5588571 DYSLIPIDEMIA IN TRANSFUSION-DEPENDENT-THALASSEMIA PATIENTS AND ITS CORRELATION WITH SERUM VITAMIN D LEVEL

Abstract

Background: Studies showed that transfusion dependent thalassemia (TDT) patients may develop premature atherosclerosis due to chronic hemolysis, iron deposition in blood vessels and dyslipidemia. Serum lipids abnormalities have been reported in TDT increasing the risk for premature atherosclerosis and other cardiovascular complications. Iron overload and oxidative stress are the main contributing factors to dyslipidemia in TDT patients. Few studies revealed that vitamin D is associated with favorable lipid profile in children and had relation to total cholesterol, low-density lipoproteins (LDL), high-density lipoprotein (HDL) level and triglyceride (TG) levels. However, its role in patients with TDT needs to be determined. Aim: To investigate the correlation between serum lipid profile and dyslipidemia with serum vitamin D level in TDT patients. Methods: This cross-sectional observational study conducted at Pediatric Hematology Unit, Cairo University Children Hospital included 50 children aged 3-18 years diagnosed with TDT and 30 apparently healthy unrelated age and sex matched children as a control group. Subjects were enrolled after obtaining willingly informed consents from parents. Vitamin D (25-OHD) level was measured using HPLC-UV method and 10-12 hour overnight fasting serum lipid profile including total cholesterol, HDL, LDL, and triglyceride (TG) were performed using automated chemistry analyzer Cobas C 311. Atherogenic index of plasma (AIP), an index composed of TG and HDL-C, was measured. Results: TDT patients had significantly lower cholesterol, HDL and LDL and higher TG levels compared to control group (p=0.00 for all parameters respectively). The median AIP was significantly higher in TDT patients compared to control group (0.36 vs -0.08 respectively with p=0.00). Vitamin D deficiency and insufficiency (defined as 25-OH D3 level less than 20 ng/ml and 20-29 ng/ml respectively) were evident in 20% and 24% of TDT patients respectively. Mean Vitamin D level among TDT patients was 33.91 ng/ml. Vitamin D had a statistically significant negative correlation with total cholesterol (r = -0.288, p = 0.010), LDL (r = -0.287, p = 0.010), and HDL (r = -0.280, p = 0.012) but had no significant correlation with TG (p = 0.379). Lower hemoglobin and hematocrit levels were associated with lower total cholesterol, LDL and HDL levels (p=0.00 for all parameters respectively) and with higher TG (p=0.00). No correlation was evident between serum ferritin level and any of lipid profile parameters. Conclusion: Serum lipid abnormalities in TDT patients includes hypocholesterolemia, decreased HDL, LDL and increased TG levels Measurement of serum lipid profile may help in early detection of cardiovascular complications such as premature atherosclerosis among these patients. AIP may serve as an additional indicator of dyslipidemia. Our results reinforce previous reports of vitamin D deficiency in TDT patients and demonstrate its correlation with dyslipidemia. Key words: Thalassemia- Dyslipidemia- Lipid profile- Vitamin D.