The fat mass index, not the fat-free mass index, is associated with impaired physical performance in older adult subjects: Evidence from a cross-sectional study

Association between the risk of malnutrition and sarcopenia at 4.2 years of follow-up in community-dwelling older adults

Introduction

Currently, there is only scarce evidence of a causal association between risk of malnutrition (RM) by the mini-nutritional assessment (MNA) and the incidence of sarcopenia. This study was designed to assess such an association at 4.2 years of follow-up in community-dwelling subjects over 60 years old.

Methods

The data used were from the FraDySMex cohort study. The exposition variables were RM diagnosed by the long forma of the MNA (MNA-LF) and short form (MNA-SF). The last one included the body mass index and calf circumference at baseline, while sarcopenia was diagnosed by the EWGSOP2 at follow-up and taken as the response variable. Several covariates involved in the association were also considered. A multiple logistic regression analysis was performed to test the association.

Results

At baseline, 27.0 and 37.9% of subjects had RM by the MNA-LF and MNA-SF, respectively. The incidence of sarcopenia was 13.7%. The fat mass variable significantly modified the association, so it was tested in each stratum. Two independent models showed that subjects with RM by the MNA-LF in the normal fat mass stratum were at a higher risk for developing sarcopenia at follow-up than those without RM (OR 9.28; IC 95% 1.57-54.76) after adjusting for age, sex, and waist circumference. No association was found for the excess fat mass stratum subjects. Subjects with RM by the MNA-SF in the excess fat mass stratum were more likely to develop sarcopenia at follow-up than those without RM by the MNA-SF (OR 3.67; IC 95% 1.29-10.43). This association was not found in the subjects in the normal fat mass stratum.

Conclusion

The association was dependent on the variable fat mass. The two forms of the MNA should not be applied indistinctly with older adults. Based on these results, it is clear that the risk of malnutrition precedes the onset of sarcopenia.

Assessment of the performance of the body mass index in diagnosing obesity in community-dwelling older adults in Latin American and Caribbean countries

BACKGROUND

The body mass index (BMI) ≥30 kg/m2 is the universally accepted cut-off point for defining obesity; however, its accuracy in classifying obesity in older adults is poorly understood.

OBJECTIVES

To assess the performance of the BMI cut-off point ≥30 kg/m2 in classifying obesity in older adults, using the fat mass index (FMI) and fat mass percentage (FM%) as reference criteria; and to establish region- and sex-specific BMI-based cut-off points to classify obesity in older adults.

METHODS

The present study is a secondary analysis derived from a cross-sectional project that included a sample of 1463 older adults from ten Latin American and Caribbean countries. Volunteers underwent total body water measurements using the deuterium dilution technique to determine FMI and FM%. Accuracy of the BMI and derived cutoff points was assessed by the area under the receiver operating characteristic curve (AUC).

RESULTS

The BMI cut-off point ≥30 kg/m2 had low sensitivity for classifying obesity in these older adults compared to the FMI and FM%. The AUC values for the optimal BMI-derived cut-off points showed an acceptable-to-outstanding discriminatory capacity in diagnosing obesity defined by the FMI. There was also a better balance between sensitivity and specificity than with the values obtained by a BMI ≥30 kg/m2 in older subjects in both regions.

CONCLUSION

The BMI cut-off point ≥30 kg/m2 had poor sensitivity for accurately diagnosing obesity in older adults from two regions. The region- and sex-specific BMI-derived cut-off points for defining obesity using the FMI are more accurate in classifying obesity in older men and women subjects from both regions.

Incidence of the Risk of Malnutrition and Excess Fat Mass, and Gait Speed as Independent Associated Factors in Community-Dwelling Older Adults

BACKGROUND AND AIMS

Only one cohort study exists on the incidence of the risk of malnutrition (RM) in older adults, though numerous cross-sectional reports, identified several risk factors associated with the prevalence and incidence of this condition. However, alterations in body composition and impaired physical performance as exposition variables of RM have not been explored. This study assessed the incidence of RM and determined its association with excess fat mass, low total lean tissue, gait speed, and handgrip strength as exposition variables for RM in community-dwelling older adults.

METHODS

This is a secondary analysis of older adults (≥60 years) derived from the study "Frailty, dynapenia, and sarcopenia in Mexican adults (FraDySMex)", a prospective cohort project conducted from 2014 to 2019 in Mexico City. At baseline, volunteers underwent body composition analysis and physical performance tests. Several covariates were identified through comprehensive geriatric assessment. At baseline and follow-up, RM was assessed using the long form of the mini nutritional assessment (MNA-LF) scale. Associations between the exposition variables and RM were assessed by multiple logistic regression.

RESULTS

The cohort included 241 subjects. The average age was 75.6 ± 7.8 years, and 83.4% were women. The mean follow-up period was 4.1 years, during which 28.6% of subjects developed RM. This condition was less likely to occur in those with an excess fat mass, even after adjusting for several covariates. Regarding total lean tissue, the unadjusted model showed that RM was more likely to occur in men and women with a low TLT by the TLTI classification, compared to the normal group. However, after adjusting for several covariates (models 1 and 2), the association lost significance. Results on the association between gait speed and RM showed that this condition was also more likely to occur in subjects with low gait speed, according to both the unadjusted and adjusted models. Similar results were found for RM in relation to low handgrip strength; however, after adjusting for the associated covariates, models 1 and 2 no longer reached the level of significance.

CONCLUSIONS

RM diagnosed by MNA-LF was significantly less likely to occur among subjects with excess fat mass, and a significant association emerged between low gait speed and RM after 4.1 years of follow-up in these community-dwelling older adults. These results confirm the association between some alterations of body composition and impaired physical performance with the risk of malnutrition and highlight that excess fat mass and low gait speed precede the risk of malnutrition, not vice versa.

Determination of Fat-Free Mass Density and its Components in Older Hispanic Adults by In Vivo Methods

The densitometry method estimates body composition based on cadaver reference values, mainly the fat-free mass density value of 1.100 g/cm³. However, several changes in fat-free mass components by aging, ethnicity, and excess adiposity could influence their density and affect body composition estimations. The present study aimed to compare the mean fat-free mass component values in older Hispanic adults to cadaver reference values. This cross-sectional study included a sample of 420 subjects aged ≥60 yr from northern Mexico. Fat-free mass was determined by the four-compartment model using air displacement plethysmography, the deuterium dilution technique, and dual-energy X-ray absorptiometry for body density, aqueous and mineral fractions of body weight, respectively. A 1-sample t test was used to compare the fat-free mass density and aqueous, mineral, and residue fractions of fat-free mass from subjects in the study to the assumed cadaver reference values. The mean fat-free mass density value for the total sample of older Hispanic adults (1.096 ± 0.011 g/cm³) was significantly (p < 0.001) lower than the assumed value of 1.100 g/cm³, except in obese older men. The mean aqueous fraction of fat-free mass (74.8 ± 3.3%) was higher than the assumed value of 73.8%, and the mean residue fraction of fat-free mass value was lower (18.3 ± 3.4%) than the reference value of 19.4%. Indeed, only the mean mineral fraction of fat-free mass value (6.8 ± 0.8%) was similar to the reference value. In the total sample, all characteristic mean fat-free mass values in these older Hispanic adults differed from cadaver reference values, except the mineral fraction of fat-free mass value.

External validation of BIA equations to estimate appendicular skeletal muscle mass in older adults: Importance of the bias analysis and derivation of correction factors to achieve agreement

There are several equations based on bioelectrical impedance analysis (BIA) to estimate with high precision appendicular skeletal muscle mass (ASM). However, most of the external validation studies have reported that these equations are inaccurate or biased when applied to different populations. Furthermore, none of the published studies has derived correction factors (CFs) in samples of community-dwelling older adults, and none of the published studies have assessed the influence of the dual-energy X-ray absorptiometry (DXA) model on the validation process. This study assessed the agreement between six BIA equations and DXA to estimate ASM in non-Caucasian older adults considering the DXA model and proposed a CF for three of them. This analysis included 547 non-institutionalized subjects over 60 years old from the northwest of Mexico who were physically independent and without cognitive impairment: 192 subjects were measured using DXA Hologic, while 355 were measured by DXA Lunar. The agreement between each of the equations and DXA was tested considering the DXA model used as a reference method for the design of each equation, using the Bland and Altman procedure, a paired t test, and simple linear regression as objective tests. This process was supported by the differences reported in the literature and confirmed in a subsample of 70 subjects measured with both models. Only six published BIA equations were included. The results showed that four equations overestimated ASM_DXA, and two underestimated it (p < 0.001, 95% CI for Kim's equation:−5.86-−5.45, Toselli's:−0.51-−0.15, Kyle's: 1.43–1.84, Rangel-Peniche's: 0.32–0.74, Sergi's: 0.83–1.23, and Yoshida's: 4.16–4.63 kg). However, Toselli's, Kyle's and Rangel-Peniche's equations were the only ones that complied with having a homogeneous bias. This finding allowed the derivation of CFs, which consisted of subtracting or adding the mean of the differences from the original equation. After estimating ASM applying the respective CF, the new ASM estimations showed no significant bias and its distribution remained homogeneously distributed. Therefore, agreement with DXA in the sample of non-Caucasian was achieved. Adding valid CFs to some BIA equations allowed to reduce the bias of some equations, making them valid to estimate the mean values of ASM at group level.

Prevalence of sarcopenia in idiopathic dropped head syndrome patients is similar to healthy volunteers

Dropped head syndrome (DHS) exhibits cervical deformity due to weakness of the cervical extensor group, and sarcopenia is characterized by progressive and systemic reduction in skeletal muscle mass. These clinical finding are associated with reduced activity of daily living, reduced quality of life, and increased risk of mortality. We collected and reviewed prospective registry data for 16 patients with idiopathic DHS continuously collected without dropping out and 32 healthy individuals who matched their gender and age. The prevalence of sarcopenia and body composition data were compared. There were no differences in the prevalence of sarcopenia, appendicular muscle mass, and leg muscle mass between DHS patients and the healthy elderly. Trunk muscle mass in DHS patients was significantly lower than that in healthy individuals. A significant correlation was found between appendicular muscle mass and trunk muscle mass in healthy subjects but not in DHS patients. Sarcopenia was not associated with the onset of idiopathic DHS. The prevalence of sarcopenia was not high in patients with idiopathic DHS due to the preservation of their appendicular skeletal muscle mass. Patients with DHS were characterized by a significant loss of trunk muscle mass that may be related to the disease but not aging.

Lifestyle exercise attenuates immunosenescence; flow cytometry analysis

Background

Interaction of physical activity and overall immune profile is very complex and depends on the intensity, duration and frequency of undertaken physical activity, the exposure to cytomegalovirus (CMV) infection and the age-related changes in the immune system. Daily physical activity, which particularly influences immunity, declines dramatically with age. Therefore, the aim of the study was to explain whether physical activity sustained throughout life can attenuate or reverse immunosenescence.

Methods

Ninety-nine older adults (60–90 years) were recruited for the study. According to the 6-min walk test (6WMT), the Åstrand-Ryhming bike test (VO₂max) and Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire, the individuals were classified as physically active (n = 34) and inactive (n = 20) groups. The analysis of T lymphocytes between active vs. inactive participants was performed using eight-parameter flow cytometry.

Results

Analysis of the baseline peripheral naïve and memory T lymphocytes showed a significant relationship of lifestyle exercise with the CD4/CD8 ratio. Above 50% of physically active participants demonstrated the CD4/CD8 ratio ≥ 1 or ≤ 2.5 contrary to the inactive group who showed the ratio < 1. The older adults with the result of 6WMT > 1.3 m/s and VO₂max > 35 mL/kg/min had a significantly higher CD4⁺CD45RA⁺ T lymphocyte percentage and also a higher ratio of CD4⁺CD45RA⁺/CD4⁺CD45RO⁺. Interestingly, in active older adults with IgG CMV⁺ (n = 30) the count of CD4⁺CD45RA⁺ T lymphocytes was higher than in the inactive group with IgG CMV⁺ (n = 20).

Conclusion

Based on the flow cytometry analysis, we concluded that lifestyle exercise could lead to rejuvenation of the immune system by increasing the percentage of naïve T lymphocytes or by reducing the tendency of the inverse CD4/CD8 ratio.

Sex differences in association between body composition and frailty or physical performance in community-dwelling older adults

Frailty is a common geriatric condition due to aging, defined as a decrease in the functional reserve to maintain the homeostasis. As part of the aging process, body composition changes occur. This study investigated the relationship between body composition and frailty in a community-dwelling elderly Korean population.This cross-sectional cohort study analyzed data of 2,385 elderly participants (aged 70-84 years, 1131 males and 1254 females) of the Korean Frailty and Aging Cohort Study from 2016 to 2017. Body composition, including total and trunk fat masses and fat-free mass, were measured with dual-energy X-ray absorptiometry. Fat mass index (FMI), trunk fat mass index, and fat-free mass index (FFMI) represented total fat mass, trunk fat mass, and fat-free mass according to height. Based on the frailty index developed by Fried, we compared the frail and non-frail groups. Poor physical performance assessed with the short physical performance battery score of < 9 is considered frailty. To evaluate the relationship between the variables, simple and fully adjusted multivariable logistic regression analyses were performed according to sex.Among the participants, 462 (19.3%) were defined as the frail group, with a significantly high mean age of 77.9 ± 4.0 years. In the logistic regression analysis of frailty based on body mass index (BMI) categories, underweight (BMI < 18 kg/m2) participants showed a high incidence of frailty in both sexes. BMI showed an association with frailty only in males. Lower FFMI was associated with a higher incidence of frailty in both sexes, which was statistically significant in the fully adjusted models. In the female, fat-related indexes including body fat percentage, FMI, and trunk fat mass index showed a significant association with poor physical performance. In contrast, males with low FFMI only showed a significant association with poor physical performance.Frailty was closely correlated with lower FFMI in both sexes. The poor physical performance associated with frailty correlated with fat-related body composition in females and fat-free mass in males, owing to the difference in body composition between the sexes. In the assessment of frailty, body composition and sex-related differences should be analyzed.

Performance on sit-to-stand tests in relation to measures of functional fitness and sarcopenia diagnosis in community-dwelling older adults

BACKGROUND

The sit-to-stand (STS) test has been deployed as surrogate measures of strength or physical performance in sarcopenia diagnosis. This study examines the relationship of two common STS variants - Five Times Sit-to-Stand Test (5TSTS) and 30 s Chair Stand Test (30CST) - with grip strength, muscle mass and functional measures, and their impact on sarcopenia prevalence in community-dwelling older adults.

METHODS

This is a cross-sectional analysis of 887 community-dwelling adults aged ≥50 years. Participants completed a battery of physical fitness tests - 5TSTS, 30CST, grip strength, gait speed, Timed-Up-and-Go (TUG) for dynamic balance and six-minute walk test (6MWT) for cardiorespiratory endurance. Muscle mass was measured using multi-frequency segmental bioelectrical impedance analysis (BIA). We performed correlation analysis between STS performance and other fitness measures and muscle mass, followed by multiple linear regression for the independent determinants of STS performance.

RESULTS

Mean participant age was 67.3±7 years, with female predominance (72.9%). STS tests exhibited weak correlations with grip strength (30CST, r = 0.290; 5TSTS, r = - 0.242; both p< 0.01), and stronger correlations with gait speed (30CST, r = 0.517; 5TSTS, r = - 0.533; both p< 0.01), endurance (30CST, r = 0.558; 5TSTS, r = - 0.531; both p < 0.01) and dynamic balance (30CST, r = - 0.501; 5TSTS, r = 0.646; both p< 0.01). Muscle mass correlated with grip strength but not STS. In multiple regression analysis, all fitness measures were independently associated with 30CST performance. Performance in both STS tests remained independent of muscle mass. There was no significant difference in prevalence of possible sarcopenia diagnosis using grip strength or STS (30CST, 25.0%; 5TSTS, 22.1%; grip strength, 22.3%; p = 0.276). When both measures are used, prevalence is significantly higher (42.0%; p = 0.276). Prevalence of confirmed sarcopenia with inclusion of muscle mass was significantly lower using STS compared with grip strength (30CST, 4.6%; 5TSTS, 4.1% vs. grip strength, 7.1%; p< 0.05).

CONCLUSION

In the sarcopenia construct, STS tests better represents muscle physical performance rather than muscle strength. Different subsets of population with possible sarcopenia are identified depending on the test used. The lack of association of STS performance with muscle mass results in a lower prevalence of confirmed sarcopenia compared with grip strength, but may better reflect changes in muscle quality.

Body Composition and Bone Mineral Density in Craniopharyngioma Patients: A Longitudinal Study Over 10 Years

CONTEXT

Patients with craniopharyngioma suffer from obesity and impaired bone health. Little is known about longitudinal changes in body composition and bone mineral density (BMD).

OBJECTIVE

To describe body composition and BMD (change).

DESIGN

Retrospective longitudinal study.

SETTING

Two Dutch/Swedish referral centers.

PATIENTS

Patients with craniopharyngioma (n = 112) with a dual X-ray absorptiometry (DXA) scan available (2 DXA scans, n = 86; median Δtime 10.0 years; range 0.4-23.3) at age ≥ 18 years (58 [52%] male, 50 [45%] childhood onset).

MAIN OUTCOME MEASURES

Longitudinal changes of body composition and BMD, and associated factors of ΔZ-score (sex and age standardized).

RESULTS

BMI (from 28.8 ± 4.9 to 31.2 ± 5.1 kg/m2, P < .001), fat mass index (FMI) (from 10.5 ± 3.6 to 11.9 ± 3.8 kg/m2, P = .001), and fat free mass index (FFMI) (from 18.3 ± 3.2 to 19.1 ± 3.2 kg/m2, P < .001) were high at baseline and increased. Fat percentage and Z-scores of body composition did not increase, except for FFMI Z-scores (from 0.26 ± 1.62 to 1.06 ± 2.22, P < .001). Z-scores of total body, L2-L4, femur neck increased (mean difference 0.61 ± 1.12, P < .001; 0.74 ± 1.73, P < .001; 0.51 ± 1.85, P = .02). Linear regression models for ΔZ-score were positively associated with growth hormone replacement therapy (GHRT) (femur neck: beta 1.45 [95% CI 0.51-2.39]); and negatively with radiotherapy (femur neck: beta -0.79 [-1.49 to -0.09]), glucocorticoid dose (total body: beta -0.06 [-0.09 to -0.02]), and medication to improve BMD (L2-L4: beta -1.06 [-1.84 to -0.28]).

CONCLUSIONS

Z-scores of BMI, fat percentage, and FMI remained stable in patients with craniopharyngioma over time, while Z-scores of FFMI and BMD increased. Higher glucocorticoid dose and radiotherapy were associated with BMD loss and GHRT with increase.

Sarcopenia: Influence of Regional Skeletal Muscle Cutoff Points and Fat-Free Mass in Older Mexican People-A Pilot Study

BACKGROUND

Variation in the prevalence of sarcopenia is related to the skeletal muscle index cutoff points applied. The objective of this pilot study was to examine the recruitment process for testing different sarcopenia definitions (ASMI cutoffs) in older Mexican adults. It explored whether the prevalence of sarcopenia decreased by applying ethnic- and gender-specific, DXA-derived appendicular skeletal muscle index (ASMI)-cutoff points in the definitions, as well as some associated factors in a sample of community-dwelling older Mexican people.

METHODS

This is a pilot feasibility study that included a convenience sample of 217 community-dwelling older adults. Volunteers underwent DXA measurements and an assessment of functional status based on hand grip strength and physical performance. Six definitions were formed based on the 2010 EWGSOP criteria, but using different cutoff points for each of the three components, including regional cutoff points for ASMI derived from young Mexican adults. Several risk factors for sarcopenia were also assessed.

RESULTS

The prevalence of sarcopenia varied according to the different definitions applied. The lowest level was found with the definition that applied regional ASMI-cutoff points (p < 0.01). The sarcopenic older adults had significant lower body weight, fat mass, and fat-free mass (FFM) than the nonsarcopenic subjects. The risk of sarcopenia increased with age and low FFM (p < 0.001).

CONCLUSION

The present study demonstrates the feasibility of the main study, and our data support the notion that using regional ASMI cutoff points resulted in a low prevalence of sarcopenia. Therefore, it is preferable to estimate the prevalence of this condition using ethnic- and gender-specific cutoff points and to explore associated factors such as low FFM.