Epidemiology of Sarcopenia: Determinants Throughout the Lifecourse

Abstract

Sarcopenia is an age-related syndrome characterised by progressive and generalised loss of skeletal muscle mass and strength; it is a major contributor to the risk of physical frailty, functional impairment in older people, poor health-related quality of life and premature death. Many different definitions have been used to describe sarcopenia and have resulted in varying estimates of prevalence of the condition. The most recent attempts of definitions have tried to integrate information on muscle mass, strength and physical function and provide a definition that is useful in both research and clinical settings. This review focuses on the epidemiology of the three distinct physiological components of sarcopenia, and highlights the similarities and differences between their patterns of variation with age, gender, geography and time and the individual risk factors that cluster selectively with muscle mass, strength and physical function. Methods used to measure muscle mass, strength and physical functioning and how differences in these approaches can contribute to the varying prevalence rates will also be described. The evidence for this review was gathered by undertaking a systematic search of the literature. The descriptive characteristics of muscle mass, strength and function described in this review point to the urgent need for a consensual definition of sarcopenia incorporating these parameters.

Prevalence of Sarcopenia and Sarcopenic Obesity Vary with Race/Ethnicity and Advancing Age

“…Similarly, data from the Chicago Health and Aging Project indicated that Black men and women have lower physical function compared with White men and women [38]. Finally, a recent systematic literature review on the epidemiology of sarcopenia concluded Non-White populations experience a more rapid decline in muscle strength and function compared to White populations [39]. Such differences were not reflected in the current study, where NH Black men and women were found to have lower rates of sarcopenia and SO compared to NH Whites.…”

Frailty, Sarcopenia and Falls

“…Osteoporosis predicts the future risk of fracture; and sarcopenia is a powerful predictor of future disability [32]. Reduced muscle mass and strength are also associated with lower bone mineral density [47,48], consistent with the "mechanostat" theory of bone loss due to reduced forces of muscle on bone [49].…”

“…Changes in body composition occur with normal physiological ageing [32]; usually, body weight increases during adulthood and peaks at the age of 65 years in women and 54 years in men [33]. Muscle mass is lost at a rate of approximately 8% per decade between the ages 50 and 70 years; then weight loss is coupled with an accelerated loss of muscle mass, reaching a rate of 15% each decade [33].…”

“…Sarcopenia has also been linked to higher hospitalisation rates, increased morbidity and mortality [52,53]. Sarcopenia may also be associated with metabolic and cardiovascular diseases such as diabetes, dyslipidaemia and hypertension [32].…”

Músculo esquelético: del nacimiento a la vejez, rutas hacia la falla mecánica y metabólica

“…El aporte de aminoácidos del músculo al resto de las células sugiere un aumento en la proteó-lisis de las proteínas estructurales. La tasa anual de pérdida muscular se ha estimado en un rango del 1 al 2% en las personas mayores de 50 años, el 25% hasta los 70 años y el 40% en las personas mayores de 80 años 32 . Nuestros resultados en el modelo animal sugieren que la proteólisis del músculo como mecanismo compensatorio sistémico en la vejez, expresado como hipotrofia y sarcopenia, no es un proceso reversible, principalmente debido a la disminución en la expresión de transportadores de aminoácidos y RI en los TT.…”