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Biomedical subjects

F Andreasen

Publications and source records attributed to F Andreasen.

At least 19 recordsLinked to original sources

Cardiac troponin levels following monitored epileptic seizures.

Cardiac arrhythmia associated with myocardial injury is a proposed mechanism for sudden unexplained death in epilepsy. The authors measured serial cardiac troponin levels in 11 patients after monitored seizures. Using highly sensitive assays and criteria, no troponin elevations were seen, indicating that myocardial injury does not occur during uncomplicated seizures. An elevation in postictal troponin elevations should suggest the presence of cardiac injury secondary to neurocardiogenic mechanisms or primary cardiac factors, prompting further evaluation.

Adult↗

Dose-effect relations of loop- and thiazide-diuretics on calcium homeostasis: a randomized, double-blinded Latin-square multiple cross-over study in postmenopausal osteopenic women.

BACKGROUND: Thiazide diuretics (TDs) reduce whereas loop diuretics (LDs) increase urinary calcium. We studied the effects of different doses of a TD and LD on electrolytes, calcitropic hormones and biochemical bone markers. SUBJECTS AND METHODS: In a five-period crossover study, comparing four active doses with placebo, 40 postmenopausal women with osteopenia were treated with different doses of LD bumetanide (n = 20, 0.5-2.0 mg per day) or TD bendroflumethiazide (n = 20, 2.5-10 mg per day). Each treatment period lasted 1 week. RESULTS: Urinary calcium decreased dose-dependently in response to the bendroflumethiazide. The best hypocalciuric effect was achieved by 5 mg day-1 of bendroflumethiazide. Total plasma calcium levels increased, whereas ionised calcium at ambient pH-values decreased because of increased pH-values in response to the bendroflumethiazide. Plasma PTH levels did not change, whereas a slight dose-dependent increase occurred in plasma 1,25(OH)2D levels. As a marker of bone formation, plasma osteocalcin levels increased. Conversely, bumetanide dose-dependently increased renal calcium losses with a concomitant increase in plasma PTH and 1,25(OH)2D levels. Plasma osteocalcin levels increased and bone-specific alkaline phosphatase levels decreased dose-dependently. CONCLUSION: Whether a LD or TD is chosen as diuretic therapy affects calcium homeostasis. The effects of LDs are potentially harmful to bone. Further studies are needed to evaluate whether long-term treatment with LDs causes osteoporosis. Until then, we suggest using, if possible, a TD rather than a LD as diuretic therapy in order not to risk deleterious effects on bone metabolism.

Alkaline Phosphatase↗

Statins decrease bone turnover in postmenopausal women: a cross-sectional study.

BACKGROUND: Statins have been suggested as potential agents in the management of osteoporosis. Reviews of medical records have shown an increased bone mass and some studies have shown a reduced occurrence of fractures in subjects on long-term treatment with statins. We studied the effects of treatment with statins on calcium homeostasis, bone turnover and bone mineral density. DESIGN: In a cross-sectional design, plasma levels of parathyroid hormone (PTH) and biochemical markers of bone turnover, bone mineral density (BMD) and body composition (fat- and lean tissue-mass) were measured in 140 postmenopausal women who had been treated with a statin for more than 2 years (median 4 years) and compared to 140 age- and gender-matched, population-based controls. RESULTS: Plasma levels of bone turnover markers were lower in the statin-treated subjects than in the controls: osteocalcin (-9%, P = 0.03), bone-specific alkaline phosphatase (-14%, P < 0.01), and C-terminal telopeptide of type I collagen (-11%, P < 0.01). On the other hand, plasma PTH levels were 16% higher in the statin-treated subjects than in the controls (P < 0.01). However, body composition and BMD at the lumbar spine, hip, forearm and whole body did not differ between the two groups. No correlation could be demonstrated between changes in biochemical quantities and dose or duration of statin use. CONCLUSION: Our data show that statins affect the function of bone cells. Most likely, the effect is antiresorptive.

Aged↗

Drug therapy in the elderly: what doctors believe and patients actually do.

AIMS: To examine the medication adherence among old persons living in their own homes, to assess their knowledge of their medication, and to indicate target areas for intervention. METHODS: A cross-sectional study of data collected from randomly selected samples of 348 persons, aged 75 years recruited from a population-based register in the municipality of Aarhus, Denmark. Information on all drugs was collected from the subjects during a home visit, and their drug storage was examined. Information was collected from the general practitioners (GP). The measures of adherence were scores of agreements between the GPs' lists and the subjects' actual drug consumption. RESULTS: We found disagreement between the drug information collected from the study population and from the GPs: concerning drugs in 22% of the study-population, concerning doses in 71%, and concerning regimens prescribed by the GP in 66%. Twenty-four percent stated that they did not always follow prescriptions. Most of the deviations from prescriptions were toward lower doses and less frequent drug intake. The drugs most often involved in deviations were hypnotics, analgesics, bronchodilators and diuretics. Sixty percent of the participants knew the purpose of medication, and 21% knew the consequences of omission of the drugs. Less than 6% of the subjects knew about the toxic risks, side-effects, or potential drug interactions. The participants' knowledge of the drugs was positively associated with their adherence. We found a correlation between an increased number of prescribed frequency of drug intake per day and deviation from the regimen (r = 0.25, P = 0.01). There was a positive association between nonadherence and the use of three or more drugs (odds ratio (OR) 2.5; 95% confidence interval (CI) 1.5,4.1), prescriptions from more than one doctor (OR 2.5; 95% CI 1.3,4.8), and probability of dementia (OR 9.0; 95% CI 1.1,72.5). Moreover compliance aids facilitated adherence (OR 4.4; 95% CI 1.6,12.3). Persons living alone were more prone to medication errors (OR 2.0; 95% CI 1.1,3.5). CONCLUSIONS: A differentiated evaluation of adherence by considering the drug, the dose, and the regimen separately produced quantifiable data concerning the subjects' medication habits. Non-adherence ranged from 20 to 70% depending on the measuring method. The participants' knowledge of the treatment was poor. Our results suggest that better information on medication and the use of compliance aids may prevent nonadherence. Special attention should be paid to persons receiving three or more drugs, living alone, receiving drugs from other doctors, and to persons with predementia symptoms, as they are at higher risk of nonadherence.

Aged↗

Loop diuretics alter the diurnal rhythm of endogenous parathyroid hormone secretion. A randomized-controlled study on the effects of loop- and thiazide-diuretics on the diurnal rhythms of calcitropic hormones and biochemical bone markers in postmenopausal women.

BACKGROUND: Thiazide diuretics (TD) reduce urinary calcium, bone loss and fracture risk. Loop diuretics (LD) may have opposite effects. These effects could depend on induced rhythmic changes in bone and calcium homeostasis. DESIGN: After a run-in period of 7 days, we studied (in a factorial design) the diurnal rhythms of plasma levels of calcium, phosphate, parathyroid hormone (PTH), 1,25-dihydroxyvitamin D and osteocalcin, as well as renal excretions rates of calcium, phosphate, and cross-linked N-terminal telopeptide of type 1 collagen (NTx) in 50 postmenopausal women randomized to treatment with either a thiazide diuretic (TD; bendroflumethiazide, n = 14), a loop diuretic (LD; bumetanide, n = 13), LD plus TD (bendroflumethiazide plus bumetanide, n = 11), or placebo (n = 12). RESULTS: In all four groups, all measured quantities showed a diurnal variation. LD caused a steep increase, with a subsequent decrease, in urinary calcium and plasma PTH. The mean 24 h plasma PTH concentration was increased (8.5 +/- 0.9 mmol L-1) compared with placebo (4.4 +/- 0.4 mmol L-1), whereas net 24 h renal calcium excretion did not differ from that of the placebo group due to a rebound hypocalciuria. Compared with placebo, diurnal rhythms of plasma phosphate and osteocalcin were changed with an increase during daytime and a decrease during the night. TD did not alter the diurnal rhythm of any of the measured quantities. However, the 24-h renal calcium excretion decreased, whereas the mean 24-h plasma calcium concentration increased without PTH suppression. LD plus TD caused changes similar to those observed with LD alone. CONCLUSION: One daily dose of LD increases parathyroid activity with alterations in the diurnal pattern of osteocalcin. This could indicate a potential anabolic effect of LD.

Aged↗

Effects of thiazide- and loop-diuretics, alone or in combination, on calcitropic hormones and biochemical bone markers: a randomized controlled study.

OBJECTIVE: Diuretics are commonly used drugs that in addition to their effect on the cardiovascular system also affect calcium homeostasis and bone metabolism. We evaluated the effects of loop diuretics (LD) and thiazide diuretics (TD) on calcitropic hormones and biochemical bone markers. DESIGN: A total of 50 postmenopausal women were randomized to 7 days of treatment with either the TD bendroflumethiazide, the LD bumetanide, bendroflumethiazide plus bumetanide, or placebo. Blood and urine (24 h) were sampled on each day. Statistical inferences were made versus the concomitant changes in the placebo group. RESULTS: Bendroflumethiazide increased the tubular reabsorption of calcium (TRCa) (+0.46 +/- 0.11%, P=0.009), plasma levels of parathyroid hormones (PTH) (+24 +/- 10%, P=0.06), and 1,25(OH)2D (+12 +/- 6%, P=0.03). Bumetanide decreased the TRCa (-0.5 +/- 0.1%, P=0.01) and increased plasma PTH and 1,25(OH)2D levels (+27 +/- 9%, P=0.02 and +36 +/- 12%, P=0.006, respectively). Treatment with either of the drugs did not alter plasma calcium, osteocalcin, bone alkaline phosphatase (bone-ALP) or urinary NTx/creatinine ratio. However, treatment with both drugs caused an increased plasma calcium level (+2.7 +/- 1.0%, P=0.007) and decreased plasma levels of bone-ALP (-21 +/- 3%, P=0.001), osteocalcin (-6 +/- 3%, P=0.03), and urinary NTx/creatinine ratio (-39 +/- 6%, P=0.001). CONCLUSION: Calcium homeostasis and bone metabolism are to a major degree influenced by diuretic treatment. Surprisingly, LD and TD exerted a similar effect on calcitropic hormones despite their opposite effects on the renal calcium excretion. In clinical practice, treatment with diuretics has to be considered as a cause of parathyroid stimulation.

Aged↗

The consumption of drugs by 75-year-old individuals living in their own homes.

OBJECTIVE: To examine the drug consumption and the extent of polypharmacy (defined as daily intake of three or more drugs) among 75-year-old persons living in their own homes and to point out potential problems associated with it. METHODS: Information on the intake of all drugs was collected from 492 subjects randomly selected. The subjects were interviewed at home, and their drug storage was examined. Information was also collected from the general practitioners (GPs) and from prescription databases. Database information comprised prescribed drugs used by the study population and the background population. RESULTS: Eighty-seven percent of the study population received prescribed drugs and 72% used over-the-counter (OTC) drugs. Only 3% of the subjects did not take any drugs. Eighty percent of females and 60% of males used central nervous system (CNS) drugs, the most commonly used category. The subjects took on average 4.2 different prescribed drugs and 2.5 OTC drugs. Sixty percent used three or more prescribed drugs and 34% used five or more. Thirty percent used three or more OTC drugs. Seventeen percent had prescribed drugs not in use at the time of the examination in their drug storage. Twenty-five percent of the prescribed drugs were used without the GPs' knowledge. Thirty-one percent of the study population received prescribed drugs from two or more physicians. Potential drug interactions with clinical significance were found among 15.3% of the participants and were positively correlated to polypharmacy. CONCLUSION: Almost all 75-year-old persons receive drugs. The observed polypharmacy may increase drug-related risks. The discrepancies between the GPs' knowledge of their patients' medication and the actual intake may involve a potential risk. A better registration of the patients' total medication and the implementation of a common medication database for the use of all involved physicians may improve medication and reduce risks.

Adult↗

Postoperative hepatic catabolic stress response in patients with cirrhosis and chronic hepatitis.

Open (OC) or laparoscopic (LC) cholecystectomy is considered a relative contraindication in patients with liver cirrhosis. The effect of LC and OC on the hepatic catabolic stress response was studied in patients with postnecrotic liver cirrhosis and chronic hepatitis to define the most suitable procedure from a metabolic point of view. Altogether 14 patients with cirrhosis and 14 with chronic hepatitis were randomized to LC or OC (n = 7 in each group). The increase in the functional hepatic nitrogen clearance (FHNC) was quantified. Changes in glucose, insulin, glucagon, cortisol, epinephrine, norepinephrine, and prostaglandin E(2) (PGE(2)) were observed. There was no difference in FHNC between LC and OC in any of the patients. Among cirrhotic patients OC caused a 132% increase in FHNC (p < 0.05) and among the hepatitis patients a 69% increase (p < 0.05). In contrast, there was no significant increase following LC in any of the patients. OC increased fasting glucose and insulin in the hepatitis patients (p < 0.01 and p < 0.001, respectively) and in the cirrhosis group (p < 0.01 and p < 0.05, respectively). Alanine stimulation increased glucose in hepatitis patients after OC (p < 0.05) and after LC (p < 0.01). Stimulated glucagon increased after OC in the hepatitis group (p < 0.05). During stimulation cortisol was higher following LC in hepatitis patients (p < 0.01) and cirrhotic patients (p < 0.05). Fasting PGE(2) was down-regulated after LC in hepatitis patients (p < 0.05) and cirrhotic patients (p < 0.01) and after OC in the hepatitis group (p < 0.001). FHNC is similar after LC and OC. Thus from a metabolic point of view, LC has no advantage over OC.

Cholecystectomy↗

Dose-related cardiac electrophysiological effects of intravenous magnesium. A double-blind placebo-controlled dose-response study in patients with paroxysmal supraventricular tachycardia.

AIMS: The role of magnesium as an antiarrhythmic drug is yet not conclusive. Therefore, we performed a double-blind, randomized, placebo-controlled dose-response study of cardiac electrophysiological effects of intravenous magnesium. METHODS AND RESULTS: Thirty-six patients undergoing an electrophysiological evaluation for paroxysmal supraventricular tachycardia were randomized to one of the following dosages of intravenous magnesium (0, 5, 10 or 20 mmol). Conventional electrophysiological variables for sinus node function, atrial, atrioventricular node and ventricular conduction and refractoriness were measured before and after magnesium administration. Prolongation of the atrial-His interval was found at 5 mmol of magnesium compared with placebo and no further prolongation was observed at higher doses (-3 +/- 8, 11 +/- 9, 7 +/- 15, 11 +/- 16, for the dosages of 0, 5, 10 and 20 mmol of magnesium, respectively, P < 0.05). Measures of sinus node function, intra-atrial conduction and conduction through the Purkinje system were unaffected by magnesium. Male gender was associated with prolongation in atrial effective refractory period, in contrast to shortening in females: 2 +/- 43, 35 +/- 44, 36 +/- 33, 13 +/- 12 ms for males and 3 +/- 6, -12 +/- 11, -13 +/- 12, 0 +/- 23 ms for females, respectively (P < 0.001). CONCLUSION: Atrioventricular node conduction was prolonged by 5 mmol intravenous magnesium and no further prolongation was observed at higher dosages. At dosages of 5 and 10 mmol magnesium the atrial effective refractoriness was prolonged in males and shortened in females.

Adolescent↗

Increased natriuretic efficiency of furosemide in rats with carbon tetrachloride-induced cirrhosis.

The authors examined the natriuretic efficiency of furosemide in rats with cirrhosis induced by carbon tetrachloride (CCl(4)). Rats were treated for 17 weeks with intraperitoneal injections of CCl(4) in groundnut oil twice a week throughout the study. Control rats were treated with vehicle (groundnut oil). Studies in metabolic cages showed that sodium retention was present from week 14. Renal clearance experiments were performed in chronically, instrumented conscious rats at the end of week 14 and at the termination of the study (end week 16) when ascites and hyponatremia were present. After 14 weeks, cirrhotic rats had sodium retention along with increased renal plasma flow, normal GFR, normal renal lithium handling, and a significantly increased diuretic (+41% vs. control) and natriuretic (+56% vs. control) response to a test dose furosemide (7.5 mg/kg b.w., intravenously). The natriuretic efficiency of furosemide, i.e., the natriuresis expressed relative to the furosemide excretion rate (triangle upU(Na)V/U(FUR)V) was increased by 51% versus control. After 17 weeks, ascites and hyponatremia had developed, and significant decreases in renal plasma flow (-33%), GFR (-30%), and fractional lithium excretion (-44%) were observed. At this stage urinary recovery of furosemide was significantly decreased and the diuretic (-27% vs. Control) and natriuretic (-38% vs. control) responses to furosemide were significantly impaired. However, the increased natriuretic efficiency of furosemide was still present (+34% vs. control). Together these results suggest that increased sodium reabsorption in the thick ascending limb of Henle's loop is involved in the renal sodium retention in cirrhosis in rats that eventually results in decompensation with the formation of ascites.

Animals↗

Enhanced exercise-induced hyperkalemia in patients with syndrome X.

OBJECTIVES: The purpose of this study was to determine whether patients with syndrome X have altered potassium metabolism. BACKGROUND: Patients with syndrome X have angina pectoris and exercise induced ST segment depression on the electrocardiogram despite normal coronary angiograms. Increasing evidence suggests that myocardial ischemia is uncommon in these patients. Altered potassium metabolism causing interstitial potassium accumulation in the myocardium may be an alternative mechanism for chest pain and ST segment depression in syndrome X. METHODS: We compared the magnitude of exercise-induced hyperkalemia in 16 patients with syndrome X (12 female and four male, mean +/- SD age 53 +/- 6 years) and 15 matched healthy control subjects. The participants underwent a bicycle test at a fixed load of 75 W for 10 min, and blood samples were taken for analysis of potassium, catecholamines and lactate before, during and in the recovery period after exercise. In five patients with syndrome X, the test was repeated during alpha1 adrenoceptor blockade. RESULTS: Baseline concentrations of serum potassium, plasma catecholamines and plasma lactate were similar in patients and control subjects. The rate of exercise-induced increment of serum potassium was increased in the patients (70 +/- 29 vs. 30 +/- 21 micromol/liter/min in control subjects, p < 0.001). Six patients, who stopped before 10 min of exercise, showed very rapid increments in serum potassium concentration. Compared to the control subjects, patients also demonstrated larger increments in rate-pressure product, plasma norepinephrine and lactate concentrations during exercise. The rate of serum potassium increment correlated with the rate of plasma norepinephrine increment in the patients (r = 0.63, p < 0.02), but not in the control subjects (r = 0.01, p = 0.97). Blockade of alpha1 adrenoceptors decreased systolic blood pressure at baseline, but did not influence the increment of serum potassium, plasma catecholamines and lactate. CONCLUSIONS: Patients with syndrome X have enhanced exercise induced hyperkalemia in parallel with augmented increases of circulating norepinephrine and lactate. The prevailing mechanisms behind the abnormal potassium handling comprise sources distinct from alpha1-adrenoceptor activation.

Exercise Test↗

Effects of chronic octreotide treatment on renal changes during cirrhosis in rats.

We examined the effect of a new long-acting release formula (LAR) of the somatostatin analogue, octreotide, on development of sodium retention and functional and structural changes in the thick ascending limb of Henle's loop (TAL) in rats with cirrhosis induced by common bile duct ligation (CBL). CBL and sham-operated control rats were treated with octreotide-LAR (10 mg/kg body weight subcutaneously, as a single dose) or vehicle at the time of CBL or sham-CBL. The rats were instrumented with chronic catheters, and sodium balance and renal function were examined 4 weeks after CBL or sham operation. Octreotide-LAR treatment significantly inhibited sodium retention in CBL rats and prevented renal vasodilatation without changes in glomerular filtration rate (GFR). The natriuretic response to a test dose of furosemide (7.5 mg/kg body weight intravenously) was significantly increased in CBL rats, and when expressed in terms of natriuretic efficiency (mmol Na/mg furosemide in urine), the natriuretic response was increased by 57% relative to sham-operated controls. Stereological examination of kidneys demonstrated a 53% increase in the volume of the inner stripe of the outer medulla and a 108% increase in the volume of TAL epithelium in cirrhotic rats relative to controls. The increased natriuretic efficiency of furosemide as well as the hypertrophy of the inner stripe and the TAL in this renal zone were absent in CBL rats treated with octreotide-LAR. These results suggest that octreotide-LAR treatment inhibits sodium retention in cirrhotic rats, partly by inhibition of increased furosemide-sensitive sodium reabsorption in the TAL.

Animals↗

Effects of laparotomy vs pneumoperitoneum on the hepatic catabolic stress response in ambulatory and stationary settings in pigs.

BACKGROUND: We recently demonstrated that laparoscopic cholecystectomy is followed by a much smaller hepatic catabolic stress response than conventional cholecystectomy. It is not known what is responsible for this difference. METHODS: Thirty pigs were randomly allocated to the following five treatment groups: (1) laparotomy, (2) pneumoperitoneum, (3) pneumoperitoneum with insertion of four trocars, (4) laparotomy, (5) pneumoperitoneum. Groups 1-3 were operated on in an ambulatory setting, whereas groups 4 and 5 were operated on in a stationary setting. Urea synthesis, as quantified by functional hepatic nitrogen clearance, and the response of stress hormones and cytokines were assessed. RESULTS: Laparotomy increased the functional hepatic nitrogen clearance by 195% (p < 0.001); pneumoperitoneum and trocars increased it by 145% (p < 0.001); and pneumoperitoneum alone increased it by 113% (p < 0. 001). The difference between laparotomy and both pneumoperitoneum groups was significant. If the stress factor of ambulatory surgery was eliminated, the increase in functional hepatic nitrogen clearance was reduced to 87% (p < 0.01) after laparotomy and 38% (NS) for animals subject to pneumoperitoneum. There were significant differences in concentrations of stress hormones, tumor necrosis factor alpha, and interleukin 8 among groups intra- and postoperatively. CONCLUSIONS: The magnitude of the postoperative hepatic stress response after laparotomy compared to pneumoperitoneum with and without insertion of trocars seems to be caused by the greater trauma to the abdominal wall. Furthermore, an ambulatory setting seems to be an important postoperative stress factor in itself.

Ambulatory Care↗

Differential effects of growth hormone and prednisolone on energy metabolism and leptin levels in humans.

Short-term growth hormone (GH) exposure has been shown to stimulate energy expenditure (EE) without concomitant changes in body composition. To what extent this is related to thyroid function, sympathetic activity, hyperinsulinemia, or leptin secretion is unknown. It is also unknown whether the calorigenic effect of GH is influenced by glucocorticoids, which are known to antagonize the anabolic actions of GH. To pursue this, eight normal male subjects (aged 22 to 28 years; body mass index, 21.6 to 26.3 kg/m2) were randomly studied during four 4-day treatment periods with (1) daily subcutaneous (SC) placebo injections and placebo tablets, (2) daily SC GH injections (0.1 IU/kg x d) and placebo tablets, (3) daily prednisolone administration (25 mg morning and evening) plus placebo injections, and (4) daily GH injections plus prednisolone administration. GH administration decreased plasma epinephrine significantly (mean +/- SE, 34.7 +/- 5.7 ng/L for control v 24.8 +/- 5.8 for GH, P < .05), had no effect on plasma norepinephrine or serum leptin, and increased both free triiodothyronine (FT3) levels (5.7 +/- 0.3 pmol/L for control v 6.7 +/- 0.3 for GH, P < .05) and resting EE ([REE] 1,861 +/- 61 kcal/24 h for control v 1,996 +/- 69 for GH, P < .05). Prednisolone administration did not affect epinephrine and REE, decreased norepinephrine (116 +/- 13, P < .05) and FT3 (4.7 +/- 0.2, P < .05), and increased leptin (3.93 +/- 0.71, P < .05). Concomitant GH and prednisolone administration increased REE (2,068 +/- 85, P +/- .05) and leptin (4.82 +/- 0.93, P +/- .05), had no effect on either epinephrine or norepinephrine, and decreased FT3 (5.0 +/- 0.2, P < .05). Resting heart rate (HR) increased only during GH, whereas sympathetic nerve activity was unchanged in all studies. Our data suggest that (1) the calorigenic effect of GH is not mediated by changes in sympathetic activity or leptin secretion, (2) rapid elevations in leptin induced by glucocorticoids do not affect EE in humans, and (3) the acute calorigenic effects of GH are probably related to increased cardiac workload.

Adult↗

[Diuretics and osteoporosis].

Thiazide diuretics lower while loop diuretics promote calcium excretion by the kidney. Several studies have found thiazide use to be associated with higher bone mineral density and some have found that thiazides reduce the risk of hip fracture. The mechanisms by which thiazides favour preservation of the bones are uncertain. Thiazide use results in decreased renal calcium excretion and thiazide users have been shown to have lower levels of S-PTH and S-1,25-dihydroxy-vitamin D. The beneficial bone effects may result from a decrease in PTH-stimulated bone resorption and an associated reduction in the bone turn-over rate. Whether loop diuretics increases the bone turn-over by augmenting the urinary calcium excretion is more controversial as only few studies have been carried out on loop diuretics. However, in these studies the use of loop diuretics have been associated with decreased bone mineral density and increased risk of fractures. Future research should determine the minimal dose of thiazide therapy necessary to produce a sustained hypocalciuric effect and in addition the influence of diuretic dose on bone turn-over. Equally important is the need to evaluate potential unwanted effects of loop diuretics. In the mean time, thiazide diuretics may be used safely while some caution is necessary in the long term use of loop diuretics in patients who are prone to osteoporosis.

Aged↗

Aldosterone receptor blockade inhibits increased furosemide-sensitive sodium reabsorption in rats with liver cirrhosis.

We examined the role of chronic aldosterone receptor blockade on the altered furosemide-sensitive sodium reabsorption in rats with liver cirrhosis induced by common bile duct ligation. CBL and sham-operated control animals were treated with the aldosterone receptor antagonist canrenoate (20 mg/day i.v.) for 4 weeks. Untreated CBL and sham-CBL served as control groups. The plasma concentration of aldosterone was within the normal range in all groups. Sodium balance studies showed that aldosterone receptor blockade prevented sodium retention in cirrhotic rats. Clearance studies showed that the glomerular filtration rate was unchanged, whereas the renal plasma flow was increased in CBL rats. A test dose of furosemide (7.5 mg/kg b.wt. i.v.) produced significantly greater diuretic (+59%) and natriuretic (+56%) responses in CBL rats than in sham-operated controls. The urinary furosemide excretion rate (UFURV) reflects delivery of furosemide to the thick ascending limb. When the natriuresis was expressed relative to UFURV (i.e., the natriuretic efficiency), we found that natriuretic efficiency of furosemide was significantly increased in untreated CBL rats (+59%). However, the natriuretic efficiency of furosemide was normalized in CBL rats treated with canrenoate. The urinary excretion of furosemide was unchanged in untreated CBL rats, but it was significantly increased in cirrhotic rats treated with canrenoate (+43%). This suggests that in CBL rats, chronic canrenoate treatment increases the renal elimination of furosemide as a consequence of reduced metabolism. These data suggest that chronic aldosterone receptor blockade with canrenoate prevents sodium retention in cirrhotic rats partly by inhibition of increased sodium reabsorption in the thick ascending limb.

Animals↗

The effect of NaO Li Su on memory functions and blood chemistry in elderly people.

In traditional Chinese medicine a mixture of bee pollen, radix polygoni multiflore, semen ziziphi spinosae, radix salviae multiorhizae, fructus schisandrae and fructus ligustris lucidae, known as NaO Li Su, has a reputation as a remedy against declining memory functions. In the present study the effect of the preparation on failing memory was assessed in 100 elderly Danish volunteers who complained of a deteriorating memory. The study was a double-blind placebo controlled cross-over trial. The effect was evaluated after treatment periods of 3 months' duration by a battery of psychological and biochemical tests. No desirable effects on memory functions were achieved by the active treatment. Increases in the number of red blood cells and in the serum creatinine levels were seen after active treatment. In the subgroup initially showing a number of red blood cells below the median a significant positive correlation was found between changes in the number of red blood cells and changes in the Wechsler Memory Scale scores.

Aged↗