Effect of intensive therapy on the development and progression of diabetic nephropathy in the Diabetes Control and Complications Trial. The Diabetes Control and Complications (DCCT) Research Group

CUBN is a gene locus for albuminuria

Identification of genetic risk factors for albuminuria may alter strategies for early prevention of CKD progression, particularly among patients with diabetes. Little is known about the influence of common genetic variants on albuminuria in both general and diabetic populations. We performed a meta-analysis of data from 63,153 individuals of European ancestry with genotype information from genome-wide association studies (CKDGen Consortium) and from a large candidate gene study (CARe Consortium) to identify susceptibility loci for the quantitative trait urinary albumin-to-creatinine ratio (UACR) and the clinical diagnosis microalbuminuria. We identified an association between a missense variant (I2984V) in the CUBN gene, which encodes cubilin, and both UACR (P = 1.1 × 10(-11)) and microalbuminuria (P = 0.001). We observed similar associations among 6981 African Americans in the CARe Consortium. The associations between this variant and both UACR and microalbuminuria were significant in individuals of European ancestry regardless of diabetes status. Finally, this variant associated with a 41% increased risk for the development of persistent microalbuminuria during 20 years of follow-up among 1304 participants with type 1 diabetes in the prospective DCCT/EDIC Study. In summary, we identified a missense CUBN variant that associates with levels of albuminuria in both the general population and in individuals with diabetes.

Epigenetics: mechanisms and implications for diabetic complications

Epigenetic modifications regulate critical functions that underlie chromosome metabolism. Understanding the molecular changes to chromatin structure and the functional relationship with altered signaling pathways is now considered to represent an important conceptual challenge to explain diabetes and the phenomenon of metabolic or hyperglycemic memory. Although it remains unknown as to the specific molecular mechanisms whereby hyperglycemic memory leads to the development of diabetic vascular complications, emerging evidence now indicates that critical gene-activating epigenetic changes may confer future cell memories. Chemical modification of the H3 histone tail of lysine 4 and 9 has recently been identified with gene expression conferred by hyperglycemia. The persistence of these key epigenetic determinants in models of glycemic variability and the development of diabetic complications has been associated with these primary findings. Transient hyperglycemia promotes gene-activating epigenetic changes and signaling events critical in the development and progression of vascular complications. As for the role of specific epigenomic changes, it is postulated that further understanding enzymes involved in writing and erasing chemical changes could transform our understanding of the pathways implicated in diabetic vascular injury providing new therapeutic strategies.

Equations to estimate creatinine excretion rate: the CKD epidemiology collaboration

BACKGROUND AND OBJECTIVES

Creatinine excretion rate (CER) indicates timed urine collection accuracy. Although equations to estimate CER exist, their bias and precision are untested and none simultaneously include age, sex, race, and weight.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Participants (n = 2466) from three kidney disease trials were randomly allocated into equation development (2/3) and internal validation (1/3) data sets. CER served as the dependent variable in linear regression to develop new equations. Their stability was assessed within the internal validation data set. Among 987 individuals from three additional studies the equations were externally validated and compared with existing equations.

RESULTS

Mean age was 46 years, 42% were women, and 9% were black. Age, sex, race, weight, and serum phosphorus improved model fit. Two equations were developed, with or without serum phosphorus. In external validation, the new equations showed little bias (mean difference [measured - estimated CER] -0.7% [95% confidence interval -2.5% to 1.0%] and 0.3% [95% confidence interval -2.6% to 3.1%], respectively) and moderate precision (estimated CER within 30% of measured CER among 79% [76% to 81%] and 81% [77% to 85%], respectively). Corresponding numbers within 15% were 51% [48% to 54%] and 54% [50% to 59%]). Compared with existing equations, the new equations had similar accuracy but showed less bias in individuals with high measured CER.

CONCLUSIONS

CER can be estimated with commonly available variables with little bias and moderate precision, which may facilitate assessment of accuracy of timed urine collections.

Diagnóstico de enfermagem Eliminação urinária prejudicada em pessoas com Diabetes Mellitus

Estudo exploratório descritivo com o objetivo de descrever os diagnósticos de enfermagem em pessoas com diabetes mellitus que apresentaram diagnóstico de enfermagem Eliminação urinária prejudicada. Os dados foram obtidos através do exame físico e a técnica de entrevista dirigida. Após a coleta de dados, procedeu-se a identificação dos diagnósticos de enfermagem nomeados de acordo com a Taxonomia II da NANDA, utilizando o processo de raciocínio diagnóstico de Risner. Das 31 pessoas entrevistadas, identificou-se 10 (32%) sujeitos que apresentaram o diagnóstico de enfermagem eliminação urinária prejudicada. Conhecer os fatores relacionados e as caracteristicas definidoras desse diagnóstico possibilita que o enfermeiro trace intervenções de enfermagem que preservem a função renal, e consequentemente a nefropatia diabética.

The effect of obesity on the assessment of diabetic peripheral neuropathy: a comparison of Michigan patient version test and Michigan physical assessment

OBJECTIVE

Nerve conduction studies (NCS) and Michigan Neuropathy Screening Instrument (MNSI) are commonly used to make the diagnosis of diabetic peripheral neuropathy. The objective of this study was to compare the diagnostic values of MNSI patient version test and physical test for the assessment of the diabetic peripheral neuropathy in obese vs. non-obese patients.

METHOD

This study was conducted on 70 type 2 diabetic patients. We carried out the MNSI patient version test and MNSI physical assessment test. Nerve conduction studies were performed for the diagnosis of the diabetic peripheral neuropathy.

RESULTS

In diabetic peripheral neuropathy (DPN) determined by NCS, the independent prediction of peripheral neuropathy was the score of Michigan physical assessment (odds 2.0; CI: 1.3-3.0). In BMI (body mass index) ≥ 30 diabetic patients who have peripheral neuropathy, Michigan patient version test is not significant. But the score of Michigan physical assessment is significantly increased in these patients compared to patients without peripheral neuropathy. In BMI<30 diabetic patients who have peripheral neuropathy, scores of both Michigan patient version and physical assessment instruments are significantly increased.

CONCLUSION

To screen diabetic peripheral neuropathy, Michigan physical assessment may be more useful instrument than Michigan patient version test in obese diabetic patients.

Review: metformin: potential benefits and use in chronic kidney disease

Diabetes mellitus is the commonest cause of end-stage renal failure in both Australia and New Zealand. In addition, the burden of diabetes is prominent in those with chronic kidney disease who have not yet reached the requirement for renal replacement therapy. While diabetes is associated with a higher incidence of mortality and morbidity in all populations studied with kidney disease, little is known about optimal treatment strategies for hyperglycaemia and the effects of glycaemic treatment in this large group of patients. Metformin is recommended as the drug of first choice in patients diagnosed with type 2 diabetes in the USA, Europe and Australia. There are potential survival benefits associated with the use of metformin in additional to recent studies suggesting benefits in respect to cardiovascular outcomes and metabolic parameters. The use of metformin has been limited in patients with renal disease because of the perceived risk of lactic acidosis; however, it is likely that use of this drug would be beneficial in many with chronic kidney disease. Thus the potential benefits and harms of metformin are outlined in this review with suggestions for its clinical use in those with kidney disease.

Genetic variant in the promoter of connective tissue growth factor gene confers susceptibility to nephropathy in type 1 diabetes

BACKGROUND The evidence for genetic susceptibility in the pathogenesis of diabetic nephropathy is well recognised, but the genes involved remain to be identified. It is hypothesised that mutations within the gene encoding connective tissue growth factor (CTGF/CCN2) will increase the propensity of diabetic subjects to develop nephropathy. METHODS AND RESULTS Genomic screening was performed for single nucleotide polymorphisms (SNPs) within the CTGF gene in 862 subjects from the DCCT/EDIC cohort of type 1 diabetes. A novel SNP was identified in the promoter region that changes a C-G at the position -20. The frequency of GG genotype in microalbuminuric patients (albumin excretion rate (AER) >40 mg/24 h) is significantly greater than diabetics with AER <40 mg/24 h, p<0.0001. The relative risk (RR) to develop microalbuminuria in diabetic subjects with the polymorphism is 3X higher than diabetic subjects without the polymorphism (RR 3.142, 95% CI 1.9238 to 5.1249; p<0.05). Kaplan-Meier survival curves demonstrated that the GG genotype group developed microalbuminuria and macroalbuminuria at a more rapid rate than the GC or CC genotypes. Functional studies demonstrated that the basal activity of the substituted allele/promoter (-20 GG allele) was significantly greater than that of the wild type promoter (-20 CC genotype). This higher level of basal activity of substituted allele CTGF/CCN2 promoter was abrogated upon suppression of Smad1 levels, indicating that SNP region in the CTGF/CCN2 promoter plays a vital role in the gene expression. CONCLUSIONS These findings provide the first evidence that variants within the promoter region of the CTGF/CCN2 gene predisposes diabetic subjects to develop albuminuria and demonstrate that Smad1 [corrected] controls the expression of CTGF/CCN2 promoter through this region.

A prediction model for the risk of incident chronic kidney disease

BACKGROUND

Chronic kidney disease is a health burden for the general population. We designed a cohort study to construct prediction models for chronic kidney disease in the Chinese population.

METHODS

A total of 5168 participants were followed up during a median of 2.2 (interquartile range, 1.5-2.9) years, and 190 individuals (3.7%) developed chronic kidney disease, defined by a glomerular filtration rate of less than 60 mL/min/1.73 m(2).

RESULTS

We developed a point system to estimate chronic kidney disease risk at 4 years using the following variables: age (8 points), body mass index (2 points), diastolic blood pressure (2 points), and history of type 2 diabetes (1 point) and stroke (4 points) for the clinical model, with the addition of uric acid (2 points), postprandial glucose (1 point), hemoglobin A1c (1 point), and proteinuria 100 mg/dL or greater (6 points) for the biochemical model. Similar discrimination measures were found between the clinical model (area under the receiver operating characteristic curve, 0.768; 95% confidence interval (CI), 0.738-0.798) and the biochemical model (area under the receiver operating characteristic curve, 0.765; 95% CI, 0.734-0.796). The area under the receiver operating characteristic curve of the clinical model was 0.667 (95% CI, 0.631-0.703) for the external validation data from community-based cohort participants. The optimal cutoff value for the clinical model was set as 7, with a sensitivity of 0.76 and a specificity of 0.66.

CONCLUSION

We constructed a clinical point-based model to predict the 4-year incidence of chronic kidney disease. This prediction tool may help to target Chinese subjects at risk of developing chronic kidney disease.

Cardiorenal risk factors

The chronic renocardiac syndrome, in which chronic kidney disease (CKD) contributes to impairment of cardiac function or structure, is associated with an increased risk of adverse cardiovascular events. The prevalence of CKD in the U.S. population is approximately 11% and has been increasing over time. Numerous studies have demonstrated an association of CKD, defined by the presence of reduced glomerular filtration rate and/or albuminuria with adverse cardiovascular and renal outcomes. These data suggest that both albuminuria and glomerular filtration rate, which can be performed with minimally increased costs, should be included in the assessment of risk stratification for individual patients, in addition to traditional cardiovascular risk factors.

PPARalpha: an emerging therapeutic target in diabetic microvascular damage

The global pandemic of diabetes mellitus portends an alarming rise in the prevalence of microvascular complications, despite advanced therapies for hyperglycemia, hypertension and dyslipidemia. Peroxisome proliferator-activated receptor alpha (PPARalpha) is expressed in organs affected by diabetic microvascular disease (retina, kidney and nerves), and its expression is regulated specifically in these tissues. Experimental evidence suggests that PPARalpha activation attenuates or inhibits several mediators of vascular damage, including lipotoxicity, inflammation, reactive oxygen species generation, endothelial dysfunction, angiogenesis and thrombosis, and thus might influence intracellular signaling pathways that lead to microvascular complications. PPARalpha has emerged as a novel target to prevent microvascular disease, via both its lipid-related and lipid-unrelated actions. Despite strong experimental evidence of the potential benefits of PPARalpha agonists in the prevention of vascular damage, the evidence from clinical studies in patients with diabetes mellitus remains limited. Promising findings from the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study on microvascular outcomes are countered by elevations in participants' homocysteine and creatinine levels that might potentially attenuate the benefits of PPARalpha activation. This Review focuses on the role of PPARalpha activation in diabetic microvascular disease and highlights the available experimental and clinical evidence from studies of PPARalpha agonists.

Risk markers of future microalbuminuria and hypertension based on clinical and morphological parameters in young type 1 diabetes patients

BACKGROUND

Nephropathy is a severe complication of type 1 diabetes and develops in 30% of patients. Currently, it is not possible to identify young patients at risk prior to the development of microalbuminuria (MA) and/or hypertension (HT).

OBJECTIVE

To study predictors of MA and/or HT in young normoalbuminuric (NA) patients with type 1 diabetes.

SUBJECTS AND METHODS

Forty-six NA and normotensive (NT) type 1 diabetes patients, regularly followed since onset with checks on metabolic control, kidney function, and MA, were investigated with kidney biopsies and 24-h ambulatory blood pressure measurements (ABPMs) after 10.6 yr of diabetes. The patients were followed another six and a half years with regard to the development of MA and HT.

RESULTS

Fifteen patients developed MA and/or HT during follow-up. The strongest risk markers were poor metabolic control after puberty, high day-time systolic blood pressure (BP), and increased BMT at 10 yr, which explained 62% of the outcome for MA and/or HT at 17 yr duration with 77% sensitivity and 65% specificity. The threshold values were long-term postpubertal HbA(1c) > 8.2%, day-time systolic BP > 130 mmHg, and BMT > 490 nm/1.73 m(2).

CONCLUSIONS

Normoalbuminuric and NT patients at risk of developing MA and HT could be identified and might benefit from an early start of antihypertensive therapy and improvement of metabolic control.

Dietary intake of eicosapentaenoic and docosahexaenoic acid and diabetic nephropathy: cohort analysis of the diabetes control and complications trial

OBJECTIVE

To investigate the association between dietary n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs) and the degree and development of albuminuria in type 1 diabetes.

RESEARCH DESIGN AND METHODS

We analyzed longitudinal data from 1,436 participants in the Diabetes Control and Complications Trial. We defined the average intake of eicosapentaenoic and docosahexaenoic acid from diet histories. Urinary albumin excretion rates (UAERs) were measured over 24 h; incident albuminuria was considered the first occurrence of an UAER >40 mg/24 h sustained for >or=1 year in normoalbuminuric individuals. RESULTS In a mean follow-up of 6.5 years, we observed a lower mean UAER (difference 22.7 mg/24 h [95% CI 1.6-43.8)]) in the top versus the bottom third of dietary n-3 LC-PUFAs, but we found no association with incident albuminuria.

CONCLUSIONS

Dietary n-3 LC-PUFAs appear inversely associated with the degree but not with the incidence of albuminuria in type 1 diabetes. These findings require further investigation in prospective studies.

A double-blind, randomized, placebo-controlled clinical trial on benfotiamine treatment in patients with diabetic nephropathy

OBJECTIVE

To investigate the effect of benfotiamine on urinary albumin excretion (UAE) and the tubular damage marker kidney injury molecule-1 (KIM-1) in patients with type 2 diabetes and nephropathy.

RESEARCH DESIGN AND METHODS

Patients with type 2 diabetes and UAE equivalent to 15-300 mg/24 h, despite ACE inhibitors (ACE-Is) or angiotensin receptor blockers (ARBs), were randomly assigned to 12 weeks of benfotiamine (900 mg/day) (n = 39) or placebo (n = 43).

RESULTS

Compared with placebo, benfotiamine treatment resulted in significant improvement of thiamine status (P < 0.001). Benfotiamine treatment did not significantly decrease 24-h UAE or 24-h KIM-1 excretion.

CONCLUSIONS

In patients with type 2 diabetes and nephropathy, high-dose benfotiamine treatment for 12 weeks in addition to ACE-Is or ARBs did not reduce UAE or KIM-1 excretion, despite improvement of thiamine status.

Comparison of urinary albumin-creatinine ratio and albumin excretion rate in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications study

BACKGROUND AND OBJECTIVES

The objective of this study was to compare random urine albumin-creatinine ratio (ACR) with timed urine albumin excretion rate (AER) in patients with type 1 diabetes.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A total of 1186 participants in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) Study provided spot urine specimens concurrent with 4-hour timed urine collections. ACR and AER were compared using Bland-Altman plots, cross-classification of albuminuria status and its change over time, and within-person variability.

RESULTS

Despite moderate correlation (r=0.62), ACR levels (mg/g) were lower than AER levels (mg/24 hr). This difference was greatest for men. Gender-specific estimated AER (eAER) values were empirically derived from ACR. Comparing the eAER with measured AER, agreement of prevalent microalbuminuria and macroalbuminuria classification was fair to moderate, and classification of change in albuminuria status over time was different. Intraclass correlations were 0.697 for ACR and 0.803 for AER. Effects of DCCT intensive versus conventional diabetes therapy on urine albumin excretion or classification of albuminuria were similar using the eAER versus measured AER, as were the effects of the previous glycosylated hemoglobin.

CONCLUSIONS

Systematic differences exist between urine ACR and AER, related to gender and other determinants of muscle mass. Use of ACR (or eAER) versus AER yields differences in classification of prevalent albuminuria states and changes in albuminuria states over time. These findings support the use of consistent ascertainment methods over time and further efforts to standardize and optimally interpret measurement of urine albumin excretion.

Early urinary markers of diabetic kidney disease: a nested case-control study from the Diabetes Control and Complications Trial (DCCT)

BACKGROUND

Urinary markers were tested as predictors of macroalbuminuria or microalbuminuria in patients with type 1 diabetes.

STUDY DESIGN

Nested case-control of participants in the Diabetes Control and Complications Trial (DCCT).

SETTING & PARTICIPANTS

87 cases of microalbuminuria were matched to 174 controls in a 1:2 ratio, while 4 cases were matched to 4 controls in a 1:1 ratio, resulting in 91 cases and 178 controls for microalbuminuria. 55 cases of macroalbuminuria were matched to 110 controls in a 1:2 ratio. Controls were free of micro-/macroalbuminuria when their matching case first developed micro-/macroalbuminuria.

PREDICTORS

Urinary N-acetyl-beta-d-glucosaminidase (NAG), pentosidine, advanced glycation end product (AGE) fluorescence, and albumin excretion rate (AER).

OUTCOMES

Incident microalbuminuria (2 consecutive annual AERs > 40 but < or = 300 mg/d) or macroalbuminuria (AER > 300 mg/d).

MEASUREMENTS

Stored urine samples from DCCT entry and 1-9 years later when macro- or microalbuminuria occurred were measured for the lysosomal enzyme NAG and the AGE pentosidine and AGE fluorescence. AER and adjustor variables were obtained from the DCCT.

RESULTS

Submicroalbuminuric AER levels at baseline independently predicted microalbuminuria (adjusted OR, 1.83; P < 0.001) and macroalbuminuria (adjusted OR, 1.82; P < 0.001). Baseline NAG excretion independently predicted macroalbuminuria (adjusted OR, 2.26; P < 0.001) and microalbuminuria (adjusted OR, 1.86; P < 0.001). Baseline pentosidine excretion predicted macroalbuminuria (adjusted OR, 6.89; P = 0.002). Baseline AGE fluorescence predicted microalbuminuria (adjusted OR, 1.68; P = 0.02). However, adjusted for NAG excretion, pentosidine excretion and AGE fluorescence lost the predictive association with macroalbuminuria and microalbuminuria, respectively.

LIMITATIONS

Use of angiotensin-converting enzyme inhibitors was not directly ascertained, although their use was proscribed during the DCCT.

CONCLUSIONS

Early in type 1 diabetes, repeated measurements of AER and urinary NAG excretion may identify individuals susceptible to future diabetic nephropathy. Combining the 2 markers may yield a better predictive model than either one alone. Renal tubule stress may be more severe, reflecting abnormal renal tubule processing of AGE-modified proteins, in individuals susceptible to diabetic nephropathy.

High prevalence and diversity of kidney dysfunction in patients with type 2 diabetes mellitus and coronary artery disease: the BARI 2D baseline data

BACKGROUND

We describe baseline renal function and albumin excretion rate in patients enrolled in Bypass Angioplasty Revascularization Investigation 2 Diabetes, a randomized clinical trial comparing the impact of revascularization and medical therapy with medical therapy alone and deferred or no revascularization and the impact of glycemic control with either insulin-providing or insulin-sensitizing drugs, on 5-year mortality.

METHODS

Study participants had type 2 diabetes mellitus, documented coronary artery disease, and creatinine <2 mg/dL. Albuminuria status (albumin/creatinine ratio [ACR]) and estimated glomerular filtration rate (eGFR), using the abbreviated Modified Diet in Renal Disease equation, were determined at baseline. Univariate and multivariate relationships between baseline clinical characteristics and the presence of albuminuria and reduced eGFR rate were estimated.

RESULTS

Two thousand one hundred forty-six subjects were included in the analysis. Forty-three percent of the cohort had evidence of kidney dysfunction at baseline: 23% had an eGFR > or =60 mL/min/1.73 m with either microalbuminuria ( >30 ACR; 17%) or macroalbuminuria (>300 ACR; 6%). Twenty-one percent had a reduced eGFR <60 mL/min/1.73 m; 52% with reduced eGFR had no albuminuria; 28% had microalbuminuria, and 20% had macroalbuminuria. Race, smoking status, duration of diabetes, hypertension, hemoglobin A1c, triglycerides, vascular disease, abnormal ejection fraction, and reduced eGFR were associated with greater albuminuria. Age, sex, duration of diabetes, ACR, hemoglobin A1c, high density lipoprotein, and number of hypertensive medications were associated with reduced eGFR.

CONCLUSION

Kidney dysfunction is common in older patients with type 2 diabetes mellitus and coronary artery disease; Albuminuria was present in 33%. Reduced eGFR was present in 21%, and half the patients with reduced eGFR had no evidence of albuminuria.

Automated detection of hypoglycemia-induced EEG changes recorded by subcutaneous electrodes in subjects with type 1 diabetes--the brain as a biosensor

AIMS

Hypoglycemia unawareness is a common condition associated with increased risk of severe hypoglycemia. We test the hypothesis that specific changes in the electroencephalogram (EEG) during hypoglycemia can be recorded by subcutaneous electrodes and processed by a general mathematical algorithm, and that hypoglycemia associated EEG changes appear before the development of severe hypoglycemia.

METHODS

Fifteen patients with type 1 diabetes were exposed to insulin-induced hypoglycemia and EEG was recorded. The cognitive function was evaluated by repeated cognitive testing. Insulin infusion was terminated when plasma glucose reached 1.8mmol/l or when the subjects showed obvious signs of cognitive dysfunction. EEG was analyzed by an automated mathematical algorithm with a predefined threshold of hypoglycemia.

RESULTS

Hypoglycemia associated EEG changes were detected by the mathematical algorithm in all subjects. Plasma glucose at the time of EEG changes above the threshold value ranged from 2.0 to 3.4mmol/l and occurred 29+/-28min (range 3-113min) before termination of insulin infusion.

CONCLUSIONS

Hypoglycemia associated EEG changes could be detected by an automated mathematical algorithm in all subjects exposed to insulin-induced hypoglycemia. In 12 of 15 patients, EEG changes occurred before severe hypoglycemia as evaluated by the cognitive testing.

Glycemic control and burnt-out diabetes in ESRD

Treatment of early diabetes mellitus, the most common cause of chronic kidney disease (CKD), may prevent or slow the progression of diabetic nephropathy and lower mortality and the incidence of cardiovascular disease in the general diabetic population and in patients with early stages of CKD. It is unclear whether glycemic control in patients with advanced CKD, including those with end-stage renal disease (ESRD) who undergo maintenance dialysis treatment is beneficial. Aside from the uncertain benefits of treatment in ESRD, hypoglycemic interventions in this population are also complicated by the complex changes in glucose homeostasis related to decreased kidney function and to dialytic therapies, occasionally leading to spontaneous resolution of hyperglycemia and normalization of hemoglobin A1c levels, a condition which might be termed "burnt-out diabetes." Further difficulties in ESRD are posed by the complicated pharmacokinetics of antidiabetic medications and the serious flaws in our available diagnostic tools used for monitoring long-term glycemic control. We review the physiology and pathophysiology of glucose homeostasis in advanced CKD and ESRD, the available antidiabetic medications and their specifics related to kidney function, and the diagnostic tools used to monitor the severity of hyperglycemia and the therapeutic effects of available treatments, along with their deficiencies in ESRD. We also review the concept of burnt-out diabetes and summarize the findings of studies that examined outcomes related to glycemic control in diabetic ESRD patients, and emphasize areas in need of further research.

Clinical benefits of tight glycaemic control: effect on the kidney

Acute kidney injury is a frequent and life-threatening complication of critical illness. Prevention of this condition is crucial. Two randomized single center trials in critically ill patients have shown a decrease in acute kidney injury by tight glycaemic control, an effect that appears most pronounced in surgical patients. Subsequent randomized trials did not confirm this renoprotective effect. This apparent contradiction is likely explained by methodological differences between studies, including different patient populations, insufficient patient numbers, comparison with a different control group, use of inaccurate blood glucose analyzers, and differences in the degree of reaching the target blood glucose level. The optimal glycaemic target for renoprotection in critical illness remains to be defined. Possible mechanisms underlying the renoprotective effect of tight glycaemic control are prevention of glucose overload and toxicity and the associated mitochondrial damage, an anti-inflammatory or anti-apoptotic effect, prevention of endothelial dysfunction, and an improvement of the lipid profile.

Major diabetes-related vascular events do not improve glycaemic control in a population-based cohort of type 1 diabetic individuals

OBJECTIVE

It is known that sudden serious events alter life styles related to treatment efficiency, as for example in cancer patients. However, it has not been specifically addressed if a first-time diabetes-related clinical event has impact on glycaemic regulation. We therefore assessed this in a population-based cohort of patients with long-term type 1 diabetes.

METHODS

This study was based on a cohort of type 1 diabetes patients with at least 20 years duration of diabetes. Of the 460 patients from the original cohort still alive at 1 January 1994, all patients with a major first-time diabetes-related clinical event (limb amputation, blindness, stroke, cardiac event, or panretinal photocoagulation) and glycated haemoglobin (HbA(1c)) measurements before, 3 and/or 12 months after the event were included. Differences in HbA(1c) measurements before and after the event were tested with Wilcoxon's test.

RESULTS

A total of 64 patients with a major clinical event between 1994 and 2006 entered the study. Mean HbA(1c) measurements decreased from 8.8% at baseline to 8.6% at 3 months and 8.7% after 12 months, a non-significant decrease. In all event groups, glycaemic regulation was unaltered in the majority of the patients. Only a minority worsened or improved their regulation, and in all groups only non-significant changes were seen.

CONCLUSIONS

Surprisingly, complication-related events did not improve glycaemic regulation in long-term type 1 diabetes patients. This is in contrast with the experience from other patient categories and shows how difficult it can be to alter glycaemic regulation in diabetes patients with stabilized disease.

A genome-wide association study identifies a novel major locus for glycemic control in type 1 diabetes, as measured by both A1C and glucose

OBJECTIVE

Glycemia is a major risk factor for the development of long-term complications in type 1 diabetes; however, no specific genetic loci have been identified for glycemic control in individuals with type 1 diabetes. To identify such loci in type 1 diabetes, we analyzed longitudinal repeated measures of A1C from the Diabetes Control and Complications Trial.

RESEARCH DESIGN AND METHODS

We performed a genome-wide association study using the mean of quarterly A1C values measured over 6.5 years, separately in the conventional (n = 667) and intensive (n = 637) treatment groups of the DCCT. At loci of interest, linear mixed models were used to take advantage of all the repeated measures. We then assessed the association of these loci with capillary glucose and repeated measures of multiple complications of diabetes.

RESULTS

We identified a major locus for A1C levels in the conventional treatment group near SORCS1 (10q25.1, P = 7 x 10(-10)), which was also associated with mean glucose (P = 2 x 10(-5)). This was confirmed using A1C in the intensive treatment group (P = 0.01). Other loci achieved evidence close to genome-wide significance: 14q32.13 (GSC) and 9p22 (BNC2) in the combined treatment groups and 15q21.3 (WDR72) in the intensive group. Further, these loci gave evidence for association with diabetic complications, specifically SORCS1 with hypoglycemia and BNC2 with renal and retinal complications. We replicated the SORCS1 association in Genetics of Diabetes in Kidneys (GoKinD) study control subjects (P = 0.01) and the BNC2 association with A1C in nondiabetic individuals.

CONCLUSIONS

A major locus for A1C and glucose in individuals with diabetes is near SORCS1. This may influence the design and analysis of genetic studies attempting to identify risk factors for long-term diabetic complications.

Establishing a national chronic kidney disease surveillance system for the United States

Despite the recognized importance of chronic kidney disease (CKD), the United States currently lacks a comprehensive, systematic surveillance program that captures and tracks all aspects of CKD in the population. As part of its CKD Initiative, the Centers for Disease Control and Prevention (CDC) funded two teams to jointly initiate the development of a CKD surveillance system. Here, we describe the process and methods used to establish this national CDC CKD Surveillance System. The major CKD components covered include burden (incidence and prevalence), risk factors, awareness, health consequences, processes and quality of care, and health system capacity issues. Goals include regular reporting of the data collected, plus development of a dynamic project web site and periodic issuance of a CKD fact sheet. We anticipate that this system will provide an important foundation for widespread efforts toward primary prevention, earlier detection, and implementation of optimal disease management strategies, with resultant increased awareness of CKD, decreased rates of CKD progression, lowered mortality, and reduced resource utilization. Final success will be measured by usage, impact, and endorsement.

Glomerulonephritis and managing the risks of chronic renal disease

The rising global burden of chronic renal disease, the high cost of providing renal replacement therapies, and renal disease also being a risk factor for cardiovascular disease is increasing focus on renal disease prevention. This article focuses on the aspects of renal disease (specifically poststreptococcal glomerulonephritis [PSGN] and chronic kidney disease [CKD]) in Indigenous populations in Australia, New Zealand, Canada, and the United States that diverge from those typically seen in the general population of those countries. The spectrum of renal and many other diseases seen in Indigenous people in developed countries is similar to that seen in developing countries. Diseases like PSGN that have largely disappeared in developed countries still occur frequently in Indigenous people. CKD during the childhood years is due to congenital anomalies of the kidney and urinary tract in up to 70% of cases and occurs later in polycystic kidney disease and childhood-onset diabetes. Several risk factors for CKD in adulthood are already present in childhood.

The natural progression of kidney injury in young type 1 diabetic patients

Diabetes is the most common cause of end-stage renal disease in industrialized countries. This article describes the structural changes in early diabetic nephropathy and the relationship with renal functional parameters, blood pressure, and albumin excretion. The detrimental influence of sustained hyperglycemia and/or glycemic fluctuations on renal structural change has been well documented. Tight glycemic control is paramount to preventing the development, and even the regression, of renal lesions. As much of the renal injury from diabetes occurs in clinical silence before symptoms or laboratory findings of renal injury are evident, finding early markers of risk is imperative so that nephropathy can be prevented. Currently, the only clinical surrogate marker of diabetic renal injury available is microalbuminuria. However, given the reports of regression of microalbuminuria back to normoalbuminuria, the reliability of this tool as an indicator of risk has been questioned. The need for alternative, noninvasive surrogate markers is described in this report.

Lipid abnormalities predict progression of renal disease in patients with type 1 diabetes

AIMS/HYPOTHESIS

We studied the impact of baseline lipid variables on the progression of renal disease in a large nationwide prospective cohort of patients with type 1 diabetes.

METHODS

A total of 2,304 adult patients with type 1 diabetes and available lipid profiles participating in the Finnish Diabetic Nephropathy Study (FinnDiane) were evaluated. Data on progression of renal disease were verified from medical files and patients were followed for 5.4 +/- 2.0 (mean +/- SD) years.

RESULTS

High triacylglycerol, apolipoprotein (Apo) B, ApoA-II and HDL(3)-cholesterol concentrations predicted incident microalbuminuria. Progression to macroalbuminuria was predicted by high triacylglycerol and ApoB. When AER was entered into the model, triacylglycerol was no longer an independent predictor, but when patients with normal AER and microalbuminuria at baseline were pooled, triacylglycerol, HbA(1c), male sex and AER were all independent predictors of renal disease. High total cholesterol, LDL-cholesterol, non-HDL-cholesterol and triacylglycerol as well as low HDL-cholesterol, HDL(2)-cholesterol, ApoA-I and ApoA-II concentrations were predictive of progression to end-stage renal disease. However, when estimated GFR was entered into the model, only total cholesterol remained an independent predictor of progression.

CONCLUSIONS/INTERPRETATION

Lipid abnormalities, particularly high triacylglycerol concentrations, increase the risk of progression of renal disease.

Human glomerular endothelium: interplay among glucose, free fatty acids, angiotensin II, and oxidative stress

Glomerular endothelial cells (GEC) are strategically situated within the capillary loop and adjacent to the glomerular mesangium. GEC serve as targets of metabolic, biochemical, and hemodynamic signals that regulate the glomerular microcirculation. Unequivocally, hyperglycemia, hypertension, and the local renin-angiotensin system partake in the initiation and progression of diabetic nephropathy (DN). Whether free fatty acids (FFA) and reactive oxygen species (ROS) that have been associated with the endothelial dysfunction of diabetic macrovascular disease also contribute to DN is not known. Since endothelial cells from different organs and from different species may display different phenotypes, we employed human GEC to investigate the effect of high glucose (22.5 mmol/l), FFA (800 micromol/l), and angiotensin II (ANG II; 10(-7) mol/l) on the genesis of ROS and their effects on endothelial nitric oxide synthase (eNOS), cyclooxygenase-2 (COX-2), and the synthesis of prostaglandins (PGs). We demonstrated that high glucose but not high FFA increased the expression of a dysfunctional eNOS as well as increased ROS from NADPH oxidase (100%) and likely from uncoupled eNOS. ANG II also induced ROS from NADPH oxidase. High glucose and ANG II upregulated (100%) COX-2 via ROS and significantly increased the synthesis of prostacyclin (PGI(2)) by 300%. In contrast, FFA did not upregulate COX-2 but increased PGI(2) (500%). These novel studies are the first in human GEC that characterize the differential role of FFA, hyperglycemia, and ANG II on the genesis of ROS, COX-2, and PGs and their interplay in the early stages of hyperglcyemia.

Evidence-based insulin treatment in type 1 diabetes mellitus

AIM

Evaluation of the evidence base for recommending different insulin treatment regimens in type 1 diabetes.

METHODS

A computerised literature survey was conducted using The Cochrane Controlled Trials Register and the Pub Med database for the period of 1982-2007.

RESULTS

A meta-analysis on only 49 out of 1295 references showed that CSII compared with conventional or multiple insulin injections therapy demonstrated a significant reduction in mean HbA1c (primary outcome) of 1.2% CI [0.73; 1.59] (P<0.001) without increasing the risk of hypoglycaemia. The evidence for using four versus two daily insulin injections was based on only one publication demonstrating an improved quality of life but no significant reduction in HbA1c or hypoglycaemia. A comparison of rapid-acting insulin analogues and human soluble insulin demonstrated a statistically significant reduction in HbA1c of 0.1% CI: [0.01; 0.16] (P=0.03) using rapid-acting insulin analogues. The mean frequency of hypoglycaemia was reduced with 14+/-3.7% (<0.05).

CONCLUSION

The scientific evidence supporting the three common insulin regimens was rather sparse. Only five studies during the past 25 years fulfil the optimal criteria for a clinical trial, and only 5 trials on insulin analogues were performed as double-blinded. Current evidence suggests that CSII treatment results in a significant reduction in HbA1c without inducing more hypoglycaemia. Rapid-acting insulin analogues compared to human soluble insulin provide statistically significant but clinically minor improvement in HbA1c but seem to reduce the risk for hypoglycaemia.

The Diabetes Control and Complications Trial: the gift that keeps giving

The Diabetes Control and Complications Trial (DCCT) recruited its first patients in 1983. In 1993, the investigators reported that intensive glycemic treatment of patients with type 1 diabetes mellitus was superior to conventional therapy in preventing the development of microvascular and neurological complications and thus provided definitive proof of the relationship between hyperglycemia and the subsequent risk of diabetic retinopathy, nephropathy and neuropathy. The value of this study, however, did not end there. After the original trial, most participants of the DCCT continued to be followed up in the Epidemiology of Diabetes Interventions and Complications (EDIC) study, which demonstrated the long-term benefits of close glycemic control and provided observational data of a large epidemiological cohort of patients with type 1 diabetes mellitus. Stored samples from the DCCT have also provided an invaluable resource for the identification of new markers of the disease. Recently, the complete dataset of the DCCT and of the initial years of the EDIC have been made publicly available, which allowed independent investigators to help answer their own questions about diabetes. In conclusion, the DCCT continues to provide new insights into type 1 diabetes mellitus, which are of benefit to patients over a quarter of a century after the trial was started.

Diabetic nephropathy

Diabetic nephropathy is the leading cause of chronic renal disease and a major cause of cardiovascular mortality. Diabetic nephropathy has been categorized into stages: microalbuminuria and macroalbuminuria. The cut-off values of micro- and macroalbuminuria are arbitrary and their values have been questioned. Subjects in the upper-normal range of albuminuria seem to be at high risk of progression to micro- or macroalbuminuria and they also had a higher blood pressure than normoalbuminuric subjects in the lower normoalbuminuria range. Diabetic nephropathy screening is made by measuring albumin in spot urine. If abnormal, it should be confirmed in two out three samples collected in a three to six-months interval. Additionally, it is recommended that glomerular filtration rate be routinely estimated for appropriate screening of nephropathy, because some patients present a decreased glomerular filtration rate when urine albumin values are in the normal range. The two main risk factors for diabetic nephropathy are hyperglycemia and arterial hypertension, but the genetic susceptibility in both type 1 and type 2 diabetes is of great importance. Other risk factors are smoking, dyslipidemia, proteinuria, glomerular hyperfiltration and dietary factors. Nephropathy is pathologically characterized in individuals with type 1 diabetes by thickening of glomerular and tubular basal membranes, with progressive mesangial expansion (diffuse or nodular) leading to progressive reduction of glomerular filtration surface. Concurrent interstitial morphological alterations and hyalinization of afferent and efferent glomerular arterioles also occur. Podocytes abnormalities also appear to be involved in the glomerulosclerosis process. In patients with type 2 diabetes, renal lesions are heterogeneous and more complex than in individuals with type 1 diabetes. Treatment of diabetic nephropathy is based on a multiple risk factor approach, and the goal is retarding the development or progression of the disease and to decrease the subject's increased risk of cardiovascular disease. Achieving the best metabolic control, treating hypertension (<130/80 mmHg) and dyslipidemia (LDL cholesterol <100 mg/dl), using drugs that block the renin-angiotensin-aldosterone system, are effective strategies for preventing the development of microalbuminuria, delaying the progression to more advanced stages of nephropathy and reducing cardiovascular mortality in patients with diabetes.

Similar progression of diabetic retinopathy with insulin glargine and neutral protamine Hagedorn (NPH) insulin in patients with type 2 diabetes: a long-term, randomised, open-label study

AIMS/HYPOTHESIS

This long-term study was designed to further characterise the retinal safety profile of insulin glargine and human neutral protamine Hagedorn (NPH) insulin in patients with type 2 diabetes mellitus.

METHODS

An open-label, 5 year, randomised (1:1), multicentre, stratified, parallel-group study conducted in the USA and Canada enrolled individuals with type 2 diabetes and either no or non-proliferative retinopathy (less than severe; Early Treatment Diabetic Retinopathy Study [ETDRS] level less than 53 in both eyes) who were treated with oral hypoglycaemic agents (OHAs) alone, insulin alone or OHAs with insulin for >/=3 months prior to study entry and a baseline HbA(1c) level of 6.0-12.0%. Patients were randomised by the investigator according to the centralised interactive voice response system to receive twice-daily NPH insulin (n = 509) or once-daily basal insulin glargine (n = 515). The investigator was not blinded to the treatment group to which each participant had been assigned. The main objective of this study was to compare the progression of diabetic retinopathy between treatment groups by analysing the percentage of patients with three or more step progression in the ETDRS retinopathy patient-level severity scale after treatment with either basal insulin. Masked, centralised grading of seven-field stereoscopic fundus photographs was used.

RESULTS

Similarly sustained glycaemic control was observed in both the insulin glargine and NPH insulin treatment groups. Despite a slightly greater severity of diabetic retinopathy for the insulin glargine group at baseline, three or more step progression in ETDRS score from baseline to end-of-study was similar between treatment groups (14.2% [53/374] of insulin glargine-treated patients vs 15.7% [57/363] of NPH-treated patients); the difference in the incidence of progression was -1.98% (95% CI -7.02, 3.06%). Other measures of retinopathy-the development of proliferative diabetic retinopathy and progression to clinically significant macular oedema-occurred to a similar degree in both treatment groups. No other safety issues, such as unexpected adverse events for either insulin emerged during the 5 year study. However, NPH insulin treatment was associated with a higher incidence of severe hypoglycaemia compared with insulin glargine.

CONCLUSIONS/INTERPRETATION

This study shows no evidence of a greater risk of the development or progression of diabetic retinopathy with insulin glargine vs NPH insulin treatment in patients with type 2 diabetes mellitus.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00174824

FUNDING

This study was sponsored by sanofi-aventis.

Insulin strategies for managing inpatient and outpatient hyperglycemia and diabetes

Optimal fasting and postprandial glycemic control are essential to limiting microvascular and macrovascular complications associated with diabetes. Recently, stringent control of hyperglycemia in critically ill hospitalized patients with diabetes or acute hyperglycemia has been shown to reduce the risk of morbidity and mortality. This article reviews effective strategies for insulin initiation, titration, and intensification in inpatient and outpatient settings and discusses current treatment strategies when patients are being transitioned from the intensive care unit to general wards and discharged. The development of insulin analogs and premixed insulin analogs has created new options for treating inpatients and outpatients. The more physiologic time-action profiles, improved insulin delivery systems, and standardized protocols for subcutaneous insulin administration and intravenous insulin infusion have improved the safety and convenience of insulin therapy.

Oral administration of Eucalyptus globulus extract reduces the alloxan-induced oxidative stress in rats

In light of evidence that some complications of diabetes mellitus may be caused or exacerbated by an oxidative stress, the putative protective effect of Eucalyptus globulus, a medicinal plant, was investigated in alloxan-diabetic rats. E. globulus extract was given in drinking water for 15 days at a daily dose equivalent to 130 mg dry leaves/kg of body weight. Lipids peroxidation level and activities of catalase, superoxide-dismutase and glutathione peroxidase were then measured in liver and kidney. Under our experimental conditions, eucalyptus extract was found to significantly reduce the blood glucose level in diabetic animals but failed to restore the liver glycogen level, whereas insulin lowered blood glucose and restored liver glycogen to high concentration. Our results suggest that the antihyperglycemic action of eucalyptus extract is not exerted via the stimulation of insulin secretion but rather unveil a proper effect of the extract involving the enhancement of peripheral glucose uptake. In addition, eucalyptus extract appears to exert an antioxidative activity demonstrated (1) by the increase of catalase, superoxide-dismutase and gluthatione-peroxidase activities in liver and kidney, and (2) a lowering of lipids peroxidation level in these organs. In conclusion, the present study indicates that extract of E. globulus, administered per os, could be used with some profit in diabetic patients.

Continuous subcutaneous insulin infusion is more effective than multiple daily insulin injections in preventing albumin excretion rate increase in Type 1 diabetic patients

AIMS

To compare the effect of continuous subcutaneous insulin infusion (CSII) and multiple daily insulin injections (MDI) on albumin excretion rate (AER) in Type 1 diabetic patients.

METHODS

In a 3-year multicentre retrospective observational study, 110 Type 1 diabetic patients treated with CSII were compared with 110 patients treated with MDI matched at baseline for age, sex, diabetes duration and HbA(1c). At entry, 90 patients in each group had normal AER and 20 persistent microalbuminuria. AER, estimated glomerular filtration rate (eGFR), HbA(1c,) lipids and blood pressure were assessed.

RESULTS

HbA(1c) was lower in the CSII than in the MDI group (8.1 +/- 0.9 vs. 8.4 +/- 1.3%; P < 0.005 after 3 years). Blood pressure and eGFR were similar during the study. AER [median (95% confidence interval)], similar at baseline [6.0 microg/min (9, 21) in the CSII group vs. 4.4 (8, 16) in the MDI group, NS] was significantly lower in the patients treated with CSII both at year 2 and at year 3 of follow-up [4.7 microg/min (6, 12) vs. 6.4 (13, 29), P < 0.002]. This difference was observed even when normo- and microalbuminuric patients were analysed separately. Nine patients progressed to microalbuminuria in the MDI group and only one in the CSII group. Nine patients regressed to normoalbuminuria in the CSII group, whereas only two regressed to normoalbuminuria in the MDI group.

CONCLUSIONS

Despite a small benefit in terms of improved glycaemic control, CSII therapy may be useful in decreasing the progressive increase in AER in Type 1 diabetic patients.

DreamTel; Diabetes risk evaluation and management tele-monitoring study protocol

BACKGROUND

The rising prevalence of type 2 diabetes underlines the importance of secondary strategies for the prevention of target organ damage. While access to diabetes education centers and diabetes intensification management has been shown to improve blood glucose control, these services are not available to all that require them, particularly in rural and northern areas. The provision of these services through the Home Care team is an advance that can overcome these barriers. Transfer of blood glucose data electronically from the home to the health care provider may improve diabetes management.

METHODS AND DESIGN

The study population will consist of patients with type 2 diabetes with uncontrolled A1c levels living on reserve in the Battlefords region of Saskatchewan, Canada. This pilot study will take place over three phases. In the first phase over three months the impact of the introduction of the Bluetooth enabled glucose monitor will be assessed. In the second phase over three months, the development of guidelines based treatment algorithms for diabetes intensification will be completed. In the third phase lasting 18 months, study subjects will have diabetes intensification according to the algorithms developed.

DISCUSSION

The first phase will determine if the use of the Bluetooth enabled blood glucose devices which can transmit results electronically will lead to changes in A1c levels. It will also determine the feasibility of recruiting subjects to use this technology. The rest of the Diabetes Risk Evaluation and Management Tele-monitoring (DreamTel) study will determine if the delivery of a diabetes intensification management program by the Home Care team supported by the Bluetooth enabled glucose meters leads to improvements in diabetes management.

TRIAL REGISTRATION

Protocol NCT00325624.

Glycaemic control in type 2 diabetic patients on chronic haemodialysis: use of a continuous glucose monitoring system

BACKGROUND

The proportion of diabetic patients undergoing haemodialysis is rapidly increasing. Glucose control among such patients is difficult to assess. We aimed to evaluate the clinical performance of a continuous glucose monitoring system (CGMS) in type 2 diabetic patients on chronic haemodialysis.

METHODS

We used a 4-day CGMS to monitor glucose levels in 19 haemodialysed type 2 diabetic patients (HD T2) including 2 days with and 2 days without dialysis session, and 39 non-HD T2 in a double-centre study.

RESULTS

The glucose concentration according to the glucose meter and CGMS were correlated in HD T2 patients (r = 0.90, P < 0.0001) and in non-HD T2 patients (r = 0.81, P < 0.0001). The relative absolute difference (RAD) between glucose determined by a glucose meter and glucose determined by the CGMS did not differ between HD T2 and non-HD T2 patients (9.2 +/- 10.5 vs. 8.2 +/- 7.6%; P = 0.165). Glycated haemoglobin (A1c) and mean glucose concentration were strongly correlated in non-HD T2 patients (r = 0.71; P < 0.0001) but weakly correlated in HD T2 patients (r = 0.47; P = 0.042). Fructosamine was correlated with the mean glucose concentration in non-HD T2 (r = 0.67; P < 0.0001) but not in HD T2 patients (r = 0.04; P = 0.88).

CONCLUSION

CGM is a validated marker of glycaemic control in HD diabetic patients. This tool showed that A1c and fructosamine, despite being good markers of glycaemic control in non-HD diabetic patients, are of poor value in HD diabetic patients.

Specific medical intervention for diabetic retinopathy

Diabetes is a global epidemic and the major complication of diabetes in the eye, diabetic retinopathy, is a leading cause of blindness in several countries. Medical and surgical interventions have been formally investigated for over half a century, but currently only surgical interventions are the standard of care and these treatments are not without significant side effects. Several clinical trials have investigated a protein kinase C (PKC) beta inhibitor as a possible medical intervention for diabetic retinopathy. Though successful in animal studies and smaller clinical studies, the drug showed only marginal success in clinical trials. It is likely that the clinical trials failed for two reasons: (1) enrolling patients with too severe a disease state at baseline and (2) utilizing conventional outcome measures that essentially require severe disease states at baseline for evaluation after a standard follow-up time. Additional clinical trials that enroll patients with earlier stages of diabetic retinopathy and/or utilizing more sensitive surrogate outcomes over a longer follow-up would likely show clinical success of PKC-beta inhibition for the treatment of the diabetic retinopathy.

Green tea (Camellia sinensis) attenuates nephropathy by downregulating Nox4 NADPH oxidase in diabetic spontaneously hypertensive rats

Green tea (GT), through its antioxidant properties, may be useful to treat or prevent human diseases. Because several lines of evidence suggest that oxidative stress contributes to the pathogenesis of diabetic nephropathy, we tested the hypothesis that GT prevents diabetes and hypertension-related renal oxidative stress, attenuating renal injury. Spontaneously hypertensive rats (SHR) with streptozotocin-induced diabetes and nondiabetic SHR were treated daily with tap water or freshly prepared GT (13.3 g/L). After 12 wk, the systolic blood pressure did not differ between treated and untreated nondiabetic or diabetic rats. However, body weight was less (P < 0.05) and glycemia was greater in diabetic SHR rats than in nondiabetic rats. Renal oxidative stress variables such as 8-hydroxy-2'-deoxyguanosine (8-OHdG) and nitrotyrosine expression, NADPH oxidase-dependent superoxide generation, and the expression of renal cortex Nox4 were greater (P < 0.05) in diabetic rats that received water (DW) than in nondiabetic rats that received water (CW). The 8-OHdG and NADPH oxidase-dependent superoxide generation were significantly less in rats treated with GT. Nitrotyrosine and Nox4 expression were significantly less in diabetic rats that received GT (DGT) than in DW. Likewise, the indices of renal injury, albuminuria, and renal expression of collagen IV were significantly greater in DW than in CW. These differences were significantly less in DGT than in DW. GT reestablished the redox state and reduced the indicators of nephropathy without altering glycemia and blood pressure levels in diabetic SHR. These findings suggest that the consumption of GT may ameliorate nephropathy in diabetic hypertensive patients.

Progression of diabetic nephropathy in type 1 diabetic patients

Understanding pathogenetic mechanisms of diabetic nephropathy progression risk factors is important. Structural-functional relationship studies have increased our understanding of the glomerular, vascular and tubulointerstitial lesions evolution at various stages of diabetic nephropathy. Classical and more recently described lesions of diabetic nephropathy are discussed. Structural changes associated with progression toward proteinuria and GFR loss are summarized. The relationships of renal structure and function in diabetic nephropathy are best described by non-linear models which mimic the natural history of the disease, i.e., renal pathology develops in clinical silence but, once established, leads to proteinuria and GFR decline.

Amelioration of experimental diabetic neuropathy and gastropathy in rats following the oral administration of an herbal formulation of Diabo-SS extract

The aqueous and methanolic extract of a preparation; Diabo-SS (100 mg/kg b.wt) was administered to streptozotocin-induced diabetic animals. The aqueous Diabo-SS extract showed significantly (P < .001) higher anti-diabetic activity than the methanolic extract. Continuous administration of the aqueous extract of Diabo-SS reduced the plasma glucose level by 40% on 60th day. The tail flick latency (TFL) and gastric transit percentages were significantly higher in diabetic controls versus normal control animals.

Poor glycemic control in diabetes and the risk of incident chronic kidney disease even in the absence of albuminuria and retinopathy: Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Diabetic nephropathy is the leading cause of kidney failure in the United States. The extent to which an elevated glycated hemoglobin (HbA(1c)) concentration is associated with increased risk of chronic kidney disease (CKD) in the absence of albuminuria and retinopathy, the hallmarks of diabetic nephropathy, is uncertain.

METHODS

Glycated hemoglobin concentration was measured in 1871 adults with diabetes mellitus followed up for 11 years in the Atherosclerosis Risk in Communities (ARIC) Study. Incident CKD was defined as an estimated glomerular filtration rate less than 60 mL/min/1.73 m(2) after 6 years of follow-up or a kidney disease-related hospitalization. We categorized HbA(1c) concentrations into 4 clinically relevant categories. Albuminuria and retinopathy were measured midway through follow-up.

RESULTS

Higher HbA(1c) concentrations were strongly associated with risk of CKD in models adjusted for demographic data, baseline glomerular filtration rate, and cardiovascular risk factors. Compared with HbA(1c) concentrations less than 6%, HbA(1c) concentrations of 6% to 7%, 7% to 8%, and greater than 8% were associated with adjusted relative hazard ratios (95% confidence intervals) of 1.4 (0.97-1.91), 2.5 (1.70-3.66), and 3.7 (2.76-4.90), respectively. Risk of CKD was higher in individuals with albuminuria and retinopathy, and the association between HbA(1c) concentration and incident CKD was observed even in participants without either abnormality: adjusted relative hazards, 1.46 (95% confidence intervals, 0.80-2.65), 1.17 (0.43-3.19), and 3.51 (1.67-7.40), respectively; P(trend) = .004.

CONCLUSIONS

We observed a positive association between HbA(1c) concentration and incident CKD that was strong, graded, independent of traditional risk factors, and present even in the absence of albuminuria and retinopathy. Hyperglycemia is an important indicator of risk of both diabetic nephropathy with albuminuria or retinopathy and of less specific forms of CKD.

Hypertriglyceridaemia is associated with an increased likelihood of albuminuria in extreme duration (> 50 years) Type 1 diabetes

AIMS

To explore the association between dyslipidaemia and albuminuria at the extreme of diabetes duration.

METHODS

Data and samples were collected from 400 patients with extreme duration (> 50 years) of Type 1 diabetes in the UK (Golden Years Cohort). Urinary albumin-creatinine ratio (ACR), glycated haemoglobin (HbA(1c)), creatinine, non-fasting triglycerides, total cholesterol, high-density lipoprotein- and low-density lipoprotein-cholesterol were analysed in all patients.

RESULTS

Thirty-six percent of patients had albuminuria (micro- or macroalbuminuria). After adjusting for age, gender, HbA(1c), disease duration and presence of macrovascular disease, hypertriglyceridaemia was more likely to be associated with the presence of albuminuria.

CONCLUSIONS

High triglycerides may be a potential risk factor for progression of diabetic nephropathy at the extreme of diabetes duration, but the benefit of targeting this aggressively remains to be evaluated further.