Comparative renal pathophysiology relevant to IDDM and NIDDM patients

Effects of Niaoduqing granules on inflammatory response of diabetic kidney disease: A meta‑analysis

Diabetic kidney disease (DKD) is one of the most severe chronic microvascular complications of diabetes and the leading cause of end-stage kidney disease worldwide. The mechanism of inflammation underlying DKD has been attracting attention over recent years, but effective therapeutic strategies have remained elusive. Niaoduqing (NDQ) granules are one of the most commonly used drugs for the treatment of DKD in China, and it has therapeutic effects against inflammation in DKD. Therefore, the aim of the present analysis was to evaluate the inflammatory response outcomes and safety of NDQ granules for the treatment of DKD. The following databases were searched from their inception to 31st of May 2023 to obtain published accounts of relevant randomized controlled trials: China National Knowledge Infrastructure, China Science and Technology Journal, Wanfang, The Chinese Biomedicine, PubMed, Web of Science and Cochrane Library. The 'risk of bias' evaluation tool produced by the Cochrane Collaboration Handbook was used for evaluating the quality, whereas Revman software (version 5.3) was used for meta-analysis. In total, 16 studies were included into the present study according to criteria, with a total of 1,526 patients. Compared with those in the control group, the results of the meta-analysis revealed that the combination of conventional treatment and NDQ granules may further decrease C-reactive protein [standardized mean difference (SMD), -1.33; 95% confidence interval (CI), -1.76, -0.91; P<0.00001], TNF-α (SMD, -1.90; 95% CI, -2.35,-1.45; P<0.00001) and IL-6 (SMD, -1.72; 95% CI, -2.52,-0.91; P<0.0001) levels, whilst increasing the clinical effective rate (risk ratio, 1.22; 95% CI, 1.14,1.29; P<0.00001), in patients with DKD. In terms of safety, a total of 34 and 39 patients included in the intervention and in the control group, respectively, developed adverse reactions. Results from the present analysis suggest that NDQ granules may be beneficial in suppressing inflammation caused by DKD when used in combination with conventional treatment, potentially guiding future directions in clinical practice. However, further high-quality studies are needed to confirm the anti-inflammation response in the future.

Lost in translation: assessing the nomenclature change for diabetic kidney disease in Japan

Recently in Japan, the term "tonyobyo sei jinzobyo", the Japanese translation of "diabetic kidney disease", has been increasingly used in place of the term "tonyobyo sei jinsho", the Japanese translation of "diabetic nephropathy". Many international diabetes and nephrology guidelines have defined diabetic kidney disease as a condition caused by diabetes, typically presenting with albuminuria, similar to or identical to current and historical definitions for diabetic nephropathy. However, recent guidelines from the Japanese Society of Nephrology propose a broader disease concept for the term diabetic kidney disease, including patients without albuminuria. A rationale for proposing a broader disease concept for diabetic kidney disease may have come from changes in the kidney phenotype of patients with diabetes observed in recent years. Epidemiological studies have shown that an increasing proportion of patients with diabetes have reduced kidney function, while the prevalence of those with albuminuria appears to have decreased. However, these studies also suggested that the more advanced age of patients presenting with diabetes and increased use of renin-angiotensin system blockers may have contributed to this change in disease phenotype. We believe the principal rationale for the nomenclature change from diabetic nephropathy to diabetic kidney disease was to create a more easily understood, lay-language term for English speakers, rather than to create a term to encompass a broader population of diabetes with chronic kidney disease (CKD). Further discussion and international consensus are needed for the definition of diabetic kidney disease, to avoid ambiguity or possible confusion.

Effect of sitagliptin combined with Yiqi yangyin huoxue decoction on clinical efficacy and hemorheology in early diabetic nephropathy

BACKGROUND

Early diabetic nephropathy (DN) is a complication of diabetes mellitus. It mainly affects kidney microvessels and glomerular function, and its timely and effective treatment is critical for early DN. However, the effects of treatments comprising simple Western medicine are not optimal. With the promotion and implementation of integrated Chinese and western medicine treatments, remarkable results have been achieved for many diseases. To this end, we explored the clinical efficacy of integrated traditional Chinese and western medicines for the treatment of early DN.

AIM

To investigate the effect of sitagliptin tablets combined with Yiqi yangyin huoxue decoction on clinical efficacy and hemorheology in patients with early DN.

METHODS

Through a retrospective analysis, 123 patients with early DN were admitted to the endocrinology clinic of the Changzhou NO. 7 People's Hospital from January 2021 to October 2022 and were selected as study subjects. After rigorous screening, 100 patients with early DN were enrolled. The control group (CG, n = 50) and the observation group (OG, n = 50) were divided according to the treatment method. The CG were treated with sitagliptin, and the OG were treated with sitagliptin plus the Yiqi yangyin huoxue decoction. Both groups were treated for 3 mo. For both groups, the baseline data and clinical efficacy were compared, and changes in blood glucose levels, lipid levels, renal function, and hematological indicators before (T0) and after (T1) treatment were assessed.

RESULTS

The total effective rate for the OG was 94.00% and that of the CG was 80.00% (P < 0.05). After treatment (T1), the levels of fasting blood glucose, 2 h postprandial glucose, total cholesterol, triacylglycerol, and low-density lipoprotein cholesterol in OG patients were obviously lower than those in the CG (P < 0.05), and cystatin C, homocysteine, urinary microalbumin, and blood creatinine values in OG patients were also obviously lower than those in the CG (P < 0.05); erythrocyte deposition, plasma viscosity, whole blood high shear viscosity, and whole blood low shear viscosity were markedly lower in OG patients than in the CG (P < 0.05).

CONCLUSION

Sitagliptin combined with Yiqi yangyin huoxue decoction has a remarkable effect when used to treat patients with early DN. Further, it is helpful in improving hemorheological indices and controlling disease progression.

Application of MR Imaging Characteristics in the Differentiation of Renal Changes Between Patients with Stage III Type 2 Diabetic Kidney Disease and Healthy People

Objective

To explore the value of 1.5T magnetic resonance (MR) fat saturation-T2-weighted imaging (FS-T2WI) and apparent diffusion coefficient (ADC) imaging texture features in distinguishing the renal changes of patients with stage III type 2 diabetic kidney disease (DKD) from healthy people.

Methods

This study collected 55 patients with stage III DKD (39 males and 16 females) and 33 healthy controls (13 males and 20 females) from December 2021 to June 2022 in the China-Japan Union Hospital of Jilin University. All subjects were randomly divided in a ratio of 6:4 to extract and screen the FS-T2WI and ADC texture features of the right kidney of the subjects. The area under the curve (AUC) was used to assess the diagnostic accuracy of each model.

Results

There were significant differences between urea, creatinine and sex (p<0.05) of the two groups in the training and test set, and no significant difference in age and body mass index (BMI). We extracted 1409 imaging features from the original ADC sequence and selected them by wavelet and Laplace-Gaussian filter and LASSO algorithm, and using the same methods of FS-T2WI. Finally, FS-T2WI and ADC models were selected to construct the united model, including 3 first-order features and 8 texture features. The AUC values of the training set of FS-T2WI, ADC, FS-T2WI+ADC combined logistic regression model were 0.96, 0.91, 0.98; the AUC values of the test set were 0.91, 0.89 and 0.93, and the specificity and accuracy values of the united model were 0.90 and 0.89, respectively.

Conclusion

FS-T2WI and ADC imaging features based on 1.5 T MR had diagnostic value in the early diagnosis of DKD stage III, and the combined model of FS-T2WI and ADC had high diagnostic efficiency.

Effect of safflower yellow on early type II diabetic nephropathy: a systematic review and meta-analysis of randomized controlled trials

Diabetic nephropathy (DN) is considered as one of the most popular microvascular complications of diabetes and the leading cause of death among diabetic patients. Currently, even though safflower yellow (SY) is widely adapted in the clinical treatment of DN, no meta-analysis can guarantee the safety of this treatment. This paper aims to evaluate the dominant method of SY on DN disease. The reliable source of information for randomized controlled trials (RCTs) and clinical research is listed as follows: the Chinese Biomedical Literature database, Chongqing VIP, Embase, the Cochrane Library and the China Academic Journals Full-text Database (CNKI). The CNKI search included Chinese journal articles, the full-text of important conferences and dissertations up to March 30, 2017. We picked out some particularly influential outcome variables including urinary albumin excretion rate (UAER), fasting blood sugar (FBG), blood urea nitrogen (BUN) and high-sensitivity C-reactive protein (hs-CRP) in each extracted study. In total, 1289 participants were included in this meta-analysis. The efficacy of SY alone or combined with Western medicine in the treatment of DN was better with statistically significant factors (odds ratio [OR] = 3.6, 95% confidence interval [CI] [2.37, 5.47], p < 0.00001). We found that SY lessened the UAER, heightened the proportion of blood sugar and beneficially improved other detective indicators related to DN. Therefore, SY used alone or in combination with Western medicine was significantly more efficacious with lower toxicity than Western medicine alone.

BOLD MRI to evaluate early development of renal injury in a rat model of diabetes

Objective

To investigate changes in renal oxygenation levels by blood-oxygenation-level dependent (BOLD)-magnetic resonance imaging (MRI), and to evaluate BOLD-MRI for detecting early diabetic renal injury.

Methods

Seventy-five rats, with unilateral nephrectomy, were randomly divided into streptozotocin-induced diabetes mellitus (DM, n = 65) and normal control (NC, n = 10) groups. BOLD-MRI scans were performed at baseline (both groups) and at 3, 7, 14, 21, 28, 35, 42, 49, 56, 63 and 70 days (DM only). Renal cortical (C) and medullary (M) R2* signals were measured and R2* medulla/cortex ratio (MCR) was calculated.

Results

DM-group CR2* and MR2* values were significantly higher than NC values following diabetes induction. R2* values increased gradually and peaked at day 35 (CR2*, 33.95 ± 0.34 s^–1; MR2*, 43.79 ± 1.46 s^–1), then dropped gradually (CR2*, 33.17 ± 0.69 s^–1; MR2*, 41.61 ± 0.95 s^–1 at day 70). DM-group MCR rose gradually from 1.12 to 1.32 at day 42, then decreased to 1.25 by day 70.

Conclusions

BOLD-MRI can be used to non-invasively evaluate renal hypoxia and early diabetic renal injury in diabetic rats. MCR may be adopted to reflect dynamic changes in renal hypoxia.

A Meta-Analysis of Randomized Controlled Trials of Yiqi Yangyin Huoxue Method in Treating Diabetic Nephropathy

Objective. The purpose of this systematic review is to evaluate the evidence of Yiqi Yangyin Huoxue Method for diabetic nephropathy. Methods. 11 electronic databases, through September 2015, were searched to identify randomized controlled trials of Yiqi Yangyin Huoxue Method for diabetic nephropathy. The quality of the included trials was assessed using the Jadad scale. Results. 26 randomized controlled trials were included in our review. Of all the included trials, most of them were considered as high quality. The aggregated results suggested that Yiqi Yangyin Huoxue Method is beneficial to diabetic nephropathy in bringing down the microalbuminuria (SMD = −0.98, 95% CI −1.22 to −0.74), serum creatinine (SMD = −0.56, 95% CI −0.93 to −0.20), beta-2 microglobulin (MD = 0.06, 95% CI 0.01 to 0.12), fasting plasma glucose (MD = −0.35, 95% CI −0.62 to −0.08), and 2-hour postprandial blood glucose (MD = 1.13, 95% CI 0.07 to 2.20), but not in decreasing blood urea nitrogen (SMD = −0.72, 95% CI −1.47 to 0.02) or 2-hour postprandial blood glucose (SMD = −0.48, 95% CI −1.01 to 0.04). Conclusions. Yiqi Yangyin Huoxue Method should be a valid complementary and alternative therapy in the management of diabetic nephropathy, especially in improving UAER, serum creatinine, fasting blood glucose, and beta-2 microglobulin. However, more studies with long follow-up are warrant to confirm the current findings.

Comparison of serum cystatin C, serum creatinine, measured GFR, and estimated GFR to assess the risk of kidney failure in American Indians with diabetic nephropathy

BACKGROUND

We compared values of baseline serum cystatin C (SCysC), serum creatinine (SCr), and measured glomerular filtration rate (mGFR) for predicting end-stage renal disease (ESRD) in patients with type 2 diabetes and elevated albuminuria.

STUDY DESIGN

Observational longitudinal study.

SETTING & PARTICIPANTS

Pima Indians with type 2 diabetes and elevated albumin-creatinine ratio (ACR ≥30 mg/g).

PREDICTORS

Baseline SCysC, SCr, and mGFR.

OUTCOMES & MEASUREMENTS

Individuals were followed up from their first examination with diabetes and ACR ≥30 mg/g until December 2010, onset of ESRD, or death, whichever came first. Incidence rates adjusted for age and sex were computed by Mantel-Haenszel stratification. The abilities of SCysC, SCr, and mGFR values to predict ESRD were compared with receiver operating characteristic curves.

RESULTS

Of 234 Pima Indians with a mean age of 42.8 years who were followed up for a median of 10.7 (range, 0.6-21.3) years, 68 (29%) developed ESRD. The incidence of ESRD was significantly higher in patients in the lowest versus highest tertile of 1/SCysC (incidence rate ratio, 2.43; 95% CI, 1.31-4.50). By contrast, mGFR and 1/SCr had J-shaped associations with ESRD. In unadjusted analyses, 1/SCysC had the highest area under the receiver operating characteristic curve (AUROC; 0.719 ± 0.035) and mGFR had the lowest (0.585 ± 0.042; P < 0.001); the AUROC for 1/SCr was intermediate (0.672 ± 0.040; P = 0.1 and P = 0.03 vs 1/SCysC and mGFR, respectively). In analyses adjusted for age, sex, diabetes duration, height, weight, hemoglobin A1c level, and ACR, 1/SCysC had the highest AUROC (0.845 ± 0.026). Models with mGFR or 1/SCr alone had similar AUROCs (P = 0.9) and both were lower than the model with 1/SCysC alone (P = 0.02 and P = 0.03, respectively).

LIMITATIONS

The predictive values of the filtration markers are limited to the extent that their precision is based on a single measurement.

CONCLUSIONS

SCysC level was a better predictor of ESRD than mGFR or SCr level in Pima Indians with type 2 diabetes and elevated albuminuria.

Tyrosine kinase inhibitor, genistein, reduces renal inflammation and injury in streptozotocin-induced diabetic mice

Tyrosine kinase inhibition is known to reduce diabetes-induced end-organ damage but the mechanisms remain elusive. We hypothesized that inhibition of tyrosine kinase reduces renal inflammation and injury in streptozotocin-induced diabetes. Male C57BL/6 mice were given daily injections of streptozotocin (45 mg/kg/day, i.p. for 5 days); control animals received the vehicle (citrate buffer). Thereafter, streptozotocin-treated mice were treated with genistein (10 mg/kg, i.p three times a week for 10 weeks, n=8-10/group) or the vehicle (5% DMSO). The streptozotocin-treated mice displayed significant elevation in blood glucose level and decrease in plasma insulin level compared to their vehicle-treated controls. Treatment with genistein reduced blood glucose level (~15%; p<0.05) without a significant effect on plasma insulin level; however, blood glucose remained significantly higher than the control group. The development of diabetes was associated with significant increases in total protein, albumin, nephrin and collagen excretions compared to their controls. In addition, the diabetic mice displayed increased urinary MCP-1 excretion in association with increased renal ICAM-1 expression and apoptotic cells. Furthermore, renal gp91 expression levels and urinary Thio-Barbituric Acid Reactive Substances (TBARs) excretion, indices of oxidative stress, were also elevated in diabetic mice. These changes were associated with increased renal phospho-tyrosine expression and renal phospho-ERK/ERK ratio. Importantly, treatment with genistein reduced all these parameters towards control values. Collectively, the results suggest that the reno-protective effect of genistein likely relates to reduced renal inflammation, oxidative stress and apoptosis in diabetic mice.

Twelve shifting paradigms in diabetic renal disease and hypertension

In the last 30 years we have seen considerable progress in the management of patients with diabetes, in particular with diabetic renal disease. A number of paradigms have been broken down, namely the following, as a consequence, clinical care has improved dramatically. . Significant renal involvement and albuminuria is rare in patients with essential hypertension. 2. High GFR is good for prognosis. 3. Only proteinuric diabetic patients have a poor prognosis. 4. Microalbuminuria only predicts renal disease. 5. Reducing blood pressure may cause low perfusion in the kidney and other organs with long-term negative effect, especially on the glomerular filtration rate. 6. Only in the presence of high blood pressure, should microalbuminuric patients receive anti-hypertensive treatment, including blockade of the RAS. 7. Only reducing blood pressure by blocking RAS in diabetes is relevant and justified. 8. Normoalbuminuria as indicated in the present definition is 'normal'. 9. ACE-I or ARB can only be used separately. 10. Diastolic blood pressure and later systolic pulse pressure are the best parameters for blood pressure recording. 11. Microalbuminuria is the strongest risk marker in patients with type 1 diabetes. 12. Screening for microalbuminuria is relevant, but follow-up was not proposed (also regarding microalbuminuria). In the present situation, it is well-known that patients with essential hypertension may sometimes have microalbuminuria, and it is known that it predicts a poor prognosis. Interestingly, in type 1 diabetes, hyperfiltration is a marker for poor prognosis related to metabolic control. Thus hyperfiltration is a marker for bad development, but microalbuminuria (below the proteinuric level) is also associated with a poor prognosis. It was originally believed that microalbuminuria only predicts renal disease. However, surprisingly it predicts as well cardiovascular disease and early mortality. The story about blood pressure and progression of renal disease is interesting, because it was earlier believed that a certain high blood pressure was mandatory for preservation of the renal function. This appeared to be a completely wrong concept. The data regarding microalbuminuria suggest that patients with microalbuminuria should receive anti-hypertensive treatment, even patients with so-called normal blood pressure. This was confirmed in several trials and also included in the guidelines. Reducing blood pressure is important, but it appeared to be especially beneficial to block the renin-angiontensin system, and it is clear that albuminuria is a continuous variable and is also a risk factor. Earlier it was suggested to use ACE-inhibitors or ARBs. Now it is clear that it is possible to use a combination, with good theoretical background. In the history of hypertension, it was earlier believed that diastolic blood pressure was most important, but later on it was generally accepted that systolic is a better predictor and the goal for treatment and pulse pressure may be even better. Not only is microalbuminuria an important risk marker, but it is as well clear that regression of microalbuminuria is a good marker for a better prognosis in patients. Microalbuminuria is believed to be the strongest risk factor, but new studies actually suggest that a simple parameter such as self-rated health is crucial along with other factors. Regarding new developments, it is clear that new studies have led to several advancements in management in patients, for instance the Steno II study shows positive effect on mortality by multifactorial intervention. Similarly, the ADVANCE study also showed positive effect on mortality by more intensified anti-hypertensive treatment with an ACE-inhibitor. We are eagerly awaiting the results from glucose arm in the ADVANCE study, especially in the light of the ACCORD study showing increased mortality with too strict glycemic control with a goal of 6% in HbA1c.

Nefropatia e retinopatia em diabéticos do tipo 1 de um programa de atendimento multiprofissional universitário

O diabetes mellitus (DM) tipo 1 é associado a complicações crônicas micro e macrovasculares. Propusemo-nos a estudar a associação entre nefropatia (ND) e retinopatia diabéticas (RD), e destas com variáveis clínico-laboratoriais em portadores de DM tipo 1 acompanhados em um centro universitário. Realizou-se um estudo transversal através de análise de prontuários. Foram estudados 81 pacientes; a prevalência de RD foi 21,0% e de ND, 35,8%; houve associação entre ambas. Os portadores de ND e RD possuíam maior tempo de DM, maior prevalência de hipertensão, pior controle glicêmico e LDL colesterol mais elevado. A taxa de filtração glomerular (TFG) foi associada ao tempo de DM, hipertensão e albuminúria. Identificou-se menor TFG nos portadores de complicações microvasculares, principalmente naqueles com lesões avançadas. Concluímos que, em nosso estudo com portadores de DM tipo 1, houve associação entre RD, ND e TFG, sendo tempo de DM e hipertensão variáveis associadas de forma independente.

Endothelial cell injury by high glucose and heparanase is prevented by insulin, heparin and basic fibroblast growth factor

BACKGROUND

Uncontrolled hyperglycemia is the main risk factor in the development of diabetic vascular complications. The endothelial cells are the first cells targeted by hyperglycemia. The mechanism of endothelial injury by high glucose is still poorly understood. Heparanase production, induced by hyperglycemia, and subsequent degradation of heparan sulfate may contribute to endothelial injury. Little is known about endothelial injury by heparanase and possible means of preventing this injury.

OBJECTIVES

To determine if high glucose as well as heparanase cause endothelial cell injury and if insulin, heparin and bFGF protect cells from this injury.

METHODS

Cultured porcine aortic endothelial cells were treated with high glucose (30 mM) and/or insulin (1 U/ml) and/or heparin (0.5 microg/ml) and /or basic fibroblast growth factor (bFGF) (1 ng/ml) for seven days. Cells were also treated with heparinase I (0.3 U/ml, the in vitro surrogate heparanase), plus insulin, heparin and bFGF for two days in serum free medium. Endothelial cell injury was evaluated by determining the number of live cells per culture and lactate dehydrogenase (LDH) release into medium expressed as percentage of control.

RESULTS

A significant decrease in live cell number and increase in LDH release was found in endothelial cells treated with high glucose or heparinase I. Insulin and/or heparin and/or bFGF prevented these changes and thus protected cells from injury by high glucose or heparinase I. The protective ability of heparin and bFGF alone or in combination was more evident in cells damaged with heparinase I than high glucose.

CONCLUSION

Endothelial cells injured by high glucose or heparinase I are protected by a combination of insulin, heparin and bFGF, although protection by heparin and/or bFGF was variable.

The role of surgical revascularization in the management of diabetic foot wounds

Diabetic foot wounds affect an estimated 15% of all patients with diabetes. These wounds are typically multifactorial in origin. Neuropathy of the foot and impaired wound healing are frequently associated with peripheral arterial occlusive disease. These factors combine to contribute to the development of foot ulcers. Successful wound healing and limb salvage require prompt recognition and treatment. Assessment of arterial perfusion is imperative and may be accomplished by a combination of physical examination and noninvasive vascular laboratory studies. When associated with significant ischemia, diabetic foot ulcers require arterial revascularization to achieve wound healing.

Increased urinary albumin excretion in Cushing's syndrome: remission after correction of hypercortisolaemia

OBJECTIVES

Increased urinary albumin excretion (UAE) in diabetic and nondiabetic subjects is frequently associated with insulin resistance syndrome and central obesity. Cushing's syndrome is also characterized by central obesity and insulin resistance. This study was undertaken to see whether increased UAE is found in Cushing's syndrome.

DESIGN

Cross-sectional study.

PATIENTS

Thirteen consecutive patients with Cushing's syndrome.

MEASUREMENTS

Patients collected three overnight urine samples for the measurement of UAE by radioimmunoassay. UAE was also measured in 479 nondiabetic subjects who comprised the control population for this study. In the patients who had initial microalbuminuria, UAE was remeasured 2 months after successful removal of pituitary or adrenal tumours. Kidney biopsy was performed in three patients during adrenalectomy.

RESULTS

Eleven out of 13 patients (84.6%) had increased UAE (> 9.6 micrograms/min), and eight patients (61.5%) had microalbuminuria or overt proteinuria (> 20 micrograms/min). Kidney biopsy revealed apparently normal glomerular structures without evidence of diabetic nephropathy. After correction of hypercortisolaemia, UAE declined profoundly in all of the patients.

CONCLUSIONS

More than 80% of patients with Cushing's syndrome had increased UAE. This was almost completely reversed after successful treatment of hypercortisolaemia. These results indicate that endogenous hypercortisolaemia increases UAE by a mechanism that is presently unknown.

Glomerular hyperfiltration in Koreans with non-insulin-dependent diabetes mellitus

Glomerular hyperfiltration (GHF) may play an important role in the pathogenesis of diabetic nephropathy. The prevalence of GHF in non-insulin-dependent diabetes mellitus (NIDDM) is reported to vary in different populations, ranging from 35% in black Americans with new-onset diabetes to less than 5% in whites. We measured glomerular filtration rate (GFR) by 51Cr-EDTA clearance methods in 284 Korean NIDDM patients without overt nephropathy. Glomerular hyperfiltration (defined as GFR > 140 mL/min/1.73 m2) was found in 25% (71 of 284) of the patients. Thirty percent and 15% of the patients with known duration of diabetes less than 5 years and more than 10 years, respectively, showed GHF. Microalbuminuria (defined as urinary albumin excretion rate 20 to 200 micrograms/min) was found in 23% (64 of 284) of the patients. The mean GFR of the microalbuminuric patients was not significantly different from that of the normoalbuminuric patients (121.5 +/- 30.1 mL/min/1.73 m2 v 124.9 +/- 26.4 mL/min/1.73 m2; P = NS). However, when the patients with microalbuminuria were divided according to the presence or absence of retinopathy, the microalbuminuric patients with retinopathy had a lower GFR compared with the microalbuminuric patients without retinopathy (109.6 +/- 35.5 mL/min/1.73 m2 v 130.0 +/- 26.3 mL/min/1.73 m2; P < 0.01). These results show that the prevalence of GHF in Korean NIDDM patients without overt nephropathy is higher than that reported in whites and that it is similar to that in black Americans. The high prevalence of GHF in Korean NIDDM patients may contribute to the relatively higher prevalence of clinical diabetic nephropathy in this population.

The N-acetyltransferase (NAT) gene: an early risk marker for diabetic nephropathy in Japanese type 2 diabetic patients?

A point mutation in the N-acetyltransferase gene (NAT2) leads to the recessive trait for the slow acetylator phenotype, which is suggested to be associated with microalbuminuria in Type 1 diabetic patients. Our study was designed to elucidate whether the NAT2 gene polymorphism would be a marker for diabetic nephropathy. The genotype distribution was studied in Japanese Type 2 diabetic patients with established nephropathy (n = 43), with microalbuminuria (n = 24), with normoalbuminuria (n = 18), non-diabetic patients with kidney disease (n = 62), and healthy control subjects (n = 51). The different alleles of the NAT2 gene were identified by restriction fragment length polymorphism analysis: the gene was amplified from genomic DNA (obtained from blood) and digested with restriction enzymes. The genotype was classified by the specific pattern of each allele (M1, M2, M3) in the agarose electrophoresis and ethdium bromide fluorescence. Alleles M1, M2, and M3 of NAT2 gene were found in 42.4% of all subjects (40.0% in all diabetic patients and 44.2% in all non-diabetic controls). The prevalence of the genotype, encoding the slow acetylator phenotype, was 7.0% in diabetic patients with established diabetic nephropathy, 20.8% in microalbuminuric diabetic patients, 0% in normoalbuminuric diabetic patients, 6.5% in non-diabetic patients with kidney disease, and 7.8% in healthy control subjects. The differences in the prevalence were non-significant. The results suggest that the N-acetyltransferase gene polymorphism may not be a genetic risk marker for diabetic nephropathy in Japanese Type 2 diabetic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Lipoprotein abnormalities in non-insulin-dependent diabetic patients with impaired extrahepatic insulin sensitivity, hypertension, and microalbuminuria

We investigated whether specific lipoprotein abnormalities are present in non-insulin-dependent diabetes mellitus (NIDDM) patients with hypertension and/or microalbuminuria. Fifteen normotensive normoalbuminuric (H-M-), 32 hypertensive normoalbuminuric (H+M-), and 22 hypertensive microalbuminuric (H+M+) NIDDM patients and 20 sex-, age-, and weight-matched nondiabetic control subjects were studied. Lipoprotein size was measured by nondenaturing polyacrylamide gradient gel electrophoresis; insulin sensitivity was assessed by using a euglycemic hyperinsulinemic clamp and [6,6(2)H]glucose tracer infusion for simultaneous measurement of hepatic glucose output and whole-body glucose utilization. Total plasma and very-low-density lipoprotein cholesterol were higher in H+M+ than in control subjects (5.84 +/- 0.98 versus 4.97 +/- 0.98 and 0.57 +/- 0.54 versus 0.26 +/- 0.21 mmol/L, mean +/- SD, P < .05). Plasma triglycerides were higher in H+M+ than in either control or H-M- subjects (2.17 +/- 1.32 versus 1.18 +/- 0.67 and 1.30 +/- 0.59 mmol/L, respectively; P < .05). The mean low-density lipoprotein diameter was 27.2 +/- 0.8 in control, 26.7 +/- 0.8 in H-M-, 26.5 +/- 0.8 nm in H+M- (P < .05 versus control subjects), and 26.0 +/- 0.8 nm in H+M+ subjects (P < .05 versus control subjects). The mean cholesterol level of the large high-density lipoprotein particles was lower in H+M- and H+M+ (0.37 +/- 0.14 and 0.36 +/- 0.16 mmol/L) than in control and H-M- (0.54 +/- 0.41 and 0.54 +/- 0.27 mmol/L, P < .05) subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Peripheral, rather than hepatic, insulin resistance and atherogenic lipoprotein phenotype predict cardiovascular complications in NIDDM

Microalbuminuria, hypertension and hyperinsulinaemia are three independent risk factors for cardiac disease in non insulin-dependent diabetes (NIDDM). However, it is unknown to what extent hyperinsulinaemia reflects resistance to insulin action at hepatic, extrahepatic or at both sites. A cross-sectional study from our Department showed that peripheral insulin resistance, hypertension, microalbuminuria and lipid abnormalities are associated in NIDDM. Non diabetic individuals with the so-called 'atherogenic lipoprotein phenotype', characterized by small dense low density lipoproteins (LDL subclass pattern B) have up to 3-fold higher risk of myocardial infarction. The aim of the present study was to investigate whether impaired peripheral insulin sensitivity, during euglycaemic-hyperinsulinaemic clamp, as well as abnormalities in lipid concentrations and LDL size, predict abnormalities in albumin excretion rate, blood pressure and cardiac function in 73 consecutive normotensive (< 85 mmHg diastolic level) and normoalbuminuric (< 15 micrograms min-1 daily albumin excretion rate) NIDDM patients. These patients showed a bimodal distribution of whole body glucose utilization rate, a parameter of peripheral insulin sensitivity. The cut-off point between the two modes of distribution was located close to the mean value minus one standard deviation in a population of 24 control subjects. Therefore, this latter value was used to identify two subgroups inside the overall population of NIDDM patients, i.e. 28 patients (group 1), with whole body glucose utilization rate, above, and 45 patients (group 2), below, the mean value minus 1 SD in the 24 controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Epidemiology, development and treatment of end-stage renal failure in type 2 (non-insulin-dependent) diabetes mellitus. The case of mainland France and of overseas French territories

The prevalence of diabetes mellitus among patients treated for end-stage renal failure by dialysis in France was studied in two stages (UREMIDIAB Study). The first stage consisted of a questionnaire which was mailed to all dialysis centres in mainland France. The response rate was 80.8%, resulting in a study population of 12,903 patients. Of these patients 884 were declared diabetic (6.9%). Later 295 of them were interviewed by seven specially-trained physicians who checked the medical records together with the nephrologist in charge. Plasma C-peptide was measured in almost all of the patients. Effectively, 1.4% were found to have Type 1 diabetes and 5.5%, Type 2. Diabetic nephropathy was found to be the only primary renal diagnosis among 93.9% of Type 1 diabetic patients and 36.8% of Type 2. Of the latter 51.6% had a non-diabetic cause of renal failure. In the second stage a survey was later conducted in 13 of 14 dialysis centres located in the remote overseas French territories. Among 934 patients 1.04% were Type 1 diabetic and 19.67% Type 2 (22.9% altogether). Type 2 diabetic patients treated overseas were essentially non-Caucasians (92.6%). The sex ratio was 0.54 in the overseas territories vs 1.4 in the mainland. We conclude that the prevalence of diabetes among people on dialysis is low in mainland France. But there are striking differences in the prevalence of Type 2 diabetes among dialysis patients in mainland France and its overseas territories. These differences are not related to access to dialysis facilities.

Long-term glycemic control and the rate of progression of early diabetic kidney disease

In this prospective study of 11.9 years duration (range 9 to 14), we examined the progression of albuminuria prior to and after the onset of microalbuminuria [albumin excretion rate (AER): 20 to 200 micrograms/minute]. Glycated hemoglobin (HbA1), AER and blood pressure were measured every six months. Twenty-two (13 type I, 9 type II) patients were identified in whom AER increased progressively (progressors). These patients were compared with 22 others matched for age, duration and type of diabetes in whom AER did not change significantly during the study period (non-progressors). In the progressors, the rate of increase in AER correlated with mean HbA1 for the study period in patients with type I (r = 0.68, P < 0.01) and type II diabetes (r = 0.71, P < 0.05). Furthermore, AER began increasing well before the conventional 20 micrograms/minute threshold of microalbuminuria had been reached and within the first five years of diagnosis of type I diabetes. We conclude that in predisposed diabetic patients, long-term glycemic control is correlated with the rate of development of early renal abnormalities. Repeated measurements of AER from the time of diagnosis may be useful in the early detection of patients who will develop microalbuminuria and ultimately overt diabetic nephropathy.

Urinary kallikrein excretion in type 1 (insulin-dependent) diabetes mellitus

Kidney haemodynamics appear to change after the early phases of diabetic nephropathy: increases in glomerular filtration rate and in renal plasma flow have been widely reported, while kidney size is increased. As the renal kallikrein-kinin system has been demonstrated to regulate kidney blood circulation, we have evaluated the excretion of urinary kallikrein in 87 Type 1 (insulin-dependent) diabetic patients with and without hyperfiltration. Urinary kallikrein excretion was measured in 24-h urine collections. The esterolytic activity was determined by fluorimetric assay. The excretion of urinary kallikreins was significantly higher in hyperfiltering patients (472 +/- 125 esterase units/24 h) than in normofiltering (168 +/- 77 esterase units/24 h) and control subjects (151 +/- 39 esterase units/24 h), p < 0.001. Furthermore, we observed a positive correlation between urinary kallikrein excretion and glomerular filtration rate (r = 0.785). These data suggest that variations of kallikrein and kinin concentrations may play a role in the alteration of renal haemodynamics in Type 1 diabetes. It is possible that the kinin-kallikrein system, the renin-angiotensin system and the prostaglandins may interact to determine the haemodynamic alterations which are present in the diabetic disease.

Renal hemodynamics in recent-onset type II diabetes

Glomerular hyperfiltration is thought to play an important role in the genesis of diabetic nephropathy. While hyperfiltration is well documented in early type I diabetes, the evidence for hyperfiltration in type II diabetes is conflicting. We investigated 16 nonproteinuric patients with recently diagnosed type II diabetes. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured as inulin clearance (CIN) and p-aminohippuric acid clearance (CPAH) using a constant infusion technique. Lean body mass was measured by densitometry (weighing under water). Renal hemodynamics were also measured in 31 healthy volunteers and six obese nondiabetic individuals. Median GFR in diabetics (133 mL/min/1.73 m2; range, 95 to 165) was significantly (P < 0.01) higher than in obese nondiabetic controls (median, 118; range, 95 to 139). Elevated GFR (ie, > 95th percentile of nonobese healthy controls) was found in 44% of patients. When GFR was factored for lean body mass, it was elevated in 50%. GFR did not correlate with fasting glucose, hemoglobin A1C (HbA1C), insulin-like growth factors, IGF-1 and IGF-2, or somatomedin-binding protein (SMBP). The findings document that hyperfiltration is common in recent-onset type II diabetics.

The effect of ejaculation on albumin excretion rate

Microalbuminuria predicts the development of diabetic nephropathy. Large daily variations in albumin excretion rates are frequently observed. Because seminal fluid contains protein and albumin, we reasoned that sexual activity, ejaculation, or residual urethral semen could contribute to albumin content in urine and thus effect determination of albumin excretion rate. Our study was designed to determine the effect of ejaculation of albumin excretion rate and to ascertain if patients routinely should be advised to refrain from sexual activity during or before the urine collection period. Ten normotensive, nondiabetic men (age 31.0 +/- 2.3 years) collected 24-h urine specimens on three occasions: after 3 days of abstinence from sexual activity, during a 24-h period which included one ejaculatory episode, and on a day following sexual activity. Results for albumin excretion rate were: abstinence day: 4.8 +/- 0.7 micrograms/min; sex day: 6.3 +/- 1.1 microgram/min; post-sex day: 4.9 +/- 1.0 micrograms/min. There was no significant difference between these values when compared directly or after log transformation. There also were no differences in urinary creatinine excretion or clearance. We conclude that in nondiabetic individuals ejaculation does not influence albumin excretion rate.

Effects of alpha 2-adrenergic blockade on renal hemodynamics in patients with insulin dependent diabetes mellitus

The role of renal alpha 2-adrenoceptors in the regulation of glomerular filtration and renal perfusion is unknown. We studied the effects of alpha 2-adrenergic blockade on renal hemodynamics in six patients with insulin-dependent diabetes mellitus (IDDM) and in six healthy subjects. At the basal state, glomerular filtration rate (GFR) was higher in IDDM although the difference from control levels was not statistically significant. Volume expansion, achieved by infusion of isotonic sodium chloride solution, during placebo infusion induced a significant drop in GFR in healthy subjects but not in IDDM patients. Infusion of the alpha 2-adrenoceptor antagonist idazoxan did not further modify the effect of volume expansion on GFR. Renal plasma and blood flow as well as filtration fraction were not significantly changed by volume expansion or idazoxan infusion. Plasma renin activity and plasma aldosterone levels decreased during volume expansion in both IDDM and control subjects. In conclusion, volume expansion induced decreased GFR in healthy controls but not in IDDM patients. Since infusion of idazoxan did not affect GFR or other parameters of renal hemodynamics, renal alpha 2-adrenoceptors do not seem to be involved in the regulation of renal function. Hence, enhanced renal alpha 2-adrenoceptor activity is not likely to underlie hyperfiltration as seen in IDDM.

Microalbuminuria as predictor of increased mortality in elderly people

OBJECTIVE

Correlation of the urinary albumin excretion rate and the risk of death among elderly subjects.

DESIGN

216 Subjects aged 60-74 whose urinary albumin excretion rate had been determined were followed up 62-83 months later.

SETTING

Municipality of Fredericia, Denmark.

SUBJECTS

223 People who had been selected as control subjects for diabetics found during a systematic screening for diabetes of all people aged 60-74 living in the municipality of Fredericia, Denmark. Of these subjects, 216 had an extensive clinical and biochemical examination within a few weeks of selection.

MAIN OUTCOME MEASURE

Death.

RESULTS

The median urinary albumin excretion rate was 7.52 micrograms/min. Eight of those with a rate below the median died compared with 23 with a rate equal to or greater than the median (p = 0.0078). The median albumin excretion rate in the 31 who died was 15.00 micrograms/min. Cardiovascular disease was the most common cause of death in both groups. A multivariate regression analysis of survival data was performed using the proportional hazards model. Besides albumin excretion rate, male sex, serum creatinine concentration, and hypertension were found to be of prognostic value.

CONCLUSIONS

The association between the albumin excretion rate and mortality that has been described in recent years in patients with diabetes mellitus may be present in elderly people in general, even when other known risk factors are taken into account.

Effects of very mild versus overt diabetes on vascular haemodynamics and barrier function in rats

Rats injected i.p. with a single dose of nicotinamide (250 mg/kg) 15 min prior to i.v. injection of streptozotocin (65 mg/kg) develop a very mild form of diabetes characterized by slight elevations of plasma glucose, increased levels of HbA1, and reduced insulin secretion in response to an i.v. glucose tolerance test. These rats gain weight normally and they are not hyperphagic, glycosuric, or polyuric. The effects of this very mild form of diabetes vs overt streptozotocin diabetes of three months duration on regional vascular 131I-albumin clearance, blood flow (assessed by 15 microns 85Sr-microspheres), and renal filtration function were examined in male Sprague-Dawley rats. Plasma glucose levels of rats with mild diabetes were 7.4 +/- 0.9 (mean +/- SD) (mmol/l) vs 6.5 +/- 0.6 for control rats and 31.3 +/- 6.0 for overtly diabetic rats. HbA1 levels were increased 1.4 fold in mildly diabetic and 2.3 fold in overtly diabetic rats. Vascular clearance of 131I-albumin was markedly increased in ocular tissues (anterior uvea, retina, and choroid), sciatic nerve, aorta, new (subcutaneous) granulation tissue, and kidney of both diabetic groups, although increases in overtly diabetic rats exceeded those in the mildly diabetic group (2.2-4.6 times control animals vs 1.6-3.3 times, respectively). Likewise, both overt and very mild diabetes markedly increased glomerular filtration rate (approximately 1.8 times and 1.2 times control animals, respectively), urinary excretion of endogenous albumin (approximately 9 times and 4 times) and IgG (approximately 15 times and 4 times), as well as regional blood flow in the anterior uvea, choroid, and sciatic nerve. Increases in tissue sorbitol levels were much larger in overtly diabetic rats (generally 10-20 times control animals) than in mildly diabetic rats (1.5-3 times controls). myo-Inositol levels were significantly decreased only in lens and sciatic nerve of overtly diabetic rats. These observations indicate that even very mild diabetes is associated with vascular functional changes which develop more slowly than in overtly diabetic rats, but are disproportionately large (in view of the minimal increases in glycaemia and tissue polyol levels) compared to those in overtly diabetic rats.