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Query: UMLS:C0011881 (diabetic nephropathy)
 10,836 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Diabetic nephropathy is a clinical syndrome characterized by persistent albuminuria, a relentless decline in GFR, raised arterial blood pressure, and increased relative mortality for cardiovascular diseases. Diabetic nephropathy is a leading cause of end-stage renal failure. The pathogenesis of diabetic nephropathy is multifactorial, with contributions from metabolic abnormalities, hemodynamic alterations, and various growth factors and genetic factors. Epidemiologic and family studies have demonstrated that only a subset of the patients develop this complication that family clustering of nephropathy is present, and that ethnicity plays an important role in the risk of developing this kidney disease. Short stature and low birth weight are both associated with increased risk of developing diabetic nephropathy, supporting the hypothesis that genetic predisposition or factors operating in utero, in early childhood, or both contribute to the development of diabetic nephropathy. Studies elucidating phenotypic markers such as parenteral hypertension and systemic blood pressure elevation have yielded conflicting results. The contribution from elevated blood pressure only plays a minor role in the majority of the patients developing diabetic nephropathy. The majority of the studies have demonstrated increased sodium/lithium countertransport activity in insulin-dependent diabetes mellitus patients with nephropathy, whereas studies of this phenotypic marker in parents of patients with and without nephropathy have yielded conflicting results. Recently, studies of genetic markers involved in the regulation of blood pressure and levels of cardiovascular risk factors have been conducted. Several studies have demonstrated that the deletion polymorphism in the angiotensin-I-converting enzyme acts as a risk factor for cardiovascular disease in diabetic patients. However, a meta-analysis does not support the suggestion that this factor plays any role for the initiation of diabetic nephropathy. Similar negative results have been obtained in relation to polymorphisms of the genes encoding for angiotensinogen and the angiotensin II Type 1 receptor. However, studies in diabetic and non-diabetic glomerulopathies have clearly demonstrated a deleterious effect of the deletion polymorphism in the angiotensin-converting enzyme on the progression of kidney function.
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PMID:Genetics of diabetic nephropathy. 898 28

African Americans have excess hypertension and end-stage renal disease presumed due to hypertension compared to Caucasians. The AASK was designed to examine the impact of antihypertensive therapies and two levels of blood pressure control on the rate of decline of GFR in African Americans with presumed hypertensive renal disease. During the pilot phase of the trial, eligible participants were requested to undergo renal biopsy to assess the underlying lesions in this population. Eighty-eight hypertensive (diastolic BP > 95 mm Hg) non-diabetic African American patients between the ages of 18 to 70 years, with GFR between 25 to 70 ml/min/1.73 m2 and without marked proteinuria were assessed for possible renal biopsy. Forty-three patients did not undergo renal biopsy due to refusal or contraindications. Adequate renal biopsies were obtained in 39 of the remaining 46 patients. Biopsy findings were analyzed and then compared to clinical parameters. The 39 patients studied, 29 men and 10 women, were on average 53.0 +/- 11.0 years old, and had a MAP of 109 +/- 15 mm Hg and GFR 51.7 +/- 13.6 ml/min/1.73 m2 (not significantly different from nonbiopsied patients). Thirty-eight of these 39 biopsies showed arteriosclerosis and/or arteriolosclerosis, severity on average 1.5 +/- 0.9 and 1.5 +/- 0.8, respectively on a 0 to 3+ scale. Interstitial fibrosis was moderate, 1.3 +/- 0.9 (0 to 3+ scale). Segmental glomerulosclerosis was present in five biopsies, and in one patient, biopsy and clinical findings were consistent with idiopathic focal segmental glomerulosclerosis. Additional lesions included mesangiopathic glomerulonephritis in one patient, basement membrane thickening suggestive of diabetic nephropathy in one, and cholesterol emboli in two cases. Arteriolar and arterial sclerosis were tightly linked, and correlated with interstitial fibrosis and the reciprocal of serum creatinine. Global glomerulosclerosis was extensive, involving on average 43 +/- 26% of glomeruli. The extent of this lesion did not correlate with degree of arteriolar or arterial thickening, but did correlate with systolic blood pressure (P = 0.0174), the reciprocal of serum creatinine (P = 0.0009), serum cholesterol (P = 0.0129) and interstitial fibrosis (P < 0.0001). These data underscore that renal biopsies in non-diabetic hypertensive African-Americans with mild to moderate renal insufficiency in the absence of marked proteinuria are overwhelmingly likely to show renal vascular lesions consistent with the clinical diagnosis of hypertensive nephrosclerosis.
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PMID:Accuracy of the diagnosis of hypertensive nephrosclerosis in African Americans: a report from the African American Study of Kidney Disease (AASK) Trial. AASK Pilot Study Investigators. 899 39

Diabetic nephropathy is a major cause of morbidity and mortality in patients with diabetes and occurs in about one-third of such patients. The course of nephropathy has become better defined, with patients initially developing microalbuminuria (albumin excretion rates [AER] between 20 and 200 micrograms/min), then overt nephropathy (AER > or = 200 micrograms/min) and finally a decline in GFR eventuating in end-stage renal disease (ESRD). Although metabolic control has long been hypothesized as a contributor to the development of nephropathy, it is only in recent years that this hypothesis has been proven. A number of observational studies have shown correlations between glycemic control and the development of various levels of albuminuria and also declines in GFR. Several small, prospective, randomized, interventional studies and the Diabetes Control and Complications Trial (DCCT) have now definitely proven that improved metabolic control that achieves near-normoglycemia can significantly decrease the development and progression of early nephropathy as well as other long-term complications of diabetes, including retinopathy and neuropathy. It is now conceivable that the achievement of near-normoglycemia plus the addition of angiotensin-converting enzyme inhibitors if microalbuminuria develops may greatly decrease the numbers of patients eventually requiring renal replacement therapy.
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PMID:The relationship between glucose control and the development of diabetic nephropathy in type I diabetes. 914 76

Hypertension is a common finding in non-insulin-dependent diabetes mellitus (NIDDM) nephropathy. African Americans have a high prevalence of NIDDM and hypertension, and are relatively resistant to the antihypertensive effects of converting enzyme inhibitors (CEI) but respond well to calcium channel blockers (CCB). In the long-term study presented here, the effects of isradipine, a dihydropyridine calcium antagonist, on the course of the nephropathy were investigated and compared with the effects of captopril in 31 African Americans with NIDDM and proteinuria (> or = 500 mg/day). The patients were stratified by levels of GFR and proteinuria, and they were randomized to receive isradipine (N = 16) or captopril (N = 15); doses were adjusted to maintain similar BP levels (< 140/90). At 6 months, mean arterial pressure was similar (102 +/- 3 and 104 +/- 3 mm Hg in the isradipine and captopril groups, respectively) and GFR was unchanged (delta = -4 +/- 3 and +1 +/- 3 ml/min/1.73 in the isradipine and captopril groups, respectively; P = NS). However, proteinuria in the isradipine group increased by approximately 50% (2.01 +/- 0.40 versus 3.04 +/- 0.70 mg/mg creatinine at baseline versus 6 months, respectively, P < 0.05), whereas captopril reduced proteinuria by 30% after 6 months (2.85 +/- 0.70 at baseline versus 2.30 +/- 0.70 mg/mg creatinine, P < 0.05). Dietary protein, sodium intake, and HbA1C levels were similar in both groups and did not differ from baseline. It was concluded that over 6 months, captopril reduces and isradipine increases proteinuria in African Americans with NIDDM and nephropathy. Whether this contrasting effect on proteinuria will result in different rates of progression is not known, but dihydropyridine CCB should be used cautiously in African Americans with diabetic nephropathy.
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PMID:Contrasting effects of calcium channel blockade versus converting enzyme inhibition on proteinuria in African Americans with non-insulin-dependent diabetes mellitus and nephropathy. 917 49

Hyperglycemia directly contributes to the development of diabetic nephropathy. A high-serum glucose concentration alters intraglomerular hemodynamics and promotes deposition of extracellular matrix in the kidney. Nitric oxide (NO) is a short-lived messenger molecule that participates in the regulation of renal blood flow, GFR, and mesangial matrix accumulation. Therefore, in this study it was tested whether high glucose directly modulates NO synthesis by rat mesangial cells in vitro by measuring the accumulation of nitrite, the stable metabolite of NO, in the incubation media. Raising the external glucose concentration to 33.3 mM for 24 to 72 h reduced nitrite levels in cell supernatants in a time-dependent manner to a nadir of 14 +/- 3% of the amount in normal glucose media (5.6 mM) (P < 0.01). The decline in NO synthesis in high glucose media was paralleled by decreased cyclic guanosine monophosphate generation; however, there was no alteration in rat mesangial cell expression of inducible NO synthase protein. The suppressive effect of high glucose on NO production by mesangial cells was not modified by inhibition of protein kinase C (H-7), the addition of antioxidants (vitamin E or superoxide dismutase), or a pan-specific anti-transforming growth factor-beta antibody. An elevated ambient glucose caused a time-dependent reduction in mesangial cell L-arginine content. Addition of L-arginine (10 to 20 mM) to external media partially reversed the inhibitory effect of high glucose on mesangial cell NO production in a dose-dependent manner. The highest dose of L-arginine (20 mM) increased mesangial cell L-arginine content to comparable levels in normal and high glucose media. These results indicate that high glucose causes depletion of L-arginine in mesangial cells and compromises NO synthesis. Limitation in the metabolic precursor and other, as yet unidentified, factors act to reduce NO production by mesangial cells in the presence of an elevated ambient glucose level, a change that may play a role in the development of diabetic glomerulosclerosis.
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PMID:High glucose inhibits nitric oxide production in cultured rat mesangial cells. 925 54

Initiation of antihypertensive treatment in hypertensive non-insulin-dependent diabetic (NIDDM) patients with diabetic nephropathy induces a faster initial (0 to 6 months) and slower subsequent (6 months-end) decline in GFR [delta GFR (ml.min-1.1.73 m-2.month-1) approximately 1.5 vs. 0.4]. Whether this initial phenomenon is reversible (hemodynamic) or irreversible (structural damage) after prolonged antihypertensive treatment is not known. To elucidate these mechanisms we investigated 40 hypertensive NIDDM patients (age 61 +/- 7 years, mean +/- SD), known duration of diabetes 14 years (2 to 33 years) [median (range)] with diabetic nephropathy receiving antihypertensive treatment (angiotensin converting enzyme inhibition, N = 30) for 5 years (1 to 20 years). The following variables were measured the last day on antihypertensive treatment and one month after withdrawal of treatment; GFR (51Cr-EDTA), 24-hour arterial blood pressure (24 hr MABP, Takeda TM2420) and albuminuria (ELISA); the mean 24-hour MABP rose from 102 +/- 11 to 111 +/- 10 (P < 0.0001) and albuminuria [geometric mean (antilog SEM)] increased from 634 (1.3) to 1159 (1.2) (P < 0.0001), while GFR (mean +/- SD) remained unchanged (69 +/- 25 to 70 +/- 26 ml.min-1.1.73 m-2, P = 0.21), after withdrawal of antihypertensive treatment. A significant correlation between the relative change in the 24 hour MABP measurement and the relative change in GFR (r = 0.44, P < 0.01) was found. In conclusion, our results suggest that the faster initial decline in GFR after initiating antihypertensive treatment in hypertensive NIDDM patients with diabetic nephropathy is due to a irreversible effect, and should be accounted for when evaluating the beneficial effect of antihypertensive treatment on the progression of diabetic nephropathy in these patients.
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PMID:Kidney function after withdrawal of long-term antihypertensive treatment in diabetic nephropathy. 940 21

End-stage renal disease (ESRD) is a major public health problem worldwide. The past decade has witnessed increased interest and investigative attention on therapeutic manoeuvres to retard the progression of renal disease. Reduction of albuminuria is regarded as a surrogate endpoint, because this phenomenon seems to be associated with preservation of GFR (principal endpoint) in diabetic nephropathy. Studies from our laboratory suggest that reduction in albuminuria during ACE inhibition constitutes a predictor of an attenuated rate of decline in GFR in early diabetic nephropathy. Because the rate of decline in kidney function is used to assess prognosis and the efficacy of therapy on progression of renal disease, a valid method for the determination of GFR is essential. During the last two decades, several radioactive and non-radioactive filtration markers have been validated and found to be both accurate and precise compared to inulin. Plasma clearance of such filtration markers is frequently applied in clinical trials in diabetic nephropathy because patients suffering from this complication frequently also suffer from diabetic cystopathy, precluding measurements of urine volume. Measurements of serum creatinine, creatinine clearance, calculated creatinine clearance by use of the Cockroft-Gault formula must all be regarded as surrogate measurements for glomerular filtration rate. Consequently, care must be taken to select appropriate filtration markers in order to rigorously evaluate therapeutic trials in progressive renal disease.
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PMID:Surrogate endpoints and renal protection: focus on microalbuminuria. 949 28

Although hyperlipidemia has been associated with the progression of glomerulosclerosis, little attention has been directed toward the use of lipid-lowering agents in altering diabetic nephropathy. We tested the hypothesis that lovastatin and the combination of lovastatin and enalapril would preserve renal function in streptozotocin-induced diabetic Wistar rats. Five groups of animals were studied: group 1, nondiabetic (n = 10); group 2, diabetic, insulin only (n = 12); group 3, lovastatin, (15 mg/kg/day, n = 13); group 4, enalapril, (50 mg/L drinking water, n = 10) and group 5, lovastatin plus enalapril, (n = 14). After 8 weeks of treatment, glomerular filtration rate (GFR, insulin clearance) was measured in anesthetized animals. The diabetic group was characterized by a GFR of 0.18 +/- 0.03 ml/min/g of kidney weight (gKW), a blood glucose level of 441 +/- 36 mg/dL, plasma cholesterol and triglyceride levels of 64 +/- 6.0 and 103 +/- 26.0 mg/dL. Lovastatin preserved GFR, 0.52 +/- 0.06 ml/min/gKW compared with the diabetic control subjects (P < 0.05). Enalapril also maintained GFR (0.42 +/- 0.06 ml/min/gKW, P < 0.05). In the lovastatin plus enalapril group, GFR (0.62 +/- 0.05 ml/min/gKW) was greater than in the enalapril group (P < 0.05), but was not different from the lovastatin group. Plasma lipid levels were not altered in any of the groups. Assessment of the kidneys by histology after treatment showed that the mesangial matrix injury score was better in the lovastatin, enalapril, and lovastatin plus enalapril groups compared with the diabetic group (P < 0.05). Lovastatin, enalapril, and lovastatin plus enalapril abrogated the decline in GFR and glomerular injury in diabetic rats. Lovastatin's direct renal protective effect seems to be independent of its lipid-lowering properties.
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PMID:Lovastatin preserves renal function in experimental diabetes. 1021 Mar 55

Although diabetic nephropathy is often a low renin state, the renin system appears to be implicated in its pathogenesis. In this study, it was hypothesized that the low plasma renin activity (PRA) is misleading, masking and perhaps reflecting an activated intrarenal renin system. PRA and renal vascular responses (inulin and para-aminohippurate clearance) to graded doses of an angiotensin II (AngII) antagonist, irbesartan, were assessed in eight healthy volunteers and 12 patients with type 2 diabetes mellitus and nephropathy on a 10 mmol Na intake, to activate the renin system. Basal PRA was suppressed in type 2 diabetes mellitus compared with the healthy subjects (0.58 +/- 0.14 versus 1.58 +/- 0.28 ng/L per s, mean +/- SEM; P < 0.01). Despite the low PRA, renal perfusion rose more in response to irbesartan in type 2 diabetes mellitus (714 +/- 83 to 931 +/- 116 ml/min; P = 0.002) than normal (624 +/- 29 to 772 +/- 49 ml/min; P = 0.008). The youngest patients were hyperfiltrating and showed the largest rise in renal plasma flow in response to irbesartan, whereas renal plasma flow rose less and GFR fell in patients with low basal GFR. PRA rose in response to irbesartan more gradually in the patients with type 2 diabetes mellitus, but ultimately matched the normal response. To account for the apparent paradox of a heightened renal hemodynamic response to an AngII antagonist in the face of a low PRA in type 2 diabetes mellitus, and the rise in PRA following the AngII antagonist, it is proposed that there is increased intrarenal AngII production in type 2 diabetes mellitus. This increase could account for suppressed circulating renin, the exaggerated renal vasodilator response to irbesartan, and the therapeutic effectiveness of interrupting the renin system in diabetic nephropathy.
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PMID:The paradox of the low-renin state in diabetic nephropathy. 1054 Dec 98

We determined plasma concentrations of cystatin C, beta2-microglobulin - beta2-MG (low molecular mass protein markers of glomerular filtration rate - GFR), creatinine (marker of GFR) and urinary N-acetyl-beta-D-glucosaminidase (NAG) excretion (marker of glomerular and tubular dysfunction) in 41 non-insulin-dependent diabetic patients. A significant increase of all the measured parameters (p<0.001, p<0.05, p<0.05 and p<0.001, respectively) in comparison to the control group, was observed. In the patients with microalbuminuria, only plasma cystatin C concentration and urinary NAG excretion increased significantly in comparison to patients with normoalbuminuria. At a cut-off level of 1.74 mg/l for cystatin C and 1.81 U/g creatinine for NAG (95% percentile of the normoalbuminuric group), the sensitivity of the tests for detecting microalbuminuria was 82% for cystatin C and 86% for NAG. The specificities were 88 and 92%, respectively. The present study demonstrated that determination of plasma cystatin C might be useful in the detection of incipient diabetic nephropathy and is a potentially better marker than creatinine or beta2-MG. No correlation between parameters measured in plasma or urine and glycated hemoglobin was found.
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PMID:Plasma cystatin C concentration in non-insulin-dependent diabetes mellitus: relation with nephropathy. 1060 39


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