Renovasculopathies of nephrosclerosis in relation to atherosclerosis at ages 25 to 54 years

Tag-SNPs in Phospholipase-Related Genes Modify the Susceptibility to Nephrosclerosis and its Associated Cardiovascular Risk

Nephrosclerosis patients have a high cardiovascular (CV) risk that is very often of more concern than the renal disease itself. We aimed to determine whether variants in phospholipase-related genes, associated with atherosclerosis and CV outcomes in the general population, could constitute biomarkers of nephrosclerosis and/or its associated CV risk. We screened 1,209 nephrosclerosis patients and controls for 86 tag-SNPs that were identified in the SCARB1, PLA2G4A, and PLA2G7 gene loci. Regression models were utilized to evaluate their effect on several clinical parameters. Most notably, rs10846744 and rs838880 in SCARB1 showed significant odds ratios (OR) of 0.66 (0.51–0.87), p = 0.003 and 1.48 (1.11–1.96), p = 0.007 for nephrosclerosis risk. PLA2G4A and PLA2G7 harboured several SNPs associated with atherosclerosis measurements in the patients, namely common carotid intima media thickness (ccIMT), presence of plaques, number of plaques detected and 2-years ccIMT progression (significant p-values ranging from 0.0004 to 0.047). Eight SNPs in PLA2G4A were independent risk factors for CV events in nephrosclerosis patients. Their addition to a ROC model containing classic risk factors significantly improved its predictive power from AUC = 69.1% (61.4–76.9) to AUC = 79.1% (73.1–85.1%), p = 0.047. Finally, PLA2G4A rs932476AA and rs6683619AA genotypes were associated with lower CV event-free survival after controlling for confounding variables [49.59 (47.97–51.21) vs. 51.81 (49.93–51.78) months, p = 0.041 and 46.46 (41.00–51.92) vs. 51.17 (50.25–52.08) months, p = 0.022, respectively]. Variability in phospholipase-related genes play a relevant role in nephrosclerosis and associated atherosclerosis measurements and CV events.

Ankle-Brachial Index is a Predictor of Future Incident Chronic Kidney Disease in a General Japanese Population

AIMS

The ankle-brachial index (ABI) can be a prognostic marker for chronic kidney disease (CKD) in Western populations. Since there is little relevant evidence for Asian populations, we investigated the relationship between ABI and the risk of incident CKD in a general Japanese population.

METHODS

The cohort included 5,072 participants aged 30-79 without a history of renal disease or cerebro-cardiovascular disease. Incident CKD, defined as an estimated glomerular filtration rate ＜60 (mL/min/1.73 m2) and/or proteinuria (≥ 1＋ on urine dipstick), was compared among participants grouped according to baseline ABI: 0.90-0.99, 1.00-1.09, 1.10-1.19, 1.20-1.29, and 1.30-1.39. Hazard ratios for incident CKD were estimated using a Cox proportional hazards model, with the ABI 1.10-1.19 group serving as the reference.

RESULTS

The CKD incidence rate (/100 person-years) was 1.80 during the mean follow-up period of 5.1 years. The CKD incidence rate was 3.04 in the ABI category 0.90-0.99, 1.58 in ABI 1.00-1.09, 1.72 in ABI 1.10-1.19, 2.01 in ABI 1.20-1.29, and 3.33 in ABI 1.30-1.39. The hazard ratios for developing CKD were 2.14 (95% confidence interval 1.16-3.92) in ABI 0.90-0.99, 1.08 (0.83-1.41) in ABI 1.00-1.09, 1.03 (0.83-1.29) in ABI 1.20-1.29, and 1.37 (0.77-2.47) in ABI 1.30-1.39, after adjusting for age, sex, systolic blood pressure, diabetes, and other confounding factors.

CONCLUSIONS

In a general Japanese population, an ABI of 0.90-0.99 was associated with an increased risk of incident CKD, independent of traditional cardiovascular risk factors.

Association between renal vasculature changes and generalized atherosclerosis: an autopsy survey

AIM

To examine the association between renal vasculature changes and generalized atherosclerosis using autopsy cases.

METHODS

We histologically examined 107 autopsy patients(mean age, 68.4 years; 64% men; 81% non-CVD) to investigate the association between renal vasculature changes and generalized atherosclerosis. We measured the intima/media(I/M) ratio for the renal, intrarenal and systemic arteries(coronary, cerebral, common carotid and common iliac), calculated the rates of arteriolar hyalinization and global glomerulosclerosis and evaluated the frequency of advanced lesions(AHA classification ≥IV) in the systemic arteries.

RESULTS

The I/M ratios of the renal and intrarenal arteries and the rate of global glomerulosclerosis increased with age, while the rates of arteriolar hyalinization and global glomerulosclerosis were associated with diabetes and hypertension(all p＜0.05). The I/M ratio of the coronary artery was independently associated with the rate of global glomerulosclerosis(p＜0.05). The frequency of advanced atherosclerotic lesions in the coronary and cerebral arteries was also correlated with the I/M ratio of the renal artery and rates of arteriolar hyalinization and global glomerulosclerosis(all p＜0.05). The frequency of advanced lesions in the cerebral and common carotid arteries was independently associated with the I/M ratio of the renal artery and the rate of renal arteriolar hyalinization(odds ratio(OR) with [95% confidence interval]; 5.09 [1.15-27.9] and 4.11 [1.38-13.9], respectively).

CONCLUSIONS

The results of this study demonstrated that pathological changes in four portions of the renal vasculature differ. Renal vasculature changes except the intrarenal arteries were significantly associated with those observed in the cerebral, common carotid and coronary arteries.

Risk factor profile for chronic kidney disease is similar to risk factor profile for small artery disease

BACKGROUND AND METHOD

We investigated whether chronic kidney disease detected by increased serum creatinine (S(Cr)) or urine albumin-to-creatinine ratio (U(ACR)) may reflect arteriosclerosis involving the kidneys. The sample consisted of 1585 members of sibships (804 non-Hispanic whites and 781 non-Hispanic blacks) in which at least two siblings had primary hypertension. We first evaluated the correlations of increased S(Cr) and U(ACR) with the presence of cerebral small vessel arteriosclerosis, which was determined by increased subcortical white matter hyperintensity (WMH) volume on brain magnetic resonance imaging; and with peripheral large vessel arteriosclerosis, which was determined by decreased ankle-brachial index (ABI). After age adjustment, increased S(Cr) and U(ACR) correlated with increased WMH volume (0.54 and 0.52, respectively) and with decreased ABI (0.50 and 0.54, respectively; all P < 0.001). We then used logistic regression to evaluate the dependency of each measure of disease on conventional risk factors for arteriosclerosis to assess whether the risk factors' effects were proportional across different measures of disease.

RESULTS

Age, race, sex, hypertension, diabetes, total cholesterol, and smoking made similar overall contributions to the prediction of each measure of disease, as judged by the model C-statistics, which varied in a narrow range from 0.84 to 0.85 (all P < 0.001). However, the relative contributions that the modifiable risk factors, including hypertension, diabetes, total cholesterol, and smoking made to prediction of increased S(Cr) and U(ACR) were disproportionate to their relative contributions to prediction of decreased ABI (P < 0.0001).

CONCLUSION

The findings support the view that chronic kidney disease detected by increased S(Cr) or U(ACR) primarily reflects small vessel arteriosclerosis involving the kidneys.

Progression of renal dysfunction in patients with cardiovascular disease

It has been established that patients with chronic kidney disease (CKD) suffer from frequent cardiovascular events. On the other hand, recent studies suggest that renal damage tends to worsen in patients with cardiovascular diseases (CVD). Although the mechanisms for the cardiorenal association are unclear, the presence of arteriosclerotic risk factors common to both CVD and CKD is important. In arteriosclerosis, vascular derangement progresses not only in the heart but also in the kidney. In addition, heart failure, cardiac catheterization and hesitation of medical treatments due to renal dysfunction may explain the progression of renal damage. Therefore, the goal of treatments is a total control of arteriosclerotic risk factors. Medication should be selected among agents with protective effects on both heart and kidney. It is important to always consider the presence of CKD for the treatment of the cardiovascular disease and strictly control the risk factors.

Pathologic classification of diabetic nephropathy

Although pathologic classifications exist for several renal diseases, including IgA nephropathy, focal segmental glomerulosclerosis, and lupus nephritis, a uniform classification for diabetic nephropathy is lacking. Our aim, commissioned by the Research Committee of the Renal Pathology Society, was to develop a consensus classification combining type1 and type 2 diabetic nephropathies. Such a classification should discriminate lesions by various degrees of severity that would be easy to use internationally in clinical practice. We divide diabetic nephropathy into four hierarchical glomerular lesions with a separate evaluation for degrees of interstitial and vascular involvement. Biopsies diagnosed as diabetic nephropathy are classified as follows: Class I, glomerular basement membrane thickening: isolated glomerular basement membrane thickening and only mild, nonspecific changes by light microscopy that do not meet the criteria of classes II through IV. Class II, mesangial expansion, mild (IIa) or severe (IIb): glomeruli classified as mild or severe mesangial expansion but without nodular sclerosis (Kimmelstiel-Wilson lesions) or global glomerulosclerosis in more than 50% of glomeruli. Class III, nodular sclerosis (Kimmelstiel-Wilson lesions): at least one glomerulus with nodular increase in mesangial matrix (Kimmelstiel-Wilson) without changes described in class IV. Class IV, advanced diabetic glomerulosclerosis: more than 50% global glomerulosclerosis with other clinical or pathologic evidence that sclerosis is attributable to diabetic nephropathy. A good interobserver reproducibility for the four classes of DN was shown (intraclass correlation coefficient = 0.84) in a test of this classification.

Arteriolar hyalinization predicts delayed graft function in deceased donor renal transplantation

Delayed renal graft function (DGF) remains a largely unpredictable and burdensome consequence of deceased donor renal transplantation. There is growing evidence that histologic and molecular analyses of baseline donor kidney biopsies can predict both short- and long-term graft outcome. We performed histologic analyses of 172 preimplantation kidney biopsies to determine reliable histologic risk factors for DGF. Fifty-six recipients presented a DGF (incidence 32%). Univariate analysis revealed that arteriolar hyalinization (P=0.019), arterial intima fibrosis (0.004), donor age (P=0.001), duration of cold ischemia time (P=0.001), and recipient age (P=0.001) were significantly associated with DGF. Multivariate analysis revealed that the only independent histologic factor was arteriolar hyalinization (P=0.036). This histologic predictive factor, together with previously identified clinical risk factors, could guide clinical decisions regarding use, allocation, or immunosuppression protocols for minimization of DGF.

Correlation of histologic findings on preimplant biopsy with kidney graft survival

Kidney biopsies are being used to evaluate marginal deceased donor organs, but, the literature on the utility of this practice remains conflicting. We re-examined this issue by performing a multivariate analysis of 597 kidney transplant recipients. The presence of moderate arteriosclerosis and/or moderate arteriolosclerosis (MA), defined as >or=25% luminal compromise, was a significant predictor of graft outcome in standard criteria donors (multivariate, P=0.01) and in expanded criteria donors (ECD) as defined by UNOS criteria (univariate P=0.02). One-, 3-, and 5-year overall allograft survival with MA was 71%, 58%, and 40%, respectively. Increasing degrees of glomerulosclerosis (GS) were associated with earlier graft failure on univariate (P=0.03) but not multivariate analysis (P=0.36). GS>20% and interstitial fibrosis>25% had a low frequency in the material reviewed, likely reflecting our organ utilization practices, and did not have a demonstrable effect on graft outcome. Clinical parameters independently associated with worse graft function were ECD status (P<0.05), retransplantation (P=0.004), recipient age (P<0.05), and delayed graft function (P<0.0001). Donor vascular disease is an independent risk factor for suboptimal graft survival. Great caution should be exercised in the decision to transplant kidneys with moderate arterial and/or arteriolar luminal narrowing.

Renal function and risk of coronary heart disease in general populations: new prospective study and systematic review

BACKGROUND

End-stage chronic kidney disease is associated with striking excesses of cardiovascular mortality, but it is uncertain to what extent renal function is related to risk of subsequent coronary heart disease (CHD) in apparently healthy adults. This study aims to quantify the association of markers of renal function with CHD risk in essentially general populations.

METHODS AND FINDINGS

Estimated glomerular filtration rate (eGFR) was calculated using standard prediction equations based on serum creatinine measurements made in 2,007 patients diagnosed with nonfatal myocardial infarction or coronary death during follow-up and in 3,869 people without CHD in the Reykjavik population-based cohort of 18,569 individuals. There were small and nonsignificant odds ratios (ORs) for CHD risk over most of the range in eGFR, except in the lowest category of the lowest fifth (corresponding to values of <60 ml/min/1.73 m2), in which the OR was 1.33 (95% confidence interval 1.01-1.75) after adjustment for several established cardiovascular risk factors. Findings from the Reykjavik study were reinforced by a meta-analysis of six previous reports (identified in electronic and other databases) involving a total of 4,720 incident CHD cases (including Reykjavik), which yielded a combined risk ratio of 1.41 (95% confidence interval 1.19-1.68) in individuals with baseline eGFR less than 60 ml/min/1.73 m2 compared with those with higher values.

CONCLUSIONS

Although there are no strong associations between lower-than-average eGFR and CHD risk in apparently healthy adults over most of the range in renal function, there may be a moderate increase in CHD risk associated with very low eGFR (i.e., renal dysfunction) in the general population. These findings could have implications for the further understanding of CHD and targeting cardioprotective interventions.

Prehypertension increases the risk for renal arteriosclerosis in autopsies: the Hisayama Study

Information regarding the association between prehypertension BP level and renal arteriosclerosis is limited. In 652 consecutive population-based autopsy samples without hypertension treatment before death, the relationship between the severity of renal arteriosclerosis and BP levels classified according to the criteria of the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure was examined. The age- and gender-adjusted frequencies of renal arteriosclerosis linearly increased with elevating BP levels; both hypertensive and prehypertensive subjects had significantly higher frequencies of renal arteriosclerosis than subjects with normal BP (normal 11.9%; prehypertension 28.5%; stage 1 hypertension 32.9%; stage 2 hypertension 58.2%; all P < 0.01 versus normal). In a logistic regression model, prehypertension was significantly associated with renal arteriosclerosis after adjustment for other cardiovascular risk factors (prehypertension multivariate-adjusted odds ratio [mOR] 5.99 [95% confidence interval (CI) 2.20 to 15.97]; stage 1 hypertension mOR 6.99 [95% CI 2.61 to 18.72]; stage 2 hypertension mOR 22.21 [95% CI 8.35 to 59.08]). This significant association was observed for all renal arterial sizes. The similar association was also observed for arteriolar hyalinosis. When the subjects were divided into those with and those without target organ damage, the impact of prehypertension on renal arteriosclerosis was similar for both groups (subjects without target organ damage mOR 5.04 [95% CI 1.36 to 18.62]; subjects with target organ damage mOR 6.42 [95% CI 1.29 to 32.04]). These findings suggest that both hypertension and prehypertension are associated significantly with the severity of renal arteriosclerosis, regardless of the presence or absence of target organ damage.

Assessment of renal graft function depending on pre-transplant morphology

BACKGROUND

Histopathological assessment of kidney prior to transplantation is a part of the comprehensive information gathered on the transplanted organ. In our study we monitor the influence of individual morphological findings (glomeruli, arteries, arterioles, interstitium, tubules) and degree of histopathological changes in the kidney function after transplantation.

METHODS

From 1994 to 1997, 117 cadaveric kidneys were histopathologically examined and subsequently transplanted. Biopsy in a form of wedge excision was obtained during the organ procurement after in situ kidney perfusion and its removal from donor's body. Evaluated were glomerulosclerosis, intimal fibrosis of arteries, arteriolar hyalinization, interstitial fibrosis and tubular changes (vacuolar dystrophy of tubular epithelium, desquamation of tubular epithelium, brush border of proximal tubules, tubular dilatation, haemoglobin cylinders in distal tubules). Kidney recipients were monitored both for immediate function of transplanted organ and long-term kidney function for a period of five years following.

RESULTS

In our group of patients, no unambiguously negative influence of histopathological change in individual morphologies was found either in the immediate or in the long-term function of the transplanted kidney.

CONCLUSION

It is possible to transplant kidneys and attain satisfactory results even with these types of histopathological changes: glomerulosclerosis greater or equal to 20 %, mild degree of arterial lesion, moderate arteriolar lesions, moderate lesions of interstitial fibrosis and tubular lesions. The degree of arterial lesions, arteriolar lesions and the degree of interstitial fibrosis closely correlate to the donor's age, hypertension and nontraumatic cerebrovascular accident as the cause of death. Same outcomes were also confirmed with glomerulosclerosis, with the exception of the influence of the donor's age.

Smoking as a risk factor for renal injury in essential hypertension

BACKGROUND

Smoking is an important player in the pathogenesis of hypertensive nephropathy. To shed more light on this issue, we performed a case-control cross-sectional study and stratification analyses to evaluate the influence of smoking on surrogate markers of kidney injury and oxidative stress in patients supposed to have hypertensive nephropathy. The dependence of kidney lesions on the 'extent' of smoking was determined as well.

METHODS

82 patients with essential hypertension and micro- or macro-albuminuria were recruited. The control group consisted of 41 sex- and age-matched healthy individuals. Urine albumin creatinine ratio and plasma von Willebrand factor activity were analysed as markers of endothelial injury. N-acetyl-beta-D-glucosaminidase, transforming growth factor-beta1 and 15-isoprostane F2t urine excretions were regarded as markers of tubular dysfunction, renal fibrosis and oxidative stress, respectively. Patients' smoking habits were recorded and categorized on the basis of a self-administered questionnaire.

RESULTS

In multivariate regression analysis, the independent associations between smoking and urine albumin (p < 0.05; beta = 0.27), von Willebrand factor activity (p < 0.05; beta = 0.29) and urine isoprostanes (p < 0.05; beta = 0.28) were found. When the smokers were stratified according to the number of cigarettes smoked per day and the time from which they started smoking, 'heavy smokers' and 'long-term smokers' presented with higher albumin excretion and higher von Willebrand factor activity than 'light smokers' and 'short-term smokers', respectively. The passive smokers had numerically higher albumin excretion and von Willebrand factor activity than nonsmokers.

CONCLUSION

The study showed that smoking induces oxidative stress. Smoking was also found to be a strong predictor for the extent of endothelial injury in patients with hypertensive kidney injury. Subjects who smoke heavily and for a long time, as well as passive smokers, seem to be particularly exposed to endothelial damage.

Systemic and glomerular hypertension and progression of chronic renal disease: the dilemma of nephrosclerosis

The link between the kidney and hypertension has been considered a villain-victim relationship. High blood pressure levels are a well-recognized feature in chronic renal disease, but the ability of mild-to-moderate hypertension to produce renal insufficiency has been questioned. Nephrosclerosis, benign nephrosclerosis, and hypertensive kidney disease are terms that clinicians use when renal damage is thought to be secondary to essential hypertension. Many cases of end-stage renal disease are ascribed to so-called benign nephrosclerosis. This entity could actually be a primary renal disease affecting the preglomerular microvasculature, perhaps genetically mediated and ethnically influenced, and showing a heterogeneous clinical expression. African Americans suffer from nephrosclerosis more frequently than Caucasians. Nephrosclerosis affecting Caucasians seems to show a less aggressive pattern and could represent early age-related renal sclerosis. The risk of end-stage renal disease is increased when atherosclerotic lesions in large renal arteries coexist. Age, systolic blood pressure, proteinuria, and concomitant cardiovascular disease are well-known promoters of renal failure. A multifactorial strategy, including antihypertensive and antiproteinuric drugs, and lipid-lowering and anti-platelet agents, could improve cardiovascular and renal outcomes in patients with nephrosclerosis.

Predicting subsequent decline in kidney allograft function from early surveillance biopsies

Identifying factors that are predictive of allograft loss might be an important step toward prolonging kidney allograft survival. In this study we sought to determine the association between histologic changes on 1-year surveillance biopsies, changes in graft function and survival. This analysis included 292 adults, recipients of kidneys from living donors (69%) or deceased donors (31%), transplanted between 1998 and 2001 and followed up for 46 +/- 14 months. The primary end point was death-censored graft loss or a >50% reduction in GFR beyond 1 year. One-year biopsies were classified as: (i) Normal (N = 87, 30%), (ii) inflammation (N = 6, 2%), (iii) fibrosis (N = 131, 45%), (iv) fibrosis and inflammation (N = 53, 18%) and (v) transplant glomerulopathy (N = 15, 5%). By multivariate Cox analysis, survival related to biopsy classification (HR = 4.2, p = 0.001), graft function (HR = 0.97, p = 0.001) and HLA mismatches (HR = 1.003, p = 0.004). Using normal histology as a reference, fibrosis and inflammation (HR = 8.5, p < 0.0001) and glomerulopathy (HR = 10, p < 0.0001) related to poorer survival but mild fibrosis alone did not. Importantly, the degree of inflammation associated with fibrosis generally did not qualify for the diagnosis of borderline rejection. In conclusion, inflammation and glomerulopathy 1 year post-transplant predict loss of graft function and graft failure independently of function and other variables.

Renal dysfunction and ischemic heart disease mortality in a hypertensive population

OBJECTIVE

While recent studies indicate that renal dysfunction may be predictive of all-cause mortality and cardiovascular disease (CVD) outcomes in hypertensive individuals, there has been little attention to the specific association of ischemic heart disease (IHD) mortality and renal function. This study examines the relationship between IHD mortality and baseline glomerular filtration rate (GFR) (estimated by the Cockcroft and Gault formula) among treated hypertensive subjects.

DESIGN

A prospective cohort study of participants in a worksite-based antihypertensive treatment program in New York City (1981-1999).

PATIENTS

We studied 9929 subjects who had at least 6 months follow-up (mean 9.6 years) with a baseline serum creatinine.

MAIN OUTCOME MEASURES

IHD death outcomes (n=343) ascertained from the National Death Index.

RESULTS

Multivariate Cox proportional hazard models were constructed adjusting for known cardiovascular risk factors. Mean GFR of the cohort was 91.6 ml/min per 1.73 m. Those with lower GFR were more likely to be older, female, White, report a history of cardiovascular disease, have higher cholesterol and blood urea nitrogen values, and lower hemoglobin and body mass index than those with highest GFR. After adjustment for known cardiovascular risk factors, the risk of IHD death increased progressively as the GFR decreased. Hazard ratio for IHD mortality for each 10-unit reduction of estimated GFR below the normal threshold of >or=90 ml/min per 1.73 m was 1.33 (95% confidence interval 1.17, 1.50; P<0.001).

CONCLUSIONS

The results of this study suggest an independent inverse association between estimated GFR and IHD mortality among treated hypertensive individuals.

Cigarette Smoking Enhances Increased Urine Albumin Excretion as a Risk Factor for Glomerular Filtration Rate Decline in Primary Hypertension

BACKGROUND

Subjects with severe compared with mild primary hypertension are at greater risk for decline in glomerular filtration rate (GFR), but additional risk factors are poorly defined.

METHODS

Seventy-five subjects referred for assistance with blood pressure control ("severe") and 150 not-referred hypertensive subjects ("mild") were prospectively followed for 7 years. The primary outcome was the change in calculated GFR during follow-up as predicted by various clinical parameters, including urine albumin excretion measured as urine albumin (mg)-to-creatinine (g) (alb/cr) ratio.

RESULTS

Calculated GFR declined faster (more negative slope) in patients with severe hypertension than in those with mild hypertension (-0.188+/- 0.025 versus -0.120+/- 0.008 mL/min/month; P=0.010), despite similar follow-up systolic blood pressure (133.4+/-1.2 versus 131.9+/-0.8 mm Hg). Severe subjects had higher entry alb/cr (241.3+/- 29.1 versus 11.4+/- 0.5) and a greater proportion of cigarette smokers than mild subjects (56 versus 19%). Regression analysis comparing GFR decline to alb/cr showed that GFR changed minimally for alb/cr up to 200 but declined at a progressively faster rate as alb/cr increased above 200. GFR declined faster (more negative slope) in smokers than in nonsmokers (-0.231+/- 0.023 versus -0.102+/- 0.008 mL/min/month; P<0.001). Cigarette smoking increased the risk for GFR decline in subjects with alb/cr <200 and in those with alb/cr >200, but the effect was much more robust for subjects with alb/cr >200.

CONCLUSIONS

Urine alb/cr >200 increases the risk for subsequent GFR decline in primary hypertension, and this risk is enhanced by cigarette smoking.

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.

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.

The relationship of cigarette smoking to end-stage renal disease

Cigarette smoking (CS) has been associated with augmented progression of nephropathies responsible for the 4 major causes of end-stage renal disease (ESRD) in the United States. CS has well-described ways by which it causes tissue injury in other organ systems and the mechanisms by which it adversely affects nephropathy progression might be similar. Therefore, exploring the mechanisms for CS-induced nephropathy or progression thereof might yield important insights into the general mechanisms by which some or most nephropathies progress to ESRD. In addition, CS can be discontinued and so is a potentially correctable risk factor for ESRD, a syndrome whose incidence continues to increase. Therefore, the mechanism(s) by which CS induces nephropathy progression is an important area of investigation.

The kidney as a sensor of cardiovascular risk in essential hypertension

Renal damage as a consequence of uncontrolled arterial hypertension is well recognized. Antihypertensive therapy has come to very significantly decrease the vascular damage in the kidneys of hypertensive patients. However, prevalence of mild renal insufficiency remains present in a significant proportion of the hypertensive population. This is accompanied by a marked increase in cardiovascular risk, as a consequence of the clustering of other cardiovascular risk factors and of insufficiently controlled BP. Prevention and protection of renal and cardiovascular damage in these patients will be one of the most relevant tasks in the future.

Renal function exerts only a minor influence on high plasma homocysteine concentrations in patients with acute coronary syndromes

It has been suggested that hyperhomocysteinemia observed in patients with occlusive vascular disease is caused by reduced renal function secondary to renovascular disease. We have therefore used serum cystatin C, a new sensitive marker for glomerular filtration, in 59 patients with acute coronary syndromes and high plasma homocysteine (tHcy) concentration to measure renal function. Samples were also obtained from 34 patients with low-normal plasma tHcy and 50 control subjects. The patients with low-normal plasma tHcy concentration showed decreased concentrations of serum cystatin C and serum creatinine and increased concentrations of blood folate and serum cobalamin compared to the controls and to the patients with high plasma tHcy. There was a large overlap in cystatin C concentrations between patients with high and low-normal plasma tHcy. None of the parameters investigated except plasma tHcy were significantly different in the group of patients with high plasma tHcy concentration compared to the control group. In order to further demonstrate the importance of renal impairment, a subgroup of the patients with high plasma tHcy was supplemented daily with folic acid 5 mg, pyridoxine 40 mg and cyancobalamin 1 mg for 3 months. Vitamin therapy reduced plasma tHcy from 18.3+/-4.6 pmol/l to 9.6+/-2.2 pmol/l (p<0.0001). However, vitamin treatment did not strengthen the correlation between cystatin C and plasma tHcy concentrations. These findings do not support the hypothesis that subtle renal dysfunction is an important cause of high plasma tHcy concentration in patients with acute coronary syndromes.

Hypertension and the kidney

Hypertension and kidney function are intimately related, with each having significant influences on the other. Given the major role played by the kidney in maintenance of extracellular fluid volume and peripheral vascular resistance, the kidney is justifiably a target of investigation to determine its potential role in essential hypertension. Conversely, hypertension is associated with progressive renal failure, and hypertension-associated end-stage renal disease is the second leading cause of end-stage renal disease in the United States. It is therefore important that we continue to investigate the hypertension/renal relationship in an effort to better understand the determinants of essential hypertension and to prevent a major cause of end-stage renal disease.

Renal function: the Cinderella of cardiovascular risk profile

The presence of an altered renal function in essential hypertension, advanced heart failure (HF) and after a myocardial infarction (MI) is associated with higher 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 in any of the three clinical situations. These parameters should then be routinely evaluated in clinical practice. These facts have several therapeutic implications. First, although there is no evidence-based information on the level of blood pressure that confers optimal renal protection, levels substantially lower than past recommendations are advisable. Second, hypertensive kidney damage should be prevented by early treatment of hypertensive patients, particularly those with microalbuminuria. Finally, to avoid further aggravation of high cardiovascular risk, antihypertensive agents devoid of unwanted metabolic side effects should be used for the treatment of hypertensive vascular damage. In HF, the combination of an angiotensin-converting enzyme (ACE) inhibitor and a beta-blocker seem to be the most renoprotective. Renal outcome is also improved by ACE inhibition after an MI. Finally, renal and cardiovascular outcome seem to run in parallel in all these situations.

Renal insufficiency, vitamin B(12) status, and population attributable risk for mild hyperhomocysteinemia among coronary artery disease patients in the era of folic acid-fortified cereal grain flour

Fortification of enriched cereal grain flour products with folic acid has drastically reduced the prevalence of deficient plasma folate status, a major determinant of plasma total homocysteine (tHcy) levels. We hypothesized that even more liberally defined "suboptimal" plasma folate status might no longer contribute importantly to the population attributable risk (PAR) for mild hyperhomocysteinemia, a putative atherothrombotic risk factor. We determined fasting plasma tHcy, folate, vitamin B(12), and pyridoxal 5'-phosphate levels, along with serum creatinine and albumin levels, in 267 consecutive patients (aged 61+/-9 [mean+/-SD] years, 76.4% men and 26.6% women) with stable coronary artery disease (CAD) who were nonusers of vitamin supplements or had abstained from supplement use for at least 6 weeks before examination. Subjects were evaluated a minimum of 3 months after the implementation of flour fortification was largely completed. Relative risk estimates for the calculation of PAR were derived from a multivariable-adjusted logistic regression model with >/=12 micromol/L tHcy as the dependent variable and with age, sex, pyridoxal 5'-phosphate (continuous), albumin (continuous), <5 ng/mL folate, <250 pg/mL vitamin B(12), and >/=1.3 mg/dL creatinine as the independent variables. The prevalence of >/=12 micromol/L plasma tHcy was 11.2% (30 of 267 patients). PAR estimates (percentage) for >/=12 micromol/L tHcy were as follows: <5 ng/mL folate (<1%), <250 pg/mL vitamin B(12) (24.5%), and >/=1.3 mg/dL creatinine (37.5%). In the era of folic acid-fortified cereal grain flour, renal insufficiency and suboptimal vitamin B(12) status (but not folate status) contribute importantly to the PAR for mild hyperhomocysteinemia among patients with stable CAD.

[Relationship between severity of essential arterial hypertension and the prevalence hyperuricemia]

BACKGROUND

Hyperuricemia has been associated with an increased risk of cardiovascular disease in hypertensive patients. However, the relation between serum urate and severity of hypertension has not been conclusively defined as yet. We aimed at finding out whether there exists an independent relationship between changes in the prevalence of hyperuricemia and severity of hypertension.

PATIENTS AND METHOD

We studied 3 cohorts of patients aged 35 to 60 years with essential hypertension diagnosed at a university hospital in Madrid, Spain. The first cohort (before 1981) included 325 patients, the second (from 1981 to 1989) comprised 271 patients and the third cohort (from 1990 to 1999) included 545 patients. Disease severity ranged from 1 to 6 according to blood pressure levels at diagnosis (WHO/ISH grades 1, 2 or 3 were assigned 1, 2 or 3 points, respectively) and target organ damage (left ventricular hypertrophy, hypertensive retinal vascular changes, and proteinuria above 300 mg/day; one point each).

RESULTS

Mean serum urate concentrations in the 3 cohorts were 6.6, 5.8 and 5.5 mg/dL, respectively (p < 0.05 for all comparisons). 39% of patients in the first cohort had a serum urate concentration > 7.0 mg/dL whereas only 18.1% patients in the third group showed hyperuricemia (difference: 20.9%; 95% CI, 10.1 to 32.3; p < 0.05). Severity of hypertension was higher in the first cohort (mean SD, 2.50 1.31 points) than in the third group (1.96 1.06 points; p < 0.05), with the second cohort showing an intermediate severity (2.23 1.01 points). Serum urate levels were directly related to the severity of hypertension in the 3 groups (r = 0.08, p < 0.05). In a multivariate analysis, after adjustment for confounding variables, serum urate had no significant association with severity of hypertension. However, target organ damage, systolic blood pressure and serum creatinine were all independent predictors of severity.

CONCLUSIONS

Favourable changes in the severity of hypertension for a time period significantly correlate with decreases in hyperuricemia prevalence in the same period. On the other hand, hyperuricemia appears to be an indirect marker of hypertensive renal damage.

Renal vascular changes in renal disease independent of hypertension

INTRODUCTION

Cardiovascular disease is common in patients with renal disease, but little is known about the effect of renal disease and loss of renal function on vascular morphology. Intima proliferation of small renal arteries, which correlates with atherosclerosis in the aorta, is sometimes present in renal disease and has been shown to increase with age and hypertension. We studied the effect of chronic renal disease and renal function, independent of hypertension, on intima proliferation.

METHODS

We retrospectively selected renal biopsies of subjects in whom a glomerular filtration rate (GFR) measurement with [(125)I] iothalamate had been performed. To separate the effects of renal disease and renal function, we selected biopsies from (A) normotensive controls undergoing nephrectomy because of renal carcinomas; (B) normotensive patients with renal disease and GFR > 90 ml/min; (C) normotensive patients with GFR 30-90 ml/min, and (D) hypertensive patients with a GFR < 90 ml/min. The area of the arteriolar lumen, intima, and media were measured.

RESULTS

No significant changes from control subjects were observed in group B. Intima proliferation was observed when renal function declined (intima/total vessel surface ratio was 0.262 +/- 0.071 in group C, 0.192 +/- 0.032 in group A, and 0.205 +/- 0.035 in group B, P < 0.05). The intima proliferation was aggravated in patients with renal insufficiency and hypertension (0.333 +/- 0.121, P < 0.05). Media surface area was not different between groups.

CONCLUSION

Renal disease with preserved GFR does not cause significant intima proliferation of small renal arteries. Loss of renal function is accompanied by intima proliferation, even in the absence of systemic hypertension.

Renal function and intensive lowering of blood pressure in hypertensive participants of the hypertension optimal treatment (HOT) study

This article reports further analyses of the Hypertension Optimal Treatment (HOT) Study data with the aim to describe (1) the value of baseline serum creatinine and its clearance (estimated by Cockroft and Gault formula) as predictors of cardiovascular events, (2) the effects of intensive lowering of BP on cardiovascular events and renal function in patients with reduced renal function, and (3) the effects on cardiovascular events of adding acetylsalicylic acid to antihypertensive therapy in patients with reduced renal function. The results show that (1) baseline elevation in serum creatinine and a reduction in estimated creatinine clearance are powerful predictors of cardiovascular events and death. (2) Reduced renal function at baseline did not preclude the desired control of BP. In contrast to patients with normal renal function, the incidence of major cardiovascular events did not differ in the three groups of patients with mild renal insufficiency randomized to different diastolic BP targets. No significant changes in serum creatinine were seen at the end of the 3.8-yr treatment period in the great majority of patients. However, there was a small group of patients (0.58% of the total study population) whose renal function deteriorated (increase > or =30% over baseline and final serum creatinine concentration > or =2 mg/dl) despite satisfactory reduction of diastolic BP. (3) The results of this reanalysis of the HOT Study suggest though do not prove that the association of acetylsalicylic acid with intensive antihypertensive therapy offers additional benefit in hypertensive patients with reduced renal function.

Homocysteine and cardiovascular disease: cause or effect?

Both markedly and mildly elevated circulating homocysteine concentrations are associated with increased risk of vascular occlusion. Here we review possible mechanisms that mediate these effects. Inborn errors of homocysteine metabolism result in markedly elevated plasma homocysteine (200-300 micromol/L) and thromboembolic (mainly venous) disease: treatment to lower but not to normalize these concentrations prevents vascular events. Mild homocysteine elevation (>15 micromol/L) occurs in approximately 20-30% of patients with atherosclerotic disease. Usually, this is easily normalized with oral folate and ongoing trials are assessing the effect of folate treatment on outcomes. Although there is evidence of endothelial dysfunction with both markedly and mildly elevated homocysteine concentrations, the elevated homocysteine concentration in atherosclerotic patients is also associated with most standard vascular risk factors, and importantly, with early decline in renal function, which is common in atherosclerosis. Decline in renal function alone causes elevated plasma homocysteine (and cysteine). These observations suggest that mild hyperhomocysteinemia could often be an effect rather than a cause of atherosclerotic disease. Data on the common C677T methylenetetrahydrofolate reductase polymorphism supports this, in that, although homozygosity is a frequent cause of mild hyperhomocysteinemia when plasma folate is below median population concentrations, it appears not to increase cardiovascular risk. Indeed, there is recent evidence suggesting an acute antioxidant effect of folic acid independent of its effect on homocysteine concentrations. This antioxidant mechanism may oppose an oxidant effect of homocysteine and be relevant to treatment of patients with vascular disease, especially those with chronic renal insufficiency. Such patients have moderately elevated plasma homocysteine and greatly increased cardiovascular risk that is largely unexplained.

Tobacco, hypertension, and vascular disease: risk factors for renal functional decline in an older population

BACKGROUND

A decline in renal function with age has been noted in some but not all individuals. The purpose of this study was to identify risk factors associated with a clinically significant increase in serum creatinine (of at least 0.3 mg/dL) in an older nondiabetic population.

METHODS

A retrospective case-control study was performed analyzing data obtained from 4142 nondiabetic participants of the Cardiovascular Health Study Cohort, all at least 65 years of age, who had two measurements of serum creatinine performed at least three years apart. Cases were identified as participants who developed an increase in serum creatinine of at least 0.3 mg/dL, with controls including participants who did not sustain such an increase.

RESULTS

There was an increase in the serum creatinine of at least 0.3 mg/dL in 2.8% of the population. In a multivariate "best-fit" model adjusted for gender, weight, black race, baseline serum creatinine, and age, the following factors were associated with an increase in serum creatinine: number of cigarettes smoked per day, systolic blood pressure, and maximum internal carotid artery intimal thickness.

CONCLUSIONS

These data suggest that three very preventable or treatable conditions-hypertension, smoking, and prevalent vascular disease, which are associated with large and small vessel disease-are highly associated with clinically important changes in renal function in an older population.

Adverse effect of donor arteriolosclerosis on graft outcome after renal transplantation

INTRODUCTION

In recent years less strict criteria for renal graft donors have been applied. Our study was designed to investigate whether the histological picture, with special reference to vascular changes of the donor kidney, has an effect on the development and level of graft function, and on 48-month graft survival.

METHODS

Three morphologically distinct groups were formed from 150 consecutive cadaveric kidneys donors transplanted into 290 recipients. A control group (C) consisted of kidneys with a completely normal histological picture. Group M1 included kidneys with mild arteriolosclerosis and group M2 (n=122) was comprised of kidneys showing significant arteriolosclerosis. The onset of graft function was assessed by the need for dialysis treatment post-transplantation and the levels of serum creatinine and creatinine clearance at 6, 12, 24 and 36 months post transplant.

RESULTS

The proportion of sclerotic glomeruli (P<0.001) and the incidence and severity of interstitial fibrosis was greater in groups M1 and M2 than in the control group (M1, P<0.01; M2, P<0.001). The incidence of vascular fibrinoid necrosis in M2 was greater than in controls (P<0.001). The onset of graft function did not differ significantly between the groups. Group M2 showed a significantly lower level of graft function (P<0.001). The 4-year graft survival rate of group M2 was 74.2%, significantly lower than in the combined group C+M1 (P=0.03).

CONCLUSION

Significant vascular lesions in the donor kidney should be taken into account when predicting graft function and survival.

Biopsy of marginal donor kidneys: correlation of histologic findings with graft dysfunction

BACKGROUND

Kidney biopsies are being used to evaluate marginal donors, but rigorous statistical validation of this practice with multivariate analysis has not been performed.

METHODS

To analyze histologic parameters in 78 donor biopsies for their ability to predict graft dysfunction, we used a proportional odds model that included both donor and recipient factors. Glomerulosclerosis was categorized into grades 0, 1, 2, and 3, corresponding to 0, 1-10%, 11-20%, and 21-30% global sclerosis, respectively. The degrees of interstitial fibrosis, tubular atrophy, arteriosclerosis, and arteriolar hyalinosis were graded from 0 to 3+, using definitions suggested by the Banff Schema of allograft pathology.

RESULTS

Increasing donor age was associated with higher glomerulosclerosis, tubular atrophy, and arteriosclerosis. Kidneys with any degree of interstitial fibrosis were 2.6 times [odds ratio (OR)] more likely to experience a worse outcome at 6 months (P = 0.02). This association held up after correction for acute rejection (OR 2.5, P = 0.03) and high panel-reactive antibody (OR 3.4, P = 0.006), However, the OR was reduced to 1.9 (P = 0.15) after controlling for recipient age. With each increment in the grade of glomerulosclerosis, the odds for a worse outcome at 12 months increased to 2.3 (P = 0.005). The value for OR became 2.0 (P = 0.03) when controlling for recipient age (P = 0.01), 2.4 (P = 0.005), when controlling for acute rejection, and 2.3 (P = 0.006) when controlling for high panel-reactive antibody.

CONCLUSIONS

Histopathological parameters present in donor biopsies can independently predict post-transplant graft function. Implications for the pool of donor organs available for transplantation are discussed.

Cystatin C as a determinant of fasting plasma total homocysteine levels in coronary artery disease patients with normal serum creatinine

Serum creatinine, a surrogate for both renal function and homocysteine generation, is a determinant of fasting plasma total homocysteine levels in coronary artery disease (CAD) patients. We hypothesized that among stable-CAD patients with normal creatinine levels (ie, </=1.4 mg/dL), serum cystatin C, a more sensitive indicator of glomerular filtration rate, would better predict fasting total homocysteine levels in comparison with serum creatinine. Fasting plasma total homocysteine, folate, vitamin B(12), and pyridoxal 5'-phosphate levels, along with serum cystatin C, creatinine, and albumin levels, were determined in 164 consecutive stable-CAD patients (mean+/-SD age, 61+/-9 years; 78.7% men) whose serum creatinine level was </=1.4 mg/dL. All subjects were examined at least 3 to 4 months after the widespread availability of cereal grain flour products fortified with folic acid. General linear modeling with ANCOVA revealed that serum cystatin C (P<0.001), B(12) (P<0.001), age (P=0.002), albumin (P=0.008), and sex (P=0.024) were independent determinants of fasting total homocysteine levels. Cystatin C alone determined over half of the variability (ie, R(2)) in total homocysteine levels accounted for by these 5 independent regressors. In contrast, creatinine, folate, and pyridoxal 5'-phosphate were not independently predictive of fasting total homocysteine levels (P>0.2). Consistent with the impact of folic acid fortification of cereal grain flour in the general population, only 1 of the CAD subjects (0.6%) had a plasma folate level <3 ng/mL. We conclude that serum cystatin C levels may reflect subtle decreases in renal function that independently predict fasting total homocysteine levels among stable-CAD patients with normal serum creatinine.

Smooth muscle-specific actin levels in the urine of renal transplant recipients: correlation with cyclosporine or tacrolimus nephrotoxicity

Cyclosporine A (CSA) and tacrolimus (FK506) are powerful immunosuppressive agents that have proven useful for antirejection therapy in patients with solid organ transplants, including kidney. However, both drugs are nephrotoxic, each producing similar histological patterns of injury to renal tubules and preglomerular arterioles, and this toxicity is a major cause of renal allograft dysfunction. A renal transplant biopsy presently represents the most reliable means of diagnosing nephrotoxicity caused by CSA or tacrolimus and distinguishing it from acute rejection. Because CSA and tacrolimus nephrotoxicity often involve arteriolar smooth muscle, whereas vascular smooth muscle is rarely involved in acute rejection, we investigated if the appearance of a smooth muscle-specific isoform of alpha-actin (SMA) in the urine of renal transplant recipients about to undergo a biopsy for graft dysfunction correlated with biopsy evidence of CSA or tacrolimus toxicity. Eighty-nine urine samples from 61 patients, plus 6 samples from healthy control subjects, were analyzed in a blinded manner by enzyme-linked immunosorbent assay using a specific anti-SMA monoclonal antibody. For the patient samples, the results of these assays were then correlated with the biopsy findings. Those 40 cases in which the biopsy showed evidence of CSA or tacrolimus nephrotoxicity had a significantly (P < 0.01) greater SMA level in the corresponding urine samples (0.089 +/- 0.126 microgram/mL; mean +/- SD) than the 49 cases without toxicity (0.018 +/- 0.027 microgram/mL) or 6 control subjects (0.003 +/- 0.007 microgram/mL), although there was considerable overlap of SMA values among these groups. The greatest SMA levels were seen in patients with CSA or tacrolimus nephrotoxicity that was likely to be relatively acute, namely those with thrombotic microangiopathy and those without previous biopsy evidence of toxicity. SMA levels correlated significantly with the estimated severity of arteriolopathy on biopsy. In patients with tubular but not arteriolar lesions of CSA or tacrolimus toxicity, the mean SMA level was not significantly greater than that in patients without toxicity. Urine SMA levels in patients with a biopsy specimen showing acute rejection were not significantly different from those in patients without rejection, and there was no correlation between urine SMA level and severity of rejection. Whereas the degree of overlap of SMA levels in patients with and without nephrotoxicity was far too great to consider this assay as a potential alternative to renal transplant biopsy for the diagnosis of nephrotoxicity, the assay may have potential as a marker for active arteriolar injury in renal transplant recipients and other patients receiving CSA or tacrolimus therapy.

The kidney as part of the cardiovascular system

Renal vascular damage caused by arterial hypertension brings about changes in the systemic vascular function and structure. Nephrosclerosis appears to run in parallel with systemic atherosclerosis, accounting for the increased cardiovascular morbidity and mortality in hypertensive patients. Parameters indicating a change in renal function (increased serum creatinine concentration, proteinuria, and microalbuminuria) are independent predictors of increased cardiovascular morbidity and mortality and must therefore be considered in the classification of cardiovascular risk in hypertensive patients.

Urinary albumin excretion in hospitalized patients with acute myocardial infarction. Prevalence of microalbuminuria and correlation to left ventricle wall thickness

Microalbuminuria, a subclinical rise in the urinary albumin excretion, is a risk indicator of atherosclerotic cardiovascular disease. The aim of this study was to measure the urinary albumin excretion in patients with acute myocardial infarction, and to correlate this with known atherosclerotic risk factors. One-hundred-and-twenty-six patients and 56 healthy controls matched for age and sex were studied. The albumin/creatinine concentration ratio in morning urine specimens was calculated as an index of the albumin excretion. Microalbuminuria was defined as a urinary albumin/creatinine concentration ratio above 1 mg/mmol. Urinary albumin excretion (0.88 [95% confidence interval 0.69-1.11] versus 0.51 [0.40-0.63] mg/mmol; p = 0.001) and frequency of microalbuminuria (33 [95% confidence interval 25-41] versus 16 [9-23]%; p = 0.03) were higher in patients than controls. This difference was independent of blood pressure, body weight, smoking, diabetes mellitus, renal disease, and thrombolytic treatment. There was a positive correlation between urinary albumin excretion and thickness of the left ventricle wall (R = 0.28; p = 0.001) which was independent of blood pressure. Follow-up examination of the patients will reveal whether microalbuminuria increases the risk for recurrence of acute myocardial infarction.

Ischemic renal diseases: new insights into old entities

Vascular nephropathies are a steadily increasing cause of end-stage renal failure. Arterionephrosclerosis and arteriolonephrosclerosis are common features in the hypertensive patient. This is especially true for blacks of African descent, in whom hypertension and nephrovasculopathies are a major cause of renal insufficiency. That primary hypertension leads to renal vascular lesions, glomerular obsolescence and interstitial fibrosis has long been established. It should not, however, obscure the fact that renal vascular lesions can be observed in animal models as well as in some humans, especially young blacks, in the absence of, or anticipating the onset of hypertension. This leads to considering the hypothesis that nephroangiosclerosis might stem from a genetic defect in the renal vascular bed and that this defect is strongly associated with the hypertensive trait. Atherosclerotic renal disease is a major, potentially treatable cause of chronic renal disease is a major, potentially treatable cause of chronic renal failure, especially in whites. It leads to renal atrophy, but the ischemic kidney retains a vigorous potential for tubular cell regeneration, which pleads for early recognition and treatment. Recent data suggest that renal ischemia, be it due to renal artery stenosis or to cholesterol crystal embolism, ranks among the multiple causes of secondary focal segmental glomerulosclerosis. Irrespective of its initial mechanism, ischemia induces renal fibrosis, the pathophysiology of which is centered on increased generation of angiotensin II. Finally, renal vascular lesions are commonly observed in the course of various nephropathies, even in the absence of hypertension, and the relationship between these lesions and the unfavorable prognosis of glomerulopathies, especially primary focal-segmental glomerulosclerosis, membranous glomerulopathy and IgA glomerulonephritis, remains to be elucidated. Expanding knowledge of the spectrum of nephrovasculopathies opens perspectives for investigating, understanding and treating a major mechanism of progressive renal insufficiency.

Histologic characteristics of coronary artery in relation to the renovasculopathies of hypertension

Coronary heart disease is a consequence of prior conditions in the coronary artery that invariably include atherosclerotic plaques with necrotic core. Evidence indicates that atheronecrosis is itself a late outcome of certain precursor conditions in the arteries, especially low density of intimal smooth muscle cells and extensive foam cell infiltration. A sequential process is indicated: the defined precursors set the conditions, atheronecrosis appears, and from this coronary heart disease eventually emerges. Hypertensive kidneys typically manifest intimal fibroplasia of cortical arteries and hyalinization of arterioles. Both forms of renovasculopathy, fibroplastic and hyaline, correlate with the early development of atheronecrosis and its precursor conditions. Hyalinization of renal arterioles, however, especially marks subjects with the greatest risk of further developing heart disease. These findings suggest an important prognostic significance to the finding of hyaline deposits in renocortical arterioles; the affected patient may be at exceptionally high risk for coronary heart disease. Results are derived from a series of forensic autopsies, in which morphometric assessment of paraffin sections of coronary arteries and renal cortex was performed.