Effectiveness and metabolic effects of perindopril and diuretics combination in primary hypertension.

The effectiveness as well as the metabolic effects of the combination of diuretics [hydrochlorothiazide (HCT) vs indapamide (IND)] and perindopril (P) in 14 patients (7 male, 7 female) aged 37-62 years with mild idiopathic hypertension were studied. Following a 4-week wash-out period and a 4-week period of monotherapy with P (4 mg/daily), IND (2.5 mg/daily) or HCT (25 mg/daily) was added for 4 weeks. Selection of the diuretic agent was random. Following a 4-week wash-out period from the diuretic, in which only P was given, the alternative diuretic was administered for another period of 4 weeks. P decreased blood pressure levels significantly. However, the drug was more efficacious in patients with higher plasma renin activity (PRA). Combination treatment induced an additional decrease in the blood pressure levels, mainly in patients with lower PRA. The combination of P + HCT was more effective than the combination P + IND. The addition of either HCT or IND evoked a small but statistically significant increase in serum glucose levels while fasting as well as during the 75 g oral glucose challenge. However, insulin levels did not change significantly during the study. Small but not statistically significant changes in serum electrolytes and lipid parameters were observed during the various phases of the study, while a statistically significant increase in the serum uric acid was noticed when the combination P + HCT was given. We conclude: (1) P in small doses is an effective and safe antihypertensive agent, (2) PRA has a predictive value in determining the effectiveness of P treatment, (3) the combination of P with small doses of HCT or IND is more efficacious than P alone, (4) the combination treatment has adverse effects in the carbohydrate tolerance, while there are not significant changes in serum electrolyte and lipid parameters.

Ambulatory blood pressure monitoring in hemodialysis patients.

The aim of our study was the detection of blood pressure (BP) variability during a dialysis session and in the interdialytic period in normotensive and hypertensive hemodialysis (HD) patients using ambulatory blood pressure monitoring (ABPM). Twenty-two HD patients aged 54 (range, 33-78) years who were on HD for a mean of 17.7 (range, 1-70) months were studied. Twelve patients were hypertensives, while the remaining 10 were normotensives (BP < 140/90 mm Hg). In all patients ABPM was performed for a total of 48 h including an HD session. A significant decrease in systolic BP, diastolic BP and mean BP was observed at the end of a dialysis session in hypertensive HD patients. However, in only five patients a reduction of more than 5% In mean arterial BP was noticed. No significant differences were observed in the BP values between the first and the second day after the HD in hypertensive HD patients. Interdialytic BP (both systolic and diastolic) was significantly higher than the postdialysis BP measured either in the clinic or with the ABPM in these patients. Normotensive HD patients exhibited a normal diurnal variation of BP during the first day after the HD session (decrease in BP during the night). On the second day after the HD session an increase in BP (mainly of systolic BP), as well as a loss of diurnal variation were observed. On the contrary, hypertensive HD patients did not exhibit the normal diurnal variation of BP during the first or the second day after the HD session. Hypertensive HD patients exhibited increased daytime and night time BP loads. On the other hand, normotensive HD patients presented with BP loads within normal limits, even though a small increase in these loads was observed on the second day after dialysis. In conclusion, while hypertensive HD patients present a loss of the normal diurnal variation of BP, normotensive HD patients exhibit normal variation during the first day after the HD session. The loss of the diurnal variation during the second day in these patients suggests a volume-dependent state.

Ambulatory blood pressure monitoring in normotensive pregnant women.

Ambulatory blood pressure monitoring (ABPM) provides a profile of blood pressure (BP) during daily activities and sleep and could uncover the inter-individual variability of BP. The aims of this study were to establish the normal values of the ABPM during the three trimesters of normal pregnancy, and to compare these values with those obtained in the office. ABPM was carried out on 22 normotensive pregnant women. BP values were compared with those obtained in the office. BP during the third trimester was significantly higher than the BP recorded during the first two gestational periods. In the three trimesters of pregnancy mean ambulatory systolic and diastolic BP were lower than the BP measured in the office in lying and standing positions. On the other hand, mean ambulatory BP (systolic and diastolic) measured during daily activities was not significantly different from the BP measured in the office. Sleeping BP was significantly lower than waking values in all trimesters, while there were not significant differences in the degree of BP fall among the three trimesters. Six women were sequentially studied during the three trimesters of pregnancy and particularly at the 12, 24 and 32 weeks of pregnancy. In these women, a small but significant rise in mean 24 h systolic and diastolic BP was observed at 32 weeks of pregnancy. Sleeping BP was significantly lower than waking values in the three trimesters. No significant difference in the degree of BP fall on the three gestational dates was found. It is concluded that ABPM is a useful tool for the evaluation of BP variability during pregnancy. During normal pregnancy ambulatory BP levels are highest in the day and lowest at night at all gestational ages and increased at the third trimester of pregnancy compared to the values observed during the first two gestational periods.

Renal abnormalities in patients with sickle cell-beta thalassemia.

We examined renal abnormalities in Greek patients with sickle-cell beta thalassemia (S-beta thal). A total of 17 patients aged 16-59 years suffering from S-beta thal and 17 age- and sex-matched healthy controls were studied. In all individuals we carried out a detailed study of renal function including electrolytes in serum and urine, concentrating or diluting ability, urine acidification ability, glomerular filtration rate (GFR), and hormones [such as plasma renin activity (PRA), serum aldosterone, and erythropoietin (EPO)]. Though the GFR did not differ significantly in patients and controls, half the patients had either supranormal or subnormal values. Serum potassium and uric acid were significantly higher in patients than controls. Serum phosphorus was similar in both groups, though patients with S-beta thal had significantly lower phosphate excretion indices. All patients were unable to maximally concentrate the urine, and seven also had limited ability to maximally dilute it. Five patients had incomplete distal renal tubular acidosis. Four had mild proteinuria, and six had microalbuminuria. Serum EPO and aldosterone were higher in S-beta thal patients than controls, but there was no difference in PRA between the two groups. There was a strong correlation between hemoglobin concentration and EPO levels, which was strongest in patients with GFR < 50 ml/min. We conclude that patients with S-beta thal, like sickle-cell anemia patients, present multiple abnormalities of renal function.

Peritoneal membrane transport for low molecular weight substances with the use of one bag dialysate collection.

The 24-hour collection of dialysate provides an accurate method for evaluation of both adequacy of dialysis and peritoneal membrane transport characteristics in patients on chronic ambulatory peritoneal dialysis. However, this test requires 24 hours to complete and therefore it is inconvenient for both patients and nurses in the every day practice. We determined the peritoneal membrane transport characteristics for low molecular weight substances of ten patients by using the dialysate collection of only one bag. Dialysate/plasma creatinine ratios were calculated for each of the 4 bags (DATT1, DATT2, DATT3, DATT4) as well as for the 24 hour dialysate (DATTo). We found a very good correlation between DATTo and the four DATTs. We therefore propose that the evaluation of the peritoneal membrane transport, at least for creatinine could be determined with the use of one bag dialysate collection.

Fractional excretion of magnesium in normal subjects and in patients with hypomagnesemia.

The aim of our study was the determination of fractional excretion of magnesium (FEMg++) in both normal subjects and hypomagnesemic patients. 142 subjects aged 26-72 years, recruited from our lipid clinic (control population) and 74 hypomagnesemic patients, aged 36-75 years, were studied. The mean FEMg++ in the control population was 1.8 per cent (range, 0.5-4 per cent). FEMg++ was not correlated with either serum magnesium or with serum creatinine. The mean FEMg++ in patients with hypomagnesemia of extrarenal origin was 1.4 per cent (range, 0.5-2.7 per cent), while the mean FEMg++ in hypomagnesemic patients in whom renal magnesium loss was the main etiologic factor for the pathogenesis of hypomagnesemia was 15 per cent (range, 4-48 per cent). In both groups of hypomagnesemic patients FEMg++ was positively correlated with the urinary magnesium to creatinine molar ratio, but was not correlated with serum magnesium or creatinine levels. FEMg++ could better distinguish the two groups of hypomagnesemic patients than the urinary magnesium to creatinine molar ratio. Hypomagnesemic patients exhibited a cluster of other acid-base and electrolyte abnormalities, mainly respiratory alkalosis, hypokalemia, hypophosphatemia, and hypocalcemia. In conclusion, in hypomagnesemic patients with normal renal function FEMg++ is a very useful tool for the diagnostic approach of hypomagnesemia. A value more than 4 per cent is indicative of inappropriate magnesium loss.

Acid-base and electrolyte abnormalities in febrile patients with bacteraemia.

OBJECTIVES: Very commonly febrile patients with bacteraemia develop a variety of acid-base and electrolyte disturbances which play a significant role in the morbidity and mortality of these patients. This study was undertaken to describe the pathogenetic mechanisms of these abnormalities in febrile patients with bacteraemia. METHODS: Fifteen febrile patients with bacteraemia, aged 24-62 years, were studied. In all patients blood cultures revealed Gram-negative rods. None of them had septic shock, diabetes mellitus, renal or liver failure and none was receiving drugs influencing acid-base balance and electrolyte levels or was a heavy alcohol consumer. RESULTS: Nine patients had respiratory alkalosis, which was possibly due to bacterial toxins, while the remaining 6 had a wide-gap metabolic (lactic) acidosis coexisting with respiratory alkalosis. Hypokalaemia was found in four patients and was mainly due to respiratory alkalosis. However, kaliuria due to hypomagnesaemia contributed to hypokalaemia in 2 patients. Hypomagnesaemia was detected in 3 patients and was attributed to respiratory alkalosis as well as to magnesiuria induced by metabolic acidosis or phosphate depletion. Hypophosphataemia was found in 5 patients who also had respiratory alkalosis and/or phosphaturia due to metabolic acidosis or hypomagnesaemia. Finally, one patient had multifactorial origin hypocalcaemia. CONCLUSION: Febrile patients with bacteraemia develop a number of acid-base and electrolyte disturbances attributed to various pathogenetic mechanisms.

Successful treatment of hyponatremia with angiotensin-converting enzyme inhibitors in patients with congestive heart failure.

Hyponatremia commonly complicates the clinical course of patients with congestive heart failure (CHF) and seems to be an ominous prognostic factor. Angiotensin-converting enzyme (ACE) inhibitors improve the symptomatology of CHF patients. Moreover, it has been reported that these drugs can raise serum sodium in hyponatremic patients. The aim of this prospective work was to study the mechanisms involved in the correction of hyponatremia in 6 patients aged 52-69 years with CHF and hyponatremia (serum sodium 125-128 mmol/l) who were receiving digitalis and furosemide. In these patients, captopril was introduced in progressively increasing doses. The drug induced significant clinical improvement. Additionally, a statistically significant increase in serum sodium was observed which was correlated to a rise in the diluting ability of the kidney (increase in CeH2O). A slight increase in creatinine clearance was also found, which could have contributed to the improvement in hyponatremia. Therefore, we conclude that ACE inhibitors can improve hyponatremia in CHF patients by increasing the urinary diluting ability.