Henk J. G. Bilo

Associations of kidney disease measures with mortality and end-stage renal disease in individuals with and without diabetes : a meta-analysis

BACKGROUND Chronic kidney disease is characterised by low estimated glomerular filtration rate (eGFR) and high albuminuria, and is associated with adverse outcomes. Whether these risks are modified by diabetes is unknown. METHODS We did a meta-analysis of studies selected according to Chronic Kidney Disease Prognosis Consortium criteria. Data transfer and analyses were done between March, 2011, and June, 2012. We used Cox proportional hazards models to estimate the hazard ratios (HR) of mortality and end-stage renal disease (ESRD) associated with eGFR and albuminuria in individuals with and without diabetes. FINDINGS We analysed data for 1,024,977 participants (128,505 with diabetes) from 30 general population and high-risk cardiovascular cohorts and 13 chronic kidney disease cohorts. In the combined general population and high-risk cohorts with data for all-cause mortality, 75,306 deaths occurred during a mean follow-up of 8·5 years (SD 5·0). In the 23 studies with data for cardiovascular mortality, 21,237 deaths occurred from cardiovascular disease during a mean follow-up of 9·2 years (SD 4·9). In the general and high-risk cohorts, mortality risks were 1·2-1·9 times higher for participants with diabetes than for those without diabetes across the ranges of eGFR and albumin-to-creatinine ratio (ACR). With fixed eGFR and ACR reference points in the diabetes and no diabetes groups, HR of mortality outcomes according to lower eGFR and higher ACR were much the same in participants with and without diabetes (eg, for all-cause mortality at eGFR 45 mL/min per 1·73 m(2) [vs 95 mL/min per 1·73 m(2)], HR 1·35; 95% CI 1·18-1·55; vs 1·33; 1·19-1·48 and at ACR 30 mg/g [vs 5 mg/g], 1·50; 1·35-1·65 vs 1·52; 1·38-1·67). The overall interactions were not significant. We identified much the same findings for ESRD in the chronic kidney disease cohorts. INTERPRETATION Despite higher risks for mortality and ESRD in diabetes, the relative risks of these outcomes by eGFR and ACR are much the same irrespective of the presence or absence of diabetes, emphasising the importance of kidney disease as a predictor of clinical outcomes. FUNDING US National Kidney Foundation.

Metformin associated with lower cancer mortality in type 2 diabetes: ZODIAC-16.

OBJECTIVE Several studies have suggested an association between specific diabetes treatment and cancer mortality. We studied the association between metformin use and cancer mortality in a prospectively followed cohort. RESEARCH DESIGN AND METHODS In 1998 and 1999, 1,353 patients with type 2 diabetes were enrolled in the Zwolle Outpatient Diabetes project Integrating Available Care (ZODIAC) study in the Netherlands. Vital status was assessed in January 2009. Cancer mortality rate was evaluated using standardized mortality ratios (SMRs), and the association between metformin use and cancer mortality was evaluated with a Cox proportional hazards model, taking possible confounders into account. RESULTS Median follow-up time was 9.6 years, average age at baseline was 68 years, and average A1C was 7.5%. Of the patients, 570 died, of which 122 died of malignancies. The SMR for cancer mortality was 1.47 (95% CI 1.22–1.76). In patients taking metformin compared with patients not taking metformin at baseline, the adjusted hazard ratio (HR) for cancer mortality was 0.43 (95% CI 0.23–0.80), and the HR with every increase of 1 g of metformin was 0.58 (95% CI 0.36–0.93). CONCLUSIONS In general, patients with type 2 diabetes are at increased risk for cancer mortality. In our group, metformin use was associated with lower cancer mortality compared with nonuse of metformin. Although the design cannot provide a conclusion about causality, our results suggest a protective effect of metformin on cancer mortality.

Glucose-insulin-potassium infusion inpatients treated with primary angioplasty for acute myocardial infarction ☆: The glucose-insulin-potassium study: a randomized trial

OBJECTIVES In this study we considered the question of whether adjunction of glucose-insulin-potassium (GIK) infusion to primary coronary transluminal angioplasty (PTCA) is effective in patients with an acute myocardial infarction (MI). BACKGROUND A combined treatment of early and sustained reperfusion of the infarct-related coronary artery and the metabolic modulation with GIK infusion has been proposed to protect the ischemic myocardium. METHODS From April 1998 to September 2001, 940 patients with an acute MI and eligible for PTCA were randomly assigned, by open-label, to either a continuous GIK infusion for 8 to 12 h or no infusion. RESULTS The 30-day mortality was 23 of 476 patients (4.8%) receiving GIK compared with 27 of 464 patients (5.8%) in the control group (relative risk [RR] 0.82, 95% confidence interval [CI] 0.46 to 1.46). In 856 patients (91.1%) without signs of heart failure (HF) (Killip class 1), 30-day mortality was 5 of 426 patients (1.2%) in the GIK group versus 18 of 430 patients (4.2%) in the control group (RR 0.28, 95% CI 0.1 to 0.75). In 84 patients (8.9%) with signs of HF (Killip class > or =2), 30-day mortality was 18 of 50 patients (36%) in the GIK group versus 9 of 34 patients (26.5%) in the control group (RR 1.44, 95% CI 0.65 to 3.22). CONCLUSIONS Glucose-insulin-potassium infusion as adjunctive therapy to PTCA in acute MI did not result in a significant mortality reduction in all patients. In the subgroup of 856 patients without signs of HF, a significant reduction was seen. The effect of GIK infusion in patients with signs of HF (Killip class > or =2) at admission is uncertain.

Skin Autofluorescence: A Tool to Identify Type 2 Diabetic Patients at Risk for Developing Microvascular Complications

OBJECTIVE—Skin autofluorescence is a noninvasive measure of the level of tissue accumulation of advanced glycation end products, representing cumulative glycemic and oxidative stress. Recent studies have already shown a relationship between skin autofluorescence and diabetes complications, as well as the predictive value of skin autofluorescence for total and cardiovascular mortality in type 2 diabetes. Our aim was to investigate the predictive value of skin autofluorescence for the development of microvascular complications in type 2 diabetes. RESEARCH DESIGN AND METHODS—At baseline, skin autofluorescence of 973 type 2 diabetic patients with well-controlled diabetes was noninvasively measured with an autofluorescence reader. The aggregate clinical outcome was defined as the development of any diabetes-associated microvascular complication of 881 surviving patients, which was assessed at baseline and at the end of follow-up. Single end points were the development of diabetes-associated retinopathy, neuropathy, and (micro)albuminuria. RESULTS—After a mean follow-up period of 3.1 years, baseline skin autofluorescence was significantly higher in patients who developed any microvascular complication, neuropathy, or (micro)albuminuria but not in those who developed retinopathy. Multivariate analyses showed skin autofluorescence as a predictor for development of any microvascular complication along with A1C, for development of neuropathy along with smoking, and for development of (micro)albuminuria together with sex, A1C, and diabetes duration. Skin autofluorescence did not have predictive value for the development of retinopathy, albeit diabetes duration did. CONCLUSIONS—Our study is the first observation of skin autofluorescence measurement as an independent predictor of development of microvascular complications in type 2 diabetes.

Prognostic value of troponin after elective percutaneous coronary intervention: A meta-analysis

Background: Although the prognostic importance of troponin in patients with anacute coronary syndrome is clear, the significance of troponin elevation after elective percutaneous coronary intervention (PCI) is a subject of debate. However, most studies up to now had a small sample size and insufficient events during follow‐up. Methods: Electronic and manual searches were performed of studies reporting on prognosis of troponin after elective PCI. A meta‐analysis was done of all suitable studies, with death in follow‐up as primary endpoint and the combination of death or nonfatal myocardial infarction in follow‐up as secondary endpoint. Results: 20 studies involving 15,581 patients were included. These studies were published between 1998 and 2007. Overall, troponin was elevated after elective PCI in 32.9% of patients. The follow‐up period varied between 3 and 67 months (mean 16.3). Increased mortality was significantly associated with troponin elevation after PCI (4.4% vs. 3.3%, P = 0.001; OR 1.35). Furthermore, the combined endpoint of mortality or nonfatal myocardial infarction also occurred more often in patients with post‐procedural troponin elevation (8.1% vs. 5.2%, P < 0.001; OR 1.59). Conclusions: According to this meta‐analysis, troponin elevation after elective PCI provides important prognostic information.

Glomerular and Tubular Damage Markers Are Elevated in Patients With Diabetes

OBJECTIVE We investigated in a cross-sectional study the levels of serum and urinary damage markers in diabetic patients (n = 94) and nondiabetic control subjects (n = 45) to study the association of glomerular (IgG), proximal tubular (kidney injury molecule [KIM]-1, N-acetyl-β-d-glucosaminidase [NAG], neutrophil gelatinase–associated lipocalin [NGAL], and cystatin C), and distal tubular (heart fatty acid–binding protein [H-FABP]) damage markers with kidney disease severity, as assessed by albuminuria and estimated glomerular filtration rate (eGFR). RESEARCH DESIGN AND METHODS Damage markers were measured in triplicate in fresh morning urine samples and in plasma. RESULTS Of the diabetic patients, 41 were normoalbuminuric, 41 were microalbuminuric, and 12 were macroalbuminuric. Urinary NAG (ninefold), NGAL (1.5-fold), and H-FABP (3.5-fold) were significantly elevated in normoalbuminuric diabetic patients compared with nondiabetic control subjects. Urinary concentrations of all markers increased per albuminuria stratum, except KIM-1. All urinary damage markers, except KIM-1, were significantly associated with albuminuria, independent of age, sex, and plasma concentrations of the corresponding biomarker (standard βs between 0.35 and 0.87; all P ≤ 0.001). All urinary damage markers, except KIM-1, were significantly associated with the eGFR in univariate models (standard βs between −0.38 and −0.21; all P < 0.04). After adjusting for age, sex, plasma concentration of the corresponding damage marker, and albuminuria, only the association of H-FABP with eGFR remained significant (standard β −0.26; P = 0.037). CONCLUSIONS Glomerular and tubular markers are associated with albuminuria, independently of eGFR, suggesting that albuminuria reflects both glomerular and tubulointerstitial damage. Only urinary H-FABP is associated with eGFR independently of albuminuria and, therefore, may be a promising urinary damage marker to assess diabetic kidney disease.

Prognostic Value of Admission Glycosylated Hemoglobin and Glucose in Nondiabetic Patients With ST-Segment–Elevation Myocardial Infarction Treated With Percutaneous Coronary Intervention

Background— In nondiabetic patients with ST-segment–elevation myocardial infarction, acute hyperglycemia is associated with adverse outcome. Whether this association is due merely to hyperglycemia as an acute stress response or whether longer-term glycometabolic derangements are also involved is uncertain. It was our aim to determine the association between both acute and chronic hyperglycemia (hemoglobin A1c [HbA1c]) and outcome in nondiabetic patients with ST-segment–elevation myocardial infarction. Methods and Results— This observational study included consecutive patients (n=4176) without known diabetes mellitus admitted with ST-segment–elevation myocardial infarction. All patients were treated with primary percutaneous intervention. Both glucose and HbA1c were measured on admission. Main outcome measure was total long-term mortality; secondary outcome measures were 1-year mortality and enzymatic infarct size. One-year mortality was 4.7%, and mortality after total follow-up (3.3±1.5 years) was 10%. Both elevated HbA1c levels (P<0.001) and elevated admission glucose (P<0.001) were associated with 1-year and long-term mortality. After exclusion of early mortality (within 30 days), HbA1c remained associated with long-term mortality (P<0.001), whereas glucose lost significance (P=0.09). Elevated glucose, but not elevated HbA1c, was associated with larger infarct size. After multivariate analysis, HbA1c (hazard ratio, 1.2 per interquartile range; P<0.01), but not glucose, was independently associated with long-term mortality. Conclusions— In nondiabetic patients with ST-segment–elevation myocardial infarction, both elevated admission glucose and HbA1c levels were associated with adverse outcome. Both of these parameters reflect different patient populations, and their association with outcome is probably due to different mechanisms. Measurement of both parameters enables identification of these high-risk groups for aggressive secondary risk prevention.

Diagnosis and Prediction of CKD Progression by Assessment of Urinary Peptides

Progressive CKD is generally detected at a late stage by a sustained decline in eGFR and/or the presence of significant albuminuria. With the aim of early and improved risk stratification of patients with CKD, we studied urinary peptides in a large cross-sectional multicenter cohort of 1990 individuals, including 522 with follow-up data, using proteome analysis. We validated that a previously established multipeptide urinary biomarker classifier performed significantly better in detecting and predicting progression of CKD than the current clinical standard, urinary albumin. The classifier was also more sensitive for identifying patients with rapidly progressing CKD. Compared with the combination of baseline eGFR and albuminuria (area under the curve [AUC]=0.758), the addition of the multipeptide biomarker classifier significantly improved CKD risk prediction (AUC=0.831) as assessed by the net reclassification index (0.303±-0.065; P<0.001) and integrated discrimination improvement (0.058±0.014; P<0.001). Correlation of individual urinary peptides with CKD stage and progression showed that the peptides that associated with CKD, irrespective of CKD stage or CKD progression, were either fragments of the major circulating proteins, suggesting failure of the glomerular filtration barrier sieving properties, or different collagen fragments, suggesting accumulation of intrarenal extracellular matrix. Furthermore, protein fragments associated with progression of CKD originated mostly from proteins related to inflammation and tissue repair. Results of this study suggest that urinary proteome analysis might significantly improve the current state of the art of CKD detection and outcome prediction and that identification of the urinary peptides allows insight into various ongoing pathophysiologic processes in CKD.

Multicentric Validation of Proteomic Biomarkers in Urine Specific for Diabetic Nephropathy

Background Urine proteome analysis is rapidly emerging as a tool for diagnosis and prognosis in disease states. For diagnosis of diabetic nephropathy (DN), urinary proteome analysis was successfully applied in a pilot study. The validity of the previously established proteomic biomarkers with respect to the diagnostic and prognostic potential was assessed on a separate set of patients recruited at three different European centers. In this case-control study of 148 Caucasian patients with diabetes mellitus type 2 and duration ≥5 years, cases of DN were defined as albuminuria >300 mg/d and diabetic retinopathy (n = 66). Controls were matched for gender and diabetes duration (n = 82). Methodology/Principal Findings Proteome analysis was performed blinded using high-resolution capillary electrophoresis coupled with mass spectrometry (CE-MS). Data were evaluated employing the previously developed model for DN. Upon unblinding, the model for DN showed 93.8% sensitivity and 91.4% specificity, with an AUC of 0.948 (95% CI 0.898-0.978). Of 65 previously identified peptides, 60 were significantly different between cases and controls of this study. In <10% of cases and controls classification by proteome analysis not entirely resulted in the expected clinical outcome. Analysis of patients subsequent clinical course revealed later progression to DN in some of the false positive classified DN control patients. Conclusions These data provide the first independent confirmation that profiling of the urinary proteome by CE-MS can adequately identify subjects with DN, supporting the generalizability of this approach. The data further establish urinary collagen fragments as biomarkers for diabetes-induced renal damage that may serve as earlier and more specific biomarkers than the currently used urinary albumin.

Chromium Treatment Has No Effect in Patients With Type 2 Diabetes in a Western Population A randomized, double-blind, placebo-controlled trial

OBJECTIVE—Chromium treatment has been reported to improve glycemic control in patients with type 2 diabetes. However, concern exists about the possible toxic effects of chromium picolinate. The aim of this study was to determine the effect of chromium treatment in the form of chromium yeast on glycemic control in a Western population of patients with type 2 diabetes who were being treated with oral hypoglycemic agents. RESEARCH DESIGN AND METHODS—In this 6-month, double-blind study, patients with moderate glycemic control, being treated with oral hypoglycemic agents, were randomly assigned to receive either a placebo or treatment with 400 μg of chromium daily in the form of chromium yeast. The primary efficacy parameter was a change in A1C. Secondary end points were changes in lipid profile, BMI, blood pressure, body fat, and insulin resistance. RESULTS—No differences were found for the change in A1C between the intervention and placebo groups, nor were any differences found between the groups for the secondary end points. CONCLUSIONS—There is no evidence that chromium in the form of chromium yeast is effective in improving glycemic control in Western patients with type 2 diabetes who are taking oral hypoglycemic agents.