▁f ats ▁carried ▁within ▁into ▁the ▁cells ). ▁ ▁Through ▁mechan isms ▁only ▁partially ▁understood , ▁high ▁levels ▁of ▁A po B , ▁especially ▁associated ▁with ▁the ▁higher ▁L DL ▁particle ▁concentr ations , ▁are ▁the ▁primary ▁driver ▁of ▁pla ques ▁that ▁cause ▁v asc ular ▁disease ▁( ather os cl eros is ), ▁commonly ▁first ▁becoming ▁obviously ▁sympt om atic ▁as ▁heart ▁disease , ▁stroke ▁& ▁many ▁other ▁body ▁wide ▁comp lications ▁after ▁dec ades ▁of ▁pro gression . ▁There ▁is ▁considerable ▁evidence ▁that ▁concentr ations ▁of ▁A po B ▁and ▁especially ▁the ▁N MR ▁ass ay ▁( specific ▁for ▁L DL - part icle ▁concentr ations ) ▁are ▁superior ▁indic ators ▁of ▁v asc ular / heart ▁disease ▁driving ▁phys i ology ▁than ▁either ▁total ▁ch ol ester ol ▁or ▁L DL - ch ol ester ol ▁( as ▁long ▁promoted ▁by ▁the ▁ ▁N I H ▁starting ▁in ▁the ▁early ▁ 1 9 7 0 s ). ▁However , ▁primarily ▁for ▁historic ▁cost / complex ity ▁reasons , ▁ch ol ester ol , ▁and ▁estimated ▁L DL - ch ol ester ol ▁by ▁calculation , ▁remains ▁the ▁most ▁commonly ▁promoted ▁li pid ▁test ▁for ▁the ▁risk ▁factor ▁of ▁a ther os cl eros is . ▁A po B ▁is ▁rout in ely ▁measured ▁using ▁imm uno ass ays ▁such ▁as ▁EL IS A ▁or ▁ne ph el ometry . ▁Ref ined ▁and ▁autom ated ▁N MR ▁methods ▁allow ▁measurement ▁dist in ctions ▁between ▁the ▁many ▁different ▁A po B ▁particles