Hyperphosphatemia and high calcium X phosphate product are significant and common risk factors of cardiovascular disease in patients with chronic kidney disease. However, the relationship is not clear between increased risk and hyperphosphatemia and elevated calcium X phosphate product. Carotid intima-media thickness is a marker of early atherosclerosis, especially itÕs anatomic extent and progression. In chronic renal disease fibrinogen, phosphate levels and calciumXphosphate product are thought to be potential risk factors for cardiovascular disease. The aim of this study is to investigate the assosiation between these risk factors and the measurement of carotid intima-media thickness.
Material and Methods: In this study we measured serum BUN, creatinine, uric acid, calcium, phosphate, total cholesterol, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol, triglyceride and plasma fibrinogen levels and calculated calciumXphosphate product of 40 patients in Chronic Kidney Disease of different severity (GFR=8.4-83.5 ml/min) and in 20 healthy control subjects (GFR>90 ml/min). Carotid intima-media thickness of all subjects were measured by ultrasonography. The possible contribution of serum phosphate levels and calciumXphosphate product on carotid intima-media thickness increase were evaluated.
Results: The patient group had significantly higher serum phosphate (p = 0.003), CaX P (p = 0.023) and fibrinogen (p = 0.000) values than the control group. Carotid intima-media thickness values were found to be positively correlated with CaXP (p = 0.04, r = 0.283) and age (p= 0.00, r= 0.804). We observed an independent correlation of maximum carotid intima-media thickness with age (t=7.735, p = 0.000), calciumXphosphate (t = -2.174, p= 0.036) and fibrinogen (t = -3.152, p = 0.003), by using multipl stepwise regression analysis (R2 = 0.618, F ratio = 21.536, p = 0.003).
Conclusions: Our results revealed that age, elevated calciumXphosphate product and fibrinogen levels are significant risk factors for the development of atherosclerosis in patients with chronic renal disease. In these patients controlling serum phosphate levels may be helpful to prevent the increase in vessel wall thickness.