Table 1. Cholesterol, Phospholipids,and Apolipoprotein A-i in HDL, and Ratios of These Variables. HDL-phospholipids. 1310 (321). 1040 (270)b.
and insulin binding to erythrocytes. Acta Med. Scand., in press, 1980. 4. Ivarsson, S. A., and Thorell, J. I., Meabocytes
surement
of insulin receptor
function.
Table 1. Cholesterol, Phospholipids, and Apolipoprotein A-i in HDL, and Ratios of These Variables
In vivo
Womon(n=20) Men(n=23) Concn (and SD), mg/I
contra in vitro methods. Acta Soc. Med. Suec. 88, 141 (1979).
6. Gambhir,
HDL-phospholipids HDI-apolipoprotein
receptors.
Diabetes
HDI-cholesterol/HDI-phospholipids
27,701-708
A. Ivarsson
Isotope Division, Dept. of Clin. Chem. Univ. of Lund MalmO General Hospital S-214 01 Malm#{246}, Sweden
Determination of High-Density
Lipoproteins:Comparisonof HDLCholesterol, HDL-Phospholipids, and HDL-Apolipoproteln A-I To the Editor:
The reported (1) good correlation between high-density lipoprotein
(HDL) phospholipidsby centrifugation and by precipitation is comparable to our data (2). Because the heterogeneous HDLs consist of subfractions with different lipid/protein ratios and possibly further
anti-atherogenic
properties,
information about HDL-comand distribution may be ob-
position tained by measuring
the
main
HDL-
protein, apolipoprotein A-I. We therefore determined cholesterol, phospholipids, and apolipoprotein A-I in the HDL of 43 sera. All subjects (20 women, 23 men, mean age 49, SD 13 years) were non-smokers with normal physical activity and normal body weight, who were taking no medication. HDL was separated by heparin-Mn2 precipitation (3). Cholesterol was analyzed enzymicafly (Boehringer kit, no. 187313), phospholipids as inorganic phosphorus (4), and apolipoprotein A-I by immunochemical quantitation (5).
Table 1 summarizes our results. HDL-chobesterol, HDL-phosphobipids, and the relationshipsof the HDL-bipids to the apolipoproteinA-I concentrations were significantly higher inwomen than in men. The HDL-chobesterol values were strongly correlated to the HDLphoapholipid values (y = 1.31x + 520, r = 0.91, p