BackgroundFriedewald's formula for the estimation of LDL-C concentration is the most often used formula in clinical practice. A recent formula by Anandaraja and colleagues for LDL-C estimation still needs to be evaluated before it is extensively applied in diagnosis. In the present study we validated existing formulas and derived a more accurate formula to determine LDL-C in a Serbian population.MethodsOur study included 2053 patients with TG ≤ 4.52 mmol/L. In an initial group of 1010 patients, Friedewald's and Anandaraja's formulas were compared to a direct homogenous method for LDL-C determination. The obtained results allowed us to modify Friedewald's formula and apply it in a second group of patients.ResultsThe mean LDL-C concentrations were 3.9 ± 1.09 mmol/L, 3.63 ± 1.06 mmol/L and 3.72 ± 1.04 mmol/L measured by a direct homogenous assay (D-LDL-C), calculated by Friedewald's formula (F-LDL-C) and calculated by Anandaraja's formula (A-LDL-C), respectively in the 1010 patients. The Student's paired t-test showed that D-LDL-C values were significantly higher than F-LDL-C and A-LDL-C values (p < 0.001). The Passing-Bablok regression analysis indicated good correlation between calculated and measured LDL-Cs (r > 0.89). Using lipoprotein values from the initial group we modified Friedewald's formula by replacing the term 2.2 with 3. The new modified formula for LDL-C estimation (S-LDL-C) showed no statistically significant difference compared to D-LDL-C. The absolute bias between these two methods was -0.06 ± 0.37 mmol/L with a high correlation coefficient (r = 0.96).ConclusionsOur modified formula for LDL-C estimation appears to be more accurate than both Friedewald's and Anandaraja's formulas when applied to a Serbian population.

No abstract

No abstract

Background. As a physiological condition closely linked with increased susceptibility to oxidative stress, pregnancy can be further compromised by cigarette smoking. Inadequate nutrition and reduced intake of antioxidants can also disrupt the prooxidant/antioxidant relationship and contribute to oxidative stress. Increased oxidative stress during pregnancy may be involved in several complications of pregnancy, such as preterm labor, fetal growth restriction, preeclampsia and miscarriage. Objectives. The aim of this study was to investigate the influence of maternal smoking habits before pregnancy on the parameters of oxidative stress and the antioxidative defense system, lipid profile parameters and paraoxonase-1 (PON1) activity during the third trimester of uncomplicated pregnancies. Material and Methods. Healthy pregnant women (n = 86) were divided into non-smoking and smoking groups, and into groups taking vitamin supplements and not taking them. Oxidative damage was measured through the levels of thiobarbituric acid-reacting substances (TBARS) and plasma antioxidant status was evaluated by measuring total antioxidant capacity (TAC). Results. TBARS concetration was significantly higher (p < 0.05) and PON1 activity was significantly lower (p < 0.05) in the smokers' group. No significant differences were found in the investigated parameters in relation to vitamin supplement intake. Conclusions. Habitual smoking before pregnancy is associated with increased oxidative stress. Vitamin supplementation has no effect on the oxidative stress status of healthy pregnant women (Adv Clin Exp Med 2014, 23, 4, 575-583).

No abstract