Proteomics profiling and association with cardiorenal complications in type 2 diabetes subtypes in Asian population.

AIM: Among multi-ethnic Asians, type 2 diabetes (T2D) clustered in three subtypes; mild obesity-related diabetes (MOD), mild age-related diabetes with insulin insufficiency (MARD-II) and severe insulin-resistant diabetes with relative insulin insufficiency (SIRD-RII) had differential cardio-renal complication risk. We assessed the proteomic profiles to identify subtype specific biomarkers and its association with diabetes complications. METHODS: 1448 plasma proteins at baseline were measured and compared across the T2D subtypes. Multivariable cox regression was used to assess associations between significant proteomics features and cardio-renal complications. RESULTS: Among 645 T2D participants (SIRD-RII [19%], MOD [45%], MARD-II [36%]), 295 proteins expression differed significantly across the groups. These proteins were enriched in cell adhesion, neurogenesis and inflammatory response processes. In SIRD-RII group, ADH4, ACY1, THOP1, IGFBP2, NEFL, ENTPD2, CALB1, HAO1, CTSV, ITGAV, SCLY, EDA2R, ERBB2 proteins significantly associated with progressive CKD and LILRA5 protein with incident heart failure (HF). In MOD group, TAFA5, RSPO3, EDA2R proteins significantly associated with incident HF. In MARD-II group, FABP4 protein significantly associated with progressive CKD and PTPRN2 protein with major adverse cardiovascular events. Genetically determined NEFL and CALB1 were associated with kidney function decline. CONCLUSIONS: Each T2D subtype has unique proteomics signature and association with clinical outcomes and underlying mechanisms.

Plasma ceramides predict all-cause and cause-specific mortality in individuals with type 2 diabetes.

CONTEXT: The CERT1 (Cardiovascular Event Risk Test) score derived from plasma ceramides has been applied clinically for cardiovascular risk assessment. OBJECTIVE: To study whether plasma ceramides predict risk of mortality in patients with type 2 diabetes. DESIGN, SETTING AND PARTICIPANTS: A prospective study which included 1903 outpatients with type 2 diabetes in a regional hospital and a primary care facility in Singapore. EXPOSURE AND OUTCOME: Plasma ceramides (d18:1/16:0, d18:1/18:0, d18:1/24:0, d18:1/24:1) were measured by mass spectrometry and CERT1 score was calculated accordingly. Main outcomes were all-cause and cause-specific mortality. RESULTS: 252 death events were identified during median of 9.3 years of follow-up. Compared to those with low score (≤ 2), participants with a high CERT1 score (≥ 7) had 1.86 (95% CI 1.30-3.65) fold increased risk for all-cause death after adjustment for cardio-renal risk factors including eGFR and albuminuria. As continuous variable, one- unit increment in CERT1 was associated with 8% increased risk for all-cause death (adjusted HR 1.08 [1.04-1.13]). Adding CERT1 onto RECODe (Risk Equations for Complications Of type 2 Diabetes) mortality risk engine significantly improved prediction of 10- year risk of all-cause death (AUC 0.810 to 0.823, delta 0.013 [0.005-0.022]). The association between CERT1 and non-cardiovascular death remained significant (adjusted HR 2.12 [1.32-3.42]), whereas its association with cardiovascular death became non-significant after adjustment for kidney measurements (adjusted HR 1.41 [0.78-2.56]). CONCLUSION: CERT1 score predicts mortality risk independent of clinical cardio-renal risk factors. Further studies are warranted to elucidate the mechanistic linkage between ceramide and mortality, especially non-cardiovascular mortality.

Incident heart failure and the subsequent risk of progression to end stage kidney disease in individuals with type 2 diabetes.

BACKGROUND: Diabetic kidney disease is an established risk factor for heart failure. However, the impact of incident heart failure on the subsequent risk of renal failure has not been systematically assessed in diabetic population. We sought to study the risk of progression to end stage kidney disease (ESKD) after incident heart failure in Asian patients with type 2 diabetes. METHODS: In this prospective cohort study, 1985 outpatients with type 2 diabetes from a regional hospital and a primary care facility in Singapore were followed for a median of 8.6 (interquartile range 6.2-9.6) years. ESKD was defined as a composite of progression to sustained eGFR below 15 ml/min/1.73m2, maintenance dialysis or renal death, whichever occurred first. RESULTS: 180 incident heart failure events and 181 incident ESKD events were identified during follow-up. Of 181 ESKD events, 38 (21%) occurred after incident heart failure. Compared to those did not progress to ESKD after incident heart failure (n = 142), participants who progressed to ESKD after heart failure occurrence were younger, had higher HbA1c and higher urine albumin-to-creatinine ratio at baseline. The excess risk of ESKD manifested immediately after heart failure occurrence, persisted for two years and was moderated thereafter. Cox regression suggested that, compared to counterparts with no heart failure event, participants with heart failure occurrence had 9.6 (95% CI 5.0- 18.3) fold increased risk for incident ESKD after adjustment for baseline cardio-renal risk factors including eGFR and albuminuria. It appeared that heart failure with preserved ejection fraction had a higher risk for ESKD as compared to those with reduced ejection fraction (adjusted HR 13.7 [6.3-29.5] versus 6.5 [2.3-18.6]). CONCLUSION: Incident heart failure impinges a high risk for progression to ESKD in individuals with type 2 diabetes. Our data highlight the need for intensive surveillance of kidney function after incident heart failure, especially within the first two years after heart failure diagnosis.

Association of plasma ceramide with decline in kidney function in patients with type 2 diabetes.

Circulating ceramide levels are dysregulated in kidney disease. However, their associations with rapid decline in kidney function (RDKF) and end-stage kidney disease (ESKD) in patients with type 2 diabetes (T2D) are unknown. In this prospective study of 1746 T2D participants, we examined the association of plasma ceramide Cer16:0, Cer18:0, Cer24:0, and Cer24:1 with RDKF, defined as an estimated glomerular filtration rate (eGFR) decline of 5 ml/min/1.73 m2 per year or greater, and ESKD defined as eGFR <15/min/1.73 m2 for at least 3 months, on dialysis or renal death at follow-up. During a median follow-up period of 7.7 years, 197 patients experienced RDKF. Ceramide Cer24:0 (odds ratio [OR] = 0.71, 95% CI 0.56-0.90) and ratios Cer16:0/Cer24:0 (OR = 3.54 [1.70-7.35]), Cer18:0/Cer24:0 (OR = 1.89 [1.10-3.25]), and Cer24:1/Cer24:0 (OR = 4.01 [1.93-8.31]) significantly associated with RDKF in multivariable analysis; 124 patients developed ESKD. The ratios Cer16:0/Cer24:0 (hazard ratio [HR] = 3.10 [1.44-6.64]) and Cer24:1/Cer24:0 (HR = 4.66 [1.93-11.24]) significantly associated with a higher risk of ESKD. The Cer24:1/Cer24:0 ratio improved risk discrimination for ESKD beyond traditional risk factors by small but statistically significant margin (Harrell C-index difference: 0.01; P = 0.022). A high ceramide risk score also associated with RDKF (OR = 2.28 [1.26-4.13]) compared to lower risk score. In conclusion, specific ceramide levels and their ratios are associated with RDKF and conferred an increased risk of ESKD, independently of traditional risk factors, including baseline renal functions in patients with T2D.

Plasma proteomics of diabetic kidney disease among Asians with younger-onset type 2 diabetes.

CONTEXT: Patients with younger onset of type 2 diabetes (YT2D) have increased risk for kidney failure compared to those with late onset. However, the mechanism of diabetic kidney disease (DKD) progression in this high-risk group is poorly understood. OBJECTIVES: To identify novel biomarkers and potential causal proteins associated with DKD progression in patients with YT2D. DESIGN AND PARTICIPANTS: Among YT2D (T2D onset age ≤ 40 years), 144 DKD progressors (cases) were matched for T2D onset age, sex, and ethnicity with 292 non-progressors (controls) and divided into discovery and validation sets. DKD progression was defined as decline of estimated glomerular filtration rate (eGFR) of 3ml/min/1.73m2 or greater or 40% decline in eGFR from baseline. 1472 plasma proteins were measured through a multiplex immunoassay that uses a proximity extension assay technology. Multivariable logistic regression was used to identify proteins associated with DKD progression. Mendelian randomization (MR) was used to evaluate causal relationship between plasma proteins and DKD progression. RESULTS: 42 plasma proteins were associated with DKD progression, independent of traditional cardio-renal risk factors, baseline eGFR and urine albumin-to-creatinine ratio (uACR). The proteins identified were related to inflammatory and remodelling biological processes. Our findings suggested angiogenin as one of the top signals (odds ratio =5.29, 95% CI 2.39-11.73, P = 4.03 × 10-5). Furthermore, genetically determined plasma angiogenin level was associated with increased odds of DKD progression. CONCLUSION: Large-scale proteomic analysis identified novel proteomic biomarkers for DKD progression in YT2D. Genetic evidence suggest a causal role of plasma angiogenin in DKD progression.

Urine tricarboxylic acid cycle metabolites and risk of end stage kidney disease in patients with type 2 diabetes.

CONTEXT: Metabolites in tricarboxylic acid (TCA) pathway have pleiotropic functions. OBJECTIVE: To study the association between urine TCA cycle metabolites and the risk for chronic kidney disease (CKD) progression in individuals with type 2 diabetes. DESIGN, SETTING AND PARTICIPANTS: A prospective study in a discovery (n = 1826) and a validation (n = 1235) cohort of type 2 diabetes in a regional hospital and a primary care facility. EXPOSURE AND OUTCOME: Urine lactate, pyruvate, citrate, alpha-ketoglutarate, succinate, fumarate and malate were measured by mass spectrometry. CKD progression was defined as a composite of sustained eGFR below 15 ml/min/1.73 m2 , dialysis, renal death or doubling of serum creatinine. RESULTS: During a median of 9.2 (IQR 8.1-9.7) and 4.0 (3.2-5.1) years of follow-up, 213 and 107 renal events were identified. Cox regression suggested that urine lactate, fumarate and malate were associated with an increased risk (adjusted hazard ratio, aHR [95% CI] 1.63 [1.16-2.28], 1.82 [1.17-2.82] and 1.49 [1.05-2.11], per SD), while citrate was associated with a low risk (aHR 0.83 [0.72-0.96] per SD) for the renal outcome after adjustment for cardio-renal risk factors. These findings were reproducible in the validation cohort. Noteworthy, fumarate and citrate were independently associated with the renal outcome after additional adjustment for other metabolites. CONCLUSION: Urine fumarate and citrate predict the risk for progression to ESKD independent of clinical risk factors and other urine metabolites. These two metabolites in TCA cycle pathway may play important roles in the pathophysiological network underpinning progressive loss of kidney function in patients with type 2 diabetes.

Association of plasma angiogenin with risk of major cardiovascular events in type 2 diabetes.

BACKGROUND: Angiogenin, an enzyme belonging to the ribonucleases A superfamily, plays an important role in vascular biology. Here, we sought to study the association of plasma angiogenin and major adverse cardiovascular events (MACEs) in patients with type 2 diabetes (T2D). METHODS: This prospective study included 1083 T2D individuals recruited from a secondary hospital and a primary care facility. The primary outcome was a composite of four-point MACE (nonfatal myocardial infarction, stroke, unstable angina pectoris leading to hospitalization and cardiovascular death). Circulating angiogenin was measured by a proximity extension assay. Cox regression models were used to evaluate the association of baseline plasma angiogenin with the risk of MACE. RESULTS: During a median follow-up of 9.3 years, 109 (10%) MACE were identified. Plasma angiogenin was significantly higher in participants with MACE than in those without MACE (P < 0.001). Doubling of plasma angiogenin concentration was associated with a 3.10-fold (95% CI 1.84-5.22) increased risk for MACE. The association was only moderately attenuated after adjustment for demographic and cardiometabolic risk factors (adjusted HR 2.38, 95% CI 1.34-4.23) and remained statistically significant after additional adjustment for estimated glomerular filtration rate (eGFR) and urinary albumin to creatinine ratio (uACR) (adjusted HR 1.90, 95% CI 1.02-3.53). A consistent outcome was obtained when plasma angiogenin was analysed as a categorical variable in tertiles. CONCLUSIONS: Plasma angiogenin was associated with the risk of future cardiovascular events in patients with T2D and may be a promising novel biomarker for identifying high-risk T2D patients for early management.

Reduced skeletal muscle mass to visceral fat area ratio is independently associated with reduced cognitive function in type 2 diabetes mellitus.

AIM: Skeletal muscle mass to visceral fat area ratio (SVR) has been recognised as an index of sarcopenic obesity. SVR is associated with type 2 diabetes mellitus (T2DM), metabolic syndrome and arterial stiffness which are known risk factors for cognitive dysfunction. We aimed to investigate association between SVR and cognitive function in patients with T2DM. METHODS: This was a cross-sectional study of 1326 patients with T2DM and mean age 61.3 ± 8.0 years. SVR was assessed based on bioelectrical impedance measurements of muscle mass and visceral fat area (VFA). Cognitive function was assessed using Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Linear regression was used to examine the association between SVR in quartiles and RBANS score, adjusting for demographics, education, presence of depressive symptoms, clinical covariates and medications. RESULTS: The lower SVR quartiles were negatively associated with RBANS total score in the unadjusted analysis. The corresponding coefficients for Quartiles 1 and 2 SVR were -3.79 (95 % CI -5.39 to -2.19; p < 0.001) and -1.47 (95 % CI -2.86 to -0.07; p = 0.039) in fully adjusted analysis. The negative association between Quartile 1 SVR and RBANS score was evident in immediate memory, delayed memory, visuo-spatial construction, language and attention domains. Muscle mass and VFA alone had weaker associations with RBANS scores. CONCLUSION: Our study demonstrated, for the first time, an independent association between reduced SVR and lower cognitive function. This is evident in global and multiple cognitive domains. The synergistic effects of reduced muscle mass and visceral obesity may be more pronounced than their independent effects on cognitive function.

Association Between Plasma LRG1 and Lower Cognitive Function in Asians With Type 2 Diabetes Mellitus.

CONTEXT: Leucine-rich α-2-glycoprotein 1 (LRG1) has been implicated in the pathogenesis of diabetic complications, but its association with cognitive function remains unclear. OBJECTIVE: Our primary objective is to investigate the longitudinal association between LRG1 and cognitive function in patients with type 2 diabetes mellitus (T2DM). Secondarily, we determine the causal relationship using Mendelian randomization (MR) and the role of arterial stiffness as a potential mediator. METHODS: T2DM patients (n = 1039; age = 64.1 ± 6.4 years) were followed-up for 5.3 ± 1.2 years. Plasma LRG1 was measured at baseline using enzyme-linked immunosorbent assay. Baseline and follow-up cognitive function was assessed using Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). One-sample MR was performed with rs4806985 as plasma LRG1-associated single-nucleotide polymorphism. Mediation analysis was performed to examine if pulse wave velocity (PWV), an arterial stiffness index, mediated the association between plasma LRG1 and follow-up cognitive function. RESULTS: Elevated baseline natural log (Ln)-transformed LRG1 was inversely associated with baseline and follow-up RBANS total score with adjusted coefficients -1.38 (95% CI -2.55 to -.21; P = .021) and -1.38 (95% CI -2.70 to -.07; P = .039), respectively. Genetically predicted higher levels of plasma LRG1 was associated with lower follow-up RBANS total score with coefficient -7.44 (95% CI -14.14 to -.74; P = .030) per unit increase in LnLRG1. Higher PWV accounted for 27.7% of the association between LnLRG1 and follow-up RBANS total score. CONCLUSION: Baseline plasma LRG1 was associated with lower cognitive function at follow-up in patients with T2DM, mediated by PWV. MR analysis provided evidence of an association between genetically influenced plasma LRG1 and lower cognitive function at follow-up.

Association between lower phase angle and chronic kidney disease progression in type 2 diabetes patients.

Introduction: Phase angle (PhA), derived from bioelectrical impedance analysis (BIA), is the angle of vector determined by the body's resistance and reactance. It indicates cellular integrity and hydration status. Though extracellular volume excess was associated with chronic kidney disease (CKD) progression, the association between PhA and CKD progression is unknown. Matrix metalloproteinase-2 (MMP-2) is a member of zinc-dependent endopeptidase family and promotes renal interstitial fibrosis. We investigated association between PhA and CKD progression, and whether the association was through MMP-2 in patients with type 2 diabetes mellitus (T2DM). Method: We conducted a prospective study on 1,078 patients with T2DM (mean age 58.9±9.1 years). PhA was measured using BIA. CKD progression was defined as ≥25% decrease in estimated glomerular filtration rate (eGFR) from baseline with deterioration across eGFR categories. Multiplex immunoassay was used to quantitate MMP-2. We examined association between PhA and CKD progression using Cox proportional hazards model, adjusting for demographics, clinical parameters and medications. Results: Over 8.6 years of follow-up, 43.7% of participants had CKD progression. Compared to tertile 3 PhA (higher level), tertiles 1 and 2 PhA were associated with higher hazards of CKD progression, with corresponding unadjusted hazard ratios (HRs) of 2.27 (95% confidence interval [CI] 1.80-2.87, P<0.001) and 1.57 (95% CI 1.24-2.01, P<0.001). The positive association between tertiles 1 and 2 PhA with CKD progression persisted in the fully adjusted model with corresponding HRs of 1.71 (95% CI 1.30-2.26, P<0.001) and 1.46 (95% CI 1.13-1.88, P=0.004). MMP-2 accounted for 14.7% of association between tertile 1 PhA and CKD progression. Conclusion: Our findings revealed a previously unobserved association between BIA-derived lower PhA and CKD progression through MMP-2 in patients with T2DM.