Hypertensive Renal Damage in Metabolic Syndrome Is Associated with Glucose Metabolism Disturbances

Association between metabolic syndrome and coronary heart disease in patients on hemodialysis

BACKGROUND

The metabolic syndrome (MeS) is a common risk factor for coronary heart disease (CHD) in the general population.

OBJECTIVES

We examined the association between MeS and its risk in terms of CHD in patients on hemodialysis (HD).

PATIENTS AND METHODS

This study was conducted on 300 patients on HD in six HD centers during March 2012. Patients were divided in two groups regarding presence of MeS. The rate of CHD were evaluated in each group and compared with each other.

RESULTS

A total of 300 patients on HD, 173 males and 127 females with mean age of 61.7 ± 14.2, were enrolled in the study. Prevalence of MeS was 50.3%; hypertension, 83.7%; diabetes mellitus, 52%; high triglyceride level, 34%, low HDL cholesterol, 48.3%; and abdominal obesity, 41.3%. During the study, the CHD was more frequent in patients with MeS (27.8%) than was in those without MeS (14.1%) (P = 0.004). In addition, stroke happened more frequently in the MeS group than in those without MeS (30.5% vs. 17.4%; P = 0.008). The mean number of criteria for MeS was not significantly associated with mortality causes (CHD, 2.7 ± 1.3; stroke, 2.8 ± 0.9; other causes, 2.9 ± 1.3 P = 0.78). However, hypertension (89.3%) and diabetes mellitus (53.8%) were associated with increased risk for mortality. In the group of MeS, CHD were not significantly associated with serum albumin, calcium, phosphate, blood urea nitrogen, creatinine, ferritin, C-reactive protein, and KT/V; but there was significant association with white blood cells count (P < 0.0002).

CONCLUSIONS

These findings suggested MeS might be an important risk factor for CHD, but not for mortality due to CHD in patients on HD.

17β Estradiol Modulates Perfusion Pressure and Expression of 5-LOX and CYP450 4A in the Isolated Kidney of Metabolic Syndrome Female Rats

Prevalence of metabolic syndrome and progression of nephropathy depend on sex. We examined a protective effect of estradiol against nephropathy in metabolic syndrome through the modulation of the arachidonic acid metabolism by activating the 5-lipoxygenase and cytochrome p450 4A pathways. 28 female Wistar rats were divided into four groups of seven animals each: control, intact metabolic syndrome, ovariectomized metabolic syndrome, and metabolic syndrome ovariectomized plus estradiol. Blood pressure, body weight, body fat, triglycerides, insulin, HOMA-index, albuminuria, and TNF-α were increased in ovariectomized metabolic syndrome rats (p < 0.001). The perfusion pressure in isolated kidneys of ovariectomized metabolic syndrome rats in presence of 4 μg of arachidonic acid was increased. The inhibitors of the arachidonic acid metabolism Baicalein, Miconazole, and Indomethacin in these rats decreased the perfusion pressure by 57.62%, 99.83%, and 108.5%, respectively and they decreased creatinine clearance and the arachidonic acid percentage. Phospholipase A2 expression in the kidney of ovariectomized metabolic syndrome rats was not modified. 5-lipoxygenase was increased in metabolic syndrome ovariectomized rats while cytochrome p450 4A was decreased. In conclusion, the loss of estradiol increases renal damage while the treatment with estradiol benefits renal function by modulating arachidonic acid metabolism through the 5-lipoxygenase and cytochrome p450 4A pathways.

Carotid ultrasonographic parameters as markers of atherogenesis and mortality rate in patients on hemodialysis

BACKGROUND/AIM

Vascular endothelium plays an important role in atherogenesis. The aim of this study was to estimate the correlation of endothelium malfunction and arteriosclerosis in patients on hemodialysis.

METHODS

The investigation was designed as a clinical, non-randomized, five-year study in the "Kragujevac" Clinical Center and included 146 patients. We evaluated demographic characteristics, smoking, duration of dialysis, existence of tissue calcification and duplex ultrasound parameters of the carotid artery. All lethal outcomes, including the cause and time of death were recorded.

RESULTS

The cumulative survival rate was 57.5%. Survival was short in patients with wider lumen diameter of the carotid arteries. Carotid artery lumen diameter in men was wider than in women. The area cross section was closely correlated with intima media thickness (r = 0.913; p < 0.0001), as well as with the lumen diameter of the carotid arteries (r = 0.527;p < 0.0001). Carotid artery lumen diameter was negatively associated with serum cholesterol (r = -0.278; p = 0.019), while serum triglycerides correlated negatively with the cross section of intima media (r = -0.261; p = 0.028). Positive correlations were found between the serum total protein level and carotid artery lumen diameter (r = 0.235; p = 0.047), cross section intima media (r = 0.269; p = 0.022) and cholesterol (r = 0.248; p = 0.037). Time on dialysis showed a negative correlation with carotid artery cross section (r = -0.241; p = 0.04), while age was positively correlated with intima media (r = 0.295; p = 0.013), lumen diameter (r = 0.296; p = 0.012) and intima media cross section (r = 0.347; p = 0.003). Regression analysis pointed to predictive importance of carotid artery lumen diameter for survival (Beta = 0.437; p = 0.011) of the examined patients. The cumulative rate of survival was 57%.

CONCLUSION

In our study patient age correlated positively with all parameters of arteriosclerosis. The average duration of dialysis was negatively associated with carotid artery diameter, which was significantly higher in males. Regression correlation analyses indicated that the survival rate of the patients on hemodialysis was lower if the carotid artery diameter was larger.

IgG glycan hydrolysis attenuates ANCA-mediated glomerulonephritis

Anti-neutrophil cytoplasmic autoantibodies (ANCA) directed against myeloperoxidase (MPO) and proteinase 3 (Pr3) are considered pathogenic in ANCA-associated necrotizing and crescentic glomerulonephritis (NCGN) and vasculitis. Modulation of ANCA IgG glycosylation may potentially reduce its pathogenicity by abolishing Fc receptor-mediated activation of leukocytes and complement. Here, we investigated whether IgG hydrolysis by the bacterial enzyme endoglycosidase S (EndoS) attenuates ANCA-mediated NCGN. In vitro, treatment of ANCA IgG with EndoS significantly attenuated ANCA-mediated neutrophil activation without affecting antigen-binding capacity. In a mouse model of anti-MPO IgG/LPS-induced NCGN, we induced disease with either unmodified or EndoS-treated (deglycosylated) anti-MPO IgG. In separate experiments, we administered EndoS systemically after disease induction with unmodified anti-MPO IgG. Pretreatment of anti-MPO IgG with EndoS reduced hematuria, leukocyturia, and albuminuria and attenuated both neutrophil influx and formation of glomerular crescents. After inducing disease with unmodified anti-MPO IgG, systemic treatment with EndoS reduced albuminuria and glomerular crescent formation when initiated after 3 but not 24 hours. In conclusion, IgG glycan hydrolysis by EndoS attenuates ANCA-induced neutrophil activation in vitro and prevents induction of anti-MPO IgG/LPS-mediated NCGN in vivo. Systemic treatment with EndoS early after disease induction attenuates the development of disease. Thus, modulation of IgG glycosylation is a promising strategy to interfere with ANCA-mediated inflammatory processes.

Effect of gonadectomy on the metabolism of arachidonic acid in isolated kidney of a rat model of metabolic syndrome

Influence of sex on arachidonic acid metabolism, a pathway involved in the link between metabolic syndrome (MS) and renal damage, was studied in isolated perfused kidney. Metabolic syndrome was induced by feeding 30% sucrose solution for 24 weeks to intact and gonadectomized female (Ovx) and male (Cas) rats. Systolic blood pressure, albuminuria, as well as prostaglandin E(2) and thromboxane B(2) from urine and perfusate increased in MS male and MS ovariectomized females; castration reduced them in MS males. Perfusion of arachidonic acid in kidneys from MS males increased perfusion pressure compared with controls. No difference appeared in perfusion pressure between control and MS females. Castration diminished perfusion pressure in MS; the opposite was observed in Ovx MS. Perfusion with arachidonic acid plus indomethacin decreased perfusion pressure in MS male kidneys and in Cas MS. In Ovx MS, arachidonic acid plus indomethacin decreased perfusion pressure, but not in female control, MS, and Ovx control. Increase in perfusion pressure with arachidonic acid in both male MS and Ovx MS was related to cyclooxygenase (COX)-1 and COX-2 overexpression in kidney. Castration reduced the expression of COX-1 and COX-2 in MS to control levels. The results suggest that the alteration in arachidonic acid metabolism associated with changes in the expression of COX-1 and COX-2 induced by sucrose intake, and influenced by sex hormones, may contribute to renal damage.

Impact of metabolic syndrome and malnutrition on mortality in chronic hemodialysis patients

OBJECTIVE

Metabolic abnormalities contribute to increases in the mortality rate of patients on hemodialysis. Here, we estimate the importance and influence of metabolic syndrome and malnutrition on mortality rate.

DESIGN

This was a follow-up study.

METHODS

We examined the demographic characteristics of time on dialysis, body mass index, indications for hospitalization, treatment outcomes, and biochemical parameters over a 4-year period.

RESULTS

Whereas 31.7% of patients had metabolic syndrome, 26.7% showed evidence of malnutrition. More than two thirds of the malnourished patients died. Many patients (46%) with malnutrition were hospitalized because of problems with vascular access, whereas hospitalization of half of the examined patients with metabolic syndrome was attributable to cardiovascular disorders. Differences between groups in the parameters of anemia, total proteins, albumin, and low-density lipoprotein cholesterol also occurred, with the lowest values in malnourished patients. Glycemia, total cholesterol, and fibrinogen were significantly higher in patients with metabolic syndrome, whereas those with malnutrition had a markedly higher concentration of C-reactive protein. The mean survival was 24 months with metabolic syndrome and 17.5 months with malnutrition, which was significantly shorter.

CONCLUSIONS

More than half of the examined patients had metabolic abnormalities. Patients with malnutrition had a lower rate of survival compared with those who had metabolic syndrome. Two thirds of our malnourished patients died, and the total rate of mortality in the examined sample was 38%.

[Risk factors for the development of diabetic nephropathy]

INTRODUCTION

Results of epidemiological analysis show that one third of patients with diabetes mellitus develop diabetic nephropathy (DN). Strategies used until now to slow down the progression of DN were initiated when the symptoms of DN were already present.

OBJECTIVE

Our objective was to analyze the prevalence and characteristics of DN and to determine the factors leading to DN.

METHODS

Fifty-two patients with diabetes mellitus (DM)--32 with type 1 aged 32 years and 20 with type 2 aged 59 years--were referred from the Institute of Endocrinology, Diabetes and Metabolic Diseases to the Department of Nephrology for kidney function evaluation. Apart from routine laboratory analyses, glomerular filtration rate was calculated using the MDRD formula (modification of diet in renal disease), the size of the kidney was measured by ultrasound, and kidney volume was calculated using the ellipsoid formula.

RESULTS

Thirty percent of the patients revealed normal (eight patients with DM type 1) or satisfactory kidney function (eight patients with DM type 1) with physiological proteinuria. Microalbuminuria (MAU) or pathological proteinuria (PRT) were found in 10 and 9 patients, respectively, with DM type 1, while decreased kidney function was found in one patient without proteinuria. MAU or PRT were found in four and eight patients, respectively, with DM type 2 and decreased kidney function in four patients without proteinuria. Kidney function was significantly lower in patients with DM type 2 in comparison to DM type 1, while the patients with decreased kidney function had a higher PRT. Compared to DM type 2, in DM type 1 patients, the kidney was longer, and parenchymal artery resistance index was lower in DM type 1 patients compared to DM type 2. Factors associated with DN were patient's age, duration of diabetes, systolic blood pressure, HbA1c and kidney volume.

CONCLUSION

The prevalence of DN among the studied patients was 70%. Treatable factors associated with the development of DN are strict control of blood pressure and glycaemia control.

[Frequency and characteristics of metabolic disorders in patients on haemodialysis]

BACKGROUND/AIM

. Metabolic syndrome and malnutrition represent metabolic abnormalities which significantly characterize patients on haemodialysis. The aim of the study was to determine the incidence and find characteristics of metabolic disbalance in patients on haemodialysis.

METHODS

The study involved 124 patients on chronic haemodialysis at the Clinical Centre Kragujevac. There were analyzed demographic and anthropometric characteristics of the examined patients. Of clinical characteristics, there were determined smoking habit, time on dialysis, arterial pressure; of comorbid states there were recorded heart diseases and diabetes mellitus. Routine biochemical analyses were carried out by a standard laboratory procedure.

RESULTS

Metabolic syndrome was found in 29.8% of the examined patients. The patients with metabolic syndrome were older as compared to the patients without metabolic syndrome (58.45 +/- 12.91 vs 52.25 +/- 11.63 years). The values of systolic pressure (143.88 +/- 19.75 vs 133.01 +/- 22.93 mmHg; p = 0.014), body mass index (21.2 +/- 3.71 vs 19.4 +/- 2.88 kg/m2;p = 0.001), fat body mass (19.57 +/- 8.47 vs 16.45 +/- 5.82%; p = 0.0002) and waist scope (89 +/- 12.54 vs 96 +/- 12.34 cm; p = 0.0001) were significantly higher in the patients with metabolic syndrome as compared to those without metabolic syndrome. The values of erythrocytes (3.4 +/- 0.45 vs 19 +/- 0.53 x 10(12); p = 0.04) and hemoglobin (107 +/- 15.76 vs 101 +/- 13.87 g/l; p = 0.009), glycaemia (9.5 +/- 8.15 vs 5.6 +/- 1.4 mmol/l; p = 0.04) triglycerides (2.44 +/- 1.8 vs 1.41 +/- 0.64 mmol/l; p = 0.007), HDL cholesterol (1.11 +/- 0.19 vs 0.82 +/- 0.25 mmol/l; p = 0.005) and albumins (32.5 +/- 5.6 vs 29.5 +/- 3.7 g/l; p = 0.007) were statistically higher in the patients with metabolic syndrome than in patients without disturbance. Diabetes mellitus was a significant etiological factor of renal insufficiency in the patients with metabolic syndrome (p = 0.008).

CONCLUSION

In our study approximately 30% of patients on haemodialysis had pronounced metabolic syndrome. The older, more obese men with increased levels of triglycerides and glucose in the serum dominated among them. Diabetes mellitus was a leading etiological factor of renal insufficiency in these patients.

Obesity, essential hypertension and renin–angiotensin system

Abdominal obesity is a risk factor for cardiovascular disease worldwide, and it is becoming a dramatic issue for national health systems. Overweight and obesity are highly associated with multiple comorbidities, elevated blood pressure values, dyslipidaemia, reduced insulin sensitivity and alterations of large and minor vessels.

Activation of the renin–angiotensin system (RAS) in adipose tissue may represent an important link between obesity and hypertension. Angiotensin II has been shown to play a role in adipocyte growth and differentiation. Adipocytes also secrete adiponectin, enhancing insulin sensitivity and preventing atherosclerosis. Blockade of the RAS with either an angiotensin-converting enzyme inhibitor or an angiotensin II receptor blocker results in a substantial increase in adiponectin levels and improved insulin sensitivity. Obesity-related hypertension needs a comprehensive approach to treatment including both weight loss and pharmacological therapies. Antihypertensive drugs prescription should be based on guidelines recommendations for management of hypertension, taking into account the growing evidences about the relationship between some antihypertensive drugs and the development of new-onset diabetes.

This review discusses the role of RAS in the relationship between obesity, essential hypertension and insulin resistance.

Should Hypertension Guidelines Be Changed for Hypertensive Patients With the Metabolic Syndrome?

The authors analyzed the impact of present guidelines for hypertension management on cardiovascular (CV) risk factors in hypertensive patients with and without the metabolic syndrome (MS). Results in 549 nondiabetic hypertensive patients with a mean follow-up of 3.8+/-1.2 years on usual recommended care were reviewed. At baseline, 231 (42.1%) patients had MS and, per the definition, showed significantly higher values of traditional CV risk factors than non-MS patients. At the end of follow-up, blood pressure levels were similar in both groups; the lipid profile tended to improve in MS patients. Eighteen MS patients (7.8%) and 7 non-MS patients (2.2%) developed diabetes (P<.001). Prevalence of microalbuminuria was reduced in both groups, but it remained significantly higher in MS patients. Usual care of hypertensive patients achieved similar blood pressure and low-density lipoprotein cholesterol goals, both in MS and non-MS patients. Global CV risk, however, remained higher in MS patients, as suggested by a 3-fold higher incidence of new-onset diabetes (absolute increase of 5.6%) and a 2-fold increase in microalbuminuria.

Antihypertensive therapy in patients with metabolic syndrome

PURPOSE OF REVIEW

It is amply recognized that the presence of metabolic syndrome is associated with subclinical cardiac, vascular and kidney damage, with an increased risk for cardiovascular and cerebrovascular disease and type 2 diabetes, and, as a consequence, with higher rates of cardiovascular mortality. Metabolic syndrome can be considered as a prediabetic state very frequently associated with arterial hypertension, requiring pharmacological therapy.

RECENT FINDINGS

All antihypertensive therapies have been shown to reduce the risk of total major cardiovascular events. Recently, the relevance of the type of hypertensive therapy used to treat hypertensive patients in facilitating the development of diabetes has been demonstrated in different trials. The recognition of the risk present in hypertensive patients with metabolic syndrome for developing diabetes reinforces the need to consider the ideal antihypertensive therapy, either mono or combination, in these patients.

SUMMARY

This brief review contains the available evidence showing that an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker is the most suitable therapy to be started in these patients, alone or in combination, due to their capacity to prevent or retard the development of diabetes, and the strong relationship between metabolic syndrome and arterial hypertension, focusing on the advantages and disadvantages of different antihypertensive drugs.

Epidemiology of obesity and chronic kidney disease

The obesity epidemic has reached nephrology in the form of increasing numbers of patients with chronic kidney disease (CKD) caused by obesity-related metabolic disorders, IgA nephropathy, stone disease, and a unique glomerulopathy now known as obesity-related glomerulopathy (ORG). Obesity has been identified as an independent risk factor for CKD, and patients with central adiposity or high waist-to-hip ratios appear to have the highest risk. The metabolic syndrome is a risk factor for albuminuria and CKD, and studies now show that the risk of CKD increases with increased numbers of components of the metabolic syndrome. Obesity is not just a bystander or accelerator of other kidney diseases, but has unique histopathologic characteristics that can cause progressive kidney disease. ORG may accompany and worsen IgA nephropathy, urate nephropathy, and possibly even diabetic nephropathy. The origins of obesity-related kidney disease can be traced to insufficient glomerular complement from birth, and low birth weight may be an important precursor to obesity and its many comorbidities. Intervention strategies may need to target prenatal care through the elderly to combat this problematic epidemic.

Do we need to target 'prediabetic' hypertensive patients?

Patients at risk for diabetes development have been recently characterized as those presenting higher baseline serum glucose concentration, increased body mass index, elevated systolic blood pressure, reduced serum high-density lipoprotein-cholesterol and those with history of prior use of antihypertensive drugs. Little is known, however, about the long-term outcome of patients at high risk for diabetes development, so-called 'prediabetic' patients. Prediabetes state has been defined as the presence of either impaired glucose tolerance or impaired fasting glucose, and accumulating evidence suggests that individuals with a non-diabetic range of hyperglycaemia (prediabetic) are already at risk for cardiovascular diseases. This short review analyses the need of targeting 'prediabetic' hypertensive patients in order to develop strategies for cardiovascular protection intended to diminish the consequences of precipitating the development of diabetes and its cardiovascular and renal deleterious effects.

Can renal fibrosis be reversed?

New therapeutic approaches are needed to address the current epidemic of chronic kidney disease. Beyond delaying the inevitable onset of end-stage kidney disease the ultimate dream of clinical therapy is disease regression. Degradation of the interstitial matrix proteins is potentially feasible, especially before the interstitial "scar" becomes highly organized. Currently the specific matrix-degrading proteases that perform this function in vivo have not been clearly identified although several candidates have been suggested. Reversing renal fibrosis will also mandate removal of interstitial myofibroblasts that are the major source of the fibrosis-associated interstitial matrix proteins. However, the greater therapeutic challenge pertains to the current inability to regenerate intact functional nephrons in a site where they have been destroyed. In chronic tubulointerstitial damage that typifies all progressive kidney diseases, it is not interstitial matrix accumulation per se that leads to renal functional decline but rather its destructive effects on neighboring cells. In particular, loss of peritubular capillaries and tubules are the morphological features that underlie declining renal function. Recent advances in several basic scientific fields of investigation such as matrix biology, developmental biology, angiogenesis, and stem cell biology have identified new candidate therapeutic targets. A powerful new molecular tool-box is at our disposal that can be used to begin to translate recent discoveries into the clinical research arena with the goal of reversing renal fibrosis in a functionally meaningful way.

In a type 2 diabetic nephropathy rat model, the improvement of obesity by a low calorie diet reduces oxidative/carbonyl stress and prevents diabetic nephropathy

BACKGROUND

The present study has been undertaken to unravel the critical factors involved in the progression of diabetic nephropathy (DN).

METHODS

A unique type 2 diabetic rat model with a wide range of metabolic derangements and hypertension has been utilized, the spontaneously hypertensive/NIH-corpulent rat SHR/NDmcr-cp(cp/cp). It develops histologically evident glomerular injury and tubulointerstitial damage, including mesangial activation, podocyte injury, and inflammatory cell infiltration in the tubulointerstitium.

RESULTS

A low calorie diet for 22 weeks significantly improves obesity, proteinuria and renal morphological alterations. The correction of renal injury is independent of blood pressure control. Obesity correction, although partial, normalizes the renal content of pentosidine taken as a marker of oxidative stress and advanced glycation end products (AGEs). This occurs despite the fact that, in this model, improvement of glucose control and hyperlipidaemia is limited. Proteinuria and body weight are highly correlated with renal pentosidine content, while proteinuria and body weight are also correlated with each other. Diabetic renal injury is thus inhibited by a low calorie diet with an attendant reduction of oxidative stress and AGE formation, despite sustained hypertension.

CONCLUSION

The present findings suggest a direct role of obesity in the generation of a localized oxidative stress and AGE formation, directly responsible for DN.

Minor abnormalities of renal function: a situation requiring integrated management of cardiovascular risk

Changes in renal function related with essential hypertension are associated with an elevated cardiovascular morbidity and mortality. Indices of altered renal function (e.g. microalbuminuria, increased serum creatinine concentrations, decrease in estimated creatinine clearance or overt proteinuria) are independent predictors of cardiovascular morbidity and mortality. The Framingham Heart Study documented the relevance of proteinuria for cardiovascular prognosis in the community. The Intervention as a Goal in Hypertension Treatment (INSIGHT) Study assessed the role of proteinuria as a very powerful risk factor. It has also been shown that microalbuminuria along with primary hypertension poses a high risk for cardiovascular diseases. Recent data indicate that even minor derangements of renal function are associated with the clustering of cardiovascular risk factors observed in metabolic syndrome, that promote progression of atherosclerosis. All these parameters should be routinely evaluated in clinical practice, and considered in any stratification of cardiovascular risk in hypertensive patients. The high prevalence of chronic kidney disease in the general and in the hypertensive populations implies the need for an integrative therapeutic approach to fully protect renal and cardiovascular systems simultaneously.

The Third International Symposium on Obesity and Hypertension ISOH'03: 'Genetics and Molecular Mechanisms' (October 23-25, 2003, Berlin Germany)

The Third International Symposium on Obesity and Hypertension (ISOH'03) was held on 23-25, October 2003 at the Max Delbruck Center for Molecular Medicine in Berlin-Buch, Germany. The meeting, which consisted largely of invited lectures, presented a state-of-the-art overview of the genetic and molecular mechanisms that link obesity and hypertension. The over 40 oral presentations were supplemented by around 90 poster presentations from 34 countries. The meeting was attended by around 250 participants from 54 countries. This paper briefly reviews the contents of the invited lectures presented at this meeting covering topics ranging from genetics, molecular mechanisms, pathophysiology, cardiovascular risk, to the management of patients with obesity-related hypertension. Stimulated by the continuing success of these Symposia, the organizers are currently planning to hold a Fourth International Symposium on Obesity and Hypertension (ISOH'05) in Berlin: a tentative date for this meeting has been set for 27-29, October 2005.

Renal disease in cardiovascular disorders: an underrecognized problem

Chronic renal disease is generally appreciated as a major and rapidly growing health problem. In the United States alone, as many as 19.5 million people may have markers of early renal disease, and more than 660,000 people are expected to require renal replacement therapy by the year 2010. By contrast, the presence and pathological role of renal disease in patients with cardiovascular disease are somewhat underrecognized. Evidence now shows that even minor impairments in renal function, as indicated by measures including glomerular filtration rate and microalbuminuria, are common in cardiovascular disease states and predictive of cardiovascular events. Indeed, microalbuminuria may be a marker of systemic vascular disease rather than kidney dysfunction alone. In patients with hypertension, diabetes, metabolic syndrome, acute coronary syndromes, and stroke, markers of renal disease have proved to be at least as predictive of morbidity and mortality as conventional risk factors. Yet, chart reviews in a variety of clinical settings reflect poor recognition and management of renal disease in at-risk patients. Models for renal protection are based on the control of risk factors, particularly blood pressure, that are associated with renal and cardiovascular outcomes. Screening protocols for markers of renal disease should recognize the potential inaccuracy of serum creatinine concentrations and the preferability of glomerular filtration rate estimates that take age and gender into account. Pilot programs for screening high-risk populations have shown efficacy in detecting renal disease.

On the importance of estimating renal function for cardiovascular risk assessment

Microalbuminuria has been shown to predict an increased probability of suffering a cardiovascular event or death. It has also been shown to be decreased by antihypertensive therapy and in particular by drugs counteracting the effects of angiotensin II. In this issue of Journal of Hypertension data, from the LIFE study, are reported indicating for the first time that a decrease in urinary albumin excretion rate is accompanied by a significant decrease in cardiovascular events. This evidence is of great relevance because it constitutes the first evidence showing that regression of an intermediate end-point, microalbuminuria, ensures a better cardiovascular prognosis.

Relevancia de la insuficiencia renal en el pronóstico cardiovascular de los pacientes con hipertensión arterial esencial

Recently published guidelines recognize the relevance of the finding of chronic kidney disease in the stratification of risk of the hypertensive patient. Determination of the presence of microalbuminuria and estimation of glomerular filtration rate are mandatory in order to ensure an adequate evaluation of global cardiovascular risks in the hypertensive patient. The presence of subtle elevations of serum creatinine concentrations and/or proteinuria are also potent predictors of a poor cardiovascular prognosis. Clustering of associated risk factors seems to justify the elevated cardiovascular risk observed in patients with essential hypertension and mild alterations of renal function.