Reduction of heparan sulphate-associated anionic sites in the glomerular basement membrane of rats with streptozotocin-induced diabetic nephropathy

Summary Heparan sulphate-associated anionic sites in the glomerular basement membrane were studied in rats 8 months after induction of diabetes by streptozotocin and in age- and sex-matched control rats, employing the cationic dye cuprolinic blue. Morphometric analysis at the ultrastructural level was performed using a computerized image processor. The heparan sulphate specificity of the cuprolinic blue staining was demonstrated by glycosaminoglycan-degrading enzymes, showing that pretreatment of the sections with heparitinase abolished all staining, whereas chondroitinase ABC had no effect. The majority of anionic sites (74% in diabetic and 81% in control rats) were found within the lamina rara externa of the glomerular basement membrane. A minority of anionic sites were scattered throughout the lamina densa and lamina rara interna, and were significantly smaller than those in the lamina rara externa of the glomerular basement membrane (p<0.001 and p<0.01 for diabetic and control rats, respectively). Diabetic rats progressively developed albuminuria reaching 40.3 (32.2–62.0) mg/24 h after 8 months in contrast to the control animals (0.8 (0.2–0.9) mg/24 h, p<0.002). At the same time, the number of heparan sulphate anionic sites and the total anionic site surface (number of anionic sites × mean anionic site surface) in the lamina rara externa of the glomerular basement membrane was reduced by 19% (p<0.021) and by 26% (p<0.02), respectively. Number and total anionic site surface in the remaining part of the glomerular basement membrane (lamina densa and lamina rara interna) were not significantly changed. We conclude that in streptozotocin-diabetic rats with an increased urinary albumin excretion, a reduced heparan sulphate charge barrier/density is found at the lamina rara externa of the glomerular basement membrane.Abbreviations HS Heparan sulphate - GBM glomerular basement membrane - HSPG heparan sulphate proteoglycan - STZ streptozotocin - LRE lamina rara externa - LD lamina densa - LD + LRI lamina densa + lamina rara interna - ANOVA analysis of variance     

Amiloride lowers blood pressure and attenuates urine plasminogen activation in patients with treatment–resistant hypertension

In conditions with albuminuria, plasminogen is aberrantly filtered across the glomerular barrier and activated along the tubular system to plasmin. In the collecting duct, plasmin activates epithelial sodium channels (ENaC) proteolytically. Hyperactivity of ENaC could link microalbuminuria/proteinuria to resistant hypertension. Amiloride, an ENaC inhibitor, inhibits urokinase–type plasminogen activator. We hypothesized that amiloride (1) reduces blood pressure (BP); (2) attenuates plasminogen–to–plasmin activation; and (3) inhibits urine urokinase–type plasminogen activator in patients with resistant hypertension and type 2 diabetes mellitus (T2DM).In an open–label, non–randomized, 8–week intervention study, a cohort (n = 80) of patients with resistant hypertension and T2DM were included. Amiloride (5 mg/d) was added to previous triple antihypertensive treatment (including a diuretic and an inhibitor of the renin–angiotensin–aldosterone system) and increased to 10 mg if BP control was not achieved at 4 weeks. Complete dataset for urine analysis was available in 60 patients. Systolic and diastolic BP measured by ambulatory BP monitoring and office monitoring were significantly reduced. Average daytime BP was reduced by 6.3/3.0 mm Hg. Seven of 80 cases (9%) discontinued amiloride due to hyperkalemia >5.5 mol/L, the most frequent adverse event. Urinary plasmin(ogen) and albumin excretions were significantly reduced after amiloride treatment (P < .0001). Urokinase activity was detectable in macroalbuminuric urine, with a tendency toward reduction in activity after amiloride treatment. Amiloride lowers BP, urine plasminogen excretion and activation, and albumin/creatinine ratio, and is a relevant add–on medication for the treatment of resistant hypertension in patients with T2DM and microalbuminuria.     

Association of serum bilirubin levels with development and progression of albuminuria,and decline in estimated glomerular filtration rate in patients with type 2 diabetes mellitus

Aims/Introduction

Recent observational studies suggest elevated levels of bilirubin, an endogenous anti‐oxidant, might protect against kidney disease. We carried out an observational cohort study to assess whether higher baseline levels of bilirubin, within normal range, could predict the rate of development and progression of diabetic nephropathy in patients with type 2 diabetes.

Materials and Methods

Japanese type 2 diabetic patients with normo‐ or microalbuminuria and normal serum bilirubin (<1.2 mg/dL) were recruited from a single center, and categorized according to baseline serum bilirubin levels. Two independent end‐points were specified: development or progression of diabetic nephropathy, based on transition to a more advanced stage of albuminuria (albuminuria cohort), and the rate of change in estimated glomerular filtration rate (eGFR cohort).

Results

Albuminuria and eGFR cohorts were constructed consisting of 1,915 patients and 1,898 patients, respectively, with 1,738 patients overlapping. Mean follow up was 4.4 and 5.4 years for the two cohorts, respectively. Within the albuminuria cohort, 132 (9%) of 1,418 patients with normoalbuminuria developed microalbuminuria, and 56 (11%) of 497 patients with microalbuminuria developed macroalbuminuria. Higher baseline bilirubin levels were associated with significantly lower risk of progression from microalbuminuria to macroalbuminuria in both the univariate and multivariate analyses. In normoalbuminuric patients, an inverse association was found when restricted to a subgroup with elevated hemoglobin A1c levels. There was no relationship between bilirubin levels and the rate of change in eGFR.

Conclusions

Higher serum bilirubin levels, within normal range, might be predictive of a lower risk of progression of nephropathy in type 2 diabetic patients.     

Cystatin C is better than albuminuria as a predictor of pulse wave velocity in hypertensive patients

Introduction: Arterial stiffness is important in the evaluation of the cardiovascular risk in both general population and hypertensive patients. In this study, we aimed to investigate the associations of both serum cystatin C levels and albuminuria with arterial stiffness in healthy controls and hypertensive patients.

Patients and methods: Seventy-six healthy controls (male/female?=?44/32) and 76 hypertensive patients (male/female?=?43/33) were enrolled. Arterial stiffness parameters such as augmentation index (AIx) and pulse wave velocity (PWV) were non-invasively measured with the Arteriograph (Tensiomed Ltd., Budapest, Hungary).

Results: AIx (31.92?±?14.31 vs. 27.95?±?11.03, p?=?0.03) and PWV (9.84?±?1.62 vs. 8.87?±?2.04, p?p?=?0.002) and higher serum cystatin C levels [0.76 (0.67–0.95) vs. 0.68 (0.62–0.78) mg/L, p?=?0.03]. In the hypertensive group, AIx was significantly correlated with PWV (r?=?0.519, p?r?=?–0.438, p?=?0.003), mean arterial pressure (MAP) (r?=?0.288, p?=?0.015) and urinary albumin–creatinine ratio (ACR) (r?=?0.386, p?=?0.004). PWV was associated with serum cystatin C (r?=?0.442, p?=?0.003) and MAP (r?=?0.377, p?=?0.001). In the linear regression analysis (model r?=?0.577, p?=?0.006) for the prediction of PWV in hypertensive patients, MAP, urinary ACR, age and serum cystatin C levels were included as independent variables. Cystatin C was found to be the significant determinant of PWV in hypertensive patients.

Conclusion: Multivariate analysis revealed that serum cystatin C but not albuminuria was significantly associated with PWV in hypertensive patients. Serum cystatin C may be better than albuminuria as a predictor of arterial stiffness in hypertensive patients.     

微量白蛋白尿与急性缺血性卒中的严重程度和转归的关系

目的 探讨微量白蛋白尿(microalbuminuria,MAU)与急性缺血性卒中的危险因素、病情严重程度及转归的关系.方法 前瞻性纳入连续的急性缺血性卒中患者,根据尿白蛋白/肌酐比率(urine albumin/creatinine ratio,UACR)分为MAU阳性组(≥30 mg/g)和MAU阴性组(＜30 mg/g),根据改良Rankin量表(modified Rankin Scale,mRS)评分分为转归良好组(0～2分)和转归不良组(＞2分),对各项人口统计学和临床资料进行比较,并分析急性缺血性卒中转归不良和MAU阳性的独立因素.结果 共纳入156例急性缺血性卒中患者,其中男性84例,女性72例;年龄53～ 78岁,平均(65.4±6.2)岁;发病至入院时间为1.5～28 h;94例转归良好,62例转归不良,无死亡病例;76例MAU阳性,80例MAU阴性.多变量logistic回归分析显示,高龄[优势比(odds ratio,OR)1.992,95％可信区间(c onfidence interval,CI)1.108～2.374;P=0.015]、合并糖尿病(OR 2.497,95％ CI1.177～5.298;P =0.017)和心房颤动(OR 2.338,95％ CI1.062 ～5.148;P=0.035)、高血清高半胱氨酸(homocysteine,Hcy)水平(OR 2.541,95％ CI 1.073～6.02;P=0.047)和UACR(OR 2.130,95％ CI1.396 ～3.017;P =0.001)、MAU阳性(OR 3.291,95％ CI1.681 ～6.444;P=0.001)、高基线美国国立卫生研究院卒中量表(National Institutes of Health Stroke Scale,NIHSS)评分(OR9.196,95％ CI2.828～19.815;P ＜0.001)是急性缺血性卒中患者转归不良的独立危险因素.MAU阳性组合并糖尿病的患者比例(P=0.038)以及空腹血糖水平(P=0.025)、血清Hcy水平(P=0.022)和颈动脉内膜-中膜厚度(intima-media thickness,IMT)(P=0.019)与MAU阴性组存在显著性差异.MAU阳性组前循环梗死比例较低(P=0.033),基线NIHSS评分(P=0.003)和转归不良率较高(P＜0.001).多变量logistic回归分析显示,合并糖尿病(OR 2.237,95％ CI1.036 ～4.829;P =0.040)以及空腹血糖(OR 1.223,95％ CI1.145 ～1.673;P=0.027)和Hcy水平(OR 2.542,95％ CI 1.047～6.612;P=0.025)、颈动脉IMT(OR1.295,95％ CI1.106 ～1.362;P=0.023)和基线NIHSS评分(OR1.206,95％ CI1.044 ～1.219;P =0.023)增高与急性缺血性卒中患者MAU阳性独立相关.结论 MAU阳性是急性缺血性卒中转归不良的独立危险因素之一,且与急性缺血性卒中的部分危险因素密切相关,并对急性缺血性卒中病情严重程度和转归有着显著的影响.     

Intercellular adhesion molecule, plasma adiponectin and albuminuria in type 2 diabetic patients

Aims

Our study addressed the influence of early inflammatory stages of diabetic kidney disease: leukocyte adhesion and monocyte activation (as assessed by intercellular leukocyte adhesion molecule-ICAM-1 and monocyte chemoatractant protein-MCP-1) on the degree of albuminuria. Plasma levels of adiponectin, a possible anti-inflammatory counteracting mechanism, were also studied in correlation to the above-mentioned cytokines.

Methods

79 consecutive type 2 diabetic outpatients and 46 controls were included. Routine laboratory analysis, urinary albumin to creatinine ratio (uACR), plasma adiponectin, plasma ICAM-1 and urinary MPC-1 were assessed.

Results

In multiple regression ICAM-1 (p = 0.004) and adiponectin (p = 0.04) were the main determinants of uACR. Plasma adiponectin positively correlated to ICAM-1 (p = 0.03, r = 0.24).In albuminuric patients (uACR ≥30 mg/g) plasma adiponectin was significantly higher compared to normoalbuminuric ones (uACR <30 mg/g). In albuminuric patients the main determinants of uACR were plasma ICAM-1 and adiponectin. In multiple regression ICAM-1 is the only one that retains statistical significance (p = 0.02). Urinary MCP-1 did not correlate to uACR.

Conclusions

In our type 2 diabetic patients, plasma levels of ICAM-1 and adiponectin are predictive for albuminuria. Urinary MCP-1 does not correlated to uACR. Plasma adiponectin positively correlates to adhesion molecule ICAM-1 in our cohort.     

老年2型糖尿病患者并发冠心病的危险因素分析

目的 应用主成分分析法(principal component analysis,PCA)分析老年2型糖尿病患者并发冠心病的主要危险因素. 方法 回顾性分析我院住院行冠状动脉(冠脉)造影检查的60岁以上老年2型糖尿病患者503例临床资料,测定糖尿病患者尿白蛋白排泄率( urinary albuminexcretion rate,UAER)等指标,采用Gensini系统对冠脉血管病变程度进行评分. 结果 第1～7主成分的特征值均大于1,累计贡献率为64.6％;第1～4主成分分别为UAER、血脂、血压、尿酸,贡献率分别为14.1％、11.8％、10.2％、8.7％;第5～7主成分均属血糖,累计贡献率为19.8％. 结论UAER是老年2型糖尿病患者并发冠心病最主要的危险因素,伴微量白蛋白尿的老年2型糖尿病患者冠心病患病风险增加,且严重程度增加;UAER与老年2型糖尿病患者冠心病的发生及冠脉病变严重程度呈正相关,为其独立影响因素.     

Albuminuria in type 2 diabetes mellitus: from remission to progression

Objective Albuminuria is an early marker of renal impairment and a powerful factor of progression of renal disease in type 2 diabetes (T2D). Approximately, one-third of patients with T2D have micro- or macroalbuminuria and these patients have a high risk of progression toward End Stage Renal Disease (ESRD) as well as increased cardiovascular disease. The aim of this study was to determine the prevalence of remission, regression, persistence, and progression of albuminuria, and to evaluate the impact of change in albuminuria on kidney disease and cardiovascular disease in a prospective cohort of patients with T2D. Methods This is a prospective study. The Ethics Committee of Morocco’s Mohammed V University in Rabat approved the study protocol. Inclusion criteria targeted patients who were type 2 diabetics with albuminuria?>30?mg/day, and who had been regularly followed-up in nephrology consultation for at least 36 months. Results Five-hundred twenty-four patients were included. 75.8 and 24.6% of all patients had micro- and macroalbuminuria at enrollment in the study. At the end of the study, 91, 141, 199, and 93 patients had remission, regression, persistence, and progression of albuminuria, respectively. Remission of microalbuminuria to normoalbuminuria was observed in 23.6% of cases. Regression of macroalbuminuria to micro- was observed in 29.9% of cases. Conclusion In our study, the incidence of remission and/or regression of micro- and macroalbuminuria was higher. The incidence of ESRD and the occurrence of cardiac events were greater in the regression, persistence, and progression groups than in the remission of albuminuria group.     

阿托伐他汀联合丹参酮对慢性肾病患者白蛋白尿和血脂异常的影响

目的 评价阿托伐他汀和丹参酮联用对慢性肾病（CKD）患者肾功能和糖脂代谢参数的影响。方法 前瞻性纳入伴有白蛋白尿和血脂异常非透析性CKD患者90例,随机分为观察组（n=45）和对照组（n=45）。在CKD标准化治疗的基础上,对照组给予丹参酮ⅡA磺酸钠注射液;观察组加用阿托伐他汀钙片10 mg/d。两组疗程均为6个月。比较两组患者治疗前后的糖脂代谢功能及肝肾功能。结果 治疗半年后,两组患者的总胆固醇（TC）、三酰甘油（TG）、低密度脂蛋白胆固醇（LDL-C）均下降,高密度脂蛋白胆固醇（HDL-C）增加,同组治疗前后比较差异有统计学意义（P<0.05）;且观察组患者的TC、TG、LDL-C显著低于对照组,HDL-C显著高于对照组,组间差异有统计学意义（P<0.05）。所有患者对阿托伐他汀均耐受,两组患者的天门冬氨酸氨基转移酶（AST）、丙氨酸氨基转移酶（ALT）及肌酸激酶（CK）均无显著性差异。观察组和对照组患者的肾小球滤过率（eGFR）和高尿白蛋白肌酐比（UACR）无统计学差异。结论 他汀类药物联合丹参酮改善了CKD患者的血脂异常状态,表现出一定的肾脏保护作用。