ABC | Volume 110, Nº4, April 2018

Original Article Cartolano et al LAP and lipoprotein size Arq Bras Cardiol. 2018; 110(4):339-347 Table 1 – Demographic and clinical characteristics of subjects by gender Variables Total (n = 351) Men (n = 132) Women (n = 219) p n % n % n % Age (years) ** 52.5 (10.4) 49.4 (11.1) 54.4 (9.6) < 0.001 Smoking No 282 80.3 98 74.2 184 84.0 0.026 Current illnesses 306 87.2 114 86.4 192 87.7 0.723 Diabetes mellitus 71 20.2 32 24.2 39 17.8 0.146 Hypertension 200 57.0 75 56.8 125 57.1 0.962 Dyslipidemia 192 54.7 72 54.5 120 54.8 0.964 Drugs 274 78.1 91 69.8 183 83.6 0.001 Statin 98 27.9 28 21.2 70 32.0 0.030 Antihypertensive 181 51.6 64 48.5 117 53.2 0.370 Hypoglycemic agents 73 20.8 29 22.0 44 20.1 0.674 Fibrate § 9 2.6 3 2.3 6 2.7 0.543 Family history of diseases 320 91.2 122 92.4 198 90.4 0.520 Obesity 64 18.2 28 21.2 36 16.4 0.262 Hypertension 228 65.0 83 62.9 145 66.2 0.526 Acute myocardial infarction 100 28.5 38 28.8 62 28.3 0.924 Stroke 67 19.1 25 18.9 42 19.2 0.956 Diabetes mellitus 134 38.2 49 37.1 85 38.8 0.752 Peripheral vascular disease 25 71 8 6.1 17 7.8 0.548 Comparative analysis of categorical variables was performed by Pearson chi-square or Fisher’s exact test (§) (p < 0.05). ** Data presented as mean and standard deviation. Comparative analysis of continuous variables was performed using the unpaired Student’s t-test (p < 0.05) which LAP was a better marker of glucose imbalance and a stronger predictor of DM than BMI. 13-20 The present study confirms that LAP is sensitive to identify dysfunctions related to glucose metabolism, even after adjustment for drug use and multiple confounders. The relevance of LDL-C in the development of atherosclerosis has been recognized. However, some individuals with normal LDL-C levels have cardiovascular events, indicating that other risk factors related or not with LDL exert a role in the atherosclerotic process. Epidemiological evidence shows that an increased proportion of small and dense LDL particles is strongly associated with the risk of coronary heart disease. 25 Individuals with elevated plasma concentrations of small and dense LDL are at 3–7 times greater risk to develop coronary artery disease (CAD), independent of the LDL-C level. 5 Smaller and denser LDL, known as phenotype B, has been proposed as a more atherogenic sub-fraction than large LDL. Smaller particles remain for a longer time in plasma and shows reduced affinity for the B/E receptor. 25 Phenotype-B LDL is highly recognized by scavenger receptor, and therefore is more susceptible to migration to the subendothelial layer and oxidation. 4,5 Despite that, the relationship between LAP and LDL size has not been described in the literature. Our results showed that small LDL particles and LDL size were positively and negatively associated with LAP, respectively, even if LDL-C was not related to LAP. Mirmiran et al. 26 also didn’t find any correlation between LAP and LDL-C. Reinforcing the negative role of small and dense LDL, Kwon et al. 27 described that this particle was independently associated with the incidence and extension of CAD in a Korean population, confirmed by subsequent studies. 28,29 Studies have also reported a negative correlation between LDL size and risk of acute myocardial infarction. 30,31 Similarly, small and dense LDL was associated with increased TG and decreased HDL-C levels. 32 Therefore, results presented in this study showed for the first time that the LAP was significantly and robustly associated with the more atherogenic small LDL particle in Brazilians subjects above 30 years of age and moderate cardiovascular risk. Contrary to high LDL-C level, low HDL-C level is accepted as an independent risk factor for CVD. 22,23,32 Currently, it has been proposed that reverse cholesterol transport and other HDL properties such as antithrombotic action, endothelial function, and antioxidant and anti-inflammatory activities depend on HDL size. 33 Larger HDL particles have a higher content of Apo AI and are described as more effective in reverse cholesterol transport. 3 Asztalos et al. 32 showed that a predominance of small, rather than large HDL particles, increased the risk of coronary heart disease. It was also 342