Decreased skeletal muscle capillary density is related to higher serum levels of low-density lipoprotein cholesterol and apolipoprotein B in men.
The relationships between skeletal muscle morphology, particularly muscle fiber capillary density, and serum lipid profiles were evaluated in 25 non-obese men aged 18 to 36 years (body mass index [BMI], 22.7 +/- 2.5 kg/m2; body fat, 13.6% +/- 4.0%, maximal oxygen uptake [VO2max], 46.2 < or = 6.3 mL/kg/min). Skeletal muscle samples were taken from the vastus lateralis using the needle-biopsy method. The fiber types (I, IIa, and IIx) and their percent distribution, the indices of capillary density, and the diffusion index expressed as the cross-sectional area occupied by one capillary were determined. Blood samples were drawn from the antecubital vein after a 12-hour fast. Based on Pearson's correlation analysis, the number of capillaries around type IIx fiber correlated inversely with the serum level of low-density lipoprotein cholesterol ([LDL-C] r = -.50, P < .05). The number of capillaries per fiber (cap/fiber ratio), number of capillaries per area (cap/mm2), and capillaries around each fiber type correlated inversely with the serum level of apolipoprotein B ([apo B] r = -.40 to -.54, P < .05 to .01). Further, the diffusion index for each fiber type correlated positively with LDL-C and apo B (r = .42 to .50, P < .05 to .01). Among 14 subjects in whom high-density lipoprotein cholesterol (HDL-C) subfractions were analyzed, a positive correlation was found between cap/mm2 and HDL2-C (r = .64, P < .05). Partial correlation analysis showed that these correlations either remain or improve after adjusting for age, VO2max, and body fatness. These results indicate that skeletal muscle capillary density and diffusion capacity are related to lipid and apolipoprotein concentrations for both type I and type II fibers.
Shono
N
N
Department of Community Health Science, Saga Medical School, Japan.
Mizuno
M
M
Nishida
H
H
Higaki
Y
Y
Urata
H
H
Tanaka
H
H
Quistorff
B
B
Saltin
B
B
Shindo
M
M
Nishizumi
M
M
D000273:Adipose Tissue / Q000033:anatomy & histology; D000328:Adult; D001055:Apolipoproteins B / Q000097:blood*; D001824:Body Constitution; D015992:Body Mass Index; D002196:Capillaries / Q000033:anatomy & histology*; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood*; D006801:Humans; D007564:Japan; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000166:cytology; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000098:blood supply*; D010101:Oxygen Consumption; D012016:Reference Values; D012044:Regression Analysis
D001055:Apolipoproteins B; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL