Chlamydia pneumoniae as risk factor of cardiovascular disease in dialysis patients

Cross-talk between endothelin-1 and mineral metabolism in hemodialysis patients: a cross-sectional study

Background:

Endotheline-1 (ET-1), an endothelial mediator, influences on mineral metabolism; especially vascular calcification in uremic patients.

Objectives:

The aim of the present study was to evaluate of ET-1, high-sensitivity C-reactive protein (hs-CRP) and mineral metabolites as the main factors for vascular calcification and inflammation in hemodialysis (HD) patients.

Patients and Methods:

In this cross-sectional study, 46 chronic stable HD patients were selected from nephrology departments of Tabriz University of Medical Sciences affiliated hospitals and classified based on phosphorus (P), Ca-P product (Ca × P) and intact Parathyroid Hormone (iPTH) levels. We evaluated fasting serum ET-1and hs-CRP levels by the standard methods and compared with 46 healthy control subjects.

Results:

The levels of serum hs-CRP and ET-1 were significantly higher in the patient’s group compared with controls (4.40 ± 1.26 vs. 1.38 ± 1.61, P < 0.0001, and 2.31 ± 0.87 vs. 0.75 ± 0.48, P < 0.0001, respectively) and with regard to Ca × P product cut-off point (3.99 ± 0.78 vs. 5.33 ± 1.64, P < 0.0001, and 2 ± 0.73 vs. 3.04 ± 0.73, P < 0.0001 respectively). ET-1 was correlated significantly with hs-CRP level (r = 0.776, P < 0.0001). Serum P, Ca × P and iPTH levels directly and Ca indirectly were correlated with serum ET-1 in HD patients (r = 0.932, P < 0.0001, r = 0.766, P < 0.0001, r = 0.514, P < 0.0001, r = -0.538, P < 0.0001 respectively). Multiple regression analysis demonstrated that serum P were independently associated with ET-1 levels (β = 0.932, P < 0.0001).

Conclusions:

Serum P and iPTH levels were independently associated with ET-1 and those may play a role in development of endothelial dysfunction in chronic kidney disease.

Chlamydia Pneumoniae and Cardiovascular Disease in End-Stage Renal Disease Patients: An Update

Cardiovascular diseases (CVD), due to accelerated atherosclerosis, are responsible for approximately 50% of mortality in End Stage Renal Disease (ESRD) patients undergoing haemodialysis (HD). Over the last decade, Chlamydia pneumoniae, a respiratory pathogen, has been involved in the pathogenesis of atherosclerosis and several reports have suggested the association between C. pneumoniae infection and CVD in HD patients. This report reviews the contribution of C. pneumoniae infection in cardiovascular diseases in ESRD patients, in light of recent studies on cardiovascular risk factors; we hypothesize that C. pneumoniae-infection may contribute to mineral bone disorder and, consequently, vascular calcification. However, further studies are needed to define the relationship between C pneumoniae and bone and vascular disorders in HD patients.