Mohamed M. NasrAllah

Fibroblast growth factor-23 (FGF-23) is independently correlated to aortic calcification in haemodialysis patients

BACKGROUND Vascular calcification has detrimental consequences on chronic kidney disease (CKD) patients, yet its pathogenesis is not fully understood. Fibroblast growth factor-23 (FGF-23) is involved in the regulation of mineral metabolism which may in turn affect vascular calcification. Data on the relationship between FGF-23 and peripheral vascular calcification, using conventional radiographs, are conflicting, and less is known about its relation to aortic calcification. We conducted this study to investigate the relationship between FGF-23 and aortic calcification in a standard haemodialysis setting. METHODS The study included 65 haemodialysis patients (46 prevalent and 19 incident) on a three times 4-h dialysis schedule as well as 15 controls. Those with diabetes, oral anticoagulation or parathyroidectomy were excluded. Intact FGF-23, parathormone, lipids, calcium and phosphorus were measured. Aortic calcification index (ACI) was assessed by a non-contrast computerized tomography (CT) of the abdominal aorta. RESULTS FGF-23 levels were higher among haemodialysis patients (4681.3 +/- 3906.1 pg/mL) compared to controls (98.2 +/- 51.9 pg/mL), P = 0.005. ACI was higher in haemodialysis patients (14.1 +/- 12) than controls (3.2 +/- 3.6), P = 0.009. FGF-23 (P < 0.0001) and systolic blood pressure (BP) (P < 0.0001) were independently related to ACI in stepwise multiple regression analysis of pooled analysis of haemodialysis patients, R(2) = 0.476; in subgroup analysis, the independent factors relating to ACI among prevalent dialysis patients were systolic BP (P < 0.0001), FGF-23 (P = 0.002) and age (P = 0.012), R(2)=0.48; whereas in incident patients, only FGF-23 was associated with ACI (P = 0.007), R(2) = 0.37. CONCLUSIONS In haemodialysis patients, FGF-23 and ACI were significantly increased, and FGF-23 was independently associated with aortic calcification.

The Association between Fibroblast Growth Factor-23 and Vascular Calcification Is Mitigated by Inflammation Markers.

Background: Fibroblast growth factor-23 (FGF-23) has been linked to vascular calcification, ventricular hypertrophy and mortality in chronic kidney disease (CKD), although these links may not be direct and independent. Similar grave outcomes are associated with inflammation and oxidative stress in CKD. Recently, accumulating evidence has linked components of phosphate homeostasis to inflammation and oxidative stress. The interaction between the triad of inflammation, FGF-23 and cardiovascular outcomes is underinvestigated. Methods: We studied 65 patients with stage 5 CKD on hemodialysis. Serum levels of FGF-23, high-sensitivity C-reactive protein (hsCRP), endogenous soluble receptor of advanced glycation end products (esRAGE), advanced oxidation protein products (AOPP), parathormone, lipids, calcium and phosphorous were measured. The aortic calcification index (ACI) was determined using non-contrast CT scans of the abdominal aorta. Results: FGF-23 was elevated (mean: 4,681 pg/ml, SD: 3,906) and correlated with hsCRP, esRAGE, AOPP, dialysis vintage and phosphorus in univariate analysis. In multiple regression analysis, hsCRP, AOPP and phosphorus but not esRAGE were all significantly correlated to FGF-23 (R2 = 0.7, p < 0.001). In univariate analysis, ACI correlated with hsCRP, esRAGE, FGF-23, dialysis vintage, systolic blood pressure (BP) and serum cholesterol. In multiple regression analysis not including inflammation markers, ACI was associated with FGF-23. However, inclusion of inflammation markers in another multiple regression analyses showed that ACI correlated with hsCRP, BP, dialysis vintage and esRAGE but not with FGF-23 (R2 = 0.65, p < 0.001). Conclusion: FGF-23 is strongly correlated to various markers of inflammation and oxidative stress in hemodialysis patients. The association between FGF-23 and vascular calcification was mitigated when corrected for inflammation markers.

Insulin resistance and metabolic syndrome in primary gout: relation to punched‐out erosions

To verify the relation of gout to insulin resistance (IR) and metabolic syndrome (MetS) and find any association of metatarsophalangeal (MTP) joint erosions to the features of MetS and IR.

Comparing different calcification scores to detect outcomes in chronic kidney disease patients with vascular calcification

BACKGROUND There is no consensus on the most appropriate technique to diagnose vascular calcification in chronic kidney disease. This is primarily because of the absence of direct comparisons of predictive values of the various calcification scores, especially outside the coronary vascular beds, to detect clinical outcomes. METHODS We included 93 haemodialysis patients and performed 6 vascular calcification scores: two scores utilised simple X-rays of abdominal aorta and peripheral vessels. CT scans of the thoracic, upper abdominal and lower abdominal aorta were performed to calculate the aortic calcification index and CT of the pelvis for calcification of iliac vessels. Patients were followed for 63months (mean 46.8months) for first major cardiovascular events and mortality. RESULTS Nineteen cardiovascular events and 28 deaths occurred. Calcification was detected more sensitively in central and peripheral beds using CT scans compared to X-rays (p<0.001). CT scans detected calcification more frequently in distal than proximal vascular beds (p<0.001). Calcification of the pelvic vessels and lower abdominal aorta were most predictive of events including pre-existing cardiovascular disease O.R. 6.5 (95% C.I. 2-22; p=0.001) and O.R. 3 (95% C.I. 1.1-9; p=0.035); new major cardiovascular events H.R. 4.2 (95% C.I. 1.5-11; p=0.006) and H.R. 2 (95% C.I. 0.8-5.3; p=0.1) as well as mortality H.R. 2.8 (95% C.I. 1.3-6; p=0.01) and H.R. 2.2 (95% C.I. 1.04-5; p=0.04) respectively. CONCLUSIONS CT based techniques are more sensitive than plain X-rays at detecting peripheral and aortic vascular calcifications. Distal CT scans of the aorta and pelvic vessels have the highest predictive value for cardiovascular events and mortality.

Fasting during the month of Ramadan among patients with chronic kidney disease: renal and cardiovascular outcomes

Background Fasting during the month of Ramadan is a religious obligation for Muslims who represent 20% of the world population. This study explores the safety of fasting for a whole month among patients with chronic kidney disease (CKD) with the possible risk of dehydration and hyperviscosity leading to deterioration of kidney functions and vascular thrombosis. Methods We followed CKD patients with stable kidney function who chose to fast during the month of Ramadan. A group of nonfasting CKD patients served as controls. Serum creatinine was recorded at the beginning of the month, after 1 week of fasting, at the end of the month and 3 months later. Patients were followed for major adverse cardiovascular events (MACE). Results A total of 131 CKD patients were recruited and included in two groups: fasting and nonfasting (mean baseline estimated glomerular filtration rate 27.7, SD 13 and 21.5, SD 11.8 mL/min/1.73 m2, respectively). A rise of serum creatinine was noted during fasting in 60.4% of patients by Day 7 and was associated with intake of renin angiotensin aldosterone system antagonists [relative risk (RR) 2, P = 0.002]. Adverse cardiovascular events were observed in six patients in the fasting cohort and were associated with a rise of serum creatinine after 1 week of fasting (P = 0.009) and the presence of pre-existing cardiovascular disease (RR 15, P = 0.001); the latter association was confirmed by logistic regression analysis. Only one event was recorded in the nonfasting group, P = 0.036. Conclusions MACE occurred more frequently among fasting CKD patients with pre-existing cardiovascular disease and were predicted by an early rise of serum creatinine.

VKORC1 gene (vitamin K epoxide reductase) polymorphisms are associated with cardiovascular disease in chronic kidney disease patients on hemodialysis.

Vitamin K is necessary for the carboxylation of clotting factors and matrix Gla protein (MGP). Vitamin K epoxide reductase (VKOR) is the enzyme responsible for recirculation of Vitamin K increasing its tissue availability. Polymorphisms of VKOR may alter the function of MGP, thereby influencing vascular calcification. We conducted this study to investigate the relationship of VKORC1 gene single nucleotide polymorphisms (SNPs) to vascular calcification and clinically overt cardiovascular disease in chronic kidney disease (CKD) patients on hemodialysis (HD). The study included 54 CKD patients on HD. We excluded those with diabetes or on anticoagulant therapy. Vascular calcifications were measured using computerized tomography scans and roentgenograms. Prevalent clinically overt cardiovascular disease was reported based on the evidence of documented preexisting major cardiovascular events. Genotype detection for the gene VKORC1 C1173T and G-1639A polymorphisms was carried out by polymerase chain reaction. We found a significant association between C1173T polymorphisms and vascular calcification (odds ratio [OR] = 43, P = 0.001). The mutant T allele was also linked with higher odds of vascular calcification (OR = 8.880, 95% confidence interval [CI] = 3.1-25.4, P = 0.001) and clinically overt cardiovascular disease (OR = 4.7, 95% CI = 1.5-14.7, P = 0.005). VKORC1 G-1639A polymorphisms were not associated with vascular calcification and had lower prevalence of clinically overt cardiovascular disease (OR = 0.07, 95% CI = 0.01-0.4, P = 0.001). In patients with CKD on HD, we found that VKORC1 gene polymorphisms did have an association with prevalent cardiovascular calcification and clinically overt cardiovascular disease, C1173T polymorphisms with higher risk for disease, and G-1639A with lower risk.

Subclinical renal involvement in essential cryoglobulinemic vasculitis and classic polyarteritis nodosa

OBJECTIVE Renal vasculitis is usually associated with anti-neutrophil cytoplasmic antibodies (ANCAs). However, non-ANCA patients constitute a rarely studied variant of renal vasculitis. The aim of the present study was to demonstrate the features of renal involvement in patients with primary systemic non-ANCA associated vasculitis (NAAV) and compare essential cryoglobulinemic vasculitis (ECV) with classic polyarteritis nodosa (PAN). METHODS The study included 30 patients with primary systemic non-ANCA associated vasculitis (NAAV). Fifteen with ECV and another 15 patients with classic PAN. The patients were recruited from the Rheumatology and Internal medicine departments and outpatient clinics of Cairo University Hospitals. The patients had no or mild renal involvement at entry and the ANCA was negative as tested by immunoflourescence and ELISA. Renal biopsy was performed for all the patients and histopathologically studied. RESULTS Renal biopsy abnormalities were seen in six females. One patient with PAN showed renal vasculitis and membranoproliferative glomerulonephritis (MPGN) and was HBV and ANA positive. The patient had negative HCV and cryoglobulins. Five patients with ECV-associated HCV had findings; one had chronic interstitial nephritis and was HBV positive. The other four were HBV negative with MPGN in two, focal proliferative and crescentic GN in one patient each. CONCLUSIONS Increased understanding of the manifestations of systemic vasculitis is likely to provide the basis for the use of more selective immunomodulatory therapies in the future. It is our hope that this study will raise awareness of the non ANCA-associated vasculitic renal involvement.