Prevalence, diagnostic criteria, and factors associated with sarcopenic obesity in older adults from a low middle income country: A systematic review

Sarcopenic obesity and health outcomes: An umbrella review of systematic reviews with meta-analysis

Many studies support the idea that sarcopenic obesity (SO) could be considered a potential risk factor for negative health outcomes. These results have been inconsistent, and no umbrella reviews exist regarding this topic. Several databases until November 2023 were searched for systematic reviews with meta-analysis of observational studies (cross-sectional, case-control and prospective). For each association, random-effects summary effect sizes with correspondent 95% confidence intervals (CIs) were evaluated using the GRADE tool. Among the 213 papers initially screened, nine systematic reviews with meta-analysis were included, for a total of 384 710 participants. In cross-sectional and case-control studies, 30 different outcomes were analysed, and 18 were statistically significant. In any population addressed in cross-sectional and case-control studies, compared with non-SO, SO increased the prevalence of cognitive impairment (k = 3; odds ratio [OR] = 3.46; 95% CI: 2.24-5.32; high certainty of evidence), coronary artery disease (k = 2; OR = 2.48; 95% CI: 1.85-3.31) and dyslipidaemia (k = 3; OR = 2.50; 95% CI: 1.51-4.15). When compared with sarcopenia or obesity, the results were conflicting. In prospective studies, the association between SO-compared with non-SO-and other negative outcomes was supported by low/very low certainty of evidence and limited to a few conditions. Besides, no comparison with sarcopenia or obesity was provided. Finally, only a few studies have considered muscle function/physical performance in the diagnostic workup. SO could be considered a risk factor only for a few conditions, with the literature mainly based on cross-sectional and case-control studies. Future studies with clear definitions of SO are needed for quantifying the importance of SO-particularly when compared with the presence of only sarcopenia or obesity-and the weight of muscle function/physical performance in its definition.

Prevalence of sarcopenic obesity according to different diagnostic methods and cut-off points in candidates for bariatric surgery

BACKGROUND AND AIMS

Sarcopenic obesity (SO) is defined as a combination of low strength and muscle mass along with excess adiposity. Our study aimed to determine the prevalence of sarcopenic obesity in candidates for bariatric surgery, according to ESPEN/EASO criteria using bioimpedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA).

METHODS

Retrospective study of adult patients (18-60 years) candidates for bariatric surgery (BMI ≥40 kg/m2 or ≥35 kg/m2 with associated complications). Adiposity was assessed by the percentage of fat mass by DXA, according to Gallagher's cut-off points. Muscle strength was measured by hand grip according to Sánchez-Torralvo, Dodds, and <-2SD cut-off points of healthy reference population. Muscle mass was determined by DXA (ALM/weight according to Batsis) and by BIA (SMM/weight according to Janssen and according to reference population). In addition, the agreement of the different diagnostic methods of sarcopenic obesity was analyzed.

RESULTS

A total of 124 subjects were included in the study, with 71.8 % being women. The overall mean age was 42.6 (SD 8.9) years. SO prevalence was found to be 13 %-22 % applying BIA with the SMM/weight equation according to Janssen, 14 %-23 % utilizing BIA with the SMM/weight equation according to the reference population, and 13 %-23 % employing DXA with the ALM/weight equation following Batsis criteria, depending on the specific hand grip strength cut-off points used. In general, we found good or very good concordances with the different diagnostic methods (with kappa values between 0.6 and 0.97).

CONCLUSIONS

The prevalence of SO according to ESPEN/EASO criteria in candidates for bariatric surgery was 13 %-23 % based on the diagnostic method and cut-off points used.

Sarcopenic Obesity: Involvement of Oxidative Stress and Beneficial Role of Antioxidant Flavonoids

Sarcopenic obesity, which refers to concurrent sarcopenia and obesity, is characterized by decreased muscle mass, strength, and performance along with abnormally excessive fat mass. Sarcopenic obesity has received considerable attention as a major health threat in older people. However, it has recently become a health problem in the general population. Sarcopenic obesity is a major risk factor for metabolic syndrome and other complications such as osteoarthritis, osteoporosis, liver disease, lung disease, renal disease, mental disease and functional disability. The pathogenesis of sarcopenic obesity is multifactorial and complicated, and it is caused by insulin resistance, inflammation, hormonal changes, decreased physical activity, poor diet and aging. Oxidative stress is a core mechanism underlying sarcopenic obesity. Some evidence indicates a protective role of antioxidant flavonoids in sarcopenic obesity, although the precise mechanisms remain unclear. This review summarizes the general characteristics and pathophysiology of sarcopenic obesity and focuses on the role of oxidative stress in sarcopenic obesity. The potential benefits of flavonoids in sarcopenic obesity have also been discussed.

Nutritional status as a mediator between the age-related muscle loss and frailty in community-dwelling older adults

PURPOSE

The purposes of the study were: a) to investigate the prevalence of sarcopenia, obesity and sarcopenic obesity (SO) in older adults, b) to explore the effect of nutrition as mediator of the association between these entities and frailty.

MATERIALS AND METHODS

Older adults (≥65 years) were evaluated based on European Working Group on Sarcopenia in Older People criteria for the presence/absence of sarcopenia. Obesity was diagnosed by using Zoico methodology. FRAIL scale was used to evaluate frailty and nutritional status was assessed with Mini Nutritional Assessment (MNA).

RESULTS

Five-hundred-seventy individuals (68,9% female, mean age 74,41±6,57 years) were included. The prevalence of sarcopenia, obesity and SO were 18,6%, 28,9% and 11,2%, respectively. FRAIL scores were directly affected by having sarcopenia (β: 0.42, 95% CI: (0.21-0.67), p<0.001) and SO (β: 0.31, 95% CI: (0.06-0.59), p:0.015), whereas obesity had no direct effect on FRAIL (β: 0.1, 95% CI: (-0.08-0.3), p:0.26). MNA was a mediator (β: -0.35, 95% CI: (-0.12-(-0.08)), p<0.0001) in both sarcopenic (β: -0.69, 95% CI: (-3.34-(-1.69)), p<0.0001) and SO patients (β: -0.34, 95% CI: (-2.21-(-0.26)), p:0.013), but not in obese group (β: -0.01, 95% CI: (-0.08-0.04). After the Bonferroni corrections,only sarcopenia had an association with frailty with MNA being the mediator.

CONCLUSION

The findings revealed that the frailty rate was higher in sarcopenia (20,8%) and SO (17,2%) groups than obese (5,5%) group. Frailty was associated with sarcopenia and SO, but not with obesity. Nutritional status was found to be a mediator of the association between age-related muscle loss and frailty To the best of our knowledge, this is the first study to report the mediator of the associations between age-related muscle loss and frailty.

The Critical Role of Oxidative Stress in Sarcopenic Obesity

Sarcopenic obesity (SO) is a combination of obesity and sarcopenia that primarily develops in older people. Patients with SO have high fat mass, low muscle mass, low muscle strength, and low physical function. SO relates to metabolic syndrome and an increased risk of morbimortality. The prevalence of SO varies because of lacking consensus criteria regarding its definition and the methodological difficulty in diagnosing sarcopenia and obesity. SO includes systemic alterations such as insulin resistance, increased proinflammatory cytokines, age-associated hormonal changes, and decreased physical activity at pathophysiological levels. Interestingly, these alterations are influenced by oxidative stress, which is a critical factor in altering muscle function and the generation of metabolic dysfunctions. Thus, oxidative stress in SO alters muscle mass, the signaling pathways that control it, satellite cell functions, and mitochondrial and endoplasmic reticulum activities. Considering this background, our objectives in this review are to describe SO as a highly prevalent condition and look at the role of oxidative stress in SO pathophysiology.

Metformin and tBHQ Treatment Combined with an Exercise Regime Prevents Osteosarcopenic Obesity in Middle-Aged Wistar Female Rats

Osteosarcopenic obesity (OSO) is characterized by bone density, mass, and muscle strength loss, in conjunction with adipose tissue increase. OSO impairs physical activity and mobility, provoking autonomy loss; also, it is known that augmenting body fat in the elderly decreases life expectancy. The main factors influencing this health deterioration are the inflammatory environment induced by adipose tissue and its infiltration into muscle tissue, which leads to oxidative stress generation. Currently, there are several treatments to delay OSO, among which exercise training stands out because it improves muscle fiber quality and quantity and decreases adipose tissue. We have recently demonstrated that the combined treatment between moderate exercise and metformin slows sarcopenia's onset by a mechanism that includes adipose reduction and REDOX regulation. On the other hand, tert-butylhydroquinone (tBHQ) is a well-known antioxidant that counteracts oxidative stress. Therefore, to slow down obesity's harmful effects on muscle mass and bone mineral density, we performed different interventions, including combining a Fartlek-type exercise routine with metformin and tBHQ administration, in a model of middle-aged female Wistar rats with obesity induced with a hypercaloric diet. Our results showed that the combined exercise-metformin-tBHQ treatment increased muscle mass and strength, decreased body weight, body mass index, and fat percentage, and improved redox status, thus increasing animal survival.

Low-Intensity Exercise Routine for a Long Period of Time Prevents Osteosarcopenic Obesity in Sedentary Old Female Rats, by Decreasing Inflammation and Oxidative Stress and Increasing GDF-11

The loss of skeletal muscle mass and strength is known as sarcopenia; it is characterized as a progressive and generalized muscle disorder associated with aging. This deterioration can seriously compromise the elderly's health and reduce their quality of life. In addition to age, there are other factors that induce muscle mass loss, among which are sedentary lifestyle, chronic diseases, inflammation, and obesity. In recent years, a new clinical condition has been observed in older adults that affects their physical capacities and quality of life, which is known as osteosarcopenic obesity (OSO). Osteoporosis, sarcopenia, and obesity coexist in this condition. Physical exercise and nutritional management are the most widely used interventions for the treatment and prevention of sarcopenia. However, in older adults, physical exercise and protein intake do not have the same outcomes observed in younger people. Here, we used a low-intensity exercise routine for a long period of time (LIERLT) in order to delay the OSO appearance related to sedentarism and aging in female Wistar rats. The LIERLT routine consisted of walking at 15 m/min for 30 min, five days a week for 20 months. To evaluate the effects of the LIERLT routine, body composition was determined using DXA-scan, additionally, biochemical parameters, inflammatory profile, oxidative protein damage, redox state, and serum concentration of GDF-11 at different ages were evaluated (4, 8, 12, 18, 22, and 24 months). Our results show that the LIERLT routine delays OSO phenotype in old 24-month-old rats, in a mechanism involving the decrease in the inflammatory state and oxidative stress. GDF-11 was evaluated as a protein related to muscle repair and regeneration; interestingly, rats that perform the LIERLT increased their GDF-11 levels.