APOB and metabolic syndrome: If dyslipidemia is confirmed in a second fasting sample, a complementary study (second phase) should be conducted to evaluate the remaining fractions: VLDL, apolipoprotein A1, apolipoprotein B, apolipoprotein CII, and apolipoprotein CIII, and possible (co)existence of secondary causes (blood count, blood glucose, HbA1c, creatinine, urea, aspartate [AST], and alanine [ALT] aminotransferases, free thyroxine, and thyroid-stimulating hormone; an upper abdominal ultrasound and, if pertinent, beta-human chorionic gonadotropin) [2, 34].