Background: Sarcopenia risk factors are poorly understood.
Methods: This study examines sarcopenia prevalence and risk factors in community-dwelling men (694) and women (1006) aged 55-98 years (mean=73) who attended a 1988-1992 Rancho Bernardo Study clinic visit. Height, weight, muscle strength, fat-free mass (FFM), fat mass by bioelectric impedance analysis, and grip strength were measured; alcohol and medication use, smoking, and physical activity were ascertained.
Results: Mean FFM was 43.5 kg for women and 61.7 kg for men. Sarcopenia, defined as FFM of > or =2.0 standard deviations below the gender-specific mean of a young reference population, was present in 6.0% overall. Prevalence increased dramatically from 4% of men and 3% of women aged 70-75 to 16% of men and 13% of women aged 85 and older. Both men and women with sarcopenia had a significantly lower fat mass and body mass index than those without sarcopenia. Men with sarcopenia were twice as likely to have fallen in the past year compared with those without sarcopenia. Grip strength, but not quadriceps strength, was lower in men and women with sarcopenia. Physically active women were about half as likely to have sarcopenia, but no association was found in men. Few men and women were current smokers, but they were more likely to have sarcopenia. Comorbidities (heart disease, diabetes, pulmonary disease, arthritis, cancer) and medications (thyroid hormones, corticosteroids, and hormone replacement therapy) were not associated with sarcopenia.
Conclusions: Sarcopenia increases with age. This study also identified lack of physical activity and current smoking as reversible risk factors for sarcopenia.