[Risk factors for progression of coronary artery calcification over 5 years in hemodialysis patients]

BACKGROUND

Although progression of coronary artery calcification (CAC) has been established as an important marker for cardiovascular morbidity, very few studies have studied it in end-stage renal disease patients. Thus we examined and evaluate risk factors of calcification changes in dialysis patients.

METHOD

Among 28 hemodialysis (HD) patients, CAC was measured in Agatston units at baseline and after five years using the 64 multi-slice ultra-fast CT. The HD patients were classified as progressors or no progressors according to the change in the CAC score across these 2 measurements.

RESULTS

Over an average 63 months follow-up, participants without CAC at baseline had no incident CAC. The progression of CAC was slow and was found only in 6 patients (21.4%). It was significantly associated with several cardiovascular risk factors, namely, older age (P=0.03), diabetes (P=0.05), male sex (P=0.02), hypercholesterolemia (P=0.05), anemia (P=0.017), inflammation (P=0.05), and hyperphosphataemia (P=0.012). However, calcemia, parathormone levels, dialysis duration, tobacco, high blood pressure and dialysis dose did not seem to influence the progression of CAC in our series. A strong association was found between basal calcification scores and Delta increment at 5 years.

CONCLUSIONS

Our study suggests that CAC progression in dialysis is a complex phenomenon, associated with several risk factors with special regard to elevated basal scores. This progression can be avoided or slowed with appropriate management, which must begin in the early stages of chronic kidney disease.

[Screening and risk factors of cardiac calcification in hemodialysis: contribution of ultra-fast multi-slice scanner and transthoracic echocardiography]

INTRODUCTION

Cardiovascular disease is the first leading cause of death in hemodialysis patients. In this population, cardiovascular calcifications occur at an earlier age and progress faster than in general population.

PATIENTS AND METHODS

In order to determine the prevalence and risk factors of cardiac calcifications, 49 patients on chronic hemodialysis were screened in the coronary arteries and cardiac valves by the 64 multi-slice ultra-fast CT and the transthoracic echocardiography. Different clinical and biological parameters were studied by the SPSS 10.0 statistical software to determine risk factors.

RESULT

Cardiac calcifications were identified in 81.6% of cases in at least one of the two studied sites. The coronary artery involvement was more common than valvular and concerned 69.4% of cases. The mean Agatston coronary artery calcium score (ACACS) was 331.1 and 522.2 in coronary patients and was correlated to alteration of systolic function of LV (r=-0.287, P=0.045). The severity of CACS was positively correlated with age (r=0.332, P=0.02). Coronary calcifications were associated with cardiovascular risk common to those of the general population (age, male sex, systolic blood pressure, diabetes, history of ischemic heart disease), but also to a lesser quality of dialysis. Valvular calcifications were present in 49% of cases and were correlated with left ventricular hypertrophy (P=0.006). The exclusive involvement of the aortic valve was the most common valvular abnormality. Phosphocalcic and lipid parameters, levels of hemoglobin, CRP and uric acid did not predisposed to cardiac calcifications in our patients.

DISCUSSION

In hemodialysis patients, the pathogenesis of cardiovascular calcification is complex and cannot be attributed to a passive process. This process involves several factors that can promote or inhibit calcification. The new multi-slice ultra-fast scanner is a very sensitive method for topographic and quantitative assessment of coronary calcification and is a better alternative to invasive techniques.

CONCLUSION

Our study confirms the high prevalence of cardiac calcification in hemodialysis, and highlights the importance of early screening and treatment of predisposing factors.

Argan oil reduces, in rats, the high fat diet-induced metabolic effects of obesity

BACKGROUND AND AIM

Obesity is a multi-factorial disorder which is of worldwide concern. In addition to calorie control, some specific dietary components might help resolving some of the complication of obesity, by providing antioxidant and anti-inflammatory activities. We investigated the effect of argan oil supplementation on plasma lipid profile and oxidant-antioxidant status of rats with high-fat diet (HFD)-induced obesity compared with rats fed a normal diet (ND).

METHODS AND RESULTS

We used an animal model of high fat diet-induced obesity to study the metabolic effects of argan oil and we measured several markers lipid and redox statuses. Consumption of a high-fat diet led to an increase in serum total cholesterol (TC), LDL-cholesterol (LDL-C), and triacylglycerols (TAG) concentrations; however, argan oil blunted the increases of TC, LDL-C and TG, glucose, and insulin. Plasma total antioxidant capacity, erythrocyte catalase and superoxide dismutase activities were lower, whereas plasma hydroperoxide, thiobarbituric acid-reacting substances, and susceptibility of LDL to copper-induced oxidation were higher in obese rats compared with normal rats. Administration of argan oil ameliorated all these indices of redox status.

CONCLUSIONS

Proper diet and lifestyle should be foremost implemented to reduce the lipoprotein metabolism and oxidant/antioxidant status alterations brought about by obesity. In addition, argan oil reduces the metabolic effects of obesity and its use might be promoted within the context of a balanced diet.