Serum hyaluronan and aminoterminal propeptide of type III procollagen: variation with age.

The serum levels of hyaluronan and the aminoterminal propeptide of Type III procollagen (PIIINP) were compared in 585 healthy individuals as a function of age. Newborn children displayed high hyaluronan (695 +/- 634 micrograms l-1, mean +/- SD) and PIIINP (295 +/- 152 micrograms l-1) values. The values were not correlated to the gestational week in which the children were born or to the birth weight but there was a significant correlation (p < 0.05) between the hyaluronan and PIIINP levels. During the first year the levels dropped and in childhood (1-16 years of age) both hyaluronan and PIIINP levels were fairly constant at 27 +/- 16 and 22 +/- 8.4 micrograms l-1, respectively. The PIIINP level showed a marked drop in adults compared to children. The drop continued to about 50 years of age (6.5 +/- 2.2 micrograms l-1) and then there was a slight increase in elderly people. The hyaluronan showed a continued increase with age from the level at 16 years of 29 +/- 17 micrograms l-1 to a mean value of 177 +/- 133 micrograms l-1 in people over 75 years. There was no increase in serum hyaluronan in women during pregnancy but the PIINP level increased in the later part of the gestational period. There was no correlation between the serum values of hyaluronan and PIIINP when compared throughout the life span which indicates that the blood levels of the two markers are regulated by independent factors.