Blood components in a 70-year-old population.

The concentrations of many blood components change with age, and the aim of the present study was to determine, at the age of 70, the concentrations of blood components commonly used in clinical routine, and to examine how the exclusion of probands with disease influenced their distribution. In connection with a longitudinal population study "70-year-old people in Göteborg" 30 blood components have been analyzed in a representative sample of 973 70-year-old men and women. 29% of the probands were found to be without definable disease or treatment for presumed disease. Concentrations of 13 components were found to have a gaussian distribution which was not altered after the exclusion of probands with definable disease. Three components were asymmetrically distributed in the total material and showed a normal distribution with decreased concentrations at the 97.8% level after the exclusion of probands with definable disease. The remaining 14 components had asymmetrically distributed concentrations both in the total material and in the subjects without definable diseases. For blood components with normally distributed concentrations in the probands without definable disease, acceptable reference values could be obtained without exclusion of sick probands. For asymmetrically distributed blood components the concentration at the 97.8% level usually decreased more, after exclusion of probands with definable disease, the more asymmetric the distribution was. Examples of reference intervals are (men and women) B-Hb: 130--171 and 119--159 g/l, S-iron: 6--29 and 5--28 mumol/l, S-creatinine: 52--110 and 44--100 mumol/l, P-cholesterol: 3.6--9.2 and 4.6--9.7 mmol/l, P-B12: 50--350 and 65--390 pmol/l, B-ESR: 1--30 and 2--34 mm/h and B-glucose: 4.0--7.2 and 4.0--6.8 mmol/l.