Repetitive natriuresis and blood pressure. Long-term calcium entry blockade with isradipine.

The long-term effects (3.5 months) of a new calcium entry blocker of the 1-4-dihydropyridine class, isradipine (PN 200-110), on renal hemodynamics and excretional parameters were investigated in 10 essential hypertensive subjects (World Health Organization Classes I and II). Blood pressure and renal vascular resistance fell significantly (p less than 0.001), and a slight increase in glomerular filtration rate and renal plasma flow was seen (p less than 0.05). Output of fluid from the proximal tubules, measured as clearance of lithium and uric acid, increased significantly (p less than 0.01 and p less than 0.05, respectively), and a compensatory increase in absolute reabsorption of sodium beyond the proximal tubular level accompanied by an increase in clearance of potassium was noted. A 40% increase in the resultant clearance of sodium (p less than 0.01) and an increase in diuresis (p less than 0.05) followed the morning dose of isradipine after 3.5 months of treatment. Changes in blood pressure were significantly correlated with changes in absolute proximal reabsorption of sodium (r = 0.81), excretion of sodium (r = -0.64), and diuresis (r = -0.80). Thus, the natriuretic properties of calcium entry blockers may be more important for the long-term antihypertensive effect than the vasodilator effect per se. A model for renal sodium handling following treatment with calcium entry blockers was proposed. Although a causal relationship is not implied, isradipine induced a sustained, repetitive postdose effect on proximal fluid output, net natriuresis, and diuresis, that was intimately related to the long-term blood pressure-regulating response.

Cardiac mass and peripheral vascular structure in hydralazine-treated spontaneously hypertensive rats.

We have examined the effect of antihypertensive treatment on heart weight and on structural and functional characteristics of isolated mesenteric resistance vessels (internal diameter 170-220 micron) in spontaneously hypertensive rats (SHR) and in Wistar-Kyoto rats (WKY). The SHR and WKY were treated with hydralazine from the age of 4 weeks and were examined at ages 12 to 14 weeks and 23 to 27 weeks. Treated SHR had a mean blood pressure as much as 29% below that of control WKY, which in turn was 25 to 40% less than that of control SHR. In 12- to 14-week-old rats the heart to body weight ratio (which in control SHR was 13% greater than of WKY) was unaffected by treatment. Thereafter, the heart to body weight ratio of treated SHR did not increase as much as usual. At both ages, the media thickness and contractile response of the resistance vessels of the SHR (which were, respectively, 37% and 30% greater than those of vessels of WKY) were unaffected by treatment. However, because treatment caused a small (8%) increase in the lumen diameter of the vessels of the SHR, treatment did cause small, but possibly physiologically important, decreases both in the media to lumen ratio (11%) and in the pressure against which these vessels would have been able to contract (10%). Treatment had little effect on the pharmacological characteristics of vessels of either SHR or WKY. The results suggest that the increased heart weight, media thickness, and contractile response in mesenteric resistance vessels of SHR up to ages 23 to 27 weeks are due primarily to factors other than increased pressure.

Serum potassium and uric acid changes during treatment with timolol alone and in combination with a diuretic.

Timolol, 10 to 40 mg daily, given to 103 patients with uncomplicated arterial hypertension induced significant increments of serum potassium at all dose levels (p less than 0.05). The magnitude of the increments was dependent on daily timolol dosage. When hydrochlorothiazide and amiloride were added, serum potassium decreased (p less than 0.001), but a major determinant of the magnitude of the decrease was the dosage change of the timolol. Serum uric acid was influenced in a paradoxical way during timolol monotherapy; there was a rise in all 3 dosage groups (p less than 0.02) but the lowest group showed the largest increase and vice versa. On addition of hydrochlorothiazide and amiloride, there was a further increase in serum uric acid, the magnitude of which depended on the concomitant reduction in the dose of timolol, with reductions in dose causing a larger rise in serum uric acid and increments, a smaller rise. The increments of serum uric acid were greater in females than in males during both treatment periods. The results indicate that beta blockers induce dose-dependent rises in serum potassium and may counteract undesirable effects of diuretics on serum potassium. Beta blockers seem to have a paradoxical effect on serum uric acid and may aggravate the hyperuricemia induced by diuretics.

Urine and plasma propranolol.

Eight hypertensive patients who had been followed in an outpatient clinic during long-term therapy with propranolol (40 to 160 mg twice daily) were studied during a 24-hr stay in the ward. The usual oral dose was given and the total and free plasma concentrations were determined during the 24 hr and the urinary excretion of unchanged drug was measured. Average free plasma concentration of propranolol (y free) was calculated from: y free = Excreted propranolol (ng/24 hr)/Creatinine clearance (ml/24 hr). There was a significant relationship between log y free and average free plasma concentration (means free) determined from the directly measured plasma concentration curve: log y free = 0.0743 means free - 0.0466 (r = 0.98, P less than 0.001). In another group of propranolol-treated hypertensive patients there was a significant positive relationship between orosomucoid concentration and reciprocal of the free propranolol fraction in plasma. From this relationship the average total drug concentration (y total) was calculated from y free; there was a significant correlation with directly measured total plasma level: log y total = 0.0038 . means total + 1.0895 (r = 0.91, P less than 0.001). It is suggested that individually determined values of y free below 30 ng/ml and y total below 400 ng/ml (the concentration range studied) can be used to calculate the average mean 24-hr free and total plasma concentrations.

Imipramine metabolites in blood of patients during therapy and after overdose.

Plasma or serum concentrations of imipramine and five of its nonconjugated metabolites (desipramine, 2-OH-imipramine, 2-OH-desipramine, imipramine-N-oxide, and didesipramine) were followed in three cases of imipramine overdose and during steady state in 24 patients on continuous imipramine treatment. In the overdose cases the imipramine and desipramine concentrations declined monoexponentially with t 1/2s of 12 to 21 and 31 to 37 hr. The 2-OH-imipramine and 2-OH-desipramine levels were lower and declined in parallel with their corresponding parent compounds. In the patients on continuous imipramine treatment, the steady-state levels of 2-OH-imipramine and 2-OH-desipramine were very low or immeasurable (less than 15 nmol/l) in five patients. In most patients (n = 18) the hydroxymetabolite levels were much higher with 2-OH-imipramine/imipramine ratios of 0.09 to 0.45 and 2-OH-desipramine/desipramine ratios of 0.36 to 0.86. In one patient there were particularly high ratios (2-OH-imipramine/imipramine, 0.85; 2-OH-desipramine/desipramine, 1.30). The patients with very low hydroxymetabolite levels had considerably higher desipramine levels than the others, indicating that the low metabolite levels were due to poor hydroxylation. In one of these poor hydroxylators a desipramine t 1/2 of about 120 hr was estimated after imipramine discontinuation. With increased imipramine dose the 2-OH-imipramine levels tended to rise little or not at all. Imipramine-N-oxide could only be detected in the overdose cases during the first 6 to 12 hr and didesipramine was generally present only when the desipramine levels were above 200 nmol/l.

Differential effects of isradipine and atenolol on peripheral hemodynamics and arterial compliance.

In a double-blind parallel-group randomized study, 28 patients with essential hypertension (World Health Organization class I/II) were allocated in equal numbers to one of two groups for treatment with either isradipine 5 to 20 mg twice daily or atenolol 50 to 100 mg once daily. At the end of the study, 12 patients were evaluable in the isradipine group and nine in the atenolol group. Assessments at baseline and after 20 weeks of treatment included arterial and venous compliance, mean peripheral perfusion pressure, heart rate, and digital vascular resistance using photoplethysmography. Isradipine had a direct relaxing effect on the arterioles, revealed by a significant increase in arterial compliance and a concomitant normalization of the digital vascular resistance. Atenolol had no significant effect on these parameters but, as expected, it lowered the heart rate, which was not affected by isradipine in the long term. The venous compliance remained low in both groups and, since isradipine--unlike atenolol--is known to have venodilating properties in vitro, its lack of effect in vivo is most likely due to reflex activation of sympathetically mediated venous tone. Because of the preference of isradipine for the arterial side of the peripheral vascular tree, the mean peripheral perfusion pressure remained higher in this group than in the atenolol group, although central systemic blood pressure was lowered equally and satisfactorily in both groups.

Long-term effects of isradipine on blood pressure and renal function.

The hemodynamic and renal effects of isradipine were investigated in 10 hypertensive patients treated for 3.5 months and in a further nine patients treated for two years. Both groups achieved significant and sustained reductions in systolic blood pressure/diastolic blood pressure (-15 percent/-12 percent and -15 percent/-20 percent, respectively; p less than 0.001). Renal parameters were investigated two to three hours after the morning dose of isradipine, using a water-loading procedure. After 3.5 months of treatment, the glomerular filtration rate and renal plasma flow showed small increases (+6 percent and +9 percent, respectively, p less than 0.05), whereas, after two years, these changes were no longer present (+4 percent and 0 percent). Clearance of sodium and uric acid was increased by 40 percent (p less than 0.01) and 21 percent (p less than 0.01), respectively, after 3.5 months, and by 45 percent (p less than 0.05) and 23 percent (p less than 0.01), respectively, after two years. Lithium clearance studies revealed the natriuretic effect to be located in the proximal tubule. After 3.5 months, a significant relationship was found between the blood pressure response and the change in sodium excretion, but this relationship also was no longer present after two years. In conclusion, because of a maintained blood pressure-lowering effect while preserving renal function, and sustained natriuretic and uricosuric actions, isradipine can be considered a promising agent in the long-term treatment of arterial hypertension.

Relation of left ventricular geometry and function to systemic hemodynamics in hypertension: the LIFE Study. Losartan Intervention For Endpoint Reduction in Hypertension Study.

OBJECTIVES: To clarify the relations of systemic hemodynamics to left ventricular (LV) geometric patterns in patients with moderate hypertension and target organ damage. BACKGROUND: LV geometry stratifies risk in hypertension, but relations of LV geometry to systemic hemodynamic patterns in moderately severe hypertension have not been fully elucidated. DESIGN: Cross-sectional case-control study. SETTING: Baseline findings in the echocardiographic substudy of the Losartan Intervention For Endpoint Reduction in Hypertension Study (LIFE) and in a normotensive reference group. PATIENTS/PARTICIPANTS: Nine hundred and sixty-four patients with Stage I-II hypertension and LV hypertrophy by Cornell voltage duration criteria ((SV3 + RaVL [+ 6 mm in women]) x QRS > 2440 mm x ms) or modified Sokolow- Lyon voltage criteria (SV1 + RV5/RV6 > 38 mm), and 366 apparently normal adults. INTERVENTIONS: None. METHODS: Two-dimensional and Doppler echocardiograms were used to classify hypertensive patients into groups with normal geometry, concentric remodelling and concentric and eccentric hypertrophy, and to measure stroke volume (SV), cardiac output, peripheral resistance and pulse pressure/SV as a measure of arterial stiffness. Comparisons were adjusted for covariates by general linear model with the Sidak post-hoc test RESULTS: Mean SV was higher in patients with eccentric hypertrophy (83 ml/beat) and lower with concentric remodeling (68 ml/beat) than in normal adults (73 ml/ beat). Cardiac output was highest in patients with eccentric LV hypertrophy and lower with concentric remodeling than eccentric hypertrophy; mean pressure and peripheral resistance were equally high in all hypertensive subgroups, whereas pulse pressure/SV was most elevated (by a mean of 47% versus reference subjects) with concentric remodeling and least so (mean + 15%) with eccentric hypertrophy. In multivariate analysis (Multiple R + 0.68), LV mass was independently related to higher systolic pressure, older age, SV, male gender and body mass index (all P< 0.001). Relative wall thickness was independently related (Multiple R + 0.50) to older age, higher systolic pressure, lower SV (all P< 0.001) and higher body mass index (P + 0.007). SV and cardiac output were lower in patients with low stress-corrected midwall shortening. CONCLUSION: In patients with moderate hypertension and ECG LV hypertrophy, the levels of SV and pulse pressure/ SV, are associated with, and may be stimuli to different LV geometric phenotypes.

Comparative studies on the effects of tolmesoxide (Rx71107), a tolmesoxide metabolite (Rx71112) and nifedipine in isolated blood vessels.

1 The effect was studied of tolmesoxide (Rx71107), a tolmesoxide metabolite (Rx71112) and nifedipine on active tension in human isolated crural veins and in rat thoracic aorta. The effects of tolmesoxide and nifedipine on (22)Na and (45)Ca net influx in noradrenaline-induced contractions were investigated in rat thoracic aorta.2 Tolmesoxide, Rx71112 and nifedipine caused a concentration-related inhibition of noradrenaline (NA)- and potassium (K(+))-induced contractions in human veins. Nifedipine was by far the most potent drug in these respects. Tolmesoxide (4.7 muM-4700 muM) and Rx71112 (22 muM-220 muM) inhibited the NA-induced contraction more effectively than the K(+)-induced concentration. The reverse was true for nifedipine (0.0023-3 muM).3 Nifedipine had a similar potency in inhibiting the NA-induced contraction in rat aorta and human veins, whereas the inhibitory effect of tolmesoxide was more pronounced in rat aorta than in human veins.4 Tolmesoxide was a weak antagonist of the contractile effects of the cumulative addition of calcium on human veins. In concentrations up to 470 muM, tolmesoxide was completely devoid of inhibitory effects on (22)Na and (45)Ca net influx in rat aorta. Rx71112 (220 muM) had an inhibitory effect on (22)Na net influx but no significant effect on (45)Ca net influx.5 Nifedipine was an effective antagonist of the contractile effects of cumulative addition of calcium in human veins and had a concentration-related inhibitory effect on both (22)Na and (45)Ca uptake in rat aorta.6 The results indicate that tolmesoxide and Rx71112 cause dilatation of human crural veins in vitro at concentrations that do not interfere with the net transmembranal movements of Ca and are thus clearly different from the effects of nifedipine.

Cortisol and treatment of depression: predictive value of spontaneous and suppressed cortisol levels and course of spontaneous plasma cortisol.

In 72 consecutive depressed hospitalized patients afternoon plasma cortisol was measured in three ways before treatment with antidepressants: 1) Spontaneous (n = 72), 2) 2h after oxazepam suppression (45 mg, n = 28; 60 mg, n = 37) and 3) 16 h after dexamethasone suppression (2 mg, n = 71). In addition, spontaneous cortisol was measured after 3 weeks' treatment (n = 55) and 5 weeks' treatment (n = 36). Both spontaneous and suppressed cortisol levels seemed to have a predictive value in the endogenously depressed patients: complete responders had significantly lower pretreatment cortisol levels compared to poor responders. However, other covarying factors such as distress and age may as well account for the differences in treatment effect. During treatment a significant decrease of spontaneous cortisol was found from about 400 nM in poor responders and 325 nM in complete responders to about 300 nM in all groups. There was a positive correlation between pre- and post-treatment cortisol levels and between pretreatment levels and per cent fall in spontaneous cortisol levels.

Orthostatic side effects of clomipramine and citalopram during treatment for depression.

Orthostatic hypotension, the clinically most important side effect in treatment with tricyclic antidepressants, was investigated in a double-blind study with clomipramine and the selective serotonin reuptake inhibitor citalopram given for 5 weeks. All patients were initially given placebo for 1 week. In the clomipramine group (n = 17) a significant orthostatic drop in the systolic blood pressure was observed during treatment; this remained significant over the whole investigational period. A curvilinear correlation was demonstrated between the orthostatic drop in systolic blood pressure and the plasma levels of clomipramine and desmethylclomipramine. The most pronounced orthostatic reaction was thus seen in 1-2 weeks, at plasma levels of 25-75 micrograms/l (clomipramine). The correlation between the subjective symptoms and the measured orthostatic drop was poor, as was the correlation between the subjective symptoms and the plasma levels of the two active compounds. The change in orthostatic heart rate during clomipramine treatment was insignificant. In the citalopram group (n = 15) no significant changes in orthostatic blood pressure or heart rate were demonstrated during treatment and these patients had no orthostatic complaints.

Citalopram, a selective serotonin reuptake inhibitor: clinical antidepressive and long-term effect--a phase II study.

In a phase II study the antidepressive effect of citalopram, a selective and potent serotonin reuptake inhibitor, was examined in 20 endogenously and three non-endogenously depressed hospitalized patients. Four endogenously depressed patients dropped out due to deterioration early in the treatment period. The remaining 19 patients completed a 4-6 week treatment schedule. Of 16 endogenously depressed patients 11 responded, one was a partial responder and four did not respond. Of three patients with non-endogenous depressions, two responded and one did not respond. No correlation between plasma citalopram concentration and therapeutic outcome was found. Fourteen patients were given maintenance treatment for 8-113 weeks. One patient developed depression when the dose was reduced from 60 to 40 mg and one patient became manic. After discontinuation of treatment seven patients had a depressive relapse and six of these who again were treated with citalopram responded completely. Side effect rating scores of symptoms usually associated with depression or treatment with tricyclic antidepressants declined during treatment. Three patients complained of increased need of sleep for a period after several weeks of treatment. Apart from an unspecific, transient rise in liver enzymes in two patients, detailed biochemical laboratory tests were all normal. There were no effects on blood pressure, pulse rate, orthostatic reaction, or electrocardiogram. One patient took an overdose of citalopram resulting in plasma levels about six times higher than the average therapeutic level, but there were no signs of severe toxicity. In particular no change in consciousness, electrocardiogram or blood pressure occurred. Pharmacokinetic variables such as dose schedule, steady state kinetics, and metabolism are discussed.

Dose-dependent kinetics of imipramine in elderly patients.

In a group of elderly depressed patients treated with imipramine (50-200 mg/day), six patients had the dose changed after 1-3 weeks of treatment. In all cases an increased dose resulted in a considerably disproportional rise in the plasma level of the active metabolite desipramine. In a group of elderly depressed patients treated with nortriptyline (40-100 mg/day) the dose/plasma level ratio could be examined in 6 patients, and there was no tendency towards a disproportional rise in plasma level, when the dose was raised. Dose changes, thus, may result in unpredictable changes in plasma levels during imipramine treatment and therapy control by plasma level monitoring may be difficult in these patients. Additional treatment with perphenazine (8-16 mg/day) to patients on imipramine (N = 3) or nortriptyline (N = 2) caused a marked rise in drug levels for imipramine in particular affecting the desipramine levels.

Cardiovascular effects of amitriptyline in the treatment of elderly depressed patients.

Thirteen elderly depressed patients (age 60-82 years) were treated for 5 weeks with a fixed dose of amitriptyline 100 mg (sustained release preparation). In all patients the sum of concentrations of amitriptyline and nortriptyline exceeded 130 micrograms/l, which is the recommended plasma level. Cardiovascular side effects were recorded by monitoring heart rate, blood pressure, standard ECG and systolic time intervals. During treatment, a transient increase in the supine heart rate was observed without significant changes in the supine blood pressure. The orthostatic drop in blood pressure was markedly increased during treatment without a compensatory increase in heart rate, and these changes remained significant during the whole investigational period. PQ and QRS were significantly increased during treatment, and significant changes in the systolic time intervals were found indicating impairment of myocardial conduction and contractility. In three patients medication was discontinued due to cardiovascular side effects.

Mianserin: cardiovascular effects in elderly patients.

Cardiovascular effects of the tetracyclic antidepressant drug mianserin were examined in a prospective study including ten elderly depressed patients (age 60-77 years). During 1 week on placebo and 5 weeks on mianserin, 60 mg per day, orthostatic blood pressure testing, recording of standard electrocardiogram, 24-h electrocardiographic recording and systolic time intervals were carried out along with frequent monitoring of plasma levels of mianserin (13-57 micrograms/l) and the primary metabolite desmethylmianserin (7-27 micrograms/l). Mianserin caused a significant increase in orthostatic systolic blood pressure drop, and this correlated well with the plasma mianserin levels (rs = 0.70). There were no significant changes in supine blood pressure or in orthostatic changes in heart rate. No cardiac conduction disturbances or arrhythmias were provoked, but mianserin caused changes in systolic time intervals indicating impairment of left ventricular contractility and performance. Like tricyclic antidepressants mianserin should thus be used with caution in patients with latent or overt cardiovascular disease.

Combined actions of isradipine and captopril on renal function in hypertension.

The object of this study was to test the hypothesis that the natriuretic and uricosuric effect of calcium-entry blockers could be mediated through antagonism of angiotensin II dependent intrarenal mechanisms. The antihypertensive efficacy, haemodynamic and excretional effects of superimposed calcium blockade with isradipine were investigated in seven hypertensives with unsatisfactorally controlled blood pressure with captopril 50 mg twice daily. Glomerular filtration rate (GFR) and renal plasma flow (RPF), clearances (C) of sodium (Na), potassium (K), uric acid (UA) and lithium (Li), were measured before and after a low-dose bolus of isradipine, i.v. Subsequently, measurements were repeated during constant i.v. infusion of a higher dose with definite systemic haemodynamic effects. After 4 months of combined treatment with isradipine and captopril renal investigations were carried out again. The low isradipine dose induced a slight but statistically significant increment in CNa (22% +/- 28) and heart rate (4% +/- 4), whereas no other variables changed significantly. Infusion of the high isradipine dose caused a pronounced fall in renal vascular resistance (27% +/- 14), systolic (8% +/- 2) and diastolic blood pressure (17% +/- 5). RPF increased significantly (15% +/- 18) whereas no changes were noted in GFR, filtration fraction and urinary albumin excretion rate. In spite of the pronounced fall in BP during the high dose infusion, significant increments in natriuresis (91% +/- 63) and diuresis (41% +/- 27) were induced. The natriuresis was caused by a proximal tubular action as indicated by increased CLi and CLi/GFR.(ABSTRACT TRUNCATED AT 250 WORDS)

Spontaneous afternoon plasma cortisol in depression.

Spontaneous plasma cortisol was measured in the interval from 15.00-18.00 h 74 hospitalized depressed patients (56 endogenously and 18 non-endogenously depressed according to the Newcastle index). The cortisol value at the individual time points correlated well with the mean cortisol concentration with the best correlation in the interval between 16.00 and 17.00 h (RHO = 0.89-0.92). For most patients maximum cortisol concentration was found early in the sampling period. Plasma cortisol was high during depression and was reduced after recovery in both diagnostic groups. Correlation between plasma cortisol during depression and type of depression or degree of depression was poor indicating that spontaneous plasma cortisol might have only a limited diagnostic value. However, among the endogenously depressed patients those not responding to treatment with cyclic antidepressants alone had significantly higher cortisol levels prior to treatment than responders. Afternoon plasma cortisol thus may be used as a predictor of the outcome of treatment with cyclic antidepressants.

Afternoon plasma cortisol in depressed patients: a measure of diagnosis or severity?

Plasma cortisol concentration was measured at 20 min intervals from 3 p.m. (1500 hrs) to 6 p.m. (1800 hrs) in 26 hospitalized patients classified according to the Newcastle Index as endogenously depressed (n = 16) or non-endogenously depressed (n = 10). When examined in depressed state, before treatment, maximum, mean and range of plasma cortisol concentration in this time interval was significantly higher in the endogenously depressed patients than in the non-endogenously depressed patients (p less than 0.01-0.02). The diagnostic identification of endogenous depression on the basis of these cortisol concentration measurements was at least as good as that reported by others using post-dexamethasone cortisol levels. The plasma cortisol levels (maximum, mean) and fluctuations (range) correlated significantly with the degree of depression (Hamilton Depression Scale), and differences in severity of depression could explain most of the differences in cortisol levels between the two diagnostic groups. Nine patients were reexamined after 3-12 months in a non-depressed state, and all unipolar endogenously depressed patients (n = 6) then had clearly reduced cortisol levels and fluctuations.

Serum cystatin C as an endogenous parameter of the renal function in patients with normal to moderately impaired kidney function.

BACKGROUND: Cystatin C is a proteinase inhibitor with a low molecular weight. The serum levels of cystatin C are mainly dependent on glomerular filtration rate (GFR) making cystatin C an endogenous parameter of GFR. The aim of the study was to elucidate the applicability of serum cystatin C as a parameter of GFR in patients with normal to moderately impaired kidney function and to estimate a reference interval for serum cystatin C. PATIENTS AND METHODS: Forty-six patients (25 males and 21 females) aged 22 to 83 years with various kidney diseases and 250 blood donors (164 males and 86 females) aged 19 to 64 years were included. Cystatin C was measured by an automated particle-enhanced nephelometric immunoassay, serum creatinine by an enzymatic and by Jaffé method, urine creatinine by an enzymatic method, and GFR by 99mTc-DTPA clearance. RESULTS: Serum levels ofcystatin C and creatinine showed increments with decreasing values of 99mTc-DTPA clearance and a linear relationship was found between 99mTc-DTPA clearance and l/serum cystatin C, l/serum creatinine (enzymatic method), and creatinine clearance. Comparison of the non-parametric receiver-operating characteristic (ROC) plots for serum cystatin C (area under the curve (AUC) = 0.996; SE = 0.005), serum creatinine (enzymatic method) (AUC = 0.899; SE = 0.044), serum creatinine (Jaffé method) (AUC = 0.870; SE = 0.051), measured creatinine clearance (AUC = 0.959; SE = 0.025), and estimated creatinine clearance (0.950; SE = 0.029) revealed significant differences for serum cystatin C and serum creatinine (enzymatic and Jaffé method) (p values: 0.03 and 0.01). No significant differences were demonstrated between serum cystatin C and measured and estimated creatinine clearance (p value: 0.14 and 0.12). The non-parametric reference interval for serum cystatin C was calculated to be 0.51-1.02 mg/l (median: 0.79 mg/l; range: 0.33 - 1.07 mg/l). CONCLUSION: Serum cystatin C seems to be a better parameter of GFR than serum creatinine in adults with various types of kidney disease with normal to moderately impaired kidney function.

Normalization of resistance artery structure and left ventricular morphology with a perindopril-based regimen.

Twenty-five patients with newly diagnosed or poorly regulated essential hypertension were randomly selected from a larger group referred to hospital. Treatment was initiated with perindopril (4 to 8 mg od). If normotension was not achieved, isradipine (5 to 10 mg od) was added and, if necessary, hydralazine was added. Before treatment and at the end of a nine-month period of normotension (diastolic blood pressure less than 90 mmHg), 24 h blood pressure and echocardiographic measurements were performed and resistance artery structure was determined. Twenty age- and sex-matched normotensives were used as controls. During antihypertensive treatment, mean blood pressure was reduced from 128 +/- 11 to 103 +/- 6 mmHg. Left ventricular mass was reduced from 300 +/- 76 to 198 +/- 54 g. The media:lumen ratio of the resistance arteries decreased from 9.8 +/- 2.6% to 7.8 +/- 1.9%. Control subjects exhibited a media:lumen ratio of the same magnitude (7.9 +/- 2.0). Regression of left ventricular mass correlated significantly with regression of the media:lumen ratio with a coefficient of 0.59 (P < 0.05). Results indicate that a perindopril-based regimen is extremely efficient in normalizing resistance artery and cardiac ventricular structures within one year of treatment. The impact of these findings on the excess cardiovascular morbidity and mortality in arterial hypertension still remains to be demonstrated.