Gender differences were measured in the amount of intramyocellular triglyceride (IMCL) and extramyocellular triglyceride (EMCL) in skeletal muscles using
1H-MR spectroscopy and their relation to body fat and peak VO
2was studied. Fourteen apparently healthy subjects were separated into groups by gender. Both the male and female group subjects were selected according to similar ages and BMI (male: n=7, BMI=20.5±0.6 kg/m
2, age=21.1±0.7 years, female: n=7, BMI=20.6±0.5 kg/m
2, age=18.7±0.3 years) . We found a significant correlation between IMCL and EMCL in the soleus (SQL: p<0.01) and medial gastrocnemius (MG: p<0.01) muscles. IMCL values in SQL were significantly higher than IMCL values in MG and tibialis anterior muscle (TA) in both males and females in the order of SQL>MG>TA (p<0.01) .
IMCL and EMCL values in MG and SQL among females were significantly higher (p<0.01) than their corresponding values in males. However, a gender difference in IMCL and EMCL values for TA was not found. There was no correlation between IMCL and EMCL values for each muscle and BMI ; but IMCL (r=0.63 in SQL) and EMCL (r=0.88 and r=0.73 in SQL, and MG, respectively; p< 0.01) values correlated significantly with percent FAT. There was no correlation between IMCL values for each muscle and peak VO
2; but the EMCL values of SQL correlated quite negatively with peak VO
2 (r=-0.63, p<0.05) . These results suggest that there are gender differences in intramyocellular and extramyocellular triglyceride contents. Lipids were positively related to percent body fat in SQL and MG; EMCL values may have a negative effect on endurance capacity.
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