Association of Diabetic Retinopathy with Chronic Kidney Disease Progression in Latinos with Type 2 Diabetes.

Aims: Diabetes remains a leading cause of blindness and kidney failure in the United States. Latinos are at increased risk for type 2 diabetes, and microvascular complications such as diabetic retinopathy (DR) and chronic kidney disease (CKD). We evaluated the association of DR with decline in kidney function in Latinos with type 2 diabetes with or without CKD in a multispecialty clinic. Methods: This is a retrospective cohort study of 351 self-identified Latino individuals with type 2 diabetes enrolled in the Latino Diabetes Initiative at Joslin Diabetes Center. Baseline demographic factors including age, sex, comorbidities, and laboratory values such as A1c and albuminuria were evaluated as predictors of kidney outcomes. The annualized change in estimated glomerular filtration rate (eGFR) was evaluated with a linear regression model. We used logistic regression to evaluate whether DR was associated with development of rapid progressors (>3 mL/min/y eGFR loss) and 30% change in eGFR per year. Results: DR was present in 39.2% of the cohort with mild nonproliferative DR (NPDR) in 57.1%, moderate to severe NPDR in 27.8%, and proliferative DR in 15.0%. Those with DR had a longer duration of type 2 diabetes (P<.001), higher albuminuria (P=.003), and lower baseline eGFR (P=.001). We found that individuals with moderate to severe NPDR and proliferative DR had a significant decline in GFR (coefficient -6.32; 95% CI, -11.40 to -1.23) and -7.82 (-14.99 to -0.65), compared with individuals without DR. Conclusions: The presence of DR is a marker for increased eGFR loss, emphasizing the need for routine retinal examinations as part of comprehensive diabetes care. Individuals with DR should be considered at high risk for GFR loss.

Associations between macrovascular and renal microvascular dysfunction in type 2 diabetes and non-diabetes: the HELIUS study.

BACKGROUND: Although the associations between measures of macrovascular and microvascular dysfunctions are well characterized in diabetes, there is limited data on these associations in individuals without diabetes. We compared the associations between macrovascular dysfunction and renal microvascular dysfunction in individuals with type 2 diabetes (T2D) and without diabetes. METHODS: Cross-sectional analyses of baseline data from the multiethnic Healthy Life in an Urban Setting (HELIUS) study (Amsterdam, the Netherlands), including 986 participants with T2D and 7680 participants without diabetes were done. Logistic regression analyses were used to examine the associations between macrovascular dysfunction [aortic stiffness, coronary artery disease (CAD), peripheral artery disease (PAD), and stroke] and renal microvascular dysfunction [albuminuria] with adjustments for age, sex, ethnicity, waist-to-hip ratio, systolic blood pressure, LDL-cholesterol, and smoking (and HbA1c and diabetes duration for the T2D group). RESULTS: In the fully adjusted models, aortic stiffness was associated with albuminuria in individuals with T2D [OR 2.55; 95% CI,1.30-4.98], but not without diabetes [0.96; 0.63-1.45]; stroke was associated with albuminuria in T2D [2.40;1.10-5.25], but not in non-diabetes [1.39;0.83-2.33]. In age-sex adjusted models, CAD was associated with albuminuria in T2D [1.65;1.09-2.50] and in non-diabetes [1.56;1.13-2.15]; the associations were no longer significant in the fully adjusted model. There were no associations between PAD and albuminuria in T2D and non-diabetes. CONCLUSIONS: Our study shows important differences in the associations between measures of macrovascular and renal microvascular dysfunction in T2D and non-diabetes. These findings provide opportunities for future research aimed at prevention and treatment strategies for individuals with vascular dysfunction.

How Clinically Relevant Is C-Reactive Protein for Blacks with Metabolic Syndrome to Predict Microalbuminuria?

Background: The metabolic syndrome (MetS) is associated with elevated urinary albumin (UA) excretion and C-reactive protein (CRP). However, potential differences in CRP levels on the association between individual components of the MetS and microalbuminuria (MA; 30-300 µg/mL) and/or UA (0-300 µg/mL) by race/ethnicity is unknown. Methods: We analyzed National Health and Nutrition Examination Surveys (NHANES) data, (1999-2010) for adults (≥20 years of age) with the MetS (N = 5700). The Sobel-Goodman mediation test examined the influence of CRP on the association between individual MetS components and both MA and UA by race/ethnicity. We applied machine learning models to predict UA. Results: CRP mediated the association between waist circumference (WC) and MA in Whites and Hispanics but not in Blacks. However, in general, the proportion of the total effect of MetS components on UA, mediated by CRP, was: 11% for high-density lipoprotein cholesterol (HDL-C) and 40% for WC (P < 0.001). In contrast to MA, the mediation effect of CRP for WC and UA was highest for Blacks (94%) compared with Whites (55%) or Hispanics (18%), P < 0.05. The prediction of an elevated UA concentration was increased in Blacks (∼51%) with the MetS when CRP was added to the random forest model. Conclusions: CRP mediates the association between UA and both HDL-C and WC in Whites and Blacks and between UA and WC in Hispanics. Moreover, the machine learning approach suggests that the incorporation of CRP may improve model prediction of UA in Blacks. These findings may favor screening for CRP in persons with the MetS, particularly in Blacks.

Race, APOL1 Risk Variants, and Clinical Outcomes among Older Adults: The ARIC Study.

BACKGROUND/OBJECTIVES: APOL1 high-risk genotypes confer an increased risk for kidney disease, but their clinical significance among older adults remains unclear. We aimed to determine whether APOL1 genotype status (high risk = 2 risk alleles; low risk = 0-1 risk alleles) and self-reported race (Black; White) are associated with number of hospitalizations, incident chronic kidney disease (CKD), end-stage renal disease (ESRD), and mortality among older adults participating in a community-based cohort study. DESIGN: Observational longitudinal cohort study. SETTING: The Atherosclerosis Risk in Communities (ARIC) study. PARTICIPANTS: Community-dwelling older adults (mean age = 75.8 years; range = 66-90 years). RESULTS: Among 5,564 ARIC participants (78.2% White, 19.1% APOL1 low-risk Black, and 2.7% APOL1 high-risk Black), the proportion with creatinine and cystatin C-based estimated glomerular filtration rate (eGFRCrCys ) below 60 mL/min/1.73 m2 at baseline was 40.6%, 34.8%, and 43.2%, respectively. Over a mean follow-up of 5.1 years, APOL1 high-risk Blacks had a 2.67-fold higher risk for ESRD compared with low-risk Blacks (95% confidence interval [CI] = 1.05-6.79) in models adjusted for age and sex. This association was no longer significant upon further adjustment for baseline eGFRCrCys and albuminuria (hazard ratio [HR] = 1.08; 95% CI = .39-2.96). Rate of hospitalizations and risks of mortality and incident CKD did not differ significantly by APOL1 genotype status. Compared with Whites, Blacks had 1.85-fold and 3.45-fold higher risks for incident CKD and ESRD, respectively, in models adjusted for age, sex, eGFRCrCys , and albuminuria. These associations persisted after additional adjustments for clinical/socioeconomic factors and APOL1 genotype (incident CKD: HR = 1.38; 95% CI = 1.06-1.81; ESRD: HR = 3.20; 95% CI = 1.16-8.86). CONCLUSION: Among older Black adults, APOL1 high-risk genotypes were associated with lower kidney function and therefore higher risk of ESRD. Racial disparities in incident kidney disease persisted in older age and were not fully explained by APOL1.

Albuminuria and Primary Open-Angle Glaucoma: the Singapore Chinese Eye Study (SCES).

AIMS: To determine the association between albuminuria and primary open-angle glaucoma (POAG). METHODS: Participants of the Singapore Chinese Eye study were recruited and underwent standardised ocular and systemic examinations. Albuminuria was determined using urinary albumin-to-creatinine ratio (UACR, mg/g) based on random spot urinary albumin and creatinine measurements. POAG was defined using the International Society of Geographic and Epidemiological Ophthalmology classification. Multivariable logistic regression with generalised estimating equation model was used to evaluate the association between albuminuria and POAG, while accounting for correlation between eyes. RESULTS: A total of 3009 Chinese adults (5963 eyes), aged 40-80 years, were included in this study, of which, 52 subjects (75 eyes) had POAG. Higher UACR (per 50 mg/g increase) was independently associated with POAG (OR=1.04, 95% CI 1.01 to 1.07, p=0.003) following adjustment for age, gender, intraocular pressure, diabetes mellitus, hyperlipidaemia, hypertension, anti-hypertensive medication, history of cardiovascular disease, current smoking status, alcohol intake, body mass index and estimated glomerular filtration rate. Further stratification revealed that individuals with macroalbuminuria were 8.00 times likely to have POAG (95% CI 2.97 to 21.54, p<0.001), compared with those with normoalbuminuria. Microalbuminuria was not significantly associated with POAG (OR=0.49, 95% CI 0.19 to 1.29, p=0.150). The association between macroalbuminuria and POAG remained significant among individuals who were diabetic (OR=9.89, 95% CI 2.49 to 39.30, p=0.001) and hypertensive (OR=8.39, 95% CI 3.07 to 22.94, p<0.001). CONCLUSION: In this population-based study of Chinese adults, albuminuria was independently associated with POAG. Our findings provide further understanding on the pathogenesis of POAG and may potentially help to better identify individuals at risk of POAG.

Elevated circulating luteinizing hormone levels are associated with diabetic macroalbuminuria in Chinese men and postmenopausal women: A cross-sectional study.

BACKGROUND: Associations between sex hormones and diabetic vascular complications have recently been studied, but the role luteinizing hormone (LH) plays in diabetic kidney disease (DKD) remains uncertain. We aimed to investigate the relationship of LH and DKD in Chinese men and postmenopausal women with type 2 diabetes mellitus (T2DM). METHODS: Data were collected from 1775 T2DM men and postmenopausal women in hospital. The odds ratios (OR) and corresponding 95% confidence intervals (CI) in relation to LH quartiles were obtained by multiple logistic regression analysis. RESULTS: LH levels were significantly higher in patients with macroalbuminuria than in those with microalbuminuria, but were not higher in patients with microalbuminuria than in those with normoalbuminuria. Consistently, LH in those with an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73m2 were significantly higher than in those with eGFR≥60 mL/min/1.73m2 . The prevalence of macroalbuminuria was obviously increased for subjects of the fourth quartile of LH vs the first to third quartile (20.4% vs 6.2%, 8.0%, 12.2% in men; 25.3% vs 5.5%, 3.8%, 9.3% in postmenopausal women). Multivariate logistic regression demonstrated that subjects within the highest quartile of LH had higher odds of macroalbuminuria than those within the lowest quartile (OR 4.00, 95% CI, 1.87-8.55 for men; OR 9.62, 95% CI, 3.42-27.08 for postmenopausal women), independent of age, diabetes duration, or other metabolic factors. The area under the curve for detecting macroalbuminuria based on LH was 0.662 for men, and 0.767 for postmenopausal women. CONCLUSION: High LH levels are positively associated with established DKD among Chinese men and postmenopausal women. Elevated LH may be a promising clinical factor for identifying established DKD.

A study on the correlation between remnant cholesterol and urinary albumin to creatinine ratio in Chinese community adults: A report from the REACTION study.

BACKGROUND: The correlation between remnant cholesterol (RC) and urinary albumin to creatinine ratio (UACR) has not been illustrated. The present study aims to explore the correlation between RC levels and UACR in Chinese community adults. METHODS: This study included 35 848 participants from a cohort study (REACTION). The UACR data were divided into three groups: UACR <10 mg/g, 10 ≤UACR<30 mg/g, and UACR ≥30 mg/g groups. RC was divided into two groups, according to the 75th percentile: <75% group and ≥75% group. Multiple logistic regression analysis was used to evaluate the correlation between RC and UACR. RESULTS: The RC exhibited an adjusted odds ratio that was significant in models 1-5. Although all confounders were corrected in model 5, RC and UACR were still significantly correlated， and the correlation was more significant in females，when compared to males (odds ratio [OR]: 1.117, 95% CI: 1.063-1.176, P < 0.001 for all subjects; OR: 1.092, 95% CI: 1.128-1.161, P = 0.004 for females; and OR: 1.085, 95% CI: 0.998-1.194, P = 0.088 for males). The RC was significantly correlated with UACR for subjects with 5.6 ≤ fasting blood glucose < 7.0 or 7.8 ≤ post-load blood glucose < 11.1 mmol/L, 24 ≤ body mass index (BMI) < 28 kg/m2 , 120 ≤ systolic blood pressure < 140 and/or 80 ≤ diastolic blood pressure < 90 mm Hg. CONCLUSIONS: In the Chinese community, RC is highly correlated with UACR, and the correlation is more significant in females compared with males. At higher RC levels, patients with critical values of blood pressure, BMI and blood glucose have a more significant correlation between RC and UACR.

Ambulatory Blood Pressure Phenotypes in Adults Taking Antihypertensive Medication with and without CKD.

BACKGROUND AND OBJECTIVES: Recent guidelines recommend out-of-clinic BP measurements. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We compared the prevalence of BP phenotypes between 561 black patients, with and without CKD, taking antihypertensive medication who underwent ambulatory BP monitoring at baseline (between 2000 and 2004) in the Jackson Heart Study. CKD was defined as an albumin-to-creatinine ratio ≥30 mg/g or eGFR <60 ml/min per 1.73 m2. Sustained controlled BP was defined by BP at goal both inside and outside of the clinic and sustained uncontrolled BP as BP above goal both inside and outside of the clinic. Masked uncontrolled hypertension was defined by controlled clinic-measured BP with uncontrolled out-of-clinic BP. RESULTS: CKD was associated with a higher multivariable-adjusted prevalence ratio for uncontrolled versus controlled clinic BP (prevalence ratio, 1.44; 95% CI, 1.02 to 2.02) and sustained uncontrolled BP versus sustained controlled BP (prevalence ratio, 1.66; 95% CI, 1.16 to 2.36). There were no statistically significant differences in the prevalence of uncontrolled daytime or nighttime BP, nondipping BP, white-coat effect, and masked uncontrolled hypertension between participants with and without CKD after multivariable adjustment. After multivariable adjustment, reduced eGFR was associated with masked uncontrolled hypertension versus sustained controlled BP (prevalence ratio, 1.42; 95% CI, 1.00 to 2.00), whereas albuminuria was associated with uncontrolled clinic BP (prevalence ratio, 1.76; 95% CI, 1.20 to 2.60) and sustained uncontrolled BP versus sustained controlled BP (prevalence ratio, 2.02; 95% CI, 1.36 to 2.99). CONCLUSIONS: The prevalence of BP phenotypes defined using ambulatory BP monitoring is high among adults with CKD taking antihypertensive medication.

Evaluation of lipoprotein-associated phospholipase A2 as a marker for renal microvasculopathy in adolescents with Type 1 diabetes.

AIM: To assess the relevance of lipoprotein-associated phospholipase A2 activity as a diagnostic and prognostic marker for renal microvascular diseases. METHODS: We analysed lipoprotein-associated phospholipase A2 activity and lysophosphatidylcholine levels (as a surrogate marker of oxidative stress) in 165 adolescents (aged 17.0 ± 2.3 years) with a history of Type 1 diabetes greater than 10 years. Clinical data were obtained from the German/Austrian nationwide Diabetes-Patients Follow-up (DPV) registry at blood collection and on average 2.4 ± 1.3 years later at follow-up. Relationships between lipoprotein-associated phospholipase A2 activity and clinical, demographic and laboratory variables, lysophosphatidylcholine levels and presence of albuminuria were evaluated by multivariable linear and logistic regression. RESULTS: Lipoprotein-associated phospholipase A2 activity was higher in male than female adolescents (P = 0.002). Albuminuria was present in 14% (22/158) of participants at baseline, and 5% (4/86) of participants without albuminuria at baseline developed albuminuria until follow-up. Lipoprotein-associated phospholipase A2 activity was associated neither with present nor with incident albuminuria. Lysophosphatidylcholine did not correlate with lipoprotein-associated phospholipase A2 activity. Cross-sectional bivariate correlation as well as multivariable linear regression analysis revealed a negative correlation of lipoprotein-associated phospholipase A2 activity with HbA1c and HDL-cholesterol. CONCLUSIONS: Lipoprotein-associated phospholipase activity was not associated with surrogate markers for oxidative stress and early diabetic nephropathy. The association of decreased lipoprotein-associated phospholipase A2 activity with poor glucose control might limit its function as a predictor of micro- and macrovascular diseases in Type 1 diabetes.

Interrelation of cardiovascular risk factors with high albuminury among patients with arterial hypertension living in Mountain Shoriya.

AIM: To evaluate the association of a complex of cardiovascular risk factors and genetic markers with the development of high albuminuria among patients with arterial hypertension in the population of Mountain Shoriya, taking into account ethnicity. MATERIALS AND METHODS: A clinical epidemiological study of a compactly residing population in remote areas of Mountain Shoria was carried out. 1409 people were examined [901 people - representatives of the indigenous nationality (Shorians), 508 people - representatives of non-indigenous nationality (90% of them are Caucasians)]. Hypertension was diagnosed according to the National Guidelines of the Russian Society of Cardiology/the Russian Medical Society on Arterial Hypertension (2010). All patients underwent clinical, laboratory and instrumental investigation. To study the state of the kidneys, the concentration (the presence of elevated levels) of albumin (albuminuria) in the morning portion of urine by an immunoturbidimetric method was analyzed. Polymorphisms of genes ACE (I/D, rs4340), АGT (c.803T>C, rs699), AGTR1 (А1166С, rs5186), ADRB1 (с.145A>G, Ser49Gly, rs1801252), ADRA2B (I/D, rs28365031), MTHFR (c.677С>Т, Ala222Val, rs1801133) and NOS3 (VNTR, 4b/4a) were tested using PCR. RESULTS: In the group of shors with arterial hypertension, high albuminuria was associated with polymorphisms of the ACE genes (OR=2.05), ADRA2B (OR=6.00), elevated triglyceride level (OR=2.86), decreased index of cholesterol of high density lipoproteins (OR=5.57) and increased index of low density lipoproteins (OR=2.49); in the new population - with polymorphisms of the AGTR1 genes (OR=8.66), ADRA2B (OR=6.53), MTHFR (OR=7.16), obesity (OR=2.72), and abdominal obesity (OR=3.14). CONCLUSION: The primary predictors determining the development of high albuminuria among patients with arterial hypertension in both ethnic groups were genetic ones. In addition to them, non-genetic risk factors also contributed to the development of this organ damage to the kidneys: age and lipid metabolism disorders in representatives of indigenous nationality; age and abdominal obesity in the examined patients non-indigenous nationality.

Is hyperfiltration associated with higher urine albumin-to-creatinine ratio at follow up among Indigenous Australians? The eGFR follow-up study.

BACKGROUND: Glomerular hyperfiltration is not able to be detected in clinical practice. We assessed whether hyperfiltration is associated with albuminuria progression among Indigenous Australians at high risk of diabetes and kidney disease to determine its role in kidney disease progression. METHODS: Longitudinal observational study of Indigenous Australians aged ≥18 years recruited from >20 sites, across diabetes and/or kidney function strata. At baseline, iohexol clearance was used to measure glomerular filtration rate (mGFR) and hyperfiltration was defined as (i) a mGFR of ≥125 mL/min/1.73 m2, and (ii) an age-adjusted definition, with the top 10% of the mGFR for each 10 year age group at baseline. Baseline and follow-up urine albumin-to-creatinine ratio (uACR) was collected, and linear regression was used to assess the associations of hyperfiltration and uACR at follow up. RESULTS: 407 individuals (33% men, mean age 47 years) were followed-up for a median of 3 years. At baseline, 234 had normoalbuminuria and 173 had albuminuria. Among participants with normoalbuminuria, those with mGFR ≥125 mL/min/1.73 m2 had 32% higher uACR at follow-up (p = 0.08), and those with age-adjusted hyperfiltration had 60% higher uACR (p = 0.037) compared to those who had normofiltration. These associations were independent of uACR at baseline, but attenuated by HbA1c. Associations were stronger among those without than those with albuminuria at baseline. CONCLUSIONS: Although not available for assessment in current clinical practice, hyperfiltration may represent a marker of subsequent albuminuria progression among individuals who have not yet developed albuminuria.

Relationship of fibroblast growth factor 21 with kidney function and albuminuria: multi-ethnic study of atherosclerosis.

BACKGROUND: Fibroblast growth factor 21 (FGF21) may play a role in the development of chronic kidney disease (CKD). We therefore investigated the relationship of plasma FGF21 levels with kidney function and albuminuria in the Multi-Ethnic Study of Atherosclerosis (MESA). METHODS: The analysis included 5724 MESA participants ages 45-84 years between 2000 and 2002, free of clinically apparent cardiovascular disease (CVD). Participants were followed up in person at four additional clinic visits over 10 years. Plasma FGF21 levels were measured at baseline examination by enzyme-linked immunosorbent assay. Kidney function was assessed by estimated glomerular filtration rate (eGFR). Outcomes were urinary albumin:creatinine ratio (UACR) progression, incident CKD by eGFR (reaching eGFR <60 mL/min/1.73 m2 with eGFR loss rate ≥1 mL/min/1.73 m2 per year) and rapid kidney function decline (eGFR decline >5%/year). RESULTS: At baseline, higher FGF21 levels, assessed as both continuous and categorical quartile variables, were significantly associated with lower eGFR and higher UACR, after adjusting for demographic, socioeconomic and other confounding factors [adjusted mean differences of -2.63 mL/min/1.73 m2 in eGFR and 0.134 in log normally transformed UACR (mg/g) for the highest FGF21 quartile compared with the lowest quartile, all P < 0.001]. However, in longitudinal analyses, baseline FGF21 levels did not predict incident CKD by eGFR, rapid kidney function decline or UACR progression. No significant interaction with sex and race/ethnicity was found (all P > 0.05). CONCLUSIONS: Our study does not support a role of FGF21 as a biomarker for predicting kidney function decline or albuminuria in adults free of clinically apparent CVD at baseline.

Relationship of mildly increased albuminuria and coronary artery revascularization outcomes in patients with diabetes.

BACKGROUND: The aim of this study was to examine the relationship of albuminuria to cardiovascular disease outcomes in diabetic patients undergoing treatment for stable coronary artery disease. METHODS AND RESULTS: We analyzed data from 2176 participants of the Bypass Angioplasty Revascularization Investigation in type-2 diabetes (BARI-2D) trial, a randomized clinical trial comparing Percutaneous coronary intervention/Coronary artery bypass grafting (PCI/CABG) to medical therapy for people with diabetes. The population was stratified by baseline spot urine albumin-creatinine ratio (uACR) into normal (uACR <10 mg/g), mildly (uACR ≥10 mg/g < 30 mg/g), moderately (uACR ≥30 mg/g < 300 mg/g) and severely increased (uACR ≥300 mg/g) groups, and outcomes compared between groups. Death, myocardial infarction (MI) and/or stroke were experienced by 489 patients at a mean follow-up of 4.3 ± 1.5 years. Compared with normal uACR, mildly increased uACR was associated with a 1.4 times (P = 0.042) increase in all-cause mortality. Additionally, nonwhites with type-II diabetes and stable coronary artery disease who had mildly increased albuminuria had a Hazard ratio (HR) of 3.3 times (P = 0.028) for cardiovascular death, 3.1 times for (P = 0.002) all-cause mortality, and two times for (P = 0.015) MI during follow-up. CONCLUSIONS: Mildly increased albuminuria is a significant predictor of all-cause mortality in those with type-II diabetes mellitus and stable coronary artery disease, as well as for cardiovascular events those who are nonwhites.

Relationship between transforming growth factor-ß1 and type 2 diabetic nephropathy risk in Chinese population.

BACKGROUND: Diabetes mellitus (DM) is divided into four different etiological categories: type 1 DM (T1DM), type 2 DM (T2DM), other specific types, and gestational DM. One severe complication of T2DM is type 2 diabetic nephropathy (T2DN). The possible association of serum transforming growth factor-ß1 (TGF-ß1) levels and the TGF-ß1 T869C gene polymorphism with patient susceptibility to T2DN in Chinese population is unclear at present. This study was conducted to assess these relationships in Chinese population by a meta-analysis. METHODS: Association reports were searched and pulled from the Cochrane Library, the China Biological Medicine Database (CBM), and PubMed on March 1, 2018, and eligible studies were selected and used for calculations. The results were expressed as weighted mean differences (MD) for continuous data. Odds ratios (OR) were used to express the results for dichotomous data. Additionally, 95% confidence intervals (CI) were calculated. RESULTS: Forty-eight reports for the relationship between serum TGF-ß1 levels and the risk of T2DN and 13 studies on the association of the TGF-ß1 T869C gene polymorphism with susceptibility to T2DN in Chinese population were retrieved from this study. Serum TGF-ß1 levels in the T2DM group were higher than those in the normal control group (MD = 17.30, 95% CI: 12.69-21.92, P < 0.00001). The serum TGF-ß1 level in the T2DN group was significantly higher than that in the normal control group (MD = 70.03, 95% CI: 60.81-79.26, P < 0.00001;). The serum TGF-ß1 level in the T2DN group was significantly higher than that in the T2DM group (MD = 56.18, 95% CI: 46.96-65.39, P < 0.00001). Serum TGF-ß1 levels in T2DM patients with microalbuminuria were increased when compared with those in T2DM patients with normoalbuminuria. Furthermore, serum TGF-ß1 levels in T2DM patients with macroalbuminuria were increased when compared with those in T2DM patients with microalbuminuria. The TGF-ß1 T allele, TT allele and CC genotype were associated with T2DN susceptibility in Chinese population (T: OR = 0.74, 95% CI: 0.59-0.92, P = 0.007; TT: OR = 0.55, 95% CI: 0.31-0.96, P = 0.04; CC: OR = 1.38, 95% CI: 1.14-1.67, P = 0.001). CONCLUSIONS: High levels of TGF-ß1 are associated with susceptibility to T2DM, T2DN and the progression of proteinuria in T2DN patients in Chinese population. Further, the TGF-ß1 T allele, and TT genotype were protective factors against the onset of T2DN and CC genotype was a risk factor for the susceptibility of T2DN in Chinese populations.

Cytosine methylation predicts renal function decline in American Indians.

Diabetic nephropathy accounts for most of the excess mortality in individuals with diabetes, but the molecular mechanisms by which nephropathy develops are largely unknown. Here we tested cytosine methylation levels at 397,063 genomic CpG sites for association with decline in the estimated glomerular filtration rate (eGFR) over a six year period in 181 diabetic Pima Indians. Methylation levels at 77 sites showed significant association with eGFR decline after correction for multiple comparisons. A model including methylation level at two probes (cg25799291 and cg22253401) improved prediction of eGFR decline in addition to baseline eGFR and the albumin to creatinine ratio with the percent of variance explained significantly improving from 23.1% to 42.2%. Cg22253401 was also significantly associated with eGFR decline in a case-control study derived from the Chronic Renal Insufficiency Cohort. Probes at which methylation significantly associated with eGFR decline were localized to gene regulatory regions and enriched for genes with metabolic functions and apoptosis. Three of the 77 probes that were associated with eGFR decline in blood samples showed directionally consistent and significant association with fibrosis in microdissected human kidney tissue, after correction for multiple comparisons. Thus, cytosine methylation levels may provide biomarkers of disease progression in diabetic nephropathy and epigenetic variations contribute to the development of diabetic kidney disease.

Ambulatory blood pressure in the dash diet trial: Effects of race and albuminuria.

We evaluated whether low-grade albuminuria or black race modulates ambulatory blood pressure (BP) or nocturnal BP response to the DASH diet. Among 202 adults enrolled in the DASH multicenter trial who were fed the DASH or control diet for 8 weeks, reductions in 24-hour daytime and nighttime SBP and DBP were significantly larger for DASH compared to control. Median changes in nocturnal BP dipping were not significant. Compared to urine albumin excretion of <7 mg/d, ≥7 mg/d was associated with larger significant median reductions in 24-hour SBP (-7.3 vs -3.1 mm Hg), all measures of DBP (24-hour: -5.9 vs -1.8 mm Hg; daytime: -9.9 vs -4.0 mm Hg; nighttime -9.0 vs -2.0 mm Hg), and with increased nocturnal SBP dipping (2.3% vs -0.5%). Black race was associated with larger median reduction in 24-hour SBP only (-5.5 vs -2.4 mm Hg). This analysis suggests greater effect of DASH on ambulatory BP in the presence of low-grade albuminuria.

High Baseline Levels of Tumor Necrosis Factor Receptor 1 Are Associated With Progression of Kidney Disease in Indigenous Australians With Diabetes: The eGFR Follow-up Study.

OBJECTIVE: To examine the association between soluble tumor necrosis factor receptor 1 (sTNFR1) levels and kidney disease progression in Indigenous Australians at high risk of kidney disease. RESEARCH DESIGN AND METHODS: This longitudinal observational study examined participants aged ≥18 years recruited from >20 sites across diabetes and/or kidney function strata. Baseline measures included sTNFR1, serum creatinine, urine albumin-to-creatinine ratio (uACR), HbA1c, C-reactive protein (CRP), waist-to-hip ratio, systolic blood pressure, and medical history. Linear regression was used to estimate annual change in estimated glomerular filtration rate (eGFR) for increasing sTNFR1, and Cox proportional hazards were used to estimate the hazard ratio (HR) and 95% CI for developing a combined renal outcome (first of a ≥30% decline in eGFR with a follow-up eGFR <60 mL/min/1.73 m2, progression to renal replacement therapy, or renal death) for increasing sTNFR1. RESULTS: Over a median of 3 years, participants with diabetes (n = 194) in the highest compared with the lowest quartile of sTNFR1 experienced significantly greater eGFR decline (-4.22 mL/min/1.73 m2/year [95% CI -7.06 to -1.38]; P = 0.004), independent of baseline age, sex, eGFR, and uACR. The adjusted HR (95% CI) for participants with diabetes per doubling of sTNFR1 for the combined renal outcome (n = 32) was 3.8 (1.1-12.8; P = 0.03). No association between sTNFR1 and either renal outcome was observed for those without diabetes (n = 259). CONCLUSIONS: sTNFR1 is associated with greater kidney disease progression independent of albuminuria and eGFR in Indigenous Australians with diabetes. Further research is required to assess whether TNFR1 operates independently of other metabolic factors associated with kidney disease progression.

Genome-wide association studies of albuminuria: towards genetic stratification in diabetes?

Genome-wide association studies (GWAS) have been very successful in unraveling the polygenic structure of several complex diseases and traits. In the case of albuminuria, despite the large sample size achieved by some studies, results look sparse with a limited number of loci reported so far. This review searched for GWAS studies of albumin excretion, albuminuria, and proteinuria. The resulting picture sets elements of uniqueness for albuminuria GWAS with respect to other complex traits. So far, very few loci associated with albuminuria have been validated by means of genome-wide significant evidence or formal replication. With rare exceptions, the validated loci are ethnicity specific. Within a given ethnicity, variants are common and have relatively large effects, especially in the presence of diabetes. In most cases, the identified variants were functional and a biological involvement of the target genes in renal damage was established. Recently reported variants associated with albuminuria in diabetes may be potentially combined into a genetic risk score, making it possible to rank diabetic patients by increasing risk of albuminuria. Validation of this model is required. To expand the understanding of the biological basis of albumin excretion regulation, future initiatives should achieve larger sample sizes and favor a transethnic study design.

Association Between Gestational Diabetes and Incident Maternal CKD: The Coronary Artery Risk Development in Young Adults (CARDIA) Study.

BACKGROUND: Gestational diabetes mellitus (GDM) is associated with increased risk for diabetes mellitus, metabolic syndrome, and cardiovascular disease. We evaluated whether GDM is associated with incident chronic kidney disease (CKD), controlling for prepregnancy risk factors for both conditions. STUDY DESIGN: Prospective cohort. SETTING & PARTICIPANTS: Of 2,747 women (aged 18-30 years) enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) Study in 1985 to 86, we studied 820 who were nulliparous at enrollment, delivered at least 1 pregnancy longer than 20 weeks' gestation, and had kidney function measurements during 25 years of follow-up. PREDICTOR: GDM was self-reported by women for each pregnancy. OUTCOMES: CKD was defined as the development of estimated glomerular filtration rate (eGFR)<60mL/min/1.73m2 or urine albumin-creatinine ratio ≥ 25mg/g at any one CARDIA examination in years 10, 15, 20, or 25. MEASUREMENTS: HRs for developing CKD were estimated for women who developed GDM versus women without GDM using complementary log-log models, adjusting for prepregnancy age, systolic blood pressure, dyslipidemia, body mass index, smoking, education, eGFR, fasting glucose concentration, physical activity level (all measured at the CARDIA examination before the first pregnancy), race, and family history of diabetes. We explored for an interaction between race and GDM. RESULTS: During a mean follow-up of 20.8 years, 105 of 820 (12.8%) women developed CKD, predominantly increased urine albumin excretion (98 albuminuria only, 4 decreased eGFR only, and 3 both). There was evidence of a GDM-race interaction on CKD risk (P=0.06). Among black women, the adjusted HR for CKD was 1.96 (95% CI, 1.04-3.67) in GDM compared with those without GDM. Among white women, the HR was 0.65 (95% CI, 0.23-1.83). LIMITATIONS: Albuminuria was assessed by single untimed measurements of urine albumin and creatinine. CONCLUSIONS: GDM is associated with the subsequent development of albuminuria among black women in CARDIA.

Cross-sectional associations of albuminuria among Aboriginal and Torres Strait Islander adults: the eGFR Study.

OBJECTIVE: To describe the detailed associations of albuminuria among a contemporary cohort of Aboriginal and Torres Strait Islander people to inform strategies for chronic kidney disease prevention and management. METHODS: A cross-sectional analysis of Indigenous participants of the eGFR Study. MEASURES: Clinical, biochemical and anthropometric measures were collected (including body-circumferences, blood pressure (BP); triglycerides, HbA1c, liver function tests, creatinine; urine- microscopic-haem, albumin: creatinine ratio (ACR), prescriptions- angiotensin converting enzyme inhibitor or angiotensin receptor II antagonist (ACEI/ARB). Albuminuria and diabetes were defined by an ACR>3.0 mg/mmol, and HbA1c≥48 mmol/mol or prior history respectively. Waist: hip ratio (WHR), and estimated glomerular filtration rate (eGFR) were calculated. ACR was non-normally distributed; a logarithmic transformation was applied (in base 2), with each unit increase in log2-albuminuria representing a doubling of ACR. RESULTS: 591 participants were assessed (71% Aboriginal, 61.6% female, mean age 45.1 years, BMI 30.2 kg/m2 , WHR 0.94, eGFR 99.2 ml/min/1.73m2 ). The overall prevalence of albuminuria, diabetes, microscopic-haem and ACEI/ARB use was 41.5%, 41.5%, 17.8% and 34.7% respectively; 69.3% of adults with albuminuria and diabetes received an ACEI/ARB. Using multivariable linear regression modelling, the potentially modifiable factors independently associated with log2-albuminuria were microscopic-haem, diabetes, WHR, systolic BP, alkaline phosphatase (all positive) and eGFR (inverse). CONCLUSION: Albuminuria is associated with diabetes, central obesity and haematuria. High ACEI/ARB prescribing for adults with diabetes and albuminuria was observed. Further understanding of the links between fat deposition, haematuria and albuminuria is required.