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

The purpose of our review is to delineate the pathogenic steps linking arterial hypertension in diabetes to diabetic nephropathy. The results of recent studies suggest that arterial hypertension in diabetes might lay a decisive pathogenetic role in the evolution of diabetic nephropathy: the existence of a higher ratio of erythrocytic Na/Li counter-transport in nephropathic diabetics as well as higher pressure values in the parents of diabetics who develop nephropathy indicates that hypertension may be casually related to renal complications. Diabetes-associated hypertension involves the modification of two important pressure- regulation factors: 1. an alteration in extracellular volume and increased renal absorption of sodium which leads to an expanded pool; 2. increased cardiovascular reactivity to norepinephrine and angiotensin II, an effect which might be related to increased intracellular calcium. Hyperfiltration seems to be present at the onset of diabetes, and arterial hypertension increases the transglomerular pressure gradient which is thought to play an important role in the pathogenesis of kidney damage. Antihypertensive drugs such as ACE-inhibitors and calcium channel blockers tend to protect the regulation of renal function. This could be explained by the fact that ACE-inhibitors suppress the trophic effects of angiotensin II on the nephron, while calcium channel blockers might interfere with intracellular processes involved in cell hypertrophy that require the interaction of calcium ions. In the management of diabetes prevention of diabetic nephropathy requires early and careful correction of diabetes-associated hypertension. We discuss the major groups of antihypertensive drugs, their metabolic side-effects and intrarenal induced hemodynamic changes.
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PMID:[Diabetic nephropathy and arterial hypertension: the physiopathological aspects and antihypertensive treatment]. 145 55

The offspring of essential hypertensive parents have been found to exhibit abnormalities in renal hemodynamics and sodium handling before the eventual occurrence of hypertension. The reported abnormalities represent a wide spectrum of changes including increased GFR, normal or decreased RPF, slight increase in blood pressure (although within the normal range), and an exaggerated natriuresis response to a sodium load. The heterogeneity of these abnormalities may reflect the specific conditions of the studies, the lability of the changes, or different subgroups of subjects with genetic predisposition to essential hypertension. Several lines of evidence have suggested a relationship between hypertension and the development of diabetic nephropathy in insulin-dependent diabetics. This laboratory has found that recent-onset insulin-dependent diabetics can exhibit renal hemodynamics abnormalities very early in the course of diabetes according to a positive or negative family history of essential hypertension. These changes include increased GFR and mean arterial pressure, but no differences in renal sodium and lithium handling in diabetics with a genetic predisposition to essential hypertension. In addition, diabetics with a positive family history of essential hypertension exhibited a more-marked vasodilative response to an acute interruption of the renin-angiotensin system, further suggesting inadequate angiotensin modulation of renal vascular tone. The significance of these abnormalities in relation to the development of diabetic nephropathy requires further investigation.
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PMID:Predisposition to essential hypertension and renal hemodynamics in recent-onset insulin-dependent diabetic patients. 145 59

Although many studies report an elevated Vmax of red blood cell Na/Li countertransport (CTT) activity in patients with insulin-dependent diabetes mellitus (IDDM) complicated by renal disease, divergent reports exist. This article reviews the technical issues and selection criteria that fuel this controversy. In addition, new studies from this laboratory indicate that insulin in vitro and in the nonfasted state modulate CTT activity and may contribute to the discrepant findings. Incubation of red blood cells from fasted controls with physiologic concentrations of insulin induced a twofold increase in the Km for external Na+. Similarly, Na+ activation kinetics of Li+ efflux showed saturation between 50 and 150 mM Na+ in fasted controls whereas saturation, postprandially, occurred between 100 and 150 mM Na+ as a result of an increase in Km. To clarify the role of prandial status on the measurement of Na+/Li+ CTT activity in diabetes, Na+ activation kinetics were investigated in 34 nonfasting patients with IDDM. Li+ efflux was fully saturated between 80 and 150 mM Na+ in the normoalbuminuric subjects (N = 22), whereas saturation occurred between 150 and 280 mM Na+ in the patients with diabetic nephropathy (N = 14). Patients with nephropathy have higher values of Km for Na+ than do the patients free of renal complications (86 +/- 9.5 versus 41.3 +/- 3.4 mM Na+, respectively; P < 0.000012). The higher Km prevented complete saturation of Li+ efflux at 150 mM extracellular Na+ concentration and contributed to the underestimation of Vmax at 150 mM Na+ selectively in persons with renal complications.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Sodium activation kinetics of red blood cell Na+/Li+ countertransport in diabetes: methodology and controversy. 145 60

In type I diabetes, the quality of life and, in essence, the long-term prognosis or life expectancy of the patient are invariably related to the manifestation of untoward complications. Increased arterial blood pressure (hypertension) has a great influence in these complications. Cumulative evidence has shown that proteinuric type I diabetic patients are easily susceptible to hypertension and its accompanying sequelae. The debilitating effects of hypertension on the progressive development of diabetic nephropathy leading to renal dysfunction and mortality in renal transplant patients have been documented. Proliferative retinopathy and cardiovascular lesions are also frequent devastating complications in hypertensive-diabetic patients. The mechanism of sodium/lithium countertransport activity and the genetic predisposition to hypertension require further elucidation.
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PMID:Comments on the clinical impact of hypertension in type I diabetes. 147 46

Of the many information obtainable from the urine of diabetic patients, urinary C-peptide (CPR), albumin and anti-diuretic hormone (ADH) were representatively described using my clinical and experimental data. C-peptide excretion in 24h collection of urine is a good estimate of insulin secretion from the pancreas and thus low in IDDM patients and even in NIDDM patients at a later stage, but high in pathological conditions including Graves' disease, obesity, liver cirrhosis and Cushing's syndrome. Urinary albumin excretion in small amounts (microalbuminuria) is usually observed in diabetic patients who have been under a poor control state of diabetic hyperglycemia for over 5 years and provides a good tool for monitoring early diabetic nephropathy. The grade of microalbuminuria (30-300 mg/day) is positively correlated with the HbA1 level in diabetic patients, showing that microalbuminuria is reversible along with an improvement of diabetic control at least in an early phase of diabetic nephropathy. As the albumin level measured in a spot urine sample correlates well with the value in the 24h collection of urine, the albumin measurement is conveniently feasible with a spot urine sample at every patient's visit. The amount of ADH excreted in urine is 7-10% of that secreted from the posterior pituitary. The excretion of ADH in a day was in the urine of diabetic patients positively correlated with HbA1, urinary osmolarity and concentration of sodium in urine, although the pathological meaning of the observed ADH hypersecretion in the development of diabetic complications is currently unknown.
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PMID:[Pathophysiological analysis of diabetes mellitus and complications from the urine of diabetic patients]. 150 92

Diabetic nephropathy is more common in patients with a positive family history of hypertension and with elevated red blood cell sodium-lithium countertransport, a marker of risk for essential hypertension. To evaluate whether there is a relationship between this cation transport system and indicators of risk of renal and cardiovascular complications in diabetic patients before the development of clinical proteinuria, we studied 31 type 1 (insulin-dependent) diabetic patients with arterial hypertension, without clinical proteinuria and 12 normotensive normoalbuminuric diabetic patients. Sodium-lithium countertransport activity was significantly higher in hypertensive patients (0.43 +/- 0.03 mmol/l RBC x hr) than in normotensive patients (0.23 +/- 0.03; P less than 0.001). To better explore the nature of the association between this transport system and arterial hypertension, hypertensive patients were divided in two groups, with high (greater than 0.41 mmol/l RBC x hr) or normal (less than 0.41) sodium-lithium countertransport activity. The two groups of hypertensive diabetics were similar in age, sex, body mass index and blood pressure levels.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Clustering of risk factors in hypertensive insulin-dependent diabetics with high sodium-lithium countertransport. 151 8

Genetic predisposition to essential hypertension has been proposed as a risk factor for the development of diabetic nephropathy in type 1 (insulin-dependent) diabetes mellitus. An increased sodium-lithium countertransport activity (NaLiCT) has been suggested as a genetic marker for essential hypertension. We therefore evaluated NaLiCT in diabetic patients with (N = 39) or without (N = 23) diabetic nephropathy (DNP), patients with non-diabetic renal diseases (N = 42) and in healthy controls (N = 24). The NaLiCT was elevated in both diabetic patient groups compared to healthy controls (median 244; range 134 to 390 mumol.liter cells-1.hr-1), but was not different in patients with DNP (median 314; range 162 to 676), without DNP (median 325; range 189 to 627) and patients with non-diabetic renal disease (median 300; range 142 to 655). The genetic predisposition to DNP is illustrated by the fact that diabetic sibs of probands with DNP showed a higher occurrence of DNP than diabetic sibs of patients without DNP. We analyzed whether familial DNP clustered with an increased NaLiCT. The NaLiCT in sibs concordant for the presence of DNP (N = 10; median 307; range 217 to 428 mumol.liter cells-1.hr-1) was not significantly different from that in sibs concordant for absence of DNP (N = 15; median 279; range 189 to 442). We conclude that erythrocyte sodium-lithium countertransport activity cannot be used as a marker to identify patients at risk for the development of diabetic nephropathy.
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PMID:Is increased erythrocyte sodium-lithium countertransport a useful marker for diabetic nephropathy? 151 9

Small increases in blood pressure are a feature of incipient diabetic nephropathy, and mean blood pressure often correlates with the degree of albuminuria in such patients. Antihypertensive therapy with angiotensin converting enzyme inhibitors (CEI) or calcium channel blockers (CCB) has been assessed in several studies to determine if either form of treatment modifies incipient diabetic nephropathy and its evolution to established nephropathy. The acute renal hemodynamic effects of CEI differ from those of CCB under certain circumstances. In incipient diabetic nephropathy, therapy with CEI but not CCB tends to reduce filtration fraction, especially in hyperfiltering patients. In hypertensive patients with incipient diabetic nephropathy, both treatments result in a decrease in albuminuria and the responses are mainly dependent on the lowering of systemic blood pressure. In normotensive patients with incipient diabetic nephropathy, a lowering of mean blood pressure with CEI or CCB is not found consistently while effects on albuminuria are difficult to interpret. Short- and long-term therapy with CEI lowers or stabilizes albuminuria. Short-term administration of CCB has at times been associated with increases in albuminuria, but a comparison of CEI and CCB over 12 months in the Melbourne Diabetic Nephropathy Study (MDNS) has shown that both drugs stabilize albuminuria with no significant differences in their effects. Serial analysis of urinary sodium excretion in the MDNS shows that the hypotensive response to CEI in incipient nephropathy is highly dependent on sodium intake, and that sodium intake may modulate albuminuria during both CEI and CCB therapy.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Angiotensin converting enzyme inhibition and calcium channel blockade in incipient diabetic nephropathy. The Melbourne Diabetic Nephropathy Study Group. 151 12

To assess the effects of genetic predisposition of essential hypertension on early renal function in recent insulin-dependent diabetics, we studied inulin, para-aminohippuric, sodium, and lithium clearances in 69 unselected diabetics with (n = 20) and without (n = 49) a family history of essential hypertension. Despite similar metabolic control, glomerular filtration rate and mean arterial pressure were significantly higher in diabetics with than in those without a family history of hypertension. However, no difference was found between the two groups regarding renal vascular resistance, sodium excretion, or fractional proximal and distal sodium reabsorption. Renal responses to acute captopril (75 mg) administration were evaluated in 27 patients (six with family history of hypertension). Captopril decreased filtration fraction and mean arterial pressure similarly in both groups, whereas glomerular filtration rate and renal vascular resistance decreased more dramatically in diabetics with family history of hypertension. These findings indirectly suggest an abnormal response to angiotensin of vascular tone in recent diabetics with familial predisposition to hypertension. Renal response to acute nicardipine (2.5 mg i.v.) administration was analyzed in 24 patients (five with family history of hypertension). In both groups, nicardipine similarly decreased mean arterial pressure and renal vascular resistance and induced a marked natriuretic effect due to a predominant reduction in proximal reabsorption of sodium. However, the increase in sodium excretion was twofold to threefold more pronounced in diabetics with a family history of hypertension. Whether these early renal abnormalities may contribute to the risk of diabetic nephropathy, as suggested by retrospective studies, remains to be determined.
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PMID:Renal abnormalities in normotensive insulin-dependent diabetic offspring of hypertensive parents. 155 69

Diabetes mellitus and hypertension are common diseases that coexist at a greater frequency than chance alone would predict. Hypertension in the diabetic individual markedly increases the risk and accelerates the course of cardiac disease, peripheral vascular disease, stroke, retinopathy, and nephropathy. Our understanding of the factors that markedly increase the frequency of hypertension in the diabetic individual remains incomplete. Diabetic nephropathy is an important factor involved in the development of hypertension in diabetics, particularly type I patients. However, the etiology of hypertension in the majority of diabetic patients cannot be explained by underlying renal disease and remains "essential" in nature. The hallmark of hypertension in type I and type II diabetics appears to be increased peripheral vascular resistance. Increased exchangeable sodium may also play a role in the pathogenesis of blood pressure in diabetics. There is increasing evidence that insulin resistance/hyperinsulinemia may play a key role in the pathogenesis of hypertension in both subtle and overt abnormalities of carbohydrate metabolism. Population studies suggest that elevated insulin levels, which often occurs in type II diabetes mellitus, is an independent risk factor for cardiovascular disease. Other cardiovascular risk factors in diabetic individuals include abnormalities of lipid metabolism, platelet function, and clotting factors. The goal of antihypertensive therapy in the patient with coexistent diabetes is to reduce the inordinate cardiovascular risk as well as lowering blood pressure.
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PMID:Diabetes mellitus and hypertension. 156 57


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