Serum fatty acids had been studied for more than 30 years. In the inve
stigations of the relation with the risks of coronary heart disease, f
atty acids were examined in either serum total lipids or in one or two
lipid fractions, the results were not conclusive. The purpose of this
study was to report serum fatty acid compositions in total lipids (TL
) and in lipid fractions: cholesterol esters (CE), phospholipids (PL),
and triglycerides (TG). One hundred and four postmenopausal women who
were living in Allegheny County, Pennsylvania, USA and not taking hor
mone replacement therapy at the time of their first year clinic visit
after cessation of menses were selected to be studied. Fifteen fatty a
cids in TL, CE, FL, and TG were measured and identified by capillary g
as chromatography. A aliquot control serum was measured repeatedly for
assessment of quality control. The coefficient of variation for commo
n fatty acids was 8.2% for stearic acid in TL, 12.4% for palmitic acid
in FL, 9.1% for oleic acid in CE, and 4.5% for palmitic acid in TG. W
e report results from both quantitative (mg/dl) and qualitative (mole
%) analyses. The weight of fasting serum total fatty acids were 366.6
mg/dl in TL, 80.6 mg/dl in CE, 107.8 mg/dl in FL, and 56.9 mg/dl in TG
. The p/s ratios of serum fatty acids were 1.33, 3.57, 0.64, and 0.51
in TL, CE, FL, and TG, respectively. Fatty acid distributions from bot
h quantitative and qualitative measurements are to be evaluated for th
e relation with coronary heart disease.