Reduced structural and functional skin capillaries in familial combined hyperlipidemia affected men, associated with increased remnant-like lipoprotein cholesterol levels

We determined whether abnormalities in the number of basal (BC) and post-occlusive (POC) capillaries are present in familial combined hyperlipidemia (FCHL), and investigated the possible relationship of BC and POC with lipids, remnant-like lipoprotein particles (RLP-C), blood pressure, and insulin resistance. Fifty age-matched subjects, 23 (12 men) hyperlipidemic, normotensive FCHL subjects and 27 (14 men) healthy controls participated in this study. Capillary density was measured just above the finger nailfold, before and after 4 min of arterial occlusion. The number of BC and POC were significantly lower in FCHL men compared with healthy men, 113.7±15.1 versus 132.0±18.0 (P=0.02) and 123±19.1 versus 142.3±18.3 (P=0.03), respectively. No differences were found between FCHL women and control women. In univariate analyses in FCHL men, BC was inversely correlated with total cholesterol (r=−0.63; P=0.05). POC tended to be inversely correlated with total cholesterol (r=−0.62; P=0.056). No univariate correlations (P>0.3) were observed between BC or POC and blood pressure or insulin resistance. Multivariate analyses revealed that log RLP-C was the only significant independent contributor to BC and POC. This is the first description of a reduction in skin capillaries in FCHL men, which was associated with increased atherogenic lipoprotein levels. Loss of capillary surface may be important in the pathophysiology or can result from adaptation to the hyperlipidemia in FCHL.