Muscle loss and obesity: the health implications of sarcopenia and sarcopenic obesity

Abstract

Conference on 'Nutrition and age-related muscle loss, sarcopenia and cachexia' Symposium 4: Sarcopenia and cachexia and social, clinical and public health dimensionsMuscle loss and obesity: the health implications of sarcopenia and sarcopenic obesity S. Goya Wannamethee* and Janice L. AtkinsDepartment of Primary Care and Population Health, University College London, Royal Free Campus, London NW3 2PF, UK This paper reviews the health implications of obesity, sarcopenia and sarcopenic obesity on CVD and mortality in older adults and discusses the obesity paradox seen in patients with CVD. Obesity is a major public health problem with increasing prevalence worldwide. It is an established risk factor for cardiovascular morbidity and mortality in adult populations. However, there is controversy surrounding the effects of obesity as measured by BMI in older people, and overweight and obesity (BMI ⩾ 25 kg/m 2 ) are apparently associated with increased survival in those with CVD (obesity paradox). Ageing is associated with an increase in visceral fat and a progressive loss of muscle mass which have opposing effects on mortality. Thus BMI is not a good indicator of obesity in older adults. Sarcopenia, the age-associated loss of skeletal muscle mass, is a major concern in ageing populations and has been associated with metabolic impairment, CVD risk factors, physical disability and mortality. Sarcopenia often coexists with obesity. Sarcopenic obesity is a new category of obesity in older adults who have high adiposity coupled with low muscle mass. To fully understand the effect of obesity on mortality in the elderly it is important to take muscle mass into account. The evidence suggests that sarcopenia with obesity may be associated with higher levels of metabolic disorders and an increased risk of mortality than obesity or sarcopenia alone. Efforts to promote healthy ageing should focus on both preventing obesity and maintaining or increasing muscle mass.Obesity: Muscle: Sarcopenia: CVD: Mortality: Older adults Obesity, i.e. excess body fat usually defined as BMI ⩾ 30 kg/m 2 , is a major public health problem and is well recognised as a risk factor for cardiovascular morbidity and mortality in adult populations. Obesity prevalence in middle-aged and older adults continues to increase worldwide and has doubled since 1980 (1,2) . However, there is controversy surrounding the effects of overweight and obesity in older people, with many studies showing that being overweight, as defined by BMI of 25-29 kg/m 2 , does not appear to be as harmful in the elderly as in middle-aged populations and may even be associated with lower, rather than higher, mortality (3)(4)(5) . In addition, a large body of evidence indicates that overweight and obesity (BMI ⩾ 25 kg/m 2 ) are associated with increased survival in patients with CVD and in particular those with heart failure, an unexpected finding termed the obesity paradox (6)(7)(8)(9)(10) . The mechanisms of these paradoxical association remain largely unexplained but a number of explana...

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