ABSTRACT
The aim of this study is the evaluation of intramyocellular (IMCL) and extramyocellular lipids (EMCL) in skeletal muscle in elderly female endurance-trained individuals. The subjects comprised endurance-trained elderly persons (END : n=7, age=66.1±2.0) and healthy elderly control subjects (CON : n=7, age=70.1±3.0). All subjects were female and matched by age and lower BMI. We quantified differences in IMCL and EMCL concentrations in the tibialis anterior (TA), soleus (SOL), and medial gastrocnemius (MG) muscles using <sup>1</sup>H-MR spectroscopy. The IMCL and EMCL contents in SOL and MG in END were significantly lower than those in CON (p<0.01). Total lipid content in SOL and MG was lower in END. The IMCL and EMCL contents in TA in END were slightly lower than those in CON. Water contents of all types of muscle in END were higher than those in CON. These results suggest that stored IMCL and EMCL in END are less than in CON.
ABSTRACT
This study used proton magnetic resonance spectroscopy (<sup>1</sup>H-MRS) to investigate differences in muscle group specific intramyocellular lipid (IMCL) storage characteristics associated with elevated muscle lipid storage, and to determine whether IMCL content is associated with maximal aerobic capacity. Seven healthy men [untrained (UT)], four overweight (OW) and six endurance-trained (T) subjects volunteered for this study. Data were acquired, using <sup>1</sup>H-MRS, from the tibialis anterior (TA), medial gastrocnemius (MG) and soleus (SOL) muscles. The IMCL content in TA was approximately twice as high in T subjects than in UT and OW subjects. In MG, IMCL was higher in OW and T subjects compared with UT subjects. A linear relationship existed between the VO<sub>2</sub>max and IMCL in TA and a curve of second-degree relationship between the VO<sub>2</sub>max and IMCL in MG. These results suggest that elevated IMCL deposits in TA might reflect enhancement of aerobic capacity, whereas the IMCL accretion in MG might reflect not only aerobic capacity but also overweight and obese conditions in men.
ABSTRACT
Gender differences were measured in the amount of intramyocellular triglyceride (IMCL) and extramyocellular triglyceride (EMCL) in skeletal muscles using<SUP>1</SUP>H-MR spectroscopy and their relation to body fat and peak VO<SUB>2</SUB>was 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<SUP>2</SUP>, age=21.1±0.7 years, female: n=7, BMI=20.6±0.5 kg/m<SUP>2</SUP>, 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) .<BR>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<SUB>2</SUB>; but the EMCL values of SQL correlated quite negatively with peak VO<SUB>2</SUB> (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.
ABSTRACT
Gender differences were measured in the amount of intramyocellular triglyceride (IMCL) and extramyocellular triglyceride (EMCL) in skeletal muscles using<SUP>1</SUP>H-MR spectroscopy and their relation to body fat and peak VO<SUB>2</SUB>was 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<SUP>2</SUP>, age=21.1±0.7 years, female: n=7, BMI=20.6±0.5 kg/m<SUP>2</SUP>, 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) .<BR>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<SUB>2</SUB>; but the EMCL values of SQL correlated quite negatively with peak VO<SUB>2</SUB> (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.