MiRNA Expression is Associated with Clinical Variables Related to Vascular Remodeling in the Kidney and the Brain in Type 2 Diabetes Mellitus Patients.

Background: The association of vascular remodeling in the kidney and the brain with a particular microRNAs (miRNA) profile is not well studied.Methods: Seventy-six patients with Type 2 diabetes and 11 healthy subjects were assessed concerning urine albumin: creatinine ratio (UACR), biomarkers of podocyte injury and of proximal tubule (PT) dysfunction. MiRNA were quantified in blood and urine by a real-time PCR System. Cerebrovascular ultrasound measurements were performed in the carotid and middle cerebral arteries.Results: MiRNA21 and miRNA124 correlated positively with nephrin, podocalyxin, synaptopodin, urinary N-acetyl-D-glucosaminidase (NAG), urinary kidney-injury molecule-1 (KIM-1), UACR, and negatively with eGFR; miRNA125a, 126, 146a, 192 correlated negatively with nephrin, podocalyxin, synaptopodin, urinary NAG, urinary KIM-1, UACR, and directly with eGFR. Plasma miRNA-21 and miRNA192 correlated directly with cerebral hemodynamics parameters of atherosclerosis and arteriosclerosis. MiRNA-124, 125a, 126, 146a showed negative correlations with the same parameters.Conclusions: In Type 2 diabetes patients there is an association of vascular remodeling in the brain and the kidney with a specific miRNAs pattern. Cerebrovascular changes occur even in normoalbuminuric patients, with 'high-to-normal' levels of podocyte injury and PT dysfunction biomarkers. These phenomena may be explained by the variability of miRNA expression within the two organs in early DKD.

Proximal tubule dysfunction is dissociated from endothelial dysfunction in normoalbuminuric patients with type 2 diabetes mellitus: a cross-sectional study.

INTRODUCTION: The aim of our study was to clarify the hypothesis that proximal tubule (PT) dysfunction may be responsible for early diabetic nephropathy (DN), independently of preceding glomerular endothelial dysfunction. The pattern of endothelial dysfunction and its potential variability was evaluated in two vascular beds, the kidney and the brain. METHODS: A total of 68 normoalbuminuric type 2 diabetes mellitus (DM) patients were enrolled in a cross-sectional study and the following parameters were assessed: urinary albumin:creatinine ratio (UACR), urinary α(1)-microglobulin, urinary ß(2)-microglobulin, plasma asymmetric dimethyl-arginine (ADMA), serum creatinine, glomerular filtration rate (GFR), C-reactive protein (CRP), fibrinogen, HbA(1c); pulsatility and resistance indices in the internal carotid artery and middle cerebral artery and intima-media thickness (IMT) in the common carotid artery; cerebrovascular reactivity was evaluated through the breath-holding test. RESULTS: Plasma ADMA was increased in 12 patients (17.5%), urinary α(1)-microglobulin in 19 patients (27.9%) and urinary ß(2)-microglobulin in 16 patients (23.5%). Cerebral hemodynamic indices correlated with plasma ADMA, CRP, fibrinogen, duration of DM, HbA(1c) and GFR. ADMA correlated with fibrinogen, CRP, HbA(1c), duration of DM and GFR. There were no correlations between ADMA and UACR, and urinary α(1)-/ß(2)-microglobulin. Also, no correlations were found between urinary α(1)-/ß(2)-microglobulin and UACR, HbA(1c), duration of DM and GFR. CONCLUSION: The increase in urinary α(1)-/ß(2)-microglobulin precedes the stage of albuminuria. It may be assumed that early DN is related to PT dysfunction. Endothelial dysfunction plays a pivotal role in the brain vasculature, while its involvement in the development of early DN is not conditional on the occurrence of albuminuria.

The impact of acute kidney injury on short-term survival in an Eastern European population with stroke.

BACKGROUND: Stroke is one of the leading causes of death and of serious disability with significant impact on patients' long-term survival. The short-term evolution following stroke can associate acute kidney injury (AKI) as a possible complication, frequently overlooked and underestimated in clinical trials. We aimed to describe in an East European cohort (i) the incidence of AKI and its risk factors; (ii) the 30-day mortality and its risk factors and (iii) the relationship between mortality, pre-existent renal function and subsequent AKI. METHODS: A total of 1090 consecutive cases hospitalized-during a 12-month period-with a CT-confirmed diagnosis of stroke, from a distinct administrative region were included. Demographic details, comorbidities, laboratory and outcome data were retrieved from the electronic hospital database. All patients included in the study were followed for 30 days or until death. RESULTS: The mean age of this population was 66.1 +/- 11.5 years, 49.3% were males, mean glomerular filtration rate (GFR) 68.9 +/- 22.6 ml/min/1.73 m(2). The 30-day mortality rate was 17.2%. One hundred and fifty-eight patients presented with haemorrhagic stroke and 932 patients had ischaemic stroke. Stroke mortality was-14% for ischaemic stroke and almost twice as high for haemorrhagic stroke-36.3%. One hundred fifty-eight (14.5%) patients were classified as developing AKI. The AKI patients were older, had a higher baseline serum creatinine, lower GFR, higher serum glucose, higher prevalence of chronic heart failure and ischaemic heart disease, were more likely to have suffered a haemorrhagic stroke, and had a significantly higher 30-day mortality rate (43.1 vs 12.8%) (P < 0.05 for all). Independent predictors for AKI development in the logistic regression analysis were age, GFR, presence of comorbidities (ischaemic heart disease and chronic heart failure) and type of stroke (Cox and Snell R(2) 0.244; Nagelkerke R(2) 0.431; P < 0.05). In our study, we demonstrated that the occurrence of AKI is not a rare finding in stroke patients. This is the first study to report the incidence of AKI in a distinct geographic population base, in patients with stroke. Baseline renal function emerged as both a significant independent marker for short-term survival after an acute stroke (even after adjustment for baseline comorbidities) and as a risk factor for subsequent AKI.

Cerebrovascular reactivity is impaired in patients with non-insulin-dependent diabetes mellitus and microangiopathy.

BACKGROUND: Cerebrovascular reactivity (CVR) is a hemodynamic parameter representing the increase in normal cerebral artery blood flow in response to a vasodilatory stimulus such as hypercapnia. MAIN PURPOSE: The aim of the study was to assess CVR using transcranial Doppler ultrasound and the breath-holding test (BHT) in normotensive patients with non-insulin-dependent diabetes mellitus (NIDDM). The cerebrovascular response to hypercapnia was evaluated in relation to risk factors for cerebral microangiopathy. METHODS: The study was carried out in a group of 34 normotensive NIDDM patients and a group of 31 sex- and age-matched normal controls. The NIDDM group was subdivided into 21 patients with microangiopathic complications (Group A, 12 men, 9 women; mean age 58.77 +/- 8.91 years) and 13 patients with no such complications (Group B, 8 men, 5 women; mean age 56.34 +/- 9.83 years). The control group comprised 17 men and 14 women (Group C, mean age 58.43 +/- 6.31 years). Exclusion criteria were hypertension and past or present symptomatic cerebrovascular disease. The BHT consisted of spontaneous hypercapnia induced by holding the breath for 20 seconds. CVR was estimated in relation to the increase in the mean flow velocity (MFV) compared with the basal velocity in both middle cerebral arteries during hypercapnia. RESULTS: In Group A, the CVR was significantly decreased in 71.42% of patients, whereas in Group B only 30.76% of patients presented with mildly to moderately impaired CVR. Predictors for impaired % increase in the MFV during the BHT demonstrated by univariate regression analysis were: duration of diabetes (r = 0.802; P < 0.0001), fibrinogen (r = 0.574; P < 0.0001), C-reactive protein (r = 0.525; P < 0.001), proteinuria (r = 0.924; P < 0.0001) and serum creatinine (r = 0.969; P < 0.0001). Multivariate regression analysis showed as predictors: duration of diabetes (P < 0.0001), proteinuria (P < 0.0001) and serum creatinine (P < 0.0001). CONCLUSION: CVR is impaired in normotensive NIDDM patients. These cerebral hemodynamic changes correlate significantly with the duration of DM, parameters of inflammation, proteinuria and serum creatinine.

Cerebral microangiopathy in patients with non-insulin-dependent diabetes mellitus.

INTRODUCTION: The aim of the study was to evaluate cerebral microangiopathy in type 2 noninsulin- dependent diabetes mellitus (NIDDM) patients and to establish potentially conducive factors. MATERIALS AND METHODS: A group of 34 patients with NIDDM and 31 gender- and agematched normal controls (NC) were assessed by extracranial Doppler ultrasound, in order to evaluate the pulsatility index (PI) and the resistance index (RI) in the internal carotid arteries (ICAs); transcranial Doppler was utilised to assess the same parameters in the middle cerebral arteries (MCAs). All patients underwent screening for favouring factors for cerebral vascular remodelling. RESULTS: Of the 34 NIDDM patients, 21 patients (61.76%) (subgroup A) presented with microangiopathic complications [of these, 19 patients (90.46%) had diabetic nephropathy (DN)] versus 13 NIDDM patients (38.24%) (subgroup B) without complications. In subgroup A, 16 patients (76.19%) had PI >1 and RI >0.7 in the ICAs and MCAs (changes consistent with cerebral microangiopathy) versus 5 patients (35.46%) in subgroup B, and no modifications in NC. Of the 19 patients with DN, 14 patients (73.68 %) had impaired haemodynamic indices. Univariate regression analysis showed the following risk factors for the cerebral haemodynamics changes: fibrinogen (F) (OR = 3.11), C-reactive protein (CRP) (OR = 2.40), duration of DM (OR = 2.40), proteinuria (OR = 1.80), serum creatinine (OR = 1.66). Multivariate regression analysis showed as predictors for impaired haemodynamic indices: duration of DM (HR =1.70), proteinuria (HR = 1.70). The haemodynamic indices in the ICAs correlated with duration of DM (r = 0.87, P <0.0001), F (r = 0.86; P <0.0001), CRP (r = 0.80; P <0.0001); in the MCAs with the duration of DM (r = 0.66, P <0.0001), F (r = 0.38; P <0.0001), CRP (r = 0.88; P <0.0001). CONCLUSION: Cerebral microangiopathy has a high prevalence in NIDDM patients. These cerebral vascular changes correlate with the duration of DM, parameters of inflammation, and proteinuria.

Glycated peptides are associated with the variability of endothelial dysfunction in the cerebral vessels and the kidney in type 2 diabetes mellitus patients: a cross-sectional study.

BACKGROUND: Diabetic atherosclerosis and microangiopathy parallel diabetic nephropathy. The aim of our study was to evaluate the pattern of endothelial dysfunction in two vascular territories, the kidney and the brain, both affected by diabetic vasculopathic complications. The endothelial variability was evaluated in relation to advanced glycation end-products modified peptides. METHODS: Seventy patients with type 2 diabetes mellitus and 11 healthy subjects were assessed concerning urine albumin: creatinine ratio, plasma and urinary advanced glycation end-products, plasma asymmetric dimethyl-arginine, serum cystatin C, intima-media thickness in the common carotid arteries, the pulsatility index, the resistance index in the internal carotid arteries and the middle cerebral arteries, the cerebrovascular reactivity through the breath-holding test. RESULTS: The breath-holding index correlated with asymmetric dimethyl-arginine (R²=0.151; p<0.001), plasma advanced glycation end-products (R²=0.173; p<0.001), C-reactive protein (R²=0.587; p<0.001), duration of diabetes mellitus (R²=0.146; p=0.001), cystatin C (R²=0.220; p<0.001), estimated glomerular filtration rate (R²=0.237; p=0.001). Urine albumin: creatinine ratio correlated with urinary advanced glycation end-products (R²=0.257; p<0.001), but not with asymmetric dimethyl-arginine (R²=0.029; p=0.147). CONCLUSIONS: In type 2 diabetic patients endothelial dysfunction in the cerebral vessels appears to be dissociated from glomerular endothelial dysfunction in early diabetic nephropathy. Advanced glycation end-products could impact both the cerebral vessels and the glomerular endothelium.

Nephro- and neuroprotective effects of rosiglitazone versus glimepiride in normoalbuminuric patients with type 2 diabetes mellitus: a randomized controlled trial.

BACKGROUND: Thiazolidinediones represent a novel class of drugs that exert pleiotropic effects at various levels and lower blood glucose through reduction of insulin resistance in patients with type 2 diabetes mellitus. MAIN PURPOSE: The nephro- and neuroprotective effects of rosiglitazone vs. glimepiride were evaluated in normoalbuminuric patients with type 2 diabetes mellitus. The relevance of several biomarkers in the diagnosis of incipient diabetic nephropathy and cerebral microangiopathy was also assessed. METHODS: A total of 34 normoalbuminuric patients with type 2 diabetes mellitus were enrolled in a 1-year open-label randomized controlled trial. Group A comprised 17 patients (7 men, 10 women, mean age 63 +/- 8.07 years) treated with rosiglitazone plus metformin; Group B comprised 17 patients (7 men, 10 women, mean age 63.2 +/- 7.19 years) treated with glimepiride plus metformin. All patients were assessed at initiation, at 6 months and by the end of the study concerning serum and urinary beta2-microglobulin, urinary a1-microglobulin, serum cystatin C, serum creatinine, glomerular filtration rate, C-reactive protein, fibrinogen, glycated hemoglobin, cholesterol, triglycerides, hemoglobin, and the urinary albumin/creatinine ratio (UACR). Cerebral hemodynamic parameters were also measured: pulsatility index and resistance index in the internal carotid artery and middle cerebral artery, and intima-media thickness in the common carotid artery. RESULTS: At 1 year there were differences between groups A and B regarding serum cystatin C (P < 0.04), urinary beta2-microglobulin (P < 0.004), urinary a1-microglobulin (P < 0.0001), C-reactive protein (P < 0.0001), fibrinogen (P < 0.0001), serum creatinine (P < 0.0024), glomerular filtration rate (P < 0.0010), UACR (P < 0.0001), and the cerebral hemodynamic indices. The increase in a1- and beta2-microglobulin preceded the occurrence of microalbuminuria. UACR correlated with urinary a1- microglobulin (r = 0.4854), urinary beta2-microglobulin (r = 0.4867), and serum cystatin C (r = 0.3702). The cerebrovascular parameters improved in group A vs. group B and correlated with urinary beta2- and a1-microglobulin, C-reactive protein, fibrinogen, glomerular filtration rate, and duration of diabetes. CONCLUSION: Rosiglitazone demonstrated its nephro- and neuroprotective effects in normoalbuminuric patients with type 2 diabetes mellitus by the end of the follow-up period and these effects were beyond glycemic control. Urinary beta2- and a1-microglobulin are significant biomarkers for incipient diabetic nephropathy and diabetic cerebral microangiopathy. These biomarkers showed that proximal tubule dysfunction may develop before the stage of microalbuminuria.