Neuromuscular Involvement in Glycogen Storage Disease Type III in Fifty Tunisian Patients: Phenotype and Natural History in Young Patients.

BACKGROUND: Our aim was to describe the natural history of neuromuscular involvement (NMI) in glycogen storage disease type III (GSDIII). METHODS: We conducted a longitudinal study of 50 Tunisian patients, 9.87 years old in average. RESULTS: NMI was diagnosed at an average age of 2.66 years and was clinically overt in 85% of patients. Patients with clinical features were older (p = 0.001). Complaints were dominated by exercise intolerance (80%), noticed at 5.33 years in average. Physical signs, observed at 6.75 years in average, were dominated by muscle weakness (62%). Functional impairment was observed in 64% of patients, without any link with age (p = 0.255). Among 33 patients, 7 improved. Creatine kinase (CK) and aspartate aminotransferase (AST) levels were higher with age.Electrophysiological abnormalities, diagnosed in average at 6.5 years, were more frequent after the first decade (p = 0.0005). Myogenic pattern was predominant (42%). Nerve conduction velocities were slow in two patients. Lower caloric intake was associated with more frequent clinical and electrophysiological features. Higher protein intake was related to fewer complaints and physical anomalies. CONCLUSION: Neuromuscular investigation is warranted even in asymptomatic patients, as early as the diagnosis of GSDIII is suspected. Muscle involvement can be disabling even in children. Favorable evolution is possible in case of optimal diet.

A lower energetic, protein and uncooked cornstarch intake is associated with a more severe outcome in glycogen storage disease type III: an observational study of 50 patients.

Background Glycogen storage disease type III (GSDIII), due to a deficiency of glycogen debrancher enzyme (GDE), is particularly frequent in Tunisia. Phenotypic particularities of Tunisian patients remain unknown. Our aim was to study complications of GSDIII in a Tunisian population and to explore factors interfering with its course. Methods A retrospective longitudinal study was conducted over 30 years (1986-2016) in the referral metabolic center in Tunisia. Results Fifty GSDIII patients (26 boys), followed for an average 6.75 years, were enrolled. At the last evaluation, the median age was 9.87 years and 24% of patients reached adulthood. Short stature persisted in eight patients and obesity in 19 patients. Lower frequency of hypertriglyceridemia (HTG) was associated with older patients (p<0.0001), higher protein diet (p=0.068) and lower caloric intake (p=0.025). Hepatic complications were rare. Cardiac involvement (CI) was frequent (91%) and occurred early at a median age of 2.6 years. Severe cardiomyopathy (50%) was related to lower doses of uncooked cornstarch (p=0.02). Neuromuscular involvement (NMI) was constant, leading to a functional discomfort in 64% of cases and was disabling in 34% of cases. Severe forms were related to lower caloric (p=0.005) and protein intake (p<0.015). Conclusions A low caloric, protein and uncooked cornstarch intake is associated with a more severe outcome in GSDIII Tunisian patients. Neuromuscular and CIs were particularly precocious and severe, even in childhood. Genetic and epigenetic factors deserve to be explored.

C677t polymorphism of MTHFR and G80A polymorphism of RFC genes and their relation with homocysteine levels in obese Tunisian children.

AIMS: To investigate the frequencies of C677T polymorphism in MTHFR gene and G80A polymorphism in RFC gene in obese and no obese Tunisian children and to assess their relation with homocysteine (tHcy), folate and vitamin B12 levels. METHODS: We have studied 31 obese compared to 22 no obese children. tHcy was assessed by fluorescence-immunoassay ; folate and vitamin B12 by radioimmunoassay. C677T and G80A mutations were detected using pyrosequencing. RESULTS: There were no differences in tHcy levels between obese and no obese, (10,34 ± 4,86µmoll/l vs11,00 ± 4,26µmoll/l). We found no difference for the allelic frequencies of the C677T polymorphism (29.03 % vs 30.95 %) and of the G80A polymorphism (64.52 % vs 59.52 %). Mean levels of tHcy, folic acid and vitamin B12 were not significantly different according to MTHFR and RFC genotypes. CONCLUSION: We demonstrated no difference in tHcy, folates, vitamin B12 levels and allelic frequencies of C677T and G80A polymorphisms in MTHFR and RFC genes between obese and no obese Tunisian children. These two polymorphisms don't seem to have any impact on homocysteine, folate and vitamin B12 status in the two populations.

Serum leptin concentration in Tunisian non obese children.

Leptin, an adipocyte-derived peptide hormone, is thought to play a key role in the regulation of body fat mass. Beyond this function, it appears to be an integral component of various hypothalamo-pituitary-endocrine feedback loops. Because childhood and puberty are periods of major metabolic and endocrine changes, we investigated leptin levels in 348 non overweight, non obese children (147 boys, 201 girls, age: 6-12 years) and then correlated these levels with age, anthropometric data, pubertal stage and insulin. A blood sample was collected from each subject to measure leptin and insulin levels by radioimmunoassay. Pubertal stage was assigned by physical examination, according to Tanner criteria for breast development in females and genital development in males. The results showed an increase in leptin levels in an age related way (r = 0.32, p < 0.0001 in girls; r = 0.21, p = 0.011 in boys) following a pattern that paralleled body weight (r = 0.6 in girls; r = 0.56 in boys; p < 0.0001) and BMI (r = 0.59 in girls; r = 0.6 in boys, p < 0.0001), suggesting that body fatness is a regulator of leptin levels in both girls and boys. A significant gender difference (3.39 +/- 2.79 ng/mL in girls vs 1.99 +/- 2.08 ng/mL in boys, p < 0.0001) with an increase during pubertal development in girls was also showed, while the levels remained constant in boys from Tanner stages T1 to T3. A correlation between leptin and insulinemia was noted in girls (r = 0.38, p < 0.0001) but not in boys, suggesting that insulinemia could be a stimulator of leptin synthesis in girls.

Predictors for cardiovascular morbidity and overall mortality in Tunisian ESRD patients: a six year prospective study.

OBJECTIVES: The study was aimed to test the predictive value of several potential cardiovascular factors and markers for non fatal cardiovascular events (CVE) and overall mortality in Tunisian patients with renal failure. SUBJECTS AND METHODS: One hundred and fifteen renal failure patients were followed-up from 2000 to 2006. At enrollment, each patient underwent clinical examination and blood collection for analysis of lipid parameters, albumin, C reactive protein (CRP), parathyroid hormone (PTH), homocysteine and hemoglobin. Multivariate Cox regression models were applied to identify the predictors for non fatal CVE and overall mortality. RESULTS: During the follow up, seventeen patients were lost. Among the 98 remaining patients, 29 presented a non fatal CVE (21.5%) and 15 were deceased (11.1%). In univariate analyses, non fatal CVE were more frequent in smokers and in patients with high PTH concentrations and low HDL levels. Moreover, low albumin concentrations were univariately associated with overall mortality. In the multivariate analysis, non fatal CVE was significantly and independently associated with age [hazard ratio (95% confidence interval), 1.04 (1.01-1.08); p=0.028] and the upper quartile of PTH concentrations [2.68 (1.24-5.81); p=0.013]. Overall mortality was independently predicted by the bottom quartile of albumin concentrations [5.62 (2.02-15.6); p=0.001] and the upper quartile of CRP concentrations [3.20 (1.14-8.79); p=0.027]. CONCLUSION: Advanced age and high PTH levels are the main predictors of CVE, whereas low albumin and high CRP concentrations are the independent predictors of death in Tunisian renal patients. A better control of these factors would greatly increase the patient's survival rates.

Is serum transthyretin a reliable marker of nutritional status in patients with end-stage renal disease?

OBJECTIVE: To test the value of serum transthyretin (TTR) concentration as a nutritional marker in renal patients. METHODS: The study included 115 renal patients, out of which 35 are on conservative treatment, 50 on hemodialysis and 30 renal transplant recipients, and 31 healthy control subjects. Serum TTR, albumin, transferrin, C-reactive protein (CRP) and alpha1 anti trypsine (AAT) were assessed by immunoturbidimetry, and vitamin A by HPLC. Linear regression models were applied to test the association between serum TTR and body mass index (BMI). RESULTS: Serum TTR concentrations were normal, but serum vitamin A, CRP and AAT concentrations were significantly higher in patients. In renal patients, serum TTR was positively and independently related to BMI and was significantly lower in malnourished than well-nourished patients (367+/-91 vs. 417+/-130 mg/L; p=0.05). The risk of serum TTR<300 mg/L was higher in malnourished patients [OR, 4.82 (1.78-13.2); p=0.001]. CONCLUSION: Serum TTR concentrations were at normal range in renal patients despite evidence of malnutrition and inflammation. However, they were related to BMI and were significantly lowered in malnourished patients. Thus, serum TTR would reflect nutritional status in renal patients. However, the cutoff of malnutrition should be raised to 300 mg/L.

Hb A2-Pasteur-Tunis [delta59(E3)Lys-->Asn, AAG-->AAC]: a new delta chain variant detected by DNA sequencing in a Tunisian carrier of the codon 39 (C-->T) beta0-Thalassemia mutation.

We describe a new delta-globin variant, Hb A2-Pasteur-Tunis [delta59(E3)Lys-->Asn, AAG-->AAC]. This hemoglobin (Hb) displayed an electrophoretic mobility faster than normal Hb A2 and was expressed at 2.2 %. The molecular defect was characterized by DNA sequencing and confirmed by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)-designed protocol. Hb A2-Pasteur-Tunis was found in a carrier of a codon 39 (C-->T) beta0-thalassemia (thal), presenting with a normal Hb A2 level. Phenotype and genotype investigations revealed that the total Hb A2 level of the patient was that expected for a minor beta-thal (4.8%).

Hyperhomocysteinemia is associated with deep venous thrombosis of the lower extremities in Tunisian patients.

OBJECTIVES: To test the association between hyperhomocysteinemia (HHC) and deep venous thrombosis (DVT) of lower extremities in Tunisians. DESIGN AND METHODS: This case-control study included 90 patients with DVT of the lower extremities and 160 healthy controls. Plasma homocysteine, vitamin B(12) and folate were determined using immunoenzymatic methods. Logistic regression models were performed to test whether the association between HHC and DVT is independent and to precise determinants of HHC in DVT patients. RESULTS: Plasma total homocysteine concentrations were significantly higher in patients with DVT (17.4+/-11.5 micromol/L) and in patients with idiopathic DVT (15.2+/-6.4 micromol/L) as compared to controls (11.5+/-3.3 micromol/L). HHC was significantly associated (p<0.001) with all DVT (OR, 8.82; 95% CI, 3.96-19.6) as well as idiopathic DVT (OR, 7.40; 95% CI, 3.01-10.8). These associations persisted after adjustment for several thrombosis risk factors. In patients with DVT, HHC was related to folate and vitamin B(12) concentrations, but neither to the type of occurrence nor to the recurrence of DVT. CONCLUSION: HHC is independently associated with first DVT of lower extremities in Tunisians. Homocysteine should be assessed in patients with DVT and the effect of vitamin B supplementation should be tested among them.

[Oxidative stress in end stage renal disease: evidence and association with cardiovascular events in Tunisian patients]. / Stress oxydant chez les insuffisants rénaux chroniques: evidence et association avec les maladies cardiovasculaires chez des urémiques Tunisiens.

We assessed oxidative stress in 35 chronic renal failure under conservative treatment (CRF), 50 hemodialysed (HD) and 30 renal transplant (RT) patients, and 31 age- and sex-matched healthy subjects. Compared to controls, CRF patients exhibited significantly higher conjugated dienes (139 +/- 37 versus 121 +/- 22 micromol/l) and LDL oxidation (126 +/- 65 versus 99 +/- 46 micromol/l). Glutathione peroxidase activity was decreased in CRF and HD (5.31 +/- 2.46 and 5.39 +/- 2.32 versus 7.42 +/- 2.72 U/ml in healthy subjects). Superoxide dismutase activity was lower in HD (91 +/- 38 U/ml) and higher in RT patients (132 +/- 33 U/ml) than controls (116 +/- 30 U/ml). Plasma zinc concentrations were significantly decreased in CRF and HD patients and copper concentrations were significantly decreased in TPR. Plasma selenium levels were normal in the three groups of patients. Vitamin A was significantly increased, whereas vitamin E was normal in the 3 groups of patients compared to healthy controls. Total antioxidant status was increased in CRF and HD, but not in RT patients. Patients with cardiovascular disease showed increased serum copper, and significantly decreased glutathione peroxidase activity. This study revealed an oxidative stress in CRF and HD patients that may favour the development of cardiovascular diseases.

Hyperhomocysteinaemia is associated with uveitis but not with deep venous thrombosis in Behcet's disease.

Plasma homocysteine was assessed in Behcet's disease (BD) patients in order to determine the prevalence of hyperhomocysteinaemia in BD and to test its association with clinical manifestations of the disease. The study included 59 patients with BD and 118 age- and sex-matched healthy subjects. Plasma homocysteine, vitamin B(12) and folate were assessed by automated immunoassay methods. Hyperhomo-cysteinaemia was defined as plasma homocysteine >15 micromol/l. Plasma homocysteine concentrations and the prevalence of hyperhomocysteinaemia were significantly higher in BD patients than in controls [median (5th-95th percentile), 11.3 (6.6-28.1) vs. 10.6 (6.6-17.1) micromol/l, and 25.4% vs. 9.3%, respectively]. In BD patients, hyperhomocysteinaemia was related to male gender, disease severity and uveitis [odds ratio (OR), 5.32; 95% confidence interval (CI), 1.43-21.61; p = 0.008], but not to age, smoking, disease activity, deep venous thrombosis, arthritis or neurological involvement. The association between uveitis and hyperhomocysteinaemia persisted (multi-adjusted OR, 7.46; 95% CI, 1.03-54.3; p = 0.05) after adjusting for gender, age, disease activity and duration, smoking, deep venous thrombosis, and serum concentrations of creatinine, vitamin B(12) and folate. Plasma homocysteine should be measured in patients with BD, and the effect of B-vitamin supplementation should be tested in those with hyperhomo-cysteinaemia.

Classical and "non-classical" cardiovascular risk factors in Tunisian patients with end stage renal disease: prevalence and association with cardiovascular events.

This study was aimed to determine the prevalence of several classical and non-classical cardiovascular risk factors, and to test their association with cardiovascular events in Tunisian patients with end-stage renal disease. A total of 35 chronic renal failure, 50 hemodialysed and 30 renal transplant recipient patients and 31 healthy subjects were included. Hypertension, elevated plasma concentrations of total homocysteine, fibrinogen, C-reactive protein, and lipoprotein(a) were highly prevalent in patients, whereas, smoking, hypertriglyceridemia, hypercholesterolemia, hypoHDLemia, and hypoalbuminemia were less common. In univariate analysis, cardiovascular events were associated with age, hypertension, and the top quartile of the total homocysteine and C-reactive protein values. When controlling for several potential confounding factors, cardiovascular events remained associated with age, hypertension (OR, 7.07; 95% CI, 1.76-28.34; P=0.01), and the top quartile of total homocysteine (OR, 10.41; 95% CI, 2.61-41.55; P=0.001) and C-reactive protein (OR, 3.99; 95% CI, 1.06-14.99; P=0.04).

[Osteoporosis and inflammatory bowel disease: prevalence and risk factors in Tunisian patients]. / Ostéoporose et maladies inflammatoires chroniques de l'intestin: prévalence et facteurs de risque chez des malades tunisiens.

OBJECTIVES: The study was aimed to evaluate osteoporosis prevalence in a group of Tunisian patients with inflammatory bowel disease (IBD), to determine its risk factors, and to describe its mechanisms. SUBJECTS AND METHODS: We included 67 IBD patients, 43 patients with Crohn's disease (CD) and 24 with ulcerative colitis (UC). Bone mineral density was measured at the lumbar spine and left femoral neck by dual-energy X-ray absorptiometry. We used T score to express bone loss (osteopenia: -2.5 SD 2 years and active disease tended to be associated with lumbar osteoporosis; the ORs were respectively 4.87 [0.92-25.80] (P=0.06), 4.21 [0.87-20.57] (P=0.06), and 2.33 [0.78-6.67] (P=0.13). No association was found with cumulated dose of steroids even when considering only CD. Patients with osteoporosis showed significant increased CrossLaps and interleukin-6 levels that indicate both high bone resorption and inflammatory activity. CONCLUSIONS: Osteoporosis is frequent in IBD patients, especially in CD patients. Female gender, malnutrition (body mass index <20 kg/m2), disease course (> 2 years) and active disease would be risk factors of bone mineral loss in IBD. Osteoporosis is associated with enhanced bone resorption, that seems be linked to excessive intestinal inflammation.

Hyperhomocysteinemia and end-stage renal disease: determinants and association with cardiovascular disease in Tunisian patients.

The study reports on plasma total homocysteine (tHcy) levels in Tunisian patients with chronic renal failure (CRF) and those treated with hemodialysis (HD) and renal transplant (RT). The aims of the study were to identify the determinants of tHcy concentration and to test the association between hyperhomocysteinemia and atherothrombotic disease in end-stage renal disease (ESRD). A total of 35 CRF patients on conservative treatment, 50 HD patients, and 30 RT recipients, and 31 age- and sex-matched healthy subjects were included. Plasma tHcy was assessed by a fluorescent-polarizing immunoassay method. Multivariate analysis was applied to identify the main determinants of tHcy concentration and to assess the relationship between hyperhomocysteinemia and cardiovascular disease. Plasma mean tHcy concentration was significantly increased (p < 0.001) in CRF patients (mean +/- SD) (28.9 +/- 9.8 micromol/l), in HD patients (29.4 +/- 11.1 micromol/l), and in RT (19.3 +/- 6.3 micromol/l) patients compared to controls (11.9 +/- 4.1 micromol/l). Multivariate analysis using GLM ANOVA modeling demonstrated that tHcy was significantly higher in males (p = 0.02), and was related to age (p = 0.008), albumin (p = 0.005), vitamin B12 (p = 0.002), folate (p = 0.00001), and creatinine clearance (p = 0.0008). However, tHcy was not associated with C-reactive protein and did not significantly differ between CRF, HD, or RT patients. The upper quartile of tHcy concentration was significantly associated with atherothrombotic cardiovascular disease (unadjusted odds ratio (OR) = 3.09; 95% CI, 1.11-8.61; p = 0.01). This association remained significant after adjusting for sex, age, hypertension, and smoking (multi-adjusted OR = 4.78; 95% CI, 1.92-11.9; p = 0.0008). The mean tHcy concentration was 2 to 3 times higher in ESRD patients than in subjects with normal renal function. This increase could be related to glomerular filtration rate reduction and functional B vitamins deficiency, but was not associated with inflammation. The upper quartile of tHcy concentrations confers 4.78-fold increased independent risk for atherothrombotic events in ESRD patients.

Benzene exposure monitoring of Tunisian workers.

To monitor benzene exposure and to check reliability of urinary trans,trans-Muconic Acid (t,t-MA) as a bio-marker of benzene exposure in local conditions, a study was conducted on 30 Tunisian exposed workers (20 tanker fillers and 10 filling station attendants). The analyses were carried out on environmental air and urinary t,t-MA before (t,t-MAA) and at the end of work shift (t,t-MAB). 20 nonoccupationally exposed subjects were also investigated. The average value of environmental benzene concentration was 0.17 ppm. The differences between t,t-MAA and t,t-MAB concentrations and between t,t-MAB and t,t-MA measured in controls (t,t-MAC) were both significant (p < 0.001). Benzene air concentrations were well correlated with t,t-MAB: R = 0.76. In the nonexposed group, average t,t-MA concentrations is significantly higher among smokers than nonsmokers (P < 0.02). Analysis of urinary t,t-MA offers a relatively simple and suitable method for benzene exposure monitoring.