Introduction: some of the cardiovascular risk factors which have been identified include: Dyslipidemia, Diabetes mellitus, hypertension, Smoking, Insulin resistance, Abdominal obesity, Inflammation, Prothrombotic state. In many past studies, apolipoprotein B (apo B) was mentioned as the best marker of lipid profile. This is also approved that LDL-C is the major lipoprotein that produces atherosclerosis but comparison between apo Band LDL-C has rarely performed for prediction of cardiovascular events. The present study compares exclusively this issue, for the first time in Iran. On the other hand, it is known that metabolic syndrome is defined by the presence of three or more of abdominal obesity, hypertriglyceridemia, low HDL, hypertension, high fasting blood sugar. Because of high prevalence of metabolic syndrome in Iran and high prevalence of dyslipidemia in these patients, the present study performed within them.
Material and Methods: 66 adult patients (above 20 years old) with metabolic syndrome were chosen between referred patients to endocrinology and cardiology clinics of Imam Reza hospital in Mashad. The following variables were studied: Blood pressure, Waist, Body Mass Index (BMI), Triglyceride, Cholesterol, Fasting blood sugar, HDL, LDL and apo B. The patients were divided into four groups upon high or normal levels of LDL and also high or normal levels of apo B. Then, the means of mentioned variables were compared in different groups and the correlations of apo B and LDL-C with other variables were also measured by statistical tests.
Results: Among total 66 patients there were 11 men and 55 women in the range of 21-78 years old with the mean of 46.15±13.43.15% of the patients of this study had normal LDL but high apo B. The comparison of cardiovascular risk factors between this group and the high LDL, normal apo B group did not show any significant difference, except for cholesterol which its mean was higher in second group. The correlations of apo B with cholesterol, TG, HDL, LDL and FBS were significant (P<0.001) for cholesterol and P<0.05 for the others), But LDL-C correlated with cholesterol and waist only (P<0.0001 for cholesterol and P<0.05 for waist).
Conclusions: Although, comparison between the two groups: with only high apo B and only high LDL did not show considerable significant difference but for the reason that apo B correlated with a wider array of cardiovascular risk factors, in comparison with LDL-C, it conclude, that apo B is a better predictor for cardiovascular events, generally. Patients with normal standard lipid profile but high apo B benefit from lipid lowering treatment. In conclusion, the measuring of apo B is suggested in addition to routine lipid profile tests, at least in metabolic syndrome patients.