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 5ml/min/1.73m2/yr or greater, and ESKD defined as eGFR <15/min/1.73m2 for at least three months, on dialysis, or renal death at follow-up. We performed multivariable logistic and cox regression analyses adjusted for traditional cardio-renal risk factors, including baseline renal functions. During a median (interquartile range) follow-up period of 7.7 (4.7-8.9) years, 197 (11%) 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, 95%CI 1.70-7.35), Cer18:0/Cer24:0 (OR=1.89, 95%CI 1.10-3.25) and Cer24:1/Cer24:0 (OR=4.01, 95%CI 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, 95%CI 1.44-6.64), and Cer24:1/Cer24:0 (HR=4.66, 95%CI 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, constructed using individual ceramide level and ceramide ratios, also associated with RDKF (OR=2.28, 95%CI 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 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.

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 (SNP). 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 -0.21; p = 0.021) and -1.38 (95%CI -2.70 to -0.07; p = 0.039), 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 -0.74; p = 0.030) per unit increase in LnLRG1. Higher PWV accounted for 27.7% of the association between LnLRG1 and follow-up RBANS total score. CONCLUSIONS: 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.

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.

Longitudinal profiling and tracking stability in the Singapore study of macro-angiopathy and microvascular reactivity in type 2 diabetes cohort.

INTRODUCTION: The Singapore Study of Macro-Angiopathy and microvascular Reactivity in Type 2 Diabetes (SMART2D) is a prospective cohort study which was started in 2011 to investigate the effect of risk factors on vascular function and diabetes-related complications in Asians. We aimed to compare the longitudinal change in risk factors by accounting for batch effect and assess the tracking stability of risk factors over time in patients recruited for SMART2D. In this study, we (1) described batch effect and its extent across a heterogenous range of longitudinal data parameters; (2) mitigated batch effect through statistical approach; and (3) assessed the tracking stability of the risk factors over time. METHODS: A total of 2258 patients with type 2 diabetes mellitus (T2DM) were recruited at baseline. The study adopted a three-wave longitudinal design with intervals of 3 years between consecutive waves. The changes in a few selected risk factors were assessed after calibration, assuming patients with similar demographic and anthropometry profile had similar physiology. The tracking pattern of the risk factors was determined with stability coefficients derived from generalised estimating equations. RESULTS: The medians of the longitudinal differences in risk factors between the waves were mostly modest at <10%. Larger increases in augmentation index (AI), aortic systolic blood pressure (BP) and aortic mean BP were consistently observed after calibration. The medians of the longitudinal differences in AI, aortic systolic BP and aortic mean BP between the waves were <2% before calibration, but increased slightly to <5% after calibration. Most of the risk factors had moderate to high tracking stability. Muscle mass and serum creatinine were among those with relatively high tracking stability. CONCLUSIONS: The longitudinal differences in parameters between the waves were overall modest after calibration, suggesting that calibration may attenuate longitudinal differences inflated by non-biological factors such as systematic drift due to batch effect. Changes of the hemodynamic parameters are robust over time and not entirely attributable to age. Our study also demonstrated moderate to high tracking stability for most of the parameters.

Plasma Tryptophan-Kynurenine Pathway Metabolites and Risk for Progression to End-Stage Kidney Disease in Patients With Type 2 Diabetes.

OBJECTIVE: We sought to study the associations between plasma metabolites in the tryptophan-kynurenine pathway and the risk of progression to end-stage kidney disease (ESKD) in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: Plasma tryptophan, kynurenine, 3-hydroxykynurenine, kynurenic acid, and xanthurenic acid concentrations were measured in discovery (n = 1,915) and replication (n = 346) cohorts. External validation was performed in Chronic Renal Insufficiency Cohort (CRIC) participants with diabetes (n = 1,312). The primary outcome was a composite of incident ESKD (progression to estimated glomerular filtration rate [eGFR] <15 mL/min/1.73 m2, sustained dialysis, or renal death). The secondary outcome was annual eGFR decline. RESULTS: In the discovery cohort, tryptophan was inversely associated with risk for ESKD, and kynurenine-to-tryptophan ratio (KTR) was positively associated with risk for ESKD after adjustment for clinical risk factors, including baseline eGFR and albuminuria (adjusted hazard ratios [HRs] 0.62 [95% CI 0.51, 0.75] and 1.48 [1.20, 1.84] per 1 SD). High levels of kynurenic acid and xanthurenic acid were associated with low risks of ESKD (0.74 [0.60, 0.91] and 0.74 [0.60, 0.91]). Consistently, high levels of tryptophan, kynurenic acid, and xanthurenic acid were independently associated with a slower eGFR decline, while a high KTR was predictive of a faster eGFR decline. Similar outcomes were obtained in the replication cohort. Furthermore, the inverse association between kynurenic acid and risk of ESKD was externally validated in CRIC participants with diabetes (adjusted HR 0.78 [0.65, 0.93]). CONCLUSIONS: Accelerated catabolism of tryptophan in the kynurenine pathway may be involved in progressive loss of kidney function. However, shunting the kynurenine pathway toward the kynurenic acid branch may potentially slow renal progression.

Associations of non-invasive indices of liver steatosis and fibrosis with progressive kidney impairment in adults with type 2 diabetes.

AIMS: Longitudinal data linking non-alcoholic fatty liver disease to kidney dysfunction in type 2 diabetes (T2D) are limited. This study evaluated the associations of non-invasive indices of liver steatosis and liver fibrosis with kidney impairment, and the mediatory role of the pro-angiogenic factor leucine-rich α-2 glycoprotein 1 (LRG1). METHODS: T2D adults (n = 2057) were followed for a mean period of 6.1 ± 1.6 years. Baseline liver steatosis [(hepatic steatosis index (HSI) and Zhejiang University index (ZJU)] and liver fibrosis [aspartate transaminase/alanine transaminase ratio (AAR) and BARD] indices derived from composite scoring systems were calculated. Plasma LRG1 levels were quantified using immunoassay. The study outcomes were progressive kidney function decline defined as estimated glomerular filtration rate (eGFR) decline of ≥ 40% and albuminuria progression defined as an increase in albuminuria category. RESULTS: Cross-sectionally, liver steatosis and liver fibrosis indices were associated with increased albuminuria (urinary albumin/creatinine ratio ≥ 30 µg/mg) and reduced renal function (eGFR < 60 mL/min/1.73 m2) after covariate adjustment, respectively. Approximately 32% of the participants experienced progressive kidney function decline, while 38% had albuminuria worsening over time. Longitudinal analysis revealed that baseline AAR (hazard ratio: 1.56; 95% CI 1.15-2.11) and BARD (hazard ratio: 1.16, 95% CI 1.04-1.28) predicted progressive kidney function decline, partly mediated by LRG1. In contrast, liver steatosis (HSI and ZJU) but not liver fibrosis (AAR and BARD) indices were independently associated with albuminuria progression. CONCLUSIONS: Increased liver steatosis scores were associated with albuminuria deterioration. Conversely, liver fibrosis indices may be associated with progressive kidney function decline, potentially driven by increased inflammation and angiogenesis.

Association of Triglyceride Glucose Index with Prevalence and Incidence of Diabetic Retinopathy in a Singaporean Population.

Objective: To examine the association of triglyceride glucose (TyG) index (product of fasting triglyceride and glucose) with prevalence and incidence of diabetic retinopathy (DR) in type 2 diabetes. Methods: 1339 patients from an ongoing Singapore Study of Macro-angiopathy and Micro-Vascular Reactivity in Type 2 Diabetes (SMART2D) were included in this study. Fasting triglyceride and glucose levels were quantified and color fundus photographs were assessed for DR presence and severity. Logistic regression models were used to evaluate associations of TyG index with DR prevalence and incidence (median follow-up period = 3.2 years). Results: Mean TyG index was higher in patients with DR than no DR (9.24±0.7 versus 9.04± 0.6, p<0.001). TyG index was significantly associated with DR prevalence (OR=1.4, CI 1.1-1.7, p=0.002) and incidence (OR=1.8, CI 1.04-2.9, p=0.03), after adjusting for confounders. In a stratified analysis, the association between TyG index and DR prevalence reached significance only in the subgroup with HbA1c levels < 7.0% (OR=2, CI 1.1-3.8, p=0.03). TyG index significantly predicted DR prevalence and incidence with area under receiver operating curve as 0.77 (CI 0.74-0.80, p <0.001) and 0.66 (CI 0.57-0.76, p value <0.01), respectively. Conclusion: TyG index is a good predictor for DR prevalence and incidence. It can also be a secondary treatment target for patients with optimally controlled levels of HbA1c.

Urine Leucine-Rich α-2 Glycoprotein 1 (LRG1) Predicts the Risk of Progression to End-Stage Kidney Disease in Patients With Type 2 Diabetes.

OBJECTIVE: Leucine-rich α-2 glycoprotein 1 (LRG1) was recently identified as an amplifier of transforming growth factor-ß (TGF-ß)-induced kidney fibrosis in animal models. We aimed to study whether urine LRG1 is associated with risk of progression to end-stage kidney disease (ESKD) in individuals with type 2 diabetes. RESEARCH DESIGN AND METHODS: A total of 1,837 participants with type 2 diabetes and estimated glomerular filtration rate (eGFR) >30 mL/min/1.73 m2 were recruited from a regional hospital and a primary care facility. Association of urine LRG1 with risk of ESKD (progression to sustained eGFR <15 mL/min/1.73 m2, dialysis, or death resulting from renal causes) was assessed by survival analyses. RESULTS: During a median follow-up of 8.6 (interquartile range 5.8-9.6) years, 134 incident ESKD events were identified. Compared with those in the lowest tertile, participants with baseline urine LRG1 in the highest tertile had a 1.91-fold (95% CI 1.04-3.50) increased risk of progression to ESKD, after adjustment for cardiorenal risk factors, including eGFR and albuminuria. As a continuous variable, 1 SD increment in urine LRG1 was associated with a 1.53-fold (95% CI 1.19-1.98) adjusted risk of ESKD. Of note, the association of urine LRG1 with ESKD was independent of plasma LRG1. Moreover, urine LRG1 was associated with rapid kidney function decline and progression to macroalbuminuria, two common pathways leading to ESKD. CONCLUSIONS: Urine LRG1, a TGF-ß signaling modulator, predicts risk of progression to ESKD independently of clinical risk factors in patients with type 2 diabetes, suggesting that it may be a novel factor involved in the pathophysiological pathway leading to kidney disease progression.

Triglyceride-glucose index is prospectively associated with chronic kidney disease progression in Type 2 diabetes - mediation by pigment epithelium-derived factor.

BACKGROUND: Triglyceride-glucose (TyG) index is a surrogate marker of insulin resistance. Its role in chronic kidney disease (CKD) progression in Type 2 Diabetes Mellitus (T2DM) is unclear. We investigated the association between TyG index and CKD progression, and possible mediation of the association by pigment epithelium-derived factor (PEDF). METHODS: This was a prospective study on 1571 patients with T2DM. CKD progression was defined as worsening across KDIGO estimated glomerular filtration rate (eGFR) categories with ≥25% reduction from baseline. PEDF was quantitated using enzyme-linked immunosorbent assay method. Cox proportional hazards regression model was used to assess the relationship between TyG index and CKD progression. RESULTS: Over a follow-up period of up to 8.6 years (median 4.6 years, IQR 3.0-3.6), 42.7% of subjects had CKD progression. Every unit increase in TyG was associated with hazards of 1.44 (95%CI 1.29-1.61; p < 0.001) in unadjusted analysis and 1.21 (1.06-1.37; p = 0.004) in fully adjusted model. Compared to tertile 1, tertiles 2 and 3 TyG index were positively associated with CKD progression with corresponding hazard ratios HRs 1.24 (1.01-1.52; p = 0.037) and 1.37 (1.11-1.68; p = 0.003) in fully adjusted models. PEDF accounted for 36.0% of relationship between TyG index and CKD progression. CONCLUSIONS: Higher TyG index independently predicted CKD progression in T2DM. PEDF mediated the association between TyG index and CKD progression.

Decline in skeletal muscle mass is associated with cognitive decline in type 2 diabetes mellitus.

AIMS: To examine the longitudinal association between skeletal muscle mass (SMM) loss and cognitive decline over time in type 2 diabetes mellitus (T2DM). METHODS: We conducted a prospective cohort study of 453 patients from SMART2D cohort with follow-up intervals of 1.6 to 6.4 years. Baseline and follow-up measurements included bio-impedance analysis (BIA) measure of skeletal muscle mass index (SMI) and Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) measure of cognitive function. We examined the association between annual rate of SMI and RBANS scores using linear regression, adjusting for demographics, education, depression, clinical co-variables and presence of apolipoprotein E4 (APOE) Ɛ4 allele. RESULTS: The mean age of participants was 60.3 ± 7.4 years. Compared to patients with Tertile 1 SMI change, the group with greater SMI decline (Tertile 3 SMI change) experienced 0.30 decline in RBANS total score (95%CI -0.57 to -0.03; p = 0.030) in the adjusted analysis. RBANS scores for subdomains in immediate memory and visuo-spatial/construction were lower in Tertile 3 SMI change group with corresponding coefficients -0.54 (95%CI -1.01 to -0.06; p = 0.026), and -0.71 (95%CI -1.30 to -0.12; p = 0.019) respectively. CONCLUSION: In patients with T2DM, BIA measure of muscle mass loss over time was independently associated with cognitive decline globally and in the domains of memory and visuo-spatial/construction.

Association of early-onset Type 2 diabetes with cognitive impairment is partially mediated by increased pulse pressure.

AIMS: Type 2 diabetes mellitus (T2DM) has been shown to be associated with cognitive decline and dementia. As earlier onset of diabetes implies a longer disease duration and an increased risk to complications, we sought to investigate the effect of T2DM onset on cognitive function of our patients. METHODS: We administered the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) to T2DM patients aged 45-85 from our SMART2D cohort. We assessed the association of the T2DM onset age (both continuous and stratified into 3 groups: early-onset ≤40 (n = 326), middle-aged onset 41-64 (n = 703) and late-onset ≥65 years old (n = 38)) and RBANS cognitive indices in 1067 patients. Potential mediation of this association by vascular compliance using mediation analysis was investigated. RESULTS: T2DM onset associates significantly with RBANS total score. Patients with early T2DM onset have lower RBANS total score as compared to patients with middle-aged onset (ß = -2.01, p = 0.0102) and those with late-onset (ß = -5.80, p = 0.005). This association was partially mediated by pulse pressure index (25.8%), with indirect effect of 0.028 (Bootstrapped-CI: 0.008-0.047). CONCLUSIONS: Association of early-onset T2DM with cognitive impairment is partly mediated by diminished vascular compliance. Appropriate screening and assessment of cognitive function is important for early intervention and management of cognitive impairment.

Clinical variable-based cluster analysis identifies novel subgroups with a distinct genetic signature, lipidomic pattern and cardio-renal risks in Asian patients with recent-onset type 2 diabetes.

AIMS/HYPOTHESIS: We sought to subtype South East Asian patients with type 2 diabetes by de novo cluster analysis on clinical variables, and to determine whether the novel subgroups carry distinct genetic and lipidomic features as well as differential cardio-renal risks. METHODS: Analysis by k-means algorithm was performed in 687 participants with recent-onset diabetes in Singapore. Genetic risk for beta cell dysfunction was assessed by polygenic risk score. We used a discovery-validation approach for the lipidomics study. Risks for cardio-renal complications were studied by survival analysis. RESULTS: Cluster analysis identified three novel diabetic subgroups, i.e. mild obesity-related diabetes (MOD, 45%), mild age-related diabetes with insulin insufficiency (MARD-II, 36%) and severe insulin-resistant diabetes with relative insulin insufficiency (SIRD-RII, 19%). Compared with the MOD subgroup, MARD-II had a higher polygenic risk score for beta cell dysfunction. The SIRD-RII subgroup had higher levels of sphingolipids (ceramides and sphingomyelins) and glycerophospholipids (phosphatidylethanolamine and phosphatidylcholine), whereas the MARD-II subgroup had lower levels of sphingolipids and glycerophospholipids but higher levels of lysophosphatidylcholines. Over a median of 7.3 years follow-up, the SIRD-RII subgroup had the highest risks for incident heart failure and progressive kidney disease, while the MARD-II subgroup had moderately elevated risk for kidney disease progression. CONCLUSIONS/INTERPRETATION: Cluster analysis on clinical variables identified novel subgroups with distinct genetic, lipidomic signatures and varying cardio-renal risks in South East Asian participants with type 2 diabetes. Our study suggests that this easily actionable approach may be adapted in other ethnic populations to stratify the heterogeneous type 2 diabetes population for precision medicine.

Ethnic-Specific Type 2 Diabetes Risk Factor PAX4 R192H Is Associated with Attention-Specific Cognitive Impairment in Chinese with Type 2 Diabetes.

BACKGROUND: Type 2 diabetes mellitus (T2DM) has been shown to increase the risks of cognitive decline and dementia. Paired box gene 4 (PAX4), a transcription factor for beta cell development and function, has recently been implicated in pathways intersecting Alzheimer's disease and T2DM. OBJECTIVE: In this report, we evaluated the association of the ethnic-specific PAX4 R192H variant, a T2DM risk factor for East Asians which contributes to earlier diabetes onset, and cognitive function of Chinese T2DM patients. METHODS: 590 Chinese patients aged 45-86 from the SMART2D study were genotyped for PAX4 R192H variation using Illumina OmniExpress-24 Array. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) which had been validated in the Singapore population was administered to assess five cognitive domains: immediate memory, visuospatial/constructional, language, attention, and delayed memory. Multiple linear regression was used to assess the association of the R192H risk allele and cognitive domains. RESULTS: Patients with two PAX4 R192H risk alleles showed significantly lower attention index score (ß= -8.46, 95% CI [-13.71, -3.21], p = 0.002) than patients with wild-type alleles after adjusting for age, gender, diabetes onset age, HbA1c, body-mass index, renal function, lipid profiles, systolic blood pressure, metformin usage, smoking history, education level, Geriatric Depression Scale score, and presence of APOEɛ4 allele. CONCLUSION: Ethnic-specific R192H variation in PAX4 is associated with attention-specific cognitive impairment in Chinese with T2DM. Pending further validation studies, determining PAX4 R192H genotype may be helpful for early risk assessment of early-onset T2DM and cognitive impairment to improve diabetes care.

Genetic Risk Score for Plasma Uric Acid Levels Is Associated With Early Rapid Kidney Function Decline in Type 2 Diabetes.

CONTEXT: Observational studies have shown that elevated uric acid (UA) is associated with chronic kidney disease (CKD). However, whether the relationship is causal remains unclear. OBJECTIVE: To determine the association of plasma UA and incident CKD and the causal relationship between plasma UA and rapid decline in kidney function (RDKF) in patients with type 2 diabetes (T2D). METHODS: Multivariable Cox regression was conducted to evaluate the hazard ratio (HR) between plasma UA and incident CKD among 1300 normoalbuminuric patients in 2 T2D study cohorts (DN, n = 402; SMART2D, n = 898). A weighted genetic risk score (wGRS) was calculated based on 10 single nucleotide polymorphism (SNPs) identified in genome-wide association studies of UA in East Asians. Mendelian randomization (MR) analysis was performed among 1146 Chinese T2D patients without CKD (estimated glomerular filtration rate [eGFR] > 60 mL/min/1.73m2) at baseline (DN, 478; SMART2D, 668). The wGRS and individual SNPs were used as genetic instruments and RDKF was defined as eGFR decline of 5 mL/min/1.73m2/year or greater. RESULTS: During mean follow-up of 5.2 and 5.4 years, 81 (9%) and 46 (11%) participants in SMART2D and DN developed CKD, respectively. A 1-SD increment in plasma UA conferred higher risk of incident CKD (DN, adjusted-HR = 1.40 [95% CI, 1.02-1.91], P = 0.036; SMART2D, adjusted-HR = 1.31 [95% CI, 1.04-1.64], P = 0.018). Higher wGRS was associated with increased odds for RDKF (meta-adjusted odds ratio = 1.12 [95% CI, 1.01-1.24], P = 0.030, Phet = 0.606). CONCLUSION: Elevated plasma UA is an independent risk factor for incident CKD. Furthermore, plasma UA potentially has a causal role in early eGFR loss in T2D patients.

Association Between Use of Sodium-Glucose Co-Transporter-2 (SGLT2) Inhibitors and Cognitive Function in a Longitudinal Study of Patients with Type 2 Diabetes.

BACKGROUND: The association between sodium-glucose cotransporter-2 inhibitors (SGLT2i) use and cognitive function in type 2 diabetes remains unclear. OBJECTIVE: Explore the association between SGLT2i and longitudinal changes in cognitive function in adults with type 2 diabetes (T2DM) and assessed the cognitive domains which were impacted by SGLT2i. METHODS: We conducted a prospective cohort study of 476 patients aged 60.6±7.4 years with follow-up period up to 6.4 years. Data on SGLT2i use was derived from questionnaire and verified with clinical database. We used Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) to assess cognition. The association between SGLT2i use and rate of RBANS score change was examined using multiple linear regression. RESULTS: There were 138 patients (29.0%) on SGLT2i, including 84 (17.7%) for < 3 years and 54 (11.3%) for ≥3 years. SGLT2i use was positively associated with RBANS total score increase in language (coefficient 0.60; 95% CI 0.10-1.11; p = 0.019) in unadjusted analysis. This positive association persisted in fully adjusted model (coefficient 0.74; 95% CI 0.12 to 1.36; p = 0.019). SGLT2i use for ≥3 years was positively associated with RBANS score increase globally and in language domain in fully adjusted analysis with coefficients 0.54 (95% CI 0.13 to 0.95; p = 0.010) and 1.12 (95% CI 0.27 to 1.97; p = 0.010) respectively. CONCLUSION: Our findings revealed a previously unobserved association between ≥3 years SGLT2i use and improved cognitive scores globally and in language domain and executive function. Future studies should investigate the role of SGLT2i in ameliorating cognitive decline.

Amino acid profile of skeletal muscle loss in type 2 diabetes: Results from a 7-year longitudinal study in asians.

AIMS: Little is known about pathophysiology of sarcopenia in diabetes. We aimed to study amino acid profile associated with skeletal muscle mass loss longitudinally in Type 2 Diabetes Mellitus (T2DM). METHODS: This is a prospective study of 1140 patients aged 56.6 ± 10.6 years from the SMART2D cohort. Skeletal muscle mass was measured using bio-impedance analysis at baseline and follow-up. Amino acids were measured by mass spectrometry. RESULTS: Over a period of up to 7.9 years, 43.9% experienced skeletal muscle mass loss. Lower baseline valine, leucine and isoleucine levels were associated with decreased skeletal muscle mass index (SMI) with corresponding coefficient 0.251(95 %CI 0.009 to 0.493), 0.298(95 %CI 0.051 to 0.544)) and 0.366(95 %CI 0.131 to 0.600). Higher baseline valine, leucine, isoleucine, alanine and tryptophan levels were associated with reduced odds of muscle mass loss with corresponding odds ratio (OR)0.797 (95 %CI 0.690 to 0.921), 0.825 (95 %CI 0.713 to 0.955), 0.826 (95 %CI 0.718-0.950), 0.847 (95 %CI 0.739-0.969) and 0.835 (95 %CI 0.720-0.979). CONCLUSION: The branched-chain amino acids valine, leucine and isoleucine were positively associated with change in SMI and reduced odds of muscle mass loss longitudinally. Further studies should be conducted to elucidate the pathophysiological mechanisms underlying the relationship between these amino acids and muscle mass loss in T2DM.