CHOLESTEROL AND CHOLESTEROL SULFATE CONCENTRATION IN THE CELL-MEMBRANE COMPLEX OF HUMAN SCALP HAIR - A BIOMARKER OF AGING

Cell to cell cohesion in fully keratinized hair is mediated by a cell membrane complex which contains covalently bound (integral) hair lipid s. The influence of aging on concentrations of integral cholesterol su lphate (CHSU) and cholesterol (CH) in human scalp hair shafts, and the relationship between hair and plasma lipids were examined in 50 subje cts, aged 18 to 87 years, and in one case of Werner's syndrome. Hair C HSU concentrations were distributed normally and were significantly hi gher in male subjects with elevated plasma CH levels (>5.17 mmol/l) th an in those with normal plasma CH levels (806 +/- 134 versus 624 +/- 1 55 nmol/g hair, p < 0.001). Female subjects with elevated plasma CH le vels had even lower hair CHSU, values (515 +/- 167 nmol/g hair, p < 0. 05) than men with normal plasma CH. The almost white hairs of the Wern er's syndrome patient displayed low levels of CHSU, possibly indicatin g a precarious hair stability. A small but statistically significant l inear correlation between donor age and integral CH in hair (n = 51; y = 97.7 + 0.9x; cc = 0.32; p < 0.05) was detected. No correlation betw een hair CHSU and age could be demonstrated. Since internal hair lipid concentrations do not correlate with plasma lipids, the age associate d increase of hair CH as well as the observed gender differences in ha ir CHSU concentration may be related to alterations in the process of keratinization. Hair CH analysis seems to be of little significance in the clinical diagnosis of hypercholesterolemia.