Hormonal and lifestyle determinants of appendicular skeletal muscle mass in men: the MINOS Study

Centre for In Vivo Body Composition
Gastrointestinal Investigation Unit (11E)
Royal North Shore Hospital
St Leonards, NSW 2065
Australia
E-mail: hansenr{at}med.usyd.edu.au

Dear Sir:

The recent article by Szulc et al (1) identified several lifestyle and hormonal factors as potential determinants of sarcopenia in a large sample of men aged 45–85 y. Appendicular skeletal muscle mass, corrected for body size, displayed a notable age-related decline after the age of 60 y, and routine physical activity both at work and during leisure time were shown to positively affect arm and leg muscle masses, independently of age. Importantly, this investigation indicated that relatively nonstructured, low-to-moderate intensity activities—including bicycling, walking, gardening, and housework—can help to maintain muscle mass in elderly men.

It is interesting to note that we came to a similar conclusion (2) in regard to healthy white postmenopausal women of a comparable age range (54–76 y). A curvilinear relation between muscle mass and age was found, with an accelerated decline after 60–65 y. Those women who routinely engaged in work, household, or leisure activity with a combined energy expenditure of >5 MJ per fortnight had markedly better muscle mass indexes than did their less active counterparts; this effect was evident throughout the age range studied. Moreover, as noted by Szulc et al from self-reported data in their male cohort (1), interviews with these women showed the most common leisure-time activities undertaken (walking, dancing, floor exercises, gardening, swimming, and tennis) to be relatively nonstructured and moderate in intensity (2).

Although it must be acknowledged that some training and observational studies have failed to confirm a positive effect of these predominantly aerobic types of activity on muscle mass (3, 4), accumulating evidence supports a role for these popular activities in the maintenance of muscle and the provision of other metabolic benefits, including a reduction of abdominal fat, in both men and women (5). Such activities, therefore, may be useful in preventing sarcopenic obesity, which has been shown to be significantly associated with decreased functional status and increased disability and falls in the elderly (6). The follow-up reports of cohorts such as the MINOS Study subjects should be invaluable in further quantifying these important, practical aspects of the complex relation between physical activity and sarcopenia.

ACKNOWLEDGMENTS

There were no conflicts of interest.

REFERENCES

1. Szulc P, Duboeuf F, Marchand F, Delmas PD. Hormonal and lifestyle determinants of appendicular skeletal muscle mass in men: the MINOS study. Am J Clin Nutr 2004;80:496–503.
2. Hansen RD, Allen BJ. Habitual physical activity, anabolic hormones, and potassium content of fat-free mass in postmenopausal women. Am J Clin Nutr 2002;75:314–20.
3. Starling RD, Ades PA, Poehlman ET. Physical activity, protein intake, and appendicular skeletal muscle mass in older men. Am J Clin Nutr 1999;70:91–6.
4. Klitgaard H, Mantoni M, Schiaffino S, et al. Function, morphology and protein expression of ageing skeletal muscle: a cross-sectional study of elderly men with different training backgrounds. Acta Physiol Scand 1990;140:41–54.
5. Dionne IJ, Ades PA, Poehlman ET. Impact of cardiovascular fitness and physical activity level on health outcomes in older persons. Mech Aging Dev 2003;124:259–67.
6. Baumgartner RN. Body composition in healthy aging. Ann N Y Acad Sci 2000;904:437–48.