الفهرس 
Title pageOnly 14 pages are availabe for public view
 |  | from | 96 |  |  |
| | | from | 96 | | |
Abstract
Chronic kidney disease (CKD) is a worldwide public health problem.Cardiovascular complications are major clinical problems in patients with CKD, which account for 50% of deaths in ESRD patients. Increased vascular calcification (VC) in CKD patients predicts a poor prognosis in terms of overall survival and cardiovascular (CV) morbidity and mortality. Evidence for abnormalities of bone and mineral metabolism in CKD may contribute to the development of CV disease and VC.Radiological means for detection of VC remain the gold standard, yet several biomarkers have been studied in relation to VC among which sclerostin is a potential one.
Sclerostin, a 190 amino acid residue glycoprotein, is mainly excreted from the mature osteocyte as a delayed event after mineralization has occurred to inhibit cortical bone formation and osteon infilling. It is also expressed in the calcified plaques, in the late phase of VC. It acts in a defensive manner that aims to block the Wnt signalling pathway in order to reduce mineralization in the calcified vascular tissue. The present study aimed at measuring its serum level in both dialyzed and undialyzed CKD cases and correlating its serum level with both vascular and valvular types of calcification.
The study was conducted on 82 Egyptian subjects of comparable age and gender divided into 20 apparently healthy volunteers as well as 62 chronic kidney disease cases of whom 31 cases were under maintenance hemodialysis for more than 6 months.
To all subjects, full clinical examination and anthropometric measurements (weight, height, BMI, triceps skin fold, total body water, fat free mass and total body fat) were done. For all cases a B-mode ultrasound of the common carotid artery was done to determine carotid intima media thickness and detect carotid calcification, as well as an echo cardiographic examination of the heart to detect valvular calcification. Lab investigations for all subjects included the determination of serum glucose, some renal and liver function tests, lipid profile, calcium, phosphorous, and intact parathormone as well as serum sclerostin. Data were statistically analyzed using appropriate statistical tests.
The results of the present work pointed out a significant increase in serum sclerostin median values in dialyzed group than that in non dialyzed group and control group. Also, a significant increase in its level was observed in non dialyzed cases than in control group. Correlation of serum sclerostin with different parameters revealed positive relations with old age, male gender and estimated glomerular filtration rate (total number of CKD cases). Furthermore, significant positive correlation existed between serum sclerostin and valvular type of calcification in CKD cases whether dialyzed or not, however no significant correlation existed with vascular calcification.
Receiver operating characteristics curve analysis revealed serum sclerostin as a potential sensitive rather than a specific biomarker of both vascular and valvular types of calcification in all CKD cases, generating a serum sclerostin cut off value of 39.47 pmol/L for vascular type and a serum sclerostin cut off value of 29.39 pmol/l for valvular type. The multiple regression line analysis done revealed an independent contribution of male gender, renal disease (eGFR) and valvular calcification in serum sclerostin level.