Moderate salt restriction in primary aldosteronism improves bone metabolism through attenuation of urinary calcium and phosphate losses

Accumulating evidence links osteoporosis and dietary salt consumption. Primary aldosteronism (PA) is a model disease with increased dietary salt intake and constitutes an independent risk factor for osteoporosis. We, thus, assessed whether a short-term moderate reduction in salt intake in PA results in detectable osteoanabolic effects. Forty-one patients with PA on stable mineralocorticoid receptor antagonist therapy were subjected to a 12-week salt restriction. Serum and urinary electrolytes, markers of bone turnover, and a 15 steroids plasma profile were registered. After 12 weeks, urinary calcium and phosphate decreased, while plasma testosterone, serum phosphate, and bone alkaline phosphatase (BAP) all increased significantly. Longitudinal changes in BAP were independently correlated with changes in serum phosphate, parathyroid hormone, and urinary calcium in multivariate analysis. Salt restriction in PA limits urinary calcium and phosphate losses and may confer favorable osteoanabolic effects. Our findings suggest that salt restriction should be considered in patients with PA to improve bone health.

[Inluence of osteoporosis and its causative factors on the prevention of recurrence of urinary stone disease]

INTRODUCTION

The aim of postoperative examination, treatment and follow-up of patients with urinary stone disease is a prevention of recurrence. A choice of method of prevention is based on the results of postoperative examination with consideration of etiological factors of urinary stone disease. An analysis of influence of osteoporosis and its causative factors on the recurrence of urinary stone disease is presented in the article.

AIM

to clarify the influence of osteoporosis and its causative factors on excretion of calcium, uric acid and recurrence of urinary stone disease.

MATERIALS AND METHODS

A total of 86 patients after surgical treatment of urinary stone disease were included in the study. A physicochemical analysis of stones and their fragments, excretion of calcium and uric acid were done postoperatively. The risk factors for osteoporosis were identified using specific questionnaire. Bone mineral density (BMD) was assessed by X-ray densitometry. After X-ray phasic analysis of the stones and studying of the daily excretion of calcium and uric acid, 10 and 7 patients were prescribed to thiazide diuretics and allopurinol, respectively. In 69 patients (80.2%) there were no indications to the treatment and all of them were included in control surveillance group.

RESULTS

Calcium oxalate stones were predominated in patients who were under surveillance (=0,0254). A prevalence of risk factors for osteoporosis was similar in all groups (=0,2156), as well as rate of decrease in BMD (=0,64). In patients taking thiazide diuretics, a significant decrease in daily calcium excretion was found (=0,0054) without significant changes in excretion of uric acid and diuresis volume. Among patients receiving allopurinol there was a significant decrease in daily uric acid excretion (=0,021), without significant changes in excretion of calcium and diuresis volume. There were no significant changes of these values in the control group. A recurrence of urinary stone disease in treatment group was detected in 4 patients with a decrease of BMD after 381+/-61 days, while in control group there were 5 recurrences in patients with decreased BMD and I recurrence in patient with normal BMD after 836+/-64 days.

CONCLUSION

Treatment aimed at prevention of recurrence of urinary stone disease allows to correct detected metabolic disturbances. However, such factor as the decrease in BMD can influence on the rate and frequency of recurrence of urinary stone disease. A clarifying of risk factors for osteoporosis and diagnosis of osteoporosis allow to give reliable recommendations for its treatment and to decrease risk of recurrence of urinary stone disease.

[Clinical value of Canephron N after surgical treatment of urinary stone disease]

BACKGROUND

The drug Canephron N is a combination of extracts of centaury, lovage and rosemary. Moderate antispasmoic, anti-inflammatory, antioxidant, diuretic and antimicrobial effects are of great interest for urological practice. The optimal combination of components that were made of herbal medicine allows to use their synergistic effect for prevention of recurrence of urinary stone disease. The experience of using the drug Canephron in clinical practice is of great interest.

AIM

to clarify the clinical efficiency of Canephron N in patients with urinary stone disease after surgical treatment and to evaluate the changes in diuresis and calcium excretion.

MATERIALS AND METHODS

The results of using the drug Canephron after surgical treatment of urinary stone disease are provided. The changes in diuresis and calcium excretion in 75 patients undergone surgical treatment of urinary stone disease were studied. Patients after ureteroscopy, percutaneous nephrolithotomy and extracorporeal shock-wave lithotripsy were prescribed treatment to prevent stone formation including herbal drug Canephron N.

RESULTS

At baseline, there was negative correlation between 24-hours diuresis and calcium excretion in all groups. During follow-up, a positive correlation between 24-hours diuresis and calcium excretion was found in patients receiving Canephron N and other types of treatment. The average follow-up was 390 days. During this period, recurrence was noted in 1 patient receiving Canephron, 4 patients in patients who took other drugs and in 5 patients who didnt receive any treatment.

CONCLUSION

Risk factors of stone formation persist after surgical treatment of urinary stone disease. This is reflected in a negative correlation between 24-hour diuresis and calcium excretion. During treatment, a positive correlation between diuresis and calcium excretion was noted in patients with urinary stone disease. The use of drugs that affect stone formation as well as herbal medicine Canephron N allow to obtain comparable ratio of diuresis and calcium excretion.

[Characteristic features of urinary calcium excretion and osteoporosis risk factors in patients with urolithiasis]

RELEVANCE

The prevalence of urolithiasis and osteoporosis (OP) indicates that these diseases may be found concurrently in the same patient. The detection of risk factors for OP and disorders of calcium metabolism in patients with urolithiasis is of interest in the context of primary stone formation and metaphylaxis.

AIM

To identify risk factors for osteoporosis and disorders of calcium metabolism in patients with urolithiasis.

MATERIALS AND METHODS

Osteoporosis risk factors were studied in 45 urolithiasis patients undergoing surgical treatment. Patients were asked to fill out the osteoporosis risk factor questionnaire, and urinary calcium excretion was measured in 24-h collections.

RESULTS

Risk factors for osteoporosis were detected in 20 (44.4%) urolithiasis patients. Patients with osteoporosis risk factors identified by the questionnaire were statistically significantly older (p=0.032). Osteoporosis risk factors were found in 20% of patients with newly diagnosed urolithiasis and 24.4% of patients with recurrent urolithiasis. The study patients showed increased urinary calcium excretion and decreased diuresis. The negative correlation between urinary calcium excretion and 24-h diuresis was greater in patients who had than in those who did not have osteoporosis.

CONCLUSION

An increase in urinary calcium excretion and a decrease in diuresis can be a predisposing factor for the recurrence of urolithiasis. In patients with risk factors for osteoporosis, it can provide a rationale for administering drugs aimed at preventing stone formation (thiazide diuretics).

Acute response to oral calcium loading in pregnant and lactating women with a low calcium intake: a pilot study

This pilot study in women from The Gambia with low habitual calcium intakes showed differences in calciotropic hormones between pregnant, lactating and non-pregnant, non-lactating women similar to those in Western women. The response to oral calcium loading indicates a high degree of calcium conservation independent of reproductive status.

INTRODUCTION

In pregnancy and early lactation, parathyroid hormone (PTH) concentrations may be suppressed. Uncertainty exists about how calcium metabolism is regulated, particularly when calcium intake is low.

METHODS

We investigated fasting markers of calcium metabolism and the acute calcemic and calciuric responses after an oral calcium load in 30 pregnant, lactating or non-pregnant, non-lactating (NPNL) Gambian women with low habitual calcium intakes. Women received 1 g elemental calcium (CaCO3) at 0 min. Blood was collected at -30 and 180 min. Urine was collected from -60 to 0, 0-120 and 120-240 min. Samples were analysed (blood: ionized calcium (iCa); plasma (p): total calcium (tCa), phosphate (P), creatinine (Cr), PTH, 1,25-dihydroxyvitamin D (1,25(OH)2D), osteocalcin (OC), β C-terminal cross-linked telopeptide of type 1 collagen (βCTX), cyclic adenosine monophosphate (cAMP); urine (u): Ca, P, Cr, cAMP).

RESULTS

Pre-loading, groups did not differ significantly in iCa, pP, uCa/Cr and uP/Cr. pOC concentrations were significantly lower and NcAMP and p1,25(OH)2D higher in pregnant women; pPTH and pβCTX in lactating women were higher than in NPNL women. Post-loading, iCa, ptCa and uCa/Cr concentrations increased; pPTH, NcAMP, βCTX and uP/Cr decreased in all groups, but the magnitude of change did not differ significantly between groups.

CONCLUSION

Differences between pregnant, lactating and NPNL Gambian women in pPTH, NcAMP and p1,25(OH)2D and bone markers were similar to Western women. However, the response to calcium loading indicates that there may be no differences in renal and intestinal calcium economy associated with reproductive status, potentially due to a high degree of calcium conservation associated with low intakes.

Acute gentamicin-induced hypercalciuria and hypermagnesiuria in the rat: dose-response relationship and role of renal tubular injury

1. Standard renal clearance techniques were used to assess the dose-response relationship between acute gentamicin infusion and the magnitude of hypercalciuria and hypermagnesiuria in the anaesthetized Sprague-Dawley rat. Also investigated were whether these effects occurred independently of renal tubular cell injury. 2. Acute gentamicin infusion was associated with a significant hypercalciuria and hypermagnesiuria evident within 30 min of drug infusion. The magnitude of these responses was related to the dose of drug infused (0.14-1.12 mg kg(-1) min[-1]). Increased urinary electrolyte losses resulted from a decreased tubular reabsorption of calcium and magnesium. 3. A rapid dose-related increase in urinary N-acetyl-beta-D-glucosaminidase (NAG) excretion was also observed in response to gentamicin infusion. However, there was no evidence of renal tubular cell injury and no myeloid bodies were observed within the lysosomes of the proximal tubular cells. Gentamicin may thus interfere with the mechanisms for cellular uptake and intracellular processing of NAG causing increased NAG release into the tubular lumen. 4. The absence of changes in renal cellular morphology indicates that the excessive renal losses of calcium and magnesium were an effect of gentamicin per se and not the result of underlying renal tubular injury. The renal effects described in this paper were apparent after administration of relatively low total drug doses, and with plasma concentrations calculated to be within the clinical range. These findings suggest that disturbances of plasma electrolyte homeostasis could occur in the absence of overt renal injury in patients receiving aminoglycoside antibiotics.