The combination of sarcopenia and obesity (known as sarcopenic obesity) is an important public health problem that induces fragility in the elderly.2
The current incidence of sarcopenic obesity in elderly Brazilian women suggests it plays a role as an important negative factor that counteracts a successful aging process. In comparison, an elderly Mexican population showed a higher incidence of sarcopenic obesity (48%)3
compared with our results. The reduction in muscle mass (sarcopenia) that accompanies the normal aging process is also associated with increments in fat mass. With the concurrent increment in elderly people as reported by the Brazilian Institute of Geography and Statistics24
and the prevalence of sarcopenic obesity in Brazilians, a higher fragility could be expected in this population.25
Our results suggest the necessity of proper diagnosis of sarcopenic obesity independent of the nutritional state, such as muscle cross-sectional area, because the eutrophic status or the different obesity levels do not influence the diagnosis of sarcopenic obesity.
Our study indicates that a sedentary lifestyle may be an additional risk factor for both overweight and obesity, highlighting the concurrent muscular force loss as previously suggested.27
This is in accordance with previous literature.28
The diagnosis for obesity requires the utilization of various methods because BMI has been suggested to be inappropriate for this purpose in the elderly.10
Moreover, the current results suggest some discrepancies between BMI and DXA methods regarding the nutritional status of participants. Thus, eutrophic elderly women as determined by BMI were classified as obese with various severity levels with the employment of DXA, confirming the previous observations of Pahor et al.29
In this regard, BMI has demonstrated some limitations because of the concurrent lean body mass loss and fat mass gain observed in the elderly.10
Furthermore, all participants of the present study exhibited various levels of obesity, thus confirming the findings of previous studies in Brazilian populations. 30
Although BMI has been widely used in population studies, this method considers only height and body mass. On the other hand, DXA is considered a “gold-standard” method to estimate body composition, despite the high cost. In this sense, a higher sensitivity of DXA to estimate body composition would be expected.
Adipose tissue is currently recognized as an important metabolic and hormonal secretory organ with more than 50 product molecules identified.1
Subsequently, when there is an increase in adipose tissue, the impact of these molecules is also augmented, thus favoring the development of insulin resistance, type II diabetes, atherosclerosis, and metabolic syndrome and therefore impacting the health of older individuals.8
With the current results it was possible to verify an overestimation of muscle mass as a consequence of not taking into account the true differences in water, bone mass, and FFM, as the elderly have demonstrated an excessive extracellular fluid accumulation.29
This syndrome is associated with a progressive loss of muscle force and mass with subsequent lower physical capacity and quality of life, and hence the current results should be considered for further interventions in this population.
Newman et al34
emphasized the need to consider fat mass when diagnosing sarcopenia. The premise is based on the fact that individuals with high fat mass also demonstrate a high FFM. Therefore, individuals with high fat mass and subsequently high FFM would not be diagnosed as sarcopenic, independently of its influence on total body mass or functional capacity. In order to adjust FFM with fat mass, Newman et al34
proposed a method based on the residuals of a regression equation that predicts AFFM from fat mass and height; this was helpful in the diagnosis of sarcopenic obesity in the current study.
The limitations of the present study are the reduced number of participants and lack of additional measures, such as calf circumference and other metabolic parameters, that would certainly be of interest.