Poor Physical Function as a Marker of Sarcopenia in Adults with Class II/III Obesity

Muscle Mass Adjusted by Body Height is not Correlated with Mobility of Middle-Aged and Older Adults

Background

Low muscle mass and obesity are associated with mobility disability, cardiometabolic diseases, and loss of independence. Three skeletal muscle indices (SMIs) are proposed to adjust the body size of individuals. However, it is unknown which index is better correlated with mobility. Additionally, it remains unclear whether low muscle mass or abdominal obesity has a greater impact on the mobility and cardiometabolic health of older adults.

Objectives

This study explored the association between different SMIs {appendicular skeletal muscle mass [ASM] adjusted by body height [Ht], body weight [Wt], or body mass index [BMI (kg/m2)]} and mobility/cardiometabolic health. The roles of low muscle mass and abdominal obesity in the mobility and cardiometabolic health of individuals were also identified.

Methods

Four-hundred and twenty-seven community-dwelling middle-aged and older adults underwent body composition assessments [dual-energy x-ray absorptiometry and waist circumference (WC)], grip strength, and mobility (timed up-and-go test and chair stand test). Spearman's rank correlation coefficient and regression models were used to examine research questions. This study was registered in the Thai Clinical Trials Registry (registration number: TCTR20210521007).

Results

All SMIs were positively correlated with the grip strength (ASM/Ht2: r = 0.392; ASM/Wt: r = 0.439; ASM/BMI: r = 0.569). Regarding mobility, only ASM/Ht2 wasn't relevant. After adjusting for age, sex, and WC, ASM/BMI was the only SMI associated with grip strength (β = 0.274). When age and sex were controlled, WC, but not SMI, was associated with mobility and cardiometabolic health.

Conclusions

ASM/Ht2 did not correlate with mobility in middle-aged and older adults, whereas ASM/Wt and ASM/BMI did. Abdominal obesity has a greater impact on mobility and cardiometabolic health than low muscle mass in middle-aged and older adults. We recommend using ASM/BMI to identify the low muscle mass of individuals. In addition, clinicians should note the important role of abdominal obesity when considering mobility in middle-aged and older adults.

Sitting time and associated factors among Portuguese older adults: results from Nutrition UP 65

Older adults are particularly susceptible to sedentary behaviours. Sitting time has been increasingly referred to as a potentially modifiable risk factor in the prevention of chronic diseases. Identifying factors associated with sitting time, particularly those that are modifiable, will allow for more effective public health strategies. This study aimed to describe sitting time among Portuguese older adults and to evaluate associated factors. A cross-sectional study including 1423 older adults ≥ 65 years old was conducted. Sitting time was assessed with the International Physical Activity Questionnaire. Socio-demographic, health, anthropometric and functional variables were collected. Bivariate and multivariate linear regression models were conducted to study the association between these variables and sitting time. The median of sitting time was 300 min/day (interquartile range = 240 min/day), which is equal to 5 h/day. The following factors were directly associated with longer sitting time: being male, age ≥ 80 years, living in Central or Southern Portugal, being retired from work, as well as presenting low physical activity, obesity or longer time to walk 4.6 metres. On the other hand, being married, having higher education and higher household income were inversely associated with longer sitting time. It can be concluded that Portuguese older adults spend a considerable amount of time sitting per day. Potentially modifiable risk factors associated with longer sitting time in this population were related to nutritional status and functional ability.

Sedentary Time, Physical Activity, and Sleep Duration: Associations with Body Composition in Fibromyalgia. The Al-Andalus Project

To explore the individual–independent relationships of sedentary time (ST) and physical activity (PA) (light and moderate-to-vigorous intensity (MVPA)), with sleep duration and body composition (waist circumference, body mass index (BMI), body fat percentage, and muscle mass index) in women with fibromyalgia, and to determine whether these associations are independent of physical fitness. This cross-sectional study involved 385 women with fibromyalgia. ST and PA were assessed by triaxial accelerometry, sleep duration was self-reported. Waist circumference was measured using an anthropometric tape, and body weight, body fat percentage, and muscle mass were estimated using a bio-impedance analyzer. In individual regression models, ST and sleep were directly associated with waist circumference, BMI, and body fat percentage (β between 0.10 and 0.25; all p < 0.05). Light PA and MVPA were inversely associated with waist circumference, BMI, and body fat percentage (β between −0.23 and −0.12; all p < 0.05). In multiple linear regression models, ST (β between 0.17 and 0.23), light PA (β between −0.16 and −0.21), and sleep duration (β between 0.11 and 0.14) were independently associated with waist circumference, BMI, and body fat percentage (all p < 0.05). MVPA was associated with waist circumference independent of light physical activity (LPA) and sleep duration (β = −0.11; p < 0.05). Except for MVPA, these associations were independent of physical fitness. These results suggest that longer ST and sleep duration, and lower PA levels (especially light intensity PA), are independently associated with greater adiposity, but not muscle mass, in women with fibromyalgia. These associations are, overall, independent of physical fitness.

Relationship Between Skeletal Muscle Mass Indexes and Muscular Function, Metabolic Profile and Bone Mineral Density in Women with Recommendation for Bariatric Surgery

BACKGROUND AND AIM

We evaluated low skeletal muscle mass (LMM) in women prior to bariatric surgery (BS) through different skeletal muscle mass indexes (MMIs) regarding body fat percentage (BFP), handgrip strength (HS), six-minute walk test (6MWT), metabolic profile and bone mineral density (BMD).

METHODS

Women (n=62) were allocated into two groups according to LMM: obesity with low muscle mass (OLMM) or obesity with normal muscle mass (ONMM). LMM was defined by the appendicular skeletal muscle mass (ASM) adjusted for weight (ASM/wt × 100) and ASM adjusted for body mass index (ASM/BMI), considering the lowest quintile of the indexes studied.

RESULTS

OLMM was found in 30.5% by ASM/wt × 100 and 20.3% by ASM/BMI. Using the ASM/wt × 100, OLMM group had a high BFP, low HS and BMD in L1-L4, femoral neck (FN) and total femur (TF) when compared with ONMM (p < 0.05). Using ASM/BMI, OLMM group had increased BFP, reduced HS and 6MWT in comparison to ONMM (p < 0.05). Metabolic profile was similar between OLMM and ONMM groups by the two MMIs. MMIs were negatively correlated with BFP (p < 0.05) and positively correlated with HS (p < 0.05), and none of them with 6MWT (p > 0.05). ASM/wt × 100 was positively correlated with all BMD sites assessed (p < 0.05). There was positive correlation between ASM/wt × 100 and ASM/BMI.

CONCLUSION

OLMM identified by the ASM/wt × 100 and ASM/BMI had higher adiposity and lower HS. Using ASM/BMI, we found that OLMN had a poor physical performance, while the ASM/wt × 100 identified a lower BMD at all sites.