1,720,962 research outputs found
Ageing and changes in phosphate transport: clinical implications.
No full textHyperphosphatemia is pivotal in some complications secondary to kidney dysfunction. Current guidelines suggest that hyperphosphatemia secondary to kidney dysfunction develops only when glomerular filtration rate is reduced well below the threshold of 60 ml/min. This paper deals with the relationship of age with serum phosphorus and with the possible influences of this relationship on hyperphosphatemia secondary to kidney dysfunction. A recent epidemiologic study shows that serum phosphorus decreases over time not only in pediatric age but also during adulthood. This decrease differs between men and women: continuous in men, but not in women, because of a transitory serum phosphorus increase during climacterics. Data show also that age-associated differences in serum phosphorus among adults are explained by differences in the maximal phosphorus reabsorption in the renal proximal tubule (TmP/GFR). Other studies suggest that the opposite influences on TmP/GFR of growth hormone (stimulation) and estrogen (inhibition) are the determinants of the age-associated changes in TmP/GFR and serum phosphorus. The decline of serum phosphorus with age leads to the hypothesis that, in the presence of a disorder inducing phosphorus retention, the prevalence of hyperphosphatemia should be higher in young adults than in the elderly because the healthy elderly have lower serum phosphorus. A large clinical study supports this hypothesis showing that hyperphosphatemia secondary to kidney dysfunction is approximately 4 times higher at age 65. Data suggest that the relation between kidney function and serum phosphorus should be reevaluated considering the possible confounding effect of age
La nefrolitiasi nelle malattie intestinali
No full textIntestinal diseases may cause the formation of urinary stones through changes in the metabolism of oxalate, calcium, and uric acid. The oxalate that is excreted into urine comes from the catabolism of ascorbic acid and some amino acids or from intestinal absorption of food oxalate. Calcium is absorbed by the gut after the stimulation of active vitamin D and is excreted by the kidney under the control of the bone/parathyroid hormone axis. Uric acid is generated by the oxidation of exogenous and endogenous purine bases, is excreted by the kidney through glomerular filtration/tubular secretion, and is soluble in alkaline urine. Several data indicate that patients with inflammatory bowel diseases are at high risk of urinary stones containing calcium-oxalate salt or uric acid. Calcium-oxalate stones are caused by colonic oxalate hyperabsorption (secondary to intestinal dysfunction) or by parenteral nutrition. Uric acid stones are typical of patients with severe diarrhea and/or intestinal neostomy, that is, in patients with hyperconcentrated acidic urine. Relationships between malabsorptive intestinal diseases and urinary stones are less well defined. Preventive countermeasures are not the same for all disorders. Hyperoxaluria should be controlled by diets with a low content of lipids and oxalate but supplemented with calcium and probiotics. The presence of hyperconcentrated acidic urine should be controlled by correct hydration and administration of citrate
Phosphatemia and age: a neglected relation in medical practice.
No full textHyperphosphatemia is pivotal in some complications secondary to kidney dysfunction. Current guidelines suggest that hyperphosphatemia due to kidney dysfunction develops only when kidney function is reduced to 65 years. Data suggest that the relation between kidney function and phosphatemia should be re-evaluated considering possible confounding due to age
A population-based approach for the definition of chronic kidney disease: the CKD Prognosis Consortium.
No full textIntroduction: The Kidney Disease: Improving Global
Outcomes (KDIGO) foundation promoted the establishment
of the Chronic Kidney Disease (CKD) Prognosis
Consortium to meta-analyze the association of
estimated glomerular filtration rate (eGFR) and albuminuria
with incidence of various outcomes in samples
of general populations from all over the world.
Methods: Variables in meta-analysis included eGFR
by the Modification of Diet in Renal Disease (MDRD)
Study equation, the urinary albumin to creatinine ratio
(uACR) as index of albuminuria, together with proteinuria
at dipstick urinalysis and classical markers of
cardiovascular risk. Overall, 105,872 participants had
uACR measurements, and 1,128,310 participants had
dipstick measurements.
Results: The association with mortality was continuous
over the whole range of uACR/proteinuria and Jshaped
for eGFR which was associated with an excess
risk for values <75 and ≥120 ml/min per 1.73 m2.
Results were similar for the association of eGFR or
uACR/proteinuria with renal failure. The associations
of eGFR and uACR/proteinuria with death or renal failure
were independent of each other. Findings were
consistent across population samples from North
America, Asia, Oceania and Europe, as well as in individuals
with age <65 years and individuals with age
≥65 years.
Conclusions: Data support the threshold of 60 ml/
min for CKD definition but suggest that eGFR in the
range 60-74 ml/min could represent the early stages of CKD. This first set of results of the CKD Prognosis
Consortium represents an important step in the evidence-
based definition of CKD. Conclusions should
be reevaluated with eGFR calculation by equations
less biased for normal-high eGFR
A population-based approach for the definition of chronic kidney disease: the CKD Prognosis Consortium
No full textIntroduction: The Kidney Disease: Improving Global
Outcomes (KDIGO) foundation promoted the establishment
of the Chronic Kidney Disease (CKD) Prognosis
Consortium to meta-analyze the association of
estimated glomerular filtration rate (eGFR) and albuminuria
with incidence of various outcomes in samples
of general populations from all over the world.
Methods: Variables in meta-analysis included eGFR
by the Modification of Diet in Renal Disease (MDRD)
Study equation, the urinary albumin to creatinine ratio
(uACR) as index of albuminuria, together with proteinuria
at dipstick urinalysis and classical markers of
cardiovascular risk. Overall, 105,872 participants had
uACR measurements, and 1,128,310 participants had
dipstick measurements.
Results: The association with mortality was continuous
over the whole range of uACR/proteinuria and Jshaped
for eGFR which was associated with an excess
risk for values <75 and ≥120 ml/min per 1.73 m2.
Results were similar for the association of eGFR or
uACR/proteinuria with renal failure. The associations
of eGFR and uACR/proteinuria with death or renal failure
were independent of each other. Findings were
consistent across population samples from North
America, Asia, Oceania and Europe, as well as in individuals
with age <65 years and individuals with age
≥65 years.
Conclusions: Data support the threshold of 60 ml/
min for CKD definition but suggest that eGFR in the
range 60-74 ml/min could represent the early stages of CKD. This first set of results of the CKD Prognosis
Consortium represents an important step in the evidence-
based definition of CKD. Conclusions should
be reevaluated with eGFR calculation by equations
less biased for normal-high eGFR
8-Week Study on Effects of Chlorthalidone in Hypertensives with Low eGFR
No full textBackground: Ef cacy of chlorthalidone (CT) and thiazides is considered low in low kidney function (LKF).
Methods: A parallel-arm,non-inferiority study was done on CT effects in hypertensives with LKF and hypertensives without LKF (Italian Drug Agency Registry ID#671).Study design included:screening visit,baseline visit, 8-week CT treatment with visits at week 1,2,4,6 and 8.The screening visit selected patients on antihypertensive treatment with uncontrolled hypertension (SBP140 or DBP90),ages 25-74,complete diagnostic workup. Eligible patients were prescribed lab evaluations and re-examined after 1-2 week (baseline).Exclusion criteria were treatment with diuretics,CT contraindications,refused consent,SBP180 or DBP110, severe co-morbidities.At baseline, 25 mg CT was prescribed on the top of ongoing treatments to 60 patients with LKF (eGFR by CKD-Epi equation stably <60 mL/min) and 60 patients without LKF (Control, eGFR stably 60 mL/min). Blood pressure was measured at each visit by blinded trained physicians according to WHO guidelines.Lab evaluations were repeated at visit 8. Study power was 80% (=0.01,one sided test,=15,difference in SBP reduction=8).
Results: LKF and Control were similar for men% (70.2% and 64.2%),age (mean= 57 and 53),baseline blood pressure (SBP/DBP= 150/90 and 150/91) but differed for eGFR (mean= 39 and 76, range=15-59 and 60-104).Changes over baseline were signi cant at week 8 in LKF and Control for SBP (mean= -20 and -23; 95%CI= -22/-18 and -26/-19)
and DBP (-9 and -10; -11/-7 and -13/-8).Differences between groups were not signi cant for changes in SBP (-3; -7/+1) and DBP (-1; -4/+2). Baseline eGFR did not predict SBP/DBP changes in either groups (R0.17). Week 8 changes were signi cant for eGFR
(LKF and Control, mL/min= -2 and -5; -4/-1 and -7/-3), serum potassium (mmol/L= -0.2 and -0.2; -0.3/-0.1 and -0.3/-1), serum uric acid (mg/dL= +0.8 and +0.9; +0.5/+1.1 and +0.7/+1.1). Adverse events incidence was 13.3% in both groups. The commonest events were serum sodium <135 mmol/L and SBP/DBP <110/90.
Conclusions: Data do not support the idea of reduced CT ef cacy in low kidney function
CLORTALIDONE IN IPERTESI A FUNZIONE RENALE RIDOTTA: STUDIO PARALLELO SUGLI EFFETTI AD OTTO SETTIMANE
No full text
Early identification of kidney disease by eGFR: What is the prevalence of eGFR in the population?
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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