F. Renda

Microalbuminuria, renal dysfunction and cardiovascular complication in essential hypertension

Objective To evaluate the prevalence of microalbuminuria (albumin excretion rate, AER) in a wide hypertensive population, and to evaluate any relationship with cardiovascular damage and renal dysfunction Design A transversal study Subjects and methods In 383 hospitalized Caucasian essential hypertensives (198 men, 185 women) of mean age 44 ±0.5 years and mean clinic blood pressure 170.3 ±0.95/ 103.4 ±0.47 mmHg, metabolic parameters, serum creatinine level (Cs), creatinine clearance rate (CCR), 24 AER and plasma renin activity (PRA) were measured. Furthermore, each patient underwent 24 h ambulatory blood pressure monitoring (ABPM) and echocardiography to measure left ventricular mass, which was indexed both by body surface area to obtain left ventricular mass index (LVMI) and by height to obtain the left ventricular mass indexed for height (LVMH). By Doppler echocardiography, the diastolic compliance by early:late peak filling velocity ratio was analysed. The fundus oculi was also observed. Three subsets of hypertensives were obtained by dividing the 383 essential hypertensives on the basis of their AER:<11 (group A), 11<20 (group B) and >20 µg/min (group C) Main outcome measures Microalbuminuria, creatinine clearance, PRA, ABPM, LVMI, LVMH, early Mate peak filling velocity ratio, hypertensive retinopathy Results Among the 383 essential hypertensives, AER was < 11 µg/min in 55% of the patients (group A), 18% had AER in the range 11-20µg/min (group B) and 27% had AER >20 µg/min (group C). In the entire essential hypertensive population the prevalence of left ventricular hypertrophy was 44.39% and hypertensive retinopathy was observed in 54.83%. Moreover, AER significantly correlated with clinic systolic blood pressure (SBP) and diastolic blood pressure (DBP), with 24 SBP and DBP and with 24 h daytime and night-time mean blood pressure (MBP). AER was correlated also with LVMH and creatinine clearance. The analysis of the three subsets revealed no differences in age, body mass index, serum creatinine level and PRA. Group C in comparison with group A showed higher values of clinic SBP, 24 h SBP, DBP and MBP, and of daytime and nighttime MBP. Furthermore, in group C, LVMI and LVMH were significantly greater than in group A, with a prevalence of left ventricular hypertrophy of 55% in the former group. Group C showed a prevalence of hypertensive retinopathy of 69% whereas in group A the prevalence was 48%. In group C, AER was significantly correlated with serum creatinine level Conclusion The transversal phase of our research, performed in a homogeneous population of Caucasian essential hypertensives with no metabolic disturbances, confirms the relationship between blood pressure pattern and early glomerular changes in essential hypertensives without overt proteinuria. Furthermore, these results emphasize the role of microalbuminuria as a marker of early cardiac, renal and retinal structural and functional changes in essential hypertension. The longitudinal study, which is in progress, will confirm the prognostic value of microalbuminuria in essential hypertension

Nationwide and Long-Term Survey of Primary Glomerulonephritis in Japan as Observed in 1,850 Biopsied Cases

Primary chronic glomerulonephritis is the most common cause of end-stage renal failure in Japan. The incidence in dialysis patients in Japan is about four times higher than in the United States for reason which are unclear. We conducted a nationwide survey on the natural history and treatment of primary glomerulonephritis under a program project from the Ministry of Health and Welfare of Japan entitled ‘Progressive Chronic Renal Disease’. We analyzed patient characteristics, disease onset, clinical data, and histological findings in 1,850 patients with primary glomerulonephritis from 53 institutions in 1985 who underwent renal biopsy at least 5 years ago, and the follow-up study was carried out 8 years after registration. The incidence of diffuse-mesangial proliferative glomerulonephritis is 41.9%, that of minor glomerular abnormalities 17.5%, and that of focal-mesangial proliferative glomerulonephritis 13.0%. Of 1,045 biopsy specimens that were examined by immunofluorescence microscopy, 47.4% showed IgA nephropathy. Half of all cases with primary chronic glomerulonephritis were asymptomatic and were detected on routine health examination. The survival rates at 20 years from the apparent onset or earliest known renal abnormality are: focal glomerular sclerosis 49%, membranoproliferative glomerulonephritis 58%, diffuse-mesangial proliferative glomerulonephritis 66%, focal-proliferative glomerulonephritis 81%, membranous nephropathy 82%, minor glomerular abnormalities 94%, and IgA nephropathy 61%. In conclusion, a high incidence of IgA nephropathy and a better renal survival of membranous nephropathy are the features of primary chronic glomerulonephritis in Japan. This high incidence of IgA nephropathy together with its poor prognosis is probably the reason for the increased incidence of primary chronic glomerulonephritis in dialysis patients in Japan. In addition, the importance of routine health examination including urinalysis is demonstrated.

Sympathetic Activity and Blood Pressure Pattern in Autosomal Dominant Polycystic Kidney Disease Hypertensives

To study the potential role of sympathetic activity in the pathogenesis of arterial hypertension associated with autosomal dominant polycystic kidney disease (ADPKD) and to analyze its relationship with 24-hour blood pressure pattern, plasma catecholamines and 24-hour ambulatory blood pressure monitoring were evaluated in 30 ADPKD hypertensive patients (of which 17 without and 13 with renal failure) and in 50 essential hypertensives. The groups were matched for sex, body mass index, known duration of hypertension, and clinic blood pressure. Plasma catecholamines, determined in resting position, were higher in ADPKD patients without renal failure than in essential hypertensives. Nighttime diastolic blood pressure was higher and the percentage day-night difference in mean blood pressure was lower in hypertensives with ADPKD compared to patients with essential hypertension. Blood pressure was significantly correlated with plasma noradrenaline in ADPKD patients, independently of renal function. No significant differences were observed between ADPKD patients with and without renal failure, with respect to plasma catecholamines, 24-hour daytime and nighttime ambulatory blood pressures and the percentage day-night difference in mean blood pressure.

Serum Laminin P1 Fragment and Procollagen III in Patients with Kidney Diseases

Accessible online at: http://BioMedNet.com/karger Dear Sir, The extracellular matrix is composed of collagenous and noncollagenous glycoproteins [1]. The accumulation of connective tissue components depends on a disturbance of the balance between synthesis and degradation of the macromolecules. Laminin is a major noncollagenous component of the glomerular basement membrane with a molecular weight of approximately 800 kDa [2]. Type III collagen is a glycoprotein found in the peritubular interstitium of the kidney and the vascular walls. In the present study, we determined the serum levels of laminin P1 (Lam-P1), a pepsin-resistant fragment of laminin with a molecular weight of 300 kD, and N-terminal peptide of type III procollagen (PIIIP), which is derived from type III collagen and has a molecular weight of 45 kD, in 38 patients. The study included 17 males and 21 females, mean age 47.5 (range 15–80) years, with biopsy-proven idiopathic necrotizing and crescentic glomerulonephritis (NCGN; n = 24) and IgA nephropathy (IgAN; n = 14). Patients with chronic liver diseases or other conditions characterized by extrarenal tissue fibrosis were excluded. Dialysis and kidney transplant patients were also excluded. The control group consisted of 45 healthy subjects, 22 males and 23 females, mean age 56.3 (range 33–70) years, all voluntary blood donors. In both healthy subjects and patients, serum Lam-P1 fragment and PIIIP were determined in duplicate using a specific radioimmunoassay (Behringwerke, Marburg, Germany). Routine laboratory tests included determinations of both serum creatinine and total urinary protein. Serum transaminases and hepatitis B and C serum markers were determined to exclude patients with liver diseases. Statistical analysis has been performed using analysis of variance, followed in positive cases by the Bonferroni t test and the Pearson correlation coefficient. Table 1 shows the PIIIP and Lam-P1 serum values of the three groups. The PIIIP values of the NCGN group were significantly higher than those of the IgAN and control groups (p ! 0.0001). On the other hand, serum PIIIP values of the IgAN group were similar to those of the control group. Serum Lam-P1 values of the NCGN group were also significantly higher than those of the other two groups (p ! 0.0001). No significant differences were found between IgAN and control group.