Skin tissue cholesterol assay correlates with presence of coronary calcium

Keratinocytes maintain cholesterol homoeostasis using LDL and HDL-scavenger receptor pathways implicated in atherosclerosis. We tested whether skin tissue cholesterol (SkTC) is associated with subclinical atherosclerosis, assessed using carotid intima-medial thickness (IMT) and coronary artery calcification (CAC).

Two hundred and twenty two subjects were recruited from the Baltimore site of the Multi-Ethnic Study of Atherosclerosis (MESA). Baseline MESA examination included fasting blood collection, IMT measurement by B-mode ultrasound and CAC determination by helical CT. SkTC was measured using the Cholesterol 1, 2, 3 kit (IMI Inc., Canada).

SkTC was significantly higher if CAC was present in Caucasians (p = 0.04) but not African-Americans. SkTC was not significantly correlated with IMT in either group. Using multiple logistic regression adjusting for age, sex and serum lipids, a 1-standard deviation higher SkTC was associated with 187% higher odds of the presence of CAC in Caucasians (p < 0.01) but no significant difference in odds for African-Americans. In subjects in whom CAC was present, the extent of CAC was not related to the SkTC in multiple linear regressions.

SkTC was associated with the presence of CAC independently of serum lipids/lipoproteins in Caucasians but not African-Americans. SkTC may provide a useful indicator of subclinical atherosclerosis in Caucasians.