surfaces of endothelial cells and is part of the transforming growth factor beta (TGF- β) receptor. Endoglin expression is enhanced in endothelial cells during injury and inflammation. The aim of this study was to estimate the plasma level of soluble endoglin (sEng) in type 2 diabetic patients (with and without nephropathy). Also to explore its availability as marker for disease progression.

METHODS

In this study, sixty eight patients with type 2 diabetes mellitus (T2DM) were included; the patients were sub-grouped to normoalbuminuria without nephropathy and moderately increased albuminuria (microalbuminuria) with nephropathy groups with 13 individuals as control group. Plasma soluble endoglin level was determined using ELISA technique. Fasting plasma glucose (FPG), glycated haemoglobin (HbA1c), lipid profile, and creatinine were determined using colorimetric assay, whereas glomerular filtration rate (GFR) was calculated.

RESULTS

The plasma level of sEng of both normoalbuminuria group 1 and microalbuminuria group 2 were significantly higher when compared to control group. While, the plasma level of sEng in microalbuminuria group 2 was nonsignificant lower when compared to normoalbuminuria group 1. Also, there was a significant positive association between plasma level of sEng and HbA1c, HDL-C and urinary albumin concentration in normoalbuminuria group.

CONCLUSION

Plasma level of soluble Endoglin is markedly increase prior to alteration in endothelial function, and increases to lesser extent with the developing of diabetic nephropathy which indicated disease progression and development of vascular abnormalities.

Long-term effects of various types of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors on changes in glomerular filtration rate in Korea

Few long-term follow-up studies have compared the changes in renal function according to the type of statin used in Korea. We compared the long-term effects of statin intensity and type on the changes in the glomerular filtration rate (GFR). We extracted data of patients who took statin for the first time. We analyzed whether or not different statins affect the changes in GFR at 3 months after baseline and 4 years after. We included 3678 patients and analyzed the changes in GFR. The GFR decreased by 3.2% ± 0.4% on average 4 years after the first statin prescription, indicating statistically significant deterioration (from 83.5 ± 0.4 mL/min/1.73 m² to 79.9 0.4 mL/min/1.73 m², P < 0.001). When comparing the GFR among different statins, significant differences were observed between atorvastatin and fluvastatin (-5.3% ± 0.7% vs. 1.2% ± 2.2%, P < 0.05) and between atorvastatin and simvastatin (-5.3% ± 0.7% vs. -0.7% ± 0.8%, P < 0.05). In pitavastatin (odds ratio [OR]= 0.64, 95% confidence interval [CI]= 0.46-0.87, P < 0.005) and simvastatin (OR = 0.69, 95% CI = 0.53-0.91, P < 0.008), the GFR rate that decreased by < 60 mL/min/1.73 m² was significantly lower than that of atorvastatin. Regarding long-term statin intake, GFR changed with the type of statin. This work is the first in Korea to compare each statin in terms of changes in the GFR after the statin prescription.

Diabetes Fact Sheet in Korea, 2016: An Appraisal of Current Status

BACKGROUND

This report presents the recent prevalence and comorbidities related to diabetes in Korea by analyzing the nationally representative data.

METHODS

Using data from the Korea National Health and Nutrition Examination Survey for 2013 to 2014, the percentages and the total number of subjects over the age of 30 years with diabetes and prediabetes were estimated and applied to the National Population Census in 2014. Diagnosis of diabetes was based on fasting plasma glucose (≥126 mg/dL), current taking of antidiabetic medication, history of previous diabetes, or glycosylated hemoglobin (HbA1c) ≥6.5%. Impaired fasting glucose (IFG) was defined by fasting plasma glucose in the range of 100 to 125 mg/dL among those without diabetes.

RESULTS

About 4.8 million (13.7%) Korean adults (≥30 years old) had diabetes, and about 8.3 million (24.8%) Korean adults had IFG. However, 29.3% of the subjects with diabetes are not aware of their condition. Of the subjects with diabetes, 48.6% and 54.7% were obese and hypertensive, respectively, and 31.6% had hypercholesterolemia. Although most subjects with diabetes (89.1%) were under medical treatment, and mostly being treated with oral hypoglycemic agents (80.2%), 10.8% have remained untreated. With respect to overall glycemic control, 43.5% reached the target of HbA1c <7%, whereas 23.3% reached the target when the standard was set to HbA1c <6.5%, according to the Korean Diabetes Association guideline.

CONCLUSION

Diabetes is a major public health threat in Korea, but a significant proportion of adults were not controlling their illness. We need comprehensive approaches to overcome the upcoming diabetes-related disease burden in Korea.

Correlation of vascular endothelial function and coagulation factors with renal function and inflammatory factors in patients with diabetic nephropathy

Correlation of vascular endothelial function and coagulation factors with renal function and inflammatory factors in patients with diabetic nephropathy was analyzed. A total of 86 patients diagnosed with diabetes mellitus (DM) and admitted to the 89th Hospital of the People's Liberation Army (Weifang, China) from March 2014 to May 2017 were selected. Among them, 38 patients complicated with nephropathy were divided into the observation group and 48 patients without nephropathy into the control group. The general data of patients were collected, and the relevant biochemical indexes, vascular endothelial function, coagulation factors and renal function indicators and the levels of inflammatory factors were determined. In the observation group, the duration of DM was longer than that in the control group, and the levels of glycated hemoglobin (HbA1c), fasting plasma glucose (FPG) and fasting insulin (FINS), level of fibrinogen (FIB) were higher than those in the control group (p<0.05). Homocysteine (Hcy) and brachial artery blood flow in the observation group were higher than those in the control group. The levels of nitric oxide (NO) and flow-mediated dilation (FMD) were lower than those in the control group (p<0.05). Activated partial thromboplastin time (APTT) in the observation group was shorter than that in the control group (p<0.05). The levels of cystatin-C (Cys-C), serum creatinine (SCr), urea and β2-microglobulin, levels of C-reactive protein (CRP), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in peripheral serum in the observation group were greatly higher than those in the control group (p<0.05). It was concluded via the correlation analysis of vascular endothelial function and coagulation factor with renal function and inflammatory factors that SCr and CRP were negatively correlated with NO, and SCr and CRP were positively correlated with FIB. Serum inflammatory factors, coagulation function and vascular endothelial function are closely related to diabetic nephropathy, which are good reference indexes for the assessment of diabetic nephropathy.

Meta-analysis of the benefit of sitagliptin treatment in patients with type 2 diabetes complicated with incipient nephropathy

The purpose of this meta-analysis was to evaluate the evidence of the clinical efficacy and safety of sitagliptin in diabetic patients with incipient nephropathy. PubMed, Ovid, Cochrane library, Chinese National Knowledge Infrastructure, and Wanfang databases were searched in September 2017 to identify randomized controlled trials (RCTs) of sitagliptin in diabetic patients with incipient nephropathy. Study selection, data extraction and study quality assessment were performed independently by two investigators, while disagreements were resolved by a third reviewer. The treatment effect was estimated by calculating the mean difference (MD) or standard mean difference (SMD). Heterogeneity was assessed with the χ² and I² tests. Additionally, risk of bias graphs and summaries were used to assess the quality of the included trials. Thirteen RCTs were included in this review; their results suggested that sitagliptin has obvious advantages in lowering the 24-hour urinary albumin excretion [MD, -25.71; 95% confidence interval (CI), -30.75 to -20.66; P<0.00001], serum cystatin C (MD, -0.59; 95% CI, -0.64 to -0.54; P<0.00001), inflammation (MD, -0.81; 95% CI, -1.20 to -0.42; P<0.0001), and total cholesterol (MD, -0.13; 95% CI, -0.22 to -0.03; P=0.009). However, sitagliptin did not appear to influence serum creatinine, fasting blood glucose, postprandial blood glucose, glycosylated hemoglobin A1c, or triglyceride levels, although these results may have been influenced by biases in the included trials. The most common adverse effects of sitagliptin were gastrointestinal tract reaction and hypoglycemia, although these symptoms resolved quickly. Sitagliptin appears to be effective in reducing proteinuria, ameliorating renal function, and producing an anti-inflammatory effect in patients with early-stage diabetic nephropathy. The present analysis provides important guidance for the clinical application of sitagliptin.

Glycated Albumin Is a More Useful Glycation Index than HbA1c for Reflecting Renal Tubulopathy in Subjects with Early Diabetic Kidney Disease

BACKGROUND

The aim of this study was to investigate which glycemic parameters better reflect urinary N-acetyl-β-D-glucosaminidase (uNAG) abnormality, a marker for renal tubulopathy, in subjects with type 2 diabetes mellitus (T2DM) subjects with normoalbuminuria and a normal estimated glomerular filtration rate (eGFR).

METHODS

We classified 1,061 participants with T2DM into two groups according to uNAG level-normal vs. high (>5.8 U/g creatinine)-and measured their biochemical parameters.

RESULTS

Subjects with high uNAG level had significantly higher levels of fasting and stimulated glucose, glycated albumin (GA), and glycosylated hemoglobin (HbA1c) and lower levels of homeostasis model assessment of β-cell compared with subjects with normal uNAG level. Multiple linear regression analyses showed that uNAG was significantly associated with GA (standardized β coefficient [β]=0.213, P=0.016), but not with HbA1c (β=?0.137, P=0.096) or stimulated glucose (β=0.095, P=0.140) after adjusting confounding factors. In receiver operating characteristic analysis, the value of the area under the curve (AUC) for renal tubular injury of GA was significantly higher (AUC=0.634; 95% confidence interval [CI], 0.646 to 0.899) than those for HbA1c (AUC=0.598; 95% CI, 0.553 to 0.640), stimulated glucose (AUC=0.594; 95% CI, 0.552 to 0.636), or fasting glucose (AUC=0.558; 95% CI, 0.515 to 0.600). The optimal GA cutoff point for renal tubular damage was 17.55% (sensitivity 59%, specificity 62%).

CONCLUSION

GA is a more useful glycation index than HbA1c for reflecting renal tubulopathy in subjects with T2DM with normoalbuminuria and normal eGFR.

Evaluation of the association between the number of natural teeth and anemia among Korean adults using nationally representative data

BACKGROUND

Anemia as a chronic disease is defined as anemia occurring in chronic infections with inflammatory conditions. The purpose of this study is to assess the association between the number of natural teeth and anemia using nationally representative data.

METHODS

This study involved a cross-sectional analysis using data from the Korean National Health and Nutrition Examination Survey from 2010 to 2012. A total of 16,875 respondents aged > 19 years without missing values were included in this study. The association between the number of natural teeth and anemia was evaluated by multivariable logistic regression analyses after adjusting for age, sex, body mass index, smoking habits, drinking habits, exercise levels, income levels, education levels, vitamin D levels, diabetes, toothbrushing frequency, energy intake, and percentage of fat in total energy intake among Korean adults.

RESULTS

There was a significant decrease in prevalence of anemia and a significant increase in hemoglobin levels in participants with more natural teeth (P < 0.05). Adjusted odds ratios and their 95% confidence intervals for anemia in participants with numbers of natural teeth of < 15, 15 to 19, 20 to 24, or 24 to 28 were 1 (reference), 0.856(0.591 to 1.24), 0.659(0.5 to 0.868), and 0.607(0.463 to 0.797), respectively, with adjustment for confounding factors (P < 0.05).

CONCLUSION

The number of natural teeth is negatively associated with anemia in Korean adults, and the number of natural teeth may be considered an independent risk indicator of anemia.

The Global Epidemiology of Diabetes and Kidney Disease

The prevalence of diabetes is increasing worldwide, with the greatest increases occurring in low- and middle-income countries. In most developed countries, type 2 diabetes is presently the leading cause of end-stage renal disease and also contributes substantially to cardiovascular disease. In countries with weaker economies type 2 diabetes is rapidly replacing communicable diseases as a leading cause of kidney disease and is increasingly competing for scarce health care resources. Here, we present a narrative review of the prevalence and incidence of diabetes-related kidney disease worldwide. Mortality among those with diabetes and kidney disease will also be explored. Given the high morbidity and mortality associated with chronic kidney disease, we will also examine the level of awareness of this disease among people who have it.

Cigarette smoking and risk of albuminuria in patients with type 2 diabetes: a systematic review and meta-analysis of observational studies

BACKGROUND

The aim of this study was to assess the effects of smoking on albuminuria risk in adults with type 2 diabetes mellitus (T2DM).

METHODS

A literature search was conducted using MEDLINE, EMBASE, and China National Knowledge Infrastructure from the established date to October 2017. Summary relative risks (SRR) and 95% confidence intervals (CI) were computed utilizing a random effect inverse variance method.

RESULTS

This meta-analysis included a total of 19 relevant observational studies (four prospective cohort, seven case-control, and eight cross-sectional studies), reporting 105,031 participants and 23,366 albuminuria events. Compared with never-smokers with T2DM, the SRRs of albuminuria were 1.43 (95% CIs 1.27-1.61) for ever-smokers, 2.61 (95% CIs 1.86-3.64) for current smokers, and 1.86 (95% CIs 1.37-2.52) for former smokers. Considerable heterogeneity was observed among these studies, and study design was a significant modifier for this association. There were significantly elevated risk associations for microalbuminuria (SRRs = 1.24, 95% CIs 1.05-1.46) and for macroalbuminuria (SRRs = 1.65, 95% CIs 1.03-2.66), respectively.

CONCLUSIONS

Our systematic review and meta-analysis indicates that cigarette smoking might be a potential factor for the development of albuminuria in adults with T2DM. Future studies are required to investigate the association between smoking cessation and intensity and incident albuminuria in adults with T2DM.

Association between the number of natural teeth and diabetic retinopathy among type 2 diabetes mellitus: The Korea national health and nutrition examination survey

The aim of this study was to investigate the relationship between the number of teeth and diabetic retinopathy among Korean population.This was a retrospective analysis using data of total 45,811 individuals who participated in the Korea National Health and Nutrition Examination Survey (KNHANES) 2008 to 2012. Among these, 2593 (5.7%) participants were identified as having type 2 diabetes mellitus. After excluding participants without ophthalmic evaluation or other variables, 2078 (80%) participants were included. Demographic factors including dental status were analyzed and compared between participants with and without diabetic retinopathy.Among the 2078 type 2 diabetes, 358 (17.2%) had diabetic retinopathy. Type 2 diabetes with fewer teeth were more likely to have diabetic retinopathy (P < .001). Multivariate analysis showed that type 2 diabetes with < 20 teeth had an 8.7-fold risk of having vision-threatening diabetic retinopathy when compared with type 2 diabetes with ≥28 teeth (95% confidence interval: 2.69-28.3) after adjusting for age, sex, body mass index, smoking, drinking, exercise, hypertension, diabetes mellitus duration, and glycated hemoglobin level.The number of teeth was found to be an independent risk factor for diabetic retinopathy. Thus, a comprehensive approach of dentists and ophthalmologists is needed to minimize the complications of diabetes mellitus. Whether the teeth number reflects microvascular changes of the retina among type 2 diabetes warrants further investigation.

Smoking and the risk of diabetic nephropathy in patients with type 1 and type 2 diabetes: a meta-analysis of observational studies

Background

Conflicting evidence exists for observational studies on whether tobacco smoking is a risk factor for diabetic nephropathy (DN) in patients with type 1 (T1DM) and type 2 diabetes mellitus (T2DM). In this meta-analysis, we aimed to assess the effects of tobacco smoking on the development of DN.

Materials and Methods

We searched MEDLINE and EMBASE databases from their inception to March 31^st, 2017 for cross-sectional, case-control, and prospective cohort studies. We screened reference lists of retrieved articles. Summary relative risks (SRRs) and 95% confidence intervals (CIs) were calculated using a random-effects model.

Results

A total of nineteen observational studies (1 case-control, 8 cross-sectional and 10 prospective cohort studies) were identified, involving more than 78,000 participants and a total of 17,832 DN cases. Compared with never-smokers, there was an augmented SRR (95% CI) of DN in ever-smokers in patients with T1DM (1.31 [1.06–1.62]; P = 0.006) and T2DM (1.44 [1.24–1.67]; P < 0.001), respectively. In patients with T1DM, the SRR (95% CI) was 1.25 (0.86–1.83) for microalbuminuria only, 1.27 (1.10–1.48) for macroalbuminuria only, and 1.06 (0.97–1.15) for end-stage renal disease (ESRD). In patients with T2DM, the SRR (95% CI) associated with ever smoking was 1.46 (0.94–2.26) for microalbuminuria only, 1.72 (1.04–2.84) for macroalbuminuria only, and 1.10 (0.36–3.33) for ESRD.

Conclusions

Our meta-analysis suggests evidence for cigarette smoking as an independent risk factor for the development of DN in patients with both T1DM and T2DM.

Low serum bilirubin level predicts the development of chronic kidney disease in patients with type 2 diabetes mellitus

BACKGROUND/AIMS

We evaluated whether serum bilirubin levels can predict the development of chronic kidney disease (CKD) in patients with type 2 diabetes mellitus (T2DM).

METHODS

This was a retrospective observational longitudinal study of patients presenting at the Pusan National University Hospital. A total of 349 patients with T2DM and preserved kidney function (estimated glomerular filtration rate ≥ 60 mL/min/1.73 m²) were enrolled. The main outcome was the development of CKD stage 3 or greater. The patients were divided into four groups according to the quartiles of the total serum bilirubin levels at baseline.

RESULTS

The group with the lowest range of total serum bilirubin level (Q1) showed the highest cumulative incidence of CKD stage 3 or greater than that of the other lower quartiles (Q1 vs. Q4; hazard ratio [HR], 6.75; 95% confidence interval [CI], 1.54 to 29.47; p = 0.011). In multivariate analysis, the risk of developing CKD stage 3 or greater was higher in the second lowest quartile of the serum bilirubin level than that in the highest quartile of the serum bilirubin level (Q2 vs. Q4; HR, 9.36; 95% CI, 1.33 to 65.73; p = 0.024). In the normoalbuminuria subgroup (n = 236), multivariate analysis showed that the risk of developing CKD stage 3 or greater was higher in the lowest quartile of the serum bilirubin level than that in the highest quartile of the serum bilirubin level (Q1 vs. Q4; HR, 7.36; 95% CI, 1.24 to 35.82; p = 0.019).

CONCLUSIONS

Serum bilirubin might be an early clinical marker for predicting the progression of CKD in patients with T2DM and preserved renal function.

Treatment of diabetic kidney disease: current and future targets

Diabetic kidney disease (DKD) is a leading cause of end-stage renal disease in Korea and worldwide, and is a risk factor for the development of cardiovascular complications. The conventional treatments for DKD are control of blood glucose and blood pressure levels by inhibiting the renin-angiotensin system. However, the prevalence of DKD continues to increase and additional therapies are required to prevent or ameliorate the condition. Many drugs have been, or are being, developed to target the molecular mechanisms in play in DKD. This review focuses on DVD treatment, considering current and emerging therapeutic targets and the clinical trial-based evidence.

Comparison between Atorvastatin and Rosuvastatin in Renal Function Decline among Patients with Diabetes

BACKGROUND

Although the beneficial effects of statin treatment in dyslipidemia and atherosclerosis have been well studied, there is limited information regarding the renal effects of statins in diabetic nephropathy. We aimed to investigate whether, and which, statins affected renal function in Asian patients with diabetes.

METHODS

We enrolled 484 patients with diabetes who received statin treatment for more than 12 months. We included patients treated with moderate-intensity dose statin treatment (atorvastatin 10 to 20 mg/day or rosuvastatin 5 to 10 mg/day). The primary outcome was a change in estimated glomerular filtration rate (eGFR) during the 12-month statin treatment, and rapid renal decline was defined as a >3% reduction in eGFR in a 1-year period.

RESULTS

In both statin treatment groups, patients showed improved serum lipid levels and significantly reduced eGFRs (from 80.3 to 78.8 mL/min/1.73 m² for atorvastatin [P=0.012], from 79.1 to 76.1 mL/min/1.73 m² for rosuvastatin [P=0.001]). A more rapid eGFR decline was observed in the rosuvastatin group than in the atorvastatin group (48.7% vs. 38.6%, P=0.029). Multiple logistic regression analyses demonstrated more rapid renal function loss in the rosuvastatin group than in the atorvastatin group after adjustment for other confounding factors (odds ratio, 1.60; 95% confidence interval, 1.06 to 2.42).

CONCLUSION

These results suggest that a moderate-intensity dose of atorvastatin has fewer detrimental effects on renal function than that of rosuvastatin.

Variability in glycated albumin levels predicts the progression of diabetic nephropathy

AIM

The present study was performed to assess variability in glycated albumin (GA) using a coefficient of variation (CV) to predict the progression of diabetic nephropathy in type 2 diabetic patients, independently of HbA1c and other conventional risk factors.

METHODS

The present study consecutively enrolled 369 patients with type 2 diabetes mellitus from outpatient clinic. During the follow-up period, GA and HbA1c levels were measured repeatedly (≥5 times), and the CV of GA (GA-CV) was calculated for each patient. The patients were divided into two subgroups: Group 1, a MEAN-HbA1c value <7.2% (55mmol/mol); Group 2, a MEAN-HbA1c value ≥7.2% (55mmol/mol). The primary outcome was the renal composite outcome (RCO), which was based on the progression rates of chronic kidney disease and albuminuria and renal death.

RESULTS

The median follow-up period was 33months. The RCO was developed in 109 patients (29.5%). In Group 1, the third highest and highest quartile groups for GA-CV had higher cumulative incidences of the RCO than those of the lowest quartile group (Q4 vs. Q1: HR=5.43, P=0.007, Q3 vs. Q1: HR=5.16, P=0.009). After adjusting for HbA1c levels and other risk factors, the GA-CV remained significantly associated with the development of the RCO. However, Group 2 did not exhibit any significant differences in terms of the cumulative incidence of the RCO among the four GA-CV quartile groups.

CONCLUSIONS

The present findings suggest that variability in GA may be a better predictor of the progression of diabetic nephropathy in type 2 diabetic patients regardless of HbA1c.

Determinants of diabetic nephropathy in Ayder Referral Hospital, Northern Ethiopia: A case-control study

BACKGROUND

Diabetic nephropathy is the most serious complication of diabetes which leads to end-stage renal failure and other complication of diabetes mellitus. Determinants of Diabetic nephropathy are not consistent in different studies and associated factors to chronic complications of diabetes are not specific and there are limited studies specific to diabetic nephropathy. Thus, the aim of this study is to identify determinants of diabetic nephropathy in Ayder Referral Hospital, Northern Ethiopia.

METHODS

A case-control study was conducted from February 14 to May 8 2016. Diabetic patients who developed nephropathy in the last two years were the cases and diabetic patients free of nephropathy were controls. Cases and controls were identified detailed review of the chronic care follow up chart. Then simple random sampling was used to select sample of 420 (with control to case ratio of 4:1) resulting in 84 cases and 336 controls. Record review and interviewer administered questionnaire were used to collect data. Data was coded and entered in to Epi-Data version 3.1 and then exported to STATA 12 for analysis. Variables with P-values< 0.25 in Bivariate logistic regression were selected for multiple logistic regressions to determine independent determinants of diabetic nephropathy. OR was calculated with 95% CI to show strength of association.

RESULT

The mean age (±Standard deviation) for the cases and the controls were 52(SD: ±1.34) and 42.4(SD: ±0.8) respectively. In multiple logistic regressions age of patient (AOR: 1.037 95%CI: 1.01-1.064), duration of diabetes after diagnosis (AOR for one year increase: 1.09 95%CI: 1.036-1.15), not-adhered to blood glucose measurement at home (AOR: 6.81 95%CI: 1.15-40.24), having Systolic Hypertension (AOR;2.13 (1.002-4.51), poor glycemic control (AOR;2.71 95%CI: (1.49-4.95), being overweight(AOR;2.7(1.47-4.96) were the independent predictors of diabetic nephropathy.

CONCLUSION

In the light of these findings, targeted interventions should be designed at the follow up clinic to address the risk of developing diabetic nephropathy among the risk groups.

Periodontitis is associated with diabetic retinopathy in non-obese adults

PURPOSE

Patients with diabetes retinopathy appear to show increased susceptibility to periodontal disease. This study was performed to assess the relationship between periodontitis and the prevalence of diabetic retinopathy in a large probability sample of the Korean population. A subgroup analysis was performed using body mass index <25 kg/m² as the criterion to evaluate the effect of obesity on this relationship.

METHODS

This study is based on data from the Korean National Health and Nutrition Examination Survey of the Korean population, conducted between 2008 and 2010. The presence of diabetic retinopathy in relation to demographic variables and anthropometric characteristics of the participants is presented as means with their standard errors. The presence of periodontitis and presence of retinopathy categorized by body mass index (<25 and ≥25 kg/m²) were evaluated. Multiple logistic regression analyses were used to assess the associations between periodontitis and diabetic retinopathy after adjustment with variables, including age, sex, smoking, drinking, exercise, hypertension, metabolic syndrome, HbA1c, and duration of diabetes mellitus.

RESULTS

There was a statistically significant increase in the prevalence of periodontitis in individuals who had proliferative diabetic retinopathy. The odds ratios [95% confidence intervals] of prevalence of diabetic retinopathy were 1.193 [0.757-1.881] for the whole population after adjustments with confounding factors. Subgroup analysis after adjustments with confounding factors showed that the odds ratios [95% confidence intervals] of prevalence were 2.206 [1.114-4.366] and 0.588 [0.326-1.061] among participants with body mass index <25 kg/m² and body mass index 37 ≥25 kg/m², respectively.

CONCLUSIONS

The diabetic retinopathy was positively associated with the presence of periodontitis in non-obese diabetic Korean adults after adjustment with confounding variables. Our findings suggest that when a periodontist finds the presence of periodontitis in non-obese diabetic patients, timely evaluation of the patient's ophthalmic evaluation should be 44 recommended.

Analysis and comparison of the cost-effectiveness of statins according to the baseline low-density lipoprotein cholesterol level in Korea

WHAT IS KNOWN AND OBJECTIVE

There are a few Korean studies on the economics of statins based on reduction in low-density lipoprotein cholesterol (LDL-C) data from other countries. This study aimed to analyse and compare the cost-effectiveness of statins according to the baseline LDL-C level in Korea.

METHODS

Between January 2009 and December 2015, the data of patients who were prescribed statins for the first time were extracted from electronic medical records. We performed a cost-effectiveness analysis (CEA) based on the LDL-C reduction rate (CEA-RR) and target achievement rate.

RESULTS AND DISCUSSION

Among high-intensity statins, the CEA-RR value of rosuvastatin (20 mg) was significantly lower than that of atorvastatin (40 mg) at all baseline LDL-C levels, except levels of 160-189 mg/dL. Additionally, at baseline LDL-C levels of 130-159 mg/dL, the CEA-RR value of rosuvastatin (20 mg) was three times lower than that of atorvastatin (40 mg) (9·1 ± 2·5 $/% vs. 31·7 ± 15·0 $/%, P < 0·001). Among moderate-to-low-intensity statins, rosuvastatin (5 mg) showed the lowest CEA-RR value (4·0 ± 0·6 $/%), and the value significantly increased for pitavastatin (2 mg) (8·0 ± 0·6 $/%), atorvastatin (10 mg) (9·5 ± 0·5 $/%), simvastatin (10·8 ± 1·1 $/%) and pravastatin (40 mg) (11·5 ± 0·9 $/%) in order (P < 0·0001). On changing from atorvastatin (10 mg) to atorvastatin (20 mg), the additional yearly cost was 16·0 and additional CEA-RR value was 2·74 $/%. On the other hand, on changing from atorvastatin (10 mg) to rosuvastatin (10 mg), the additional yearly cost was -16·3 and additional CEA-RR value was -1·8 $/%.

WHAT IS NEW AND CONCLUSION

We successfully compared the cost-effectiveness of statins according to the baseline LDL-C level in Korea. It is expected that our findings will help clinical decision-making with regard to statin prescription, and this will help reduce national medical expenditure.

Baseline Cardiovascular Characteristics of Adult Patients with Chronic Kidney Disease from the KoreaN Cohort Study for Outcomes in Patients With Chronic Kidney Disease (KNOW-CKD)

Cardiovascular disease (CVD) is the most common cause of death in patients with chronic kidney disease (CKD). We report the baseline cardiovascular characteristics of 2,238 participants by using the data of the KoreaN Cohort Study for Outcomes in Patients With Chronic Kidney Disease (KNOW-CKD) study. The cohort comprises 5 subcohorts according to the cause of CKD: glomerulonephritis (GN), diabetic nephropathy (DN), hypertensive nephropathy (HTN), polycystic kidney disease (PKD), and unclassified. The average estimated glomerular filtration rate (eGFR) was 50.5 ± 30.3 mL/min⁻¹/1.73 m⁻² and lowest in the DN subcohort. The overall prevalence of previous CVD was 14.4% in all patients, and was highest in the DN followed by that in the HTN subcohort. The DN subcohort had more adverse cardiovascular risk profiles (higher systolic blood pressure [SBP], and higher levels of cardiac troponin T, left ventricular mass index [LVMI], coronary calcium score, and brachial-ankle pulse wave velocity [baPWV]) than the other subcohorts. The HTN subcohort exhibited less severe cardiovascular risk profiles than the DN subcohort, but had more severe cardiovascular risk features than the GN and PKD subcohorts. All these cardiovascular risk profiles were inversely correlated with eGFR. In conclusion, this study shows that the KNOW-CKD cohort exhibits high cardiovascular burden, as other CKD cohorts in previous studies. Among the subcohorts, the DN subcohort had the highest risk for CVD. The ongoing long-term follow-up study up to 10 years will further delineate cardiovascular characteristics and outcomes of each subcohort exposed to different risk profiles.

Association between underweight and tooth loss among Korean adults

There is growing interest in the relationship between body mass index and oral health. Previous study showed that being underweight was significantly associated with having lower masticatory performance. This study was performed to assess the relationship between an underweight body mass index lower than 18.5 and the number of natural teeth using nationally representative data. Initially, a total of 25,534 individuals were candidates in the Korean National Health and Nutrition Examination Survey. The analysis in this study was confined to 17,870 subjects who were 19 years or older and without missing values for outcome variables. Body mass index and number of natural teeth were evaluated. Multiple regression analysis was used to evaluate the risk of tooth loss in relation to body mass index. Adjusted odds ratios and their 95% confidence intervals for chewing discomfort in individuals who were underweight, normal, overweight, obese, and extremely obese were 1.712(1.156–2.535), 1.111(0.939–1.315), 1(reference), 0.949(0.798–1.128), and 1.172(0.807–1.700), respectively, after adjustment. The association between underweight and tooth loss was proven by multiple logistic regression analyses after adjusting for confounding factors. Underweight may be considered a potential risk indicator for tooth loss in Korean adults.

Mechanistic Insight and Management of Diabetic Nephropathy: Recent Progress and Future Perspective

Diabetic nephropathy (DN) is the most serious microvascular complication of diabetes and the largest single cause of end-stage renal disease (ESRD) in many developed countries. DN is also associated with an increased cardiovascular mortality. It occurs as a result of interaction between both genetic and environmental factors. Hyperglycemia, hypertension, and genetic predisposition are the major risk factors. However, the exact mechanisms of DN are unclear. Despite the benefits derived from strict control of glucose and blood pressure, as well as inhibition of renin-angiotensin-aldosterone system, many patients continue to enter into ESRD. Thus, there is urgent need for improving mechanistic understanding of DN and then developing new and effective therapeutic approaches to delay the progression of DN. This review focuses on recent progress and future perspective about mechanistic insight and management of DN. Some preclinical relevant studies are highlighted and new perspectives of traditional Chinese medicine (TCM) for delaying DN progression are discussed in detail. These findings strengthen the therapeutic rationale for TCM in the treatment of DN and also provide new insights into the development of novel drugs for the prevention of DN. However, feasibility and safety of these therapeutic approaches and the clinical applicability of TCM in human DN need to be further investigated.

Arterial Stiffness Is More Associated with Albuminuria than Decreased Glomerular Filtration Rate in Patients with Type 2 Diabetes Mellitus: The REBOUND Study

AIM

The aim of this study was to evaluate the association between arterial stiffness and albuminuria and glomerular filtration rate (GFR) in patients with type 2 diabetes mellitus.

METHODS

This multicenter cohort study analyzed 2613 patients with type 2 diabetes. Brachial-ankle pulse wave velocity (baPWV) was used as a noninvasive marker of arterial stiffness. Additionally, the patients were categorized into four groups according to their albumin-to-creatinine ratio (ACR, normoalbuminuria versus albuminuria) and estimated GFR (eGFR, <60 mL/min/1.73 m² versus ≥60 mL/min/1.73 m²).

RESULTS

A univariate analysis revealed that maximal baPWV was significantly associated with both the ACR (r = 0.297, P < 0.001) and eGFR (r = -0.220, P < 0.001). A multivariate analysis adjusted for significant clinical variables and eGFR showed that baPWV remained significantly correlated with the ACR (r = 0.150, P < 0.001). Also, baPWV was correlated positively with the ACR in patients with an eGFR ≥ 60 mL/min/1.73 m² (r = 0.146, P < 0.001). However, baPWV was not correlated with eGFR after adjustment for significant clinical variables.

CONCLUSIONS

The present findings indicate that arterial stiffness is more associated with albuminuria than a decrease in GFR in patients with type 2 diabetes mellitus.

Addition of nonalbumin proteinuria to albuminuria improves prediction of type 2 diabetic nephropathy progression

BACKGROUND

Albuminuria is generally accepted as a sensitive marker of diabetic nephropathy but has limitations in predicting its progression. The aim of this study was to evaluate the use of nonalbumin proteinuria in addition to albuminuria for predicting the progression of type 2 diabetic nephropathy.

METHODS

In this retrospective observational study, the urine albumin-to-creatinine ratio (ACR) and the nonalbumin protein-to-creatinine ratio (NAPCR) were measured in 325 patients with type 2 diabetes and estimated glomerular filtration rates (eGFR) ≥30 mL/min/1.73 m². The patients were divided into four groups based on the cutoff points for the urinary ACR (30 mg/g) and NAPCR (120 mg/g). The renal outcomes were chronic kidney disease (CKD) progression and accelerated eGFR decline.

RESULTS

During the 4.3-year follow-up period, 25 (7.7%) patients showed CKD progression and 69 (21.2%) patients showed accelerated eGFR decline. After adjusting for nine clinical parameters, the group with a NAPCR greater than 120 mg/g exhibited higher cumulative incidences of CKD progression (hazard ratio 6.84; P = 0.001) and accelerated eGFR decline (hazard ratio 1.95; P = 0.011) than the group with a NAPCR < 120 mg/g. In patients with normoalbuminuria, the group with NAPCR levels greater than 120 mg/g also exhibited a higher cumulative incidence than that with NAPCR levels <120 mg/g of CKD progression (hazard ratio 21.82; P = 0.005). The addition of NAPCR to ACR improved the model fit for CKD progression and accelerated eGFR decline.

CONCLUSION

Nonalbumin proteinuria showed additional value over and above that of albuminuria for predicting the progression of CKD in patients with type 2 diabetes.

Associations between the number of natural teeth and renal dysfunction

The purpose of the present study was to investigate the association between the number of natural teeth and measures of kidney dysfunction, such as urinary albumin/creatinine ratio (ACR) and estimated glomerular filtration (eGFR) rate, using nationally representative data.The data used were from the Korea National Health and Nutrition Examination Survey with cross-sectional design, which was conducted between 2011 and 2012; the sample analyzed in this study consisted of a total of 10,388 respondents, each of whom was 19 years or older and had no missing outcome variables. The association between the number of natural teeth and kidney function was assessed by multiple logistic regression and model was adjusted for age, sex, waist conference, smoking, drinking, exercise, education, income, frequency of tooth brushing per day, diabetes, metabolic syndrome, urinary ACR, and eGFR.The mean age, body mass index, and waist circumference were significantly higher among those with lower kidney function (urinary ACR ≥30 mg/g and eGFR <60 mL/min/1.73m). Urinary ACR and eGFR were associated with loss of natural teeth. As urinary ACR increased, the number of natural teeth decreased accordingly. Conversely, the number of natural teeth increased with an increase in eGFR.This study showed that the number of natural teeth is inversely associated with the presence of kidney disease. Severity of tooth loss may be considered an independent risk indicator for kidney disease among Koreans. More epidemiological studies are warranted to investigate the role of tooth loss in kidney disease, to confirm this relationship and to test possible underlying mechanisms.

Decreased plasma α-Klotho predict progression of nephropathy with type 2 diabetic patients

AIM

The potential role of soluble α-klotho in diabetic kidney disease has not yet been evaluated. The aim of this study was to evaluate the association of plasma and/or urine α-klotho with the progression of type 2 diabetic nephropathy.

METHODS

The baseline values of plasma and urine α-klotho were measured in 147 patients with type 2 diabetes mellitus with an estimated glomerular filtration rate (eGFR) of ≥60mL/min/1.73m(2). In this prospective observational study, a total of 109 type 2 diabetic patients were followed up for 34months (8-50 months).

RESULTS

Plasma α-klotho, but not urine α-klotho, was negatively correlated with the decline of eGFR (r=-0.304, P=0.001; r=0.042, P=0.068, respectively). After adjusting for several clinical parameters, baseline eGFR and urine ACR, plasma α-klotho was significantly associated with the decline of eGFR (r=-0.219, P=0.008). In the normoalbuminuria group (n=63), the plasma α-klotho remained significantly associated with a decline in eGFR (r=0.324, P=0.004) in the final model.

CONCLUSIONS

It is suggested that plasma α-klotho may be an early biomarker for predicting renal impairment in type 2 diabetic patients. The disappearance of a compensatory increase of plasma α-klotho might be a predictive marker for the progression of type 2 diabetic nephropathy.

Current Challenges in Diabetic Nephropathy: Early Diagnosis and Ways to Improve Outcomes

Diabetes is often associated with chronic kidney disease (CKD) and is the primary cause of kidney failure in half of patients who receive dialysis therapy. Given the increasing prevalence of diabetes and its high morbidity and mortality, diabetic nephropathy is a serious drawback in individual patients and a tremendous socioeconomic burden on society. Despite growing concern for the management of diabetic nephropathy, the prevalence of CKD with diabetes is the same today as it was 20 years ago. The current strategy to manage diabetic nephropathy, including the control of hyperglycemia, dyslipidemia, and blood pressure and the wide-spread use of renin-angiotensin-aldosterone system inhibitors, is well established to be beneficial in the early stages of diabetic nephropathy. However, the effects are uncertain in patients with relatively progressed CKD. Therefore, early diagnosis or risk verification is extremely important in order to reduce the individual and socioeconomic burdens associated with diabetic nephropathy by providing appropriate management to prevent the development and progression of this condition. This review focuses on recent research and guidelines regarding risk assessment, advances in medical treatment, and challenges of and future treatments for diabetic nephropathy.