Diet in chronic kidney disease in a Mediterranean African country.

BACKGROUND: Mediterranean diet is characterized by low to moderate consumption of animal protein and high consumption of fruits, vegetables, bread, beans, nuts, seeds and other cereals. It has been associated with reduced risk of cardiovascular disease. However, it is not suitable for chronic kidney disease because of high potassium intake. DISCUSSION: Tunisia is an emerging Mediterranean country with limited resources, a high prevalence of chronic hemodialysis treatment and high dialysis expenditures. In order to limit dialysis cost, primary and secondary prevention of chronic renal disease are of paramount importance. In addition to drugs, secondary prevention includes diet measures (e.g. salt diet, protein diet). The aims of diet practice in chronic kidney disease are to slow chronic renal failure progression and to prevent its complications like hyperphosphatemia and hyperkaliemiae. A few decades ago, a Tunisian diet was exclusively Mediterranean, and protein consumption was not excessive. However, today, protein consumption is more comparable to western countries. Salt consumption is also excessive. Some Tunisian diets still include food with high potassium intake, which are not suitable for patients with chronic kidney disease. Therefore, the role of the dietician is extremely important to help calculate and create a dietary regimen tailored to each of our patients. Advice about diets should be adapted to both the patient and population habits to improve adherence rate. As such, the purpose of this article is to provide our own experience regarding medical nutrition therapy in patients with chronic kidney disease in Tunisia, with some changes in food habits. Prevention is far better than treatment. In this perspective, dietary measures must be at the core of our intervention.

Identification of compound heterozygous patients with primary hyperoxaluria type 1: clinical evaluations and in silico investigations.

BACKGROUND: Primary hyperoxaluria type 1 (PH1) is an autosomal recessive inherited disorder of glyoxylate metabolism in which excessive oxalates are formed by the liver and excreted by the kidneys. Calcium oxalate crystallizes in the urine, leading to urolithiasis, nephrocalcinosis, and consequent renal failure if treatment is not initiated promptly. Mutations in the AGXT gene which encodes the hepatic peroxisomal enzyme alanine:glyoxylate aminotransferase are responsible of PH1. In the present work, we aimed to analyze AGXT gene and in silico investigations performed in four patients with PH1 among two non consanguineous families. METHODS: Exhaustive gene sequencing was performed after PCR amplification of coding exons and introns boundaries. Bioinformatic tools were used to predict the impact of AGXT variants on gene expression as well as on the protein structure and function. RESULTS: Direct sequencing of all exons of AGXT gene revealed the emergence of multiple mutations in compound heterozygous state in the two studied families. Two patients were compound heterozygous for the c.731 T > C, c.32C > T, c.1020A > G and c.33_34insC and presented clinically with recurrent urinary tract infection, multiple urolithiasis and nephrocalcinosis under the age of 1 year and a persistent hyperoxaluria at the age of diagnosis. The two other patients presenting a less severe phenotypes were heterozygous for c.731 T > C and homozygous for the c.32C > T and c.1020A > G or compound heterozygous for c.26C > A and c.65A > G variants. CONCLUSION: In Summary, we provided relevance regarding the compound heterozygous mutations in non consanguineous PH1 families with variable severity.

Quality of life in chronic hemodialysis patients:about 71 cases.

BACKGROUND: The chronic hemodialysis imposes various limitations on patients that may affect their quality of life. However, Tunisian studies on this matter remain scarce. AIMS: To assess the quality of life among hemodialysis patients and to identify the factors influencing their quality of life. METHODS: We performed a cross-sectional study which included 71 outpatients, during the month of January 2013, in the department of Nephrology at Hedi Chaker Sfax university hospital in Tunisia. We used the specific scale Kidney Disease Quality of Life Short-Form (KDQOL-SF™) to assess the patient's quality of life. This instrument combines the short form 36 health survey questionnaire (SF-36) and a specific module adapted to renal function. Regression analysis was used to adjust for confounding factors. RESULTS: The global average score, according to KDQOL-SF and the SF-36 were respectively 51.6 and 38.2. The QOL was impaired in 90% of the cases. The logistic regression identified six variables to be correlated with impaired QOL. These six factors in descending order of importance were:  lack of autonomy, a dialysis rhythm of thrice a week, an age over 60 years, a comorbid diabetes, low social economic level and living in rural areas. CONCLUSION: Our study highlights the high frequency of QOL impairment upon patients on hemodialysis underlining the interest of a systematic effort to assess the quality of life in those patients. It also shows the interest of acting upon modifiable factors correlated with the alteration of the quality of life. In this way, the professional integration of the patients should be favored as well as peritoneal dialysis.

Twice weekly hemodialysis is safe at the beginning of kidney replacement therapy: the experience of the Nephrology Department at Hedi Chaker University Hospital, Sfax, south of Tunisia.

We re-examine the infrequent paradigm of a biweekly dialysis at the start of renal replacement therapy. The current method is to launch hemodialysis among patients using a 'full-dose' posology three times a week. As a matter of fact, recent data has suggested that frequent hemodialysis leads to high mortality at the onset of dialysis. The aim of our study is to show the factors affecting early mortality especially the hemodialysis frequency. We undertook an observational study in the hemodialysis unit of Sfax University Hospital (south Tunisia). We enrolled the incident patients during one year. Baseline demographic and clinical characteristics of patients were noted. The survival status of each patient is observed at 6 months after the onset of hemodialysis. We analyzed the factors associated with mortality, especially the hemodialysis frequency (twice or thrice weekly hemodialysis regimen). We enrolled 88 patients with mean age of 56 ± 18 years old. Thirty patients underwent twice weekly dialysis (Group 1) and 58 patients underwent thrice weekly dialysis (Group 2). The mortality at 6 months was similar in the 2 groups (the rate of death = 30% in group 1 vs 13.8% in group 2, p = 0.07). However, the mortality was lower in the group with preserved residual diuresis (35.3% vs 64.7% in the group without residual diuresis, p = 0.02). The mortality was higher in diabetes patients (64.7% vs 35.5%, p = 0.02). It was concluded that twice or threefold weekly treatment have some considerable similar outcomes on the patients survival (at 6 months).

Mutational analysis in patients with Autosomal Dominant Polycystic Kidney Disease (ADPKD): Identification of five mutations in the PKD1 gene.

Autosomal Dominant Polycystic Kidney Disease (ADPKD), the most frequent genetic disorder of the kidneys, is characterized by a typical presenting symptoms include cysts development in different organs and a non-cysts manifestations. ADPKD is caused by mutations in PKD1 or PKD2 genes. In this study, we aimed to search for molecular causative defects among PKD1 and PKD2 genes. Eighteen patients were diagnosed based on renal ultrasonography and renal/extra-renal manifestations. Then, Sanger sequencing was performed for PKD1 and PKD2 genes. Multiplex Ligation dependent Probe Amplification method (MLPA) methods was performed for both PKD genes. Mutational analysis of the PKD2 gene revealed the absence of variants and no deletions or duplications of both PKD genes were detected. But three novels mutations i.e. p.S463C exon 7; c. c.11156+2T>C IVS38 and c.8161-1G>A IVS22 and two previously reported c.1522T>C exon 7 and c.412C>T exon 4 mutations in the PKD1 gene were detected. Bioinformatics tools predicted that the novel variants have a pathogenic effects on splicing machinery, pre-mRNA secondary structure and stability and protein stability. Our results highlighted molecular features of Tunisian patients with ADPKD and revealed novel variations that can be utilized in clinical diagnosis and in the evaluation of living kidney donor. To the best of our knowledge, this is the first report of Autosomal Polycystic Kidney Disease in Tunisia.

Stimulated sweating as a therapy to reduce interdialytic weight gain and improve potassium balance in chronic hemodialysis patients: a pilot study.

Controlling the extracellular volume in hemodialysis patients is a difficult task. The aim of this study was to evaluate the capacity of different methods of stimulated sweating to reduce mean interdialytic weight gain (IWG), to improve blood pressure regulation, and potassium/urea balance. Two center, crossover pilot study. In Lausanne, hemodialysis patients took four hot-water baths a week, 30 minutes each, on nondialysis days during 1 month. In Sfax, patients visited the local Hammam Center four times a week. Hemodynamic parameters were recorded, and weekly laboratory analysis was performed. Results were compared with a preceding 1-month control period. In Lausanne, five patients (all men, median age 55 years) participated. Bathing temperature was (mean ± standard deviation) 41.2 ± 3°C and sweating-induced weight loss 600 ± 500 g. Mean IWG (control vs. intervention period) decreased from 2.3 ± 0.9 to 1.8 ± 1 kg (P = 0.004), Systolic blood pressure from 139 ± 21 to 136 ± 22 mmHg (P = 0.4), and diastolic blood pressure form 79 ± 12 to 75 ± 13 mmHg (P = 0.08); antihypertensive therapy could be reduced from 2.8 ± 0.4 to 1.9 ± 0.5 antihypertensive drugs per patient (P = 0.01). In Sfax (n = 9, median age 46 years), weight loss per Hammam session was 420 ± 100 g. No differences were found in IWG or BP, but predialysis serum potassium level decreased from 5.9 ± 0.8 to 5.5 ± 0.9 mmol/L (P = 0.04) and urea from 26.9 ± 6 to 23.1 ± 6 mmol/L (P = 0.02). Hot-water baths appear to be a safe way to reduce IWG in selected hemodialysis patients. Hammam visits reduce serum potassium and urea levels, but not IWG. More data in larger patient groups are necessary before definite conclusion can be drawn.

A double mutation in AGXT gene in families with primary hyperoxaluria type 1.

Primary hyperoxaluria type 1 (PH1) is a severe autosomal recessive inherited disorder of glyoxylate metabolism caused by mutations in the AGXT gene on chromosome 2q37.3 that encodes the hepatic peroxisomal enzyme alanine:glyoxylate aminotransferase. These mutations are found throughout the entire gene and cause a wide spectrum of clinical severity. Rare in Europe, PH1 is responsible for 13% of the end stage renal failure in the Tunisian child. In the present work, we identified the double mutation c.32C>T (Pro11Leu) and c.731T>C (p.Ile244Thr) in AGXT gene in five unrelated Tunisian families with PH1 disease. Our results provide evidence regarding the potential involvement of c.32C>T, originally described as common polymorphism, on the resulting phenotype. We also reported an extreme intrafamilial heterogeneity in clinical presentation of PH1. Despite the same genetic background, the outcome of the affected members differs widely. The significant phenotypic heterogeneity observed within a same family, with a same genotype, suggests the existence of relevant modifier factors.

Microalbuminuria: a useful marker of cardiovascular disease.

Leakage of small amounts of proteins in urine has been considered since 1980s a crucial sign of early kidney disease, especially in diabetic patients. An increasing interest in microalbuminuria as a cardiovascular risk marker has been more recently considered. Many studies linked microalbuminuria to early cardiovascular disease, as a marker of endothelial dysfunction, not only in diabetic patients, but also in hypertensive patients and in general population. Microalbuminuria is considered nowadays by guidelines as a cost-effective marker of subclinical organ damage in hypertensive patients and should be checked routinely in hypertensive patients. Assessing subclinical organ damage is recommended not only at the level of screening, but also during treatment. Microalbuminuria is also considered as a treatment outcome marker and useful for understanding the ability of a given therapeutic intervention to regress organ damage or slow down its progression.

[Stimulated sweating in order to improve the water-and-salt balance in hemodialysis patients. A case report]. / Transpiration stimulée afin d'améliorer l'équilibre hydro-sodé chez les patients hémodialysés : à propos d'un cas.

Obtaining the desired dry weight in dialysis patients is challenging once residual diuresis has disappeared, considering the trend of increasing dietary salt intake and shortening dialysis time over the last 40 years. We describe the case of a 55-year-old patient of Sudanese origin, who presented excessive interdialytic weight gain and hypertension on maintenance hemodialysis. After failure of conservative measures, a therapy of daily hot water baths of 30 minutes each on non-dialysis days was introduced. All clinical parameters improved, including potassium profile. In this article, we review the history, pathophysiological mechanisms, efficacy and possible side effects of this interesting, somewhat forgotten technique.