Derivation and validation of simple equations to predict total muscle mass from simple anthropometric and demographic data

Dynapenia and sarcopenia identify walking speed decline in women but not in men

OBJECTIVE

To determine the best indicator of mobility decline between dynapenia, low skeletal muscle mass index (SMMI), and sarcopenia defined by the EWGSOP2 using different cutoff points for grip strength.

METHODS

A longitudinal study was conducted with a follow-up of eight years, involving 2,680 individuals aged 60 and older who participated in the ELSA study with a walking speed greater than 0.8 m/s at baseline. Dynapenia was defined using different cutoff points for grip strength. SMMI was defined by the 20th percentile of the entire ELSA sample distribution and sarcopenia was defined based on the EWGSOP2, using different cutoff points for grip strength. Mobility was analysed using the walking speed test.

RESULTS

Over time, the greatest decline in walking speed occurred in dynapenic women with grip strength < 17 kg (-0.005 m/s per year; 95 % CI: -0.01 to -0.001) and < 20 kg (-0.007 m/s per year; 95 % CI: -0.01 to -0.001). With regards to sarcopenia, the greatest walking speed decline occurred in women with probable sarcopenia when defined by grip strength < 17 kg [(-0.006 m/s per year; 95 % CI: -0.01 to -0.001) or grip strength < 20 kg (-0.007 m/s per year; 95 % CI: -0.01 to -0.001)]. Dynapenia in men as well as low SMMI and sarcopenia in men and women did not enable identifying the risk of mobility decline.

CONCLUSION

Dynapenia and probable sarcopenia defined by grip strength < 17 kg and < 20 kg enabled identifying walking speed decline over time only in women.

Frailty or sarcopenia: which is a better indicator of mortality risk in older adults?

BACKGROUND

Despite the different conditions, frailty and sarcopenia overlap regarding their common link: the assessment of walking speed and muscle strength. This study aimed to compare the frailty phenotype to the sarcopenia using different cut-off points for low grip strength to determine which better identifies mortality risk over a 14-year follow-up period.

METHODS

4597 participants in the English Longitudinal Study of Ageing. Frailty was measured using the Fried phenotype. Sarcopenia (European Working Group on Sarcopenia in Older People 2) was defined using different cut-off points for low grip strength (<36, <32, <30, <27 and <26 kg for men and <23, <21, <20 and <16 kg for women), low skeletal muscle mass index (<9.36 kg/m² for men and<6.73 kg/m² for women) and slowness (gait speed: ≤0.8 m/s). Cox models were run and adjusted for sociodemographic, behavioural and clinical factors.

RESULTS

When the coexistence of frailty and sarcopenia is considered, only the cut-off points <36 kg for men and <23 kg for women to define low grip strength identified the risk of mortality among individuals classified as having probable sarcopenia (HR=1.17, 95% CI 1.02 to 1.34), sarcopenia (HR=1.31, 95% CI 1.07 to 1.60) and severe sarcopenia (HR=1.62, 95% CI 1.33 to 1.96). In this situation, frailty identified the mortality risk (HR=1.49, 95% CI 1.22 to 1.81), whereas pre-frailty did not. Sarcopenia using other cut-off points for defining low grip strength did not identify mortality risk.

CONCLUSION

Sarcopenia using <36 kg for men and <23 kg for women as cut-off points seems to be better than the frailty phenotype for identifying the risk of mortality in older adults.

Skeletal muscle estimation: A review of techniques and their applications

Quantifying skeletal muscle size is necessary to identify those at risk for conditions that increase frailty, morbidity, and mortality, as well as decrease quality of life. Although muscle strength, muscle quality, and physical performance have been suggested as important assessments in the screening, prevention, and management of sarcopenic and cachexic individuals, skeletal muscle size is still a critical objective marker. Several techniques exist for estimating skeletal muscle size; however, each technique presents with unique characteristics regarding simplicity/complexity, cost, radiation dose, accessibility, and portability that are important factors for assessors to consider before applying these modalities in practice. This narrative review presents a discussion centred on the theory and applications of current non-invasive techniques for estimating skeletal muscle size in diverse populations. Common instruments for skeletal muscle assessment include imaging techniques such as computed tomography, magnetic resonance imaging, peripheral quantitative computed tomography, dual-energy X-ray absorptiometry, and Brightness-mode ultrasound, and non-imaging techniques like bioelectrical impedance analysis and anthropometry. Skeletal muscle size can be acquired from these methods using whole-body and/or regional assessments, as well as prediction equations. Notable concerns when conducting assessments include the absence of standardised image acquisition/processing protocols and the variation in cut-off thresholds used to define low skeletal muscle size by clinicians and researchers, which could affect the accuracy and prevalence of diagnoses. Given the importance of evaluating skeletal muscle size, it is imperative practitioners are informed of each technique and their respective strengths and weaknesses.

Trajectory of mid-arm subcutaneous fat, muscle mass predicts mortality in hemodialysis patients independent of body mass index

Although decreasing body mass index (BMI) is associated with higher mortality risk in patients undergoing hemodialysis (HD), BMI neither differentiates muscle and fat mass nor provides information about the variations of fat distribution. It remains unclear whether changes over time in fat and muscle mass are associated with mortality. We examined the prognostic significance of trajectory in the triceps skinfold (TSF) thickness and mid-upper arm circumference (MUAC). In this multicenter prospective cohort study, 972 outpatients (mean age, 54.5 years; 55.3% men) undergoing maintenance HD at 22 treatment centers were included. We calculated the relative change in TSF and MUAC over a 1-year period. The outcome was all-cause mortality. Kaplan-Meier, Cox proportional hazard analyses, restricted cubic splines, and Fine and Gray sub-distribution hazards models were performed to examine whether TSF and MUAC trajectories were associated with all-cause mortality. During follow-up (median, 48.0 months), 206 (21.2%) HD patients died. Compared with the lowest trajectory group, the highest trajectories of TSF and MUAC were independently associated with lower risk for all-cause mortality (HR = 0.405, 95% CI 0.257-0.640; HR = 0.537; 95% CI 0.345-0.837; respectively), even adjusting for BMI trajectory. Increasing TSF and MUAC over time, measured as continuous variables and expressed per 1-standard deviation decrease, were associated with a 55.7% (HR = 0.443, 95% CI 0.302-0.649), and 97.8% (HR = 0.022, 95% CI 0.005-0.102) decreased risk of all-cause mortality. Reduction of TSF and MUAC are independently associated with lower all-cause mortality, independent of change in BMI. Our study revealed that the trajectory of TSF thickness and MUAC provides additional prognostic information to the BMI trajectory in HD patients.

Association of body composition indices with cardiovascular outcomes: a nationwide cohort study

BACKGROUND

Previous studies regarding BMI (kg/m2) and associated cardiovascular outcomes yield inconsistent results.

OBJECTIVES

We aimed to investigate the association between body composition and cardiovascular outcomes according to BMI categories in the Korean general population.

METHODS

A total of 2,604,401 participants were enrolled in this nationwide cohort study using the National Health Insurance Service-Health Checkup data set. Predicted lean BMI (pLBMI), body fat mass index (pBFMI), and appendicular skeletal muscle mass index (pASMMI) were calculated using validated anthropometric prediction equations. A multivariable time-dependent Cox regression analysis was conducted to assess the association with cardiovascular outcomes. The results were presented with adjusted hazard ratios (HRs) with 95% confidence intervals (CIs), considering BMI categories (BMI < 18.5, BMI 18.5-24.9, BMI 25-29.9, and BMI ≥ 30).

RESULTS

Higher pLBMI and pASMMI were correlated with a reduced risk of composite cardiovascular outcomes. For pLBMI, HR was 0.910 (95% CI: 0.908, 0.913, P < 0.001) for males and 0.905 (95% CI: 0.899, 0.910, P < 0.001) for females. For pASMMI, HR was 0.825 (95% CI: 0.820, 0.829, P < 0.001) for males and 0.788 (95% CI: 0.777, 0.800, P < 0.001) for females. Conversely, a higher pBFMI was associated with an increased risk, with HR of 1.082 (95% CI: 1.071, 1.093, P < 0.001) for males and 1.181 (95% CI: 1.170, 1.192, P < 0.001) for females. Subgroup analysis based on BMI categories revealed no significant risk association for pBFMI in the BMI < 18.5 group. In the group with BMI ≥ 30, neither pLBMI nor pASMMI demonstrated a significant risk association.

CONCLUSIONS

Our results highlight the value of pLBMI, pBFMI, and pASMMI as variables for assessing risk of composite cardiovascular outcomes. The significance of indicators may vary depending on BMI categories.

Relationship between low relative muscle mass and aortic regional morphological changes in adults underwent contrast CT scans for cancer diagnostics

OBJECTIVES

Low muscle mass is related to cardiovascular risk factors. This study aimed to investigate whether relative low muscle mass is related to the diameter and tortuosity of the aorta.

METHODS

We performed a cross-sectional study of 208 adults without known cardiovascular disease who underwent Computed Tomography (CT) enhanced scan between 2020 and 2021. Skeletal muscle index (SMI) was estimated. The morphology of the aorta was measured by diameter and tortuosity using CT. We assessed the relationship between SMI and diameter and tortuosity of the aorta using Spearman correlation analysis and univariate and multivariate-adjusted regression models.

RESULTS

Of all -individuals, 124 (59.6%) were male. The average age was 60.13 ± 16.33 years old. SMI was inversely associated with the diameter and tortuosity of the aorta (p < 0.05). Specifically, in a multivariable-adjusted model adjusting for potential confounders, a one-unit increase in the SMI was associated with a -13.56mm(95% confidence intervals (CI): -18.16 to -8.96, p < 0.001), -7.93 mm (95% CI: -10.85 to -5.02, p < 0.001), -8.01 mm (95% CI: -11.30 to -4.73, p < 0.001), -5.16 mm (95% CI: -7.57 to -2.75, p < 0.001) and -2.73 mm (95% CI: -5.18 to -0.27, p = 0.031) increase in L1-L5 diameter respectively, a -0.89 (95% CI: -1.14 to -0.64, p < 0.001) increase in the aorta tortuosity, a -0.48 (95% CI: -0.59 to -0.36, p < 0.001) increase in the descending thoracic aorta tortuosity, and a -0.44 (95% CI: -0.52 to -0.35, p < 0.001) increase in the abdominal aorta tortuosity.

CONCLUSIONS

Relative muscle mass was negatively associated with the diameter and tortuosity of the aorta, suggesting muscle mass maintenance may play a role in preventing aortic morphological changes.

Prediction equations to estimate muscle mass using anthropometric data: a systematic review

CONTEXT

Reduced muscle mass is linked to poor outcomes in both inpatients and outpatients, highlighting the importance of muscle mass assessment in clinical practice. However, laboratory methods to assess muscle mass are not yet feasible for routine use in clinical practice because of limited availability and high costs.

OBJECTIVE

This work aims to review the literature on muscle mass prediction by anthropometric equations in adults or older people.

DATA SOURCES

The following databases were searched for observational studies published until June 2022: MEDLINE, Embase, Scopus, SPORTDiscus, and Web of Science.

DATA EXTRACTION

Of 6437 articles initially identified, 63 met the inclusion criteria for this review. Four independent reviewers, working in pairs, selected and extracted data from those articles.

DATA ANALYSIS

Two studies reported new equations for prediction of skeletal muscle mass: 10 equations for free-fat mass and lean soft tissue, 22 for appendicular lean mass, 7 for upper-body muscle mass, and 7 for lower-body muscle mass. Twenty-one studies validated previously proposed equations. This systematic review shows there are numerous equations in the literature for muscle mass prediction, and most are validated for healthy adults. However, many equations were not always accurate and validated in all groups, especially people with obesity, undernourished people, and older people. Moreover, in some studies, it was unclear if fat-free mass or lean soft tissue had been assessed because of an imprecise description of muscle mass terminology.

CONCLUSION

This systematic review identified several feasible, practical, and low-cost equations for muscle mass prediction, some of which have excellent accuracy in healthy adults, older people, women, and athletes. Malnourished individuals and people with obesity were understudied in the literature, as were older people, for whom there are only equations for appendicular lean mass.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42021257200.

Smartphone prediction of skeletal muscle mass: model development and validation in adults

BACKGROUND

Skeletal muscle is a large and clinically relevant body component that has been difficult and impractical to quantify outside of specialized facilities. Advances in smartphone technology now provide the opportunity to quantify multiple body surface dimensions such as circumferences, lengths, surface areas, and volumes.

OBJECTIVES

This study aimed to test the hypothesis that anthropometric body measurements acquired with a smartphone application can be used to accurately estimate an adult's level of muscularity.

METHODS

Appendicular lean mass (ALM) measured by DXA served as the reference for muscularity in a sample of 322 adults. Participants also had digital anthropometric dimensions (circumferences, lengths, and regional and total body surface areas and volumes) quantified with a 20-camera 3D imaging system. Least absolute shrinkage and selection operator (LASSO) regression procedures were used to develop the ALM prediction equations in a portion of the sample, and these models were tested in the remainder of the sample. Then, the accuracy of the prediction models was cross-validated in a second independent sample of 53 adults who underwent ALM estimation by DXA and the same digital anthropometric estimates acquired with a smartphone application.

RESULTS

LASSO models included multiple significant demographic and 3D digital anthropometric predictor variables. Evaluation of the models in the testing sample indicated respective RMSEs in women and men of 1.56 kg and 1.53 kg and R2's of 0.74 and 0.90, respectively. Cross-validation of the LASSO models in the smartphone application group yielded RMSEs in women and men of 1.78 kg and 1.50 kg and R2's of 0.79 and 0.95; no significant differences or bias between measured and predicted ALM values were observed.

CONCLUSIONS

Smartphone image capture capabilities combined with device software applications can now provide accurate renditions of the adult muscularity phenotype outside of specialized laboratory facilities. Am J Clin Nutr 2023;x:xx. This trial was registered at clinicaltrials.gov as NCT03637855 (https://clinicaltrials.gov/ct2/show/NCT03637855), NCT05217524 (https://clinicaltrials.gov/ct2/show/NCT05217524), and NCT03771417 (https://clinicaltrials.gov/ct2/show/NCT03771417).

Dynapenic Abdominal Obesity as a Risk Factor for Metabolic Syndrome in Individual 50 Years of Age or Older: English Longitudinal Study of Ageing

OBJECTIVES

To analyse whether dynapenic abdominal obesity is a risk factor for Metabolic syndrome (MetS) and its components in individuals 50 years of age or older.

DESIGN

A longitudinal study was conducted with an eight-year follow-up.

SETTING

Representative sample of community-dwelling participants of the English Longitudinal Study of Ageing (ELSA).

PARTICIPANTS

3,952 individuals free of MetS at baseline.

MEASUREMENTS

Dynapenic abdominal obesity was defined based on waist circumference (> 102 cm for men and > 88 cm for women) and grip strength (< 26 kg for men and < 16 kg for women). The participants were classified as non-abdominally obese/non-dynapenic (NAO/ND - reference group), abdominally obese/non-dynapenic (AO/ND), non-abdominally obese/dynapenic (NAO/D) and abdominally obese/dynapenic (AO/D). The outcome was the incidence of MetS based on the presence of three or more of the following criteria: hypertriglyceridemia, hyperglycaemia, low HDL cholesterol, arterial hypertension or body mass index ≥ 30 kg/m2 throughout eight-year follow-up. Additionally, the incidence of each component of MetS was also analyzed. Poisson regression models were run and controlled for sociodemographic, behavioural and clinical variables.

RESULTS

The mean age of the participants was 65 years and 55% were women. The prevalence of AO/ND, NAO/D and AO/D were 35.3, 4.3 and 2.2%, respectively. At the end of follow-up 558 incident cases of MetS were recorded. The adjusted model demonstrated that although abdominal obesity was a risk factor for MetS (IRR: 2.26; 95% CI: 1.87 - 2.73), the IRR was greater in AO/D individuals (IRR: 3.34; 95% CI: 2.03 - 5.50) compared with ND/NAO group. Furthermore, ND/AO was a risk factor for incidence of hypertriglyceridemia (IRR: 1.27; 95% CI: 1.06 - 1.52), hyperglycaemia (IRR: 1.41; 95% CI: 1.18 - 1.69), low HDL cholesterol (IRR: 1.70; 95% CI: 1.32 - 2.19) and BMI ≥ 30 kg/m2 (IRR: 2.58; 95% CI: 2.04 - 3.26) while D/AO was a risk factor for hyperglycaemia (IRR: 1.78; 95% CI: 1.02 - 3.10), low HDL cholesterol (IRR: 2.36; 95% CI: 1.10 - 5.08), and BMI ≥ 30 kg/m2 (IRR: 2.79; 95% CI: 1.38 - 5.62).

CONCLUSIONS

Dynapenic abdominal obesity increases the risk of MetS, with a higher IRR compared to obesity alone. The understanding of this synergic action could guide specific clinical strategies, enabling the prevention of metabolic changes that can lead to cardiovascular disease, disability and death.

Treating chronic diseases without tackling excess adiposity promotes multimorbidity

Few people now reach old age without taking multiple drugs, often attending various clinics, and undergoing secondary or tertiary investigations. Most chronic conditions are, to differing extents, caused or exacerbated by excess adiposity, but weight management is rarely discussed or attempted for patients. Furthermore, progressive symptoms usually attributed to ageing (eg, musculoskeletal pains, fatigue, and breathlessness), and which create considerable health-care demands, can also be attributed to the accumulation of body fat over time. For many symptoms and diseases that are more frequently reported in people with excess adiposity (such as depression), there exist potentially multidirectional, causal relationships that generate a cycle of clinical and social deterioration. There is insufficient research on the effects of effective weight management on these clinically demanding, age and weight-mediated symptoms. Based on current evidence, we suggest that policy makers need to be more proactive in obesity prevention and effective weight management should receive research funding to match the search for novel therapeutics for secondary chronic diseases.

Are Serum 25-Hydroxyvitamin D Deficiency and Insufficiency Risk Factors for the Incidence of Dynapenia?

Epidemiological evidence showing the association between low 25(OH)D and age-related reduction in neuromuscular strength (dynapenia) is a paucity and controversial and, to date, the effect of osteoporosis and vitamin D supplementation on these associations has not been measured. Thus, we analyze whether serum 25(OH)D deficiency and insufficiency are risk factors for the incidence of dynapenia in individuals aged 50 or older and whether osteoporosis or vitamin D supplementation modify these associations. For that, 3205 participants of the ELSA study who were non-dynapenic at baseline were followed for 4 years. Vitamin D was measured at baseline by the serum concentration of 25(OH)D and classified as sufficient (&gt; 50 nmol/L), insufficient (≥ 30 and ≤ 50 nmol/L) or deficient (&lt; 30 nmol/L). The incidence of dynapenia was determined by a grip strength &lt; 26 kg for men and &lt; 16 kg for women at the end of the 4-year follow-up. Poisson regression models were adjusted by sociodemographic, behavioral, clinical and biochemical characteristics. Serum 25(OH)D deficient was a risk factor for the incidence of dynapenia (IRR = 1.70; 95% CI 1.04-2.79). When only individuals without osteoporosis and those who did not use vitamin D supplementation were analyzed, both serum 25(OH)D deficiency (IRR = 1.78; 95% CI 1.01-3.13) and insufficiency (IRR = 1.77; 95% CI 1.06-2.94) were risk factors for the incidence of dynapenia. In conclusion, a serum level of 25(OH)D &lt; 30 nmol/L is a risk factor for the incidence of dynapenia. Among individuals without osteoporosis and those who do not take vitamin D supplementation, the threshold of risk is higher (≤ 50 nmol/L).

Ultrasonography for Assessment of Sarcopenia: A Primer

The human skeletal muscle has a pivotal role in preserving health by maintaining mobility, balance, and metabolic homeostasis. Significant muscle loss as a part of aging and accelerated by disease leads to sarcopenia which becomes an important predictor of quality of life in older persons. Therefore, clinical screening for sarcopenia and validation by precise qualitative and quantitative measurement of skeletal muscle mass (MM) and function is at the center-stage of translational research. Many imaging modalities are available, each having their strengths and limitations, either in interpretation, technical processes, time constraints, or expense. B-mode ultrasonography (US) is a relatively novel approach to evaluating muscle. It can measure several parameters such as MM and architecture simultaneously including muscle thickness, cross-sectional area, echogenicity, pennate angle, and fascicle length. It can also evaluate dynamic parameters like muscle contraction force and muscle microcirculation. US has not gained global attention due to a lack of consensus on standardization and diagnostic threshold values to diagnose sarcopenia. However, it is an inexpensive and widely available technique with clinical applicability. The ultrasound-derived parameters correlate well with strength and functional capacity and provide potential prognostic information. Our aim is to present an update on the evidence-based role of this promising technique in sarcopenia, its advantages over the existing modalities, and its limitations in actual practice with the hope that it may emerge as the "stethoscope" for community diagnosis of sarcopenia.

European Working Group on Sarcopenia in Older People 2010 (EWGSOP1) and 2019 (EWGSOP2) criteria or slowness: which is the best predictor of mortality risk in older adults?

Objectives

to analyse the accuracy of grip strength and gait speed in identifying mortality; to compare the association between mortality and sarcopenia defined by the EWGSOP1 and EWGSOP2 using the best cut-off found in the present study and those recommended in the literature and to test whether slowness is better than these two definitions to identify the risk of death in older adults.

Methods

a longitudinal study was conducted involving 6,182 individuals aged 60 or older who participated in the English Longitudinal Study of Ageing. Sarcopenia was defined based on the EWGSOP1 and EWGSOP2 using different cut-off for low muscle strength (LMS). Mortality was analysed in a 14-year follow-up.

Results

compared with the LMS definitions in the literature (<32, <30, <27 and < 26 kg for men; <21, <20 and < 16 kg for women), the cut-off of <36 kg for men (sensitivity = 58.59%, specificity = 72.96%, area under the curve [AUC] = 0.66) and < 23 kg for women (sensitivity = 68.90%, specificity = 59.03%, AUC = 0.64) as well as a low gait speed (LGS) ≤0.8 m/s (sensitivity = 53.72%, specificity = 74.02%, AUC = 0.64) demonstrated the best accuracy for mortality. Using the cut-off found in the present study, probable sarcopenia [HR = 1.30 (95%CI: 1.16–1.46)], sarcopenia [HR = 1.48 (95%CI: 1.24–1.78)] and severe sarcopenia [HR = 1.78 (95%CI: 1.49–2.12)] according to EWGSOP2 were better predictors of mortality risk than EWGSOP1. LGS ≤0.8 m/s was a better mortality risk predictor only when LMS was defined by low cut-off.

Conclusions

using LMS <36 kg for men and < 23 kg for women and LGS ≤ 0.8 m/s, EWGSOP2 was the best predictor for mortality risk in older adults.

Digital Anthropometry for Body Circumference Measurements: European Phenotypic Variations throughout the Decades

This review summarizes body circumference-based anthropometrics that are in common use for research and in some cases clinical application. These include waist and hip circumference-based central body indices to predict cardiometabolic risk: waist circumference, waist-to-hip ratio, waist-to-height ratio, waist-to-thigh ratio, body adiposity index, a body shape index (ABSI), hip index (HI), and body roundness index (BRI). Limb circumference measurements are most often used to assess sarcopenia and include: thigh circumference, calf circumference, and mid-arm circumference. Additionally, this review presents fascinating recent developments in optic-based imaging technologies that have elucidated changes over the last decades in average body size and shape in European populations. The classical apple and pear shape concepts of body shape difference remain useful, but novel and exciting 3-D optical “e-taper” measurements provide a potentially powerful new future vista in anthropometrics.

The impact of breast support garments on fit, support and posture of larger breasted women

Due to current measurement, sizing and fitting approaches, poor bra fit is prevalent amongst larger breasted women. The impact of improving bra fit hasn't yet been explored. This pre-clinical study aimed to explore immediate and short-term biomechanical responses to changing breast support garment. Asymptomatic participants (n=24) performed a static standing task, drop jumps and seated typing whilst kinematic data from the breasts and spine were recorded. Three breast support conditions were assessed: Usual, professionally fitted bra in the immediate term (PFB), and the same professionally fitted bra after four weeks wear (PFB₂₈). Bra fit assessments were included for both bras. All participants failed the bra fit assessment when wearing the Usual bra and 67% (n=16) failed when wearing the PFB. Less bra fit issues were present in the PFB, resulting in immediate biomechanical changes relating to breast support and spinal posture, yet nothing in the short term (PFB₂₈). This research sets the foundations for future work to investigate whether the implementation of better fitting breast support garments can influence musculoskeletal pain amongst larger breasted women, whilst attributing potential improvement of symptoms, objective measures of breast support and spinal posture.

Changes in predicted lean body mass, appendicular skeletal muscle mass, and body fat mass and cardiovascular disease

BACKGROUND

Little is known about the association of changes in two body components, muscle and fat mass, with the risk of cardiovascular disease (CVD) among young adults. We investigated the association of changes in predicted lean body mass index (LBMI), appendicular skeletal muscle mass index (ASMI), and body fat mass index (BFMI) with the development of CVD among young adults.

METHODS

This nationwide, population-based cohort study included 3 727 738 young adults [2 406 046 (64.5%) men and 1 321 692 (35.5%) women] aged 20-39 years without a previous history of CVD who underwent two health screening examinations during 2009-2010 and 2011-2012. Using validated and robust prediction equations, we calculated the changes in predicted LBMI, ASMI, and BFMI from the first to the second examinations.

RESULTS

The mean (SD) age was 32.2 (4.9) years, and 2 406 046 (64.5%) of the participants were men. A total of 23 344 CVD events were detected during 22 257 632 person-years of follow-up. Each 1 kg/m² increase in predicted LBMI and ASMI change was associated with a reduced risk of CVD among men [adjusted hazard ratio (aHR): 0.86, 95% confidence interval (CI) 0.82-0.91; aHR: 0.76, 95% CI 0.69-0.82, respectively] and women (aHR: 0.77, 95% CI 0.63-0.95; aHR: 0.75, 95% CI 0.59-0.96). Each 1 kg/m² increase in predicted BFMI change was associated with an increased risk of CVD among men (aHR: 1.16, 95% CI 1.10-1.22) and women (aHR: 1.32, 95% CI 1.06-1.65). In both sexes, decreases in predicted LBMI and ASMI were associated with greater CVD risk, and decreased predicted BFMI was associated with a reduced CVD risk. Those who maintained their BMI between -1 and +1 kg/m² also had a decreased risk of CVD per 1 kg/m² increase in predicted LBMI and ASMI change among men (aHR: 0.86, 95% CI 0.80-0.92; aHR: 0.85, 95% CI 0.76-0.95) and women (aHR: 0.62, 95% CI 0.47-0.83; aHR: 0.59, 95% CI 0.44-0.80) and had a greater risk of CVD per 1 kg/m² increase in predicted BFMI change among men (aHR: 1.17, 95% CI 1.10-1.25) and women (aHR: 1.64, 95% CI 1.20-2.23). Regardless of changes in weight, such as from normal to obese or vice versa, these results were consistent.

CONCLUSIONS

Among young adults, increased predicted muscle mass or decreased predicted fat mass were associated with a reduced risk of development of CVD. Decreased predicted muscle mass or increased predicted fat mass were associated with an elevated risk of development of CVD.

Sarcopenia: imaging assessment and clinical application

Sarcopenia is a progressive, generalized skeletal muscle disorder characterized by reduction of muscle mass and strength. It is associated with increased adverse outcomes including falls, fractures, physical disability, and mortality, particularly, in elderly patients. Nowadays, sarcopenia has become a specific imaging biomarker able to predict clinical outcomes of patients. Muscle fibre reduction has shown to be an unfavourable pre-operative predictive factor in patients with cancer, and is associated with worse clinical outcomes in terms of postoperative complications, morbidity, mortality, and lower tolerance of chemoradiation therapy. Several imaging modalities, including dual-energy X-ray absorptiometry, CT, MRI, and US can be used to estimate muscle mass and quality to reach the diagnosis of sarcopenia. This article reviews the clinical implications of sarcopenia, how this condition can be assessed through different imaging modalities, and future perspectives of imaging of sarcopenia.

Impact of physical performance on exercise capacity in older patients with heart failure with reduced and preserved ejection fraction

BACKGROUND

Low physical performance may contribute to reduced exercise capacity in older patients with heart failure (HF). We sought to identify the determinants of exercise capacity out of a plethora of background factors, including measures of physical performance.

METHODS

We performed a post-hoc analysis of a cohort study that included 1205 consecutive older (age ≥ 65 years) hospitalized patients (the median age, 80 years; 57.4% males).

RESULTS

Low physical performance, defined as ≤1.0 m/s for gait speed, ≥12 s for the 5-time chair stand test, or ≤ 9 points for the Short Physical Performance Battery in both sexes, was seen in 83.9% of the cohort. Multivariate regression analysis revealed that each parameter of physical performance (i.e., gait speed, chair stand test, and balance test) was identified as an independent determinant of lower exercise capacity assessed using the 6-min walking distance. In a logistic regression model, low physical performance predicted short (<300 m) 6-min walking distance (adjusted odds ratio 10.28, 95% CI 6.01-17.60, p < 0.001). No interaction was detected between patients with preserved and reduced ejection fraction.

CONCLUSIONS

Low physical performance was prevalent and independently associated with exercise capacity in older patients with HF, irrespective of preserved or reduced ejection fraction.

Estimation of Muscle Mass Using Creatinine/Cystatin C Ratio in Japanese Community-Dwelling Older People

OBJECTIVES

Sarcopenia is defined as a combination of low skeletal muscle mass index (SMI), weak muscle strength, and reduced physical function. Recently, many studies have reported that the creatinine/cystatin C ratio (Cr/CysC) is useful for evaluating muscle mass. We designed a cross-sectional study with separate model development and validation groups to develop a prediction equation to estimate bioimpedance analysis (BIA)-measured SMI with Cr/CysC.

DESIGN

The current study was a retrospective cross-sectional study.

SETTING AND PARTICIPANTS

The model development group included 908 subjects (288 men and 620 women) from the Frail Elderly in the Sasayama-Tamba Area (FESTA) study, and the validation group included 263 subjects (112 men and 151 women) from participants in the medical checkup program at the Anti-Aging Center in Ehime Prefecture.

MEASURES

Multivariate regression analysis indicated that age, hemoglobin (Hb), body weight (BW), and Cr/CysC were independently associated with SMI in both men and women. The SMI prediction equation was developed as follows: Men:4.17-0.012×Age+1.24×(Cr/CysC)-0.0513×Hb+0.0598×BW Women:3.55-0.00765×Age+0.852×(Cr/CysC)-0.0627×Hb+0.0614×BW RESULTS: The SMI prediction equation was applied to the validation group and strong correlations were observed between the BIA-measured and predicted SMI (pSMI) in men and women. According to the receiver operator characteristic (ROC) analysis, the areas under the curve were 0.93 (specificity 89.0%, sensitivity 87.2%) among men and 0.88 (specificity 83.6%, sensitivity 79.6%) among women for using pSMI to identify low SMI in the model development group. The pSMI also indicated high accuracy in ROC analysis for low SMI in the validation group. The Bland-Altman plot regression showed good agreement between BIA-measured and pSMI.

CONCLUSIONS AND IMPLICATIONS

Our new prediction equation to estimate SMI is easy to calculate in daily clinical practice and would be useful for diagnosing sarcopenia.

Mid-Arm Muscle and Subcutaneous Fat Associated with All-Cause Mortality Independent of BMI: A Prospective Cohort Study

OBJECTIVE

This study aimed to systematically evaluate the association between triceps skinfold (TSF) thickness (which indicates subcutaneous fat) mid-arm muscle circumference (MAMC; which reflects muscle mass), mid-upper arm circumference (MUAC), and all-cause mortality.

METHODS

A total of 17,717 adults from the China Health and Nutrition Survey (1993-2015) were included. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause mortality. The joint effect of TSF thickness and MAMC was examined, and planned subgroup analyses were performed.

RESULTS

The highest quartiles of TSF thickness, MAMC, and MUAC were significantly associated with low all-cause mortality, independent of BMI (TSF thickness: HR = 0.704 [95% CI: 0.575-0.862]; MAMC: HR = 0.729 [95% CI: 0.607-0.876]; MUAC: HR = 0.713 [95% CI: 0.583-0.872]). A 1-SD increase showed comparable risk reductions for TSF thickness and MAMC (14.6% and 14.0%), with 16.1% risk reductions in MUAC. There were positive additive interactions between TSF thickness and MAMC. The inverse association existed in young, middle-aged, and elderly participants (P-heterogeneity > 0.05).

CONCLUSIONS

Mid-arm muscle and subcutaneous fat were inversely associated with all-cause mortality, independent of BMI, beyond the elderly population. Mid-arm muscle and subcutaneous fat made comparable contributions to and had positive joint effects on all-cause mortality.

Association of midlife body composition with old-age health-related quality of life, mortality, and reaching 90 years of age: a 32-year follow-up of a male cohort

BACKGROUND

Overweight and obesity increase the risk of morbidity and mortality. The relations between body composition at midlife, health-related quality of life (HRQoL) in old age, and longevity are, however, less studied.

OBJECTIVES

We examined the association of midlife body composition with successful aging, defined as high HRQoL and reaching 90 y of age, during 32 y follow-up.

METHODS

Participants were 1354 men from the Helsinki Businessmen Study, born 1919-1934. In 1985/1986 (mean age: 60 y) various health measurements were performed. Percentages of body fat (BF) and skeletal muscle mass (SM) were calculated using validated formulas (including waist and hip circumferences, weight, and age) and divided into quartiles. In 2000 and 2007 (mean ages: 74 and 80 y, respectively), HRQoL was assessed using RAND-36/Short Form-36 scales. Mortality was retrieved from registers through 2018, and longevity determined by calculating the proportion of participants reaching 90 y. Logistic regression was used to assess ORs with 95% CIs.

RESULTS

Higher SM% at midlife in 1985/1986 was associated (P < 0.05) with higher scores in the RAND-36 scales of physical functioning, role limitations caused by physical health problems, vitality, social functioning, and general health in old age in 2000. In 2007 only the association with physical domain (physical functioning, role limitations caused by physical health problems) remained statistically significant (P < 0.01). BF% quartiles in 1985/1986 were inversely associated with several RAND-36 scales in 2000 and 2007. During the 32-y follow-up, 982 participants died and 281 reached 90 y of age. Being in the highest SM% quartile at midlife increased (adjusted OR: 2.32; 95% CI: 1.53, 3.53; lowest SM% quartile as reference) and being in the highest BF% quartile decreased (OR: 0.43; 95% CI: 0.28, 0.66; lowest BF% quartile as reference) the odds of reaching 90 y.

CONCLUSIONS

Desirable body composition in terms of both fat and skeletal muscle mass at midlife was associated with successful aging in men.This trial was registered at clinicaltrials.gov as NCT02526082.

Grip Strength and Demographic Variables Estimate Appendicular Muscle Mass Better Than Bioelectrical Impedance in Taiwanese Older Persons

OBJECTIVES

This study aimed to develop an equation model combining physical fitness and anthropometric parameters and compare its results with those of bioelectrical impedance analysis (BIA)-measured lean mass (LM) using dual-energy X-ray absorptiometry (DXA)-measured appendicular muscle mass (AMM) as reference.

DESIGN

Observational analysis.

SETTING AND PARTICIPANTS

Healthy community-dwelling older subjects.

METHODS

A total of 1020 participants were randomly allocated to the development group (development group, n = 510) or the cross-validation group (validation group, n = 510). Body composition was measured using both DXA and BIA, and physical fitness parameters, including grip strength, timed stepping test, sit-to-stand test, flexibility, and walking speed were also assessed. A prediction equation model of AMM by stepwise linear regression analysis that included or excluded 1 independent variable at each step, based on the P value of significance (P < .05), was developed.

RESULTS

Using weight, sex, height, and handgrip strength as independent variables, the equation AMM = -9.833 + 0.397 × weight (kg) + 4.433 × sex + 0.121 × height (cm) + 0.061 × handgrip strength (kg) best predicts DXA-measured AMM (adjusted R² = 0.914, SEE = 2.062, P < .001). The predicted AMM was more highly correlated with DXA-measured AMM than the commonly used BIA-measured LM (R²= 0.9158 and 0.8427, respectively, both P < .001). Using DXA-measured AMM as reference, the Bland-Altman plot showed mean differences of -0.03 kg and -0.12 kg, with limits of agreement of -3.98 to 3.92 kg and -5.97 to 5.73 kg for the predicted AMM and BIA-measured AMM, respectively.

CONCLUSIONS AND IMPLICATIONS

The proposed equation offers a practical alternative method for estimating AMM that is less facility-dependent and more easy to use and affordable than instrumental studies.

Derivation and validation of a simple anthropometric equation to predict fat-free mass in patients with chronic hepatitis C

BACKGROUND

Loss of skeletal muscle mass is very common in chronic liver diseases and affects 30.0-70.0% of the patients with cirrhosis. Given the relevance of muscle wasting in hepatic diseases, a practical screening tool for earlier detection of skeletal muscle mass loss is of utmost significance.

AIMS

To develop and validate a simple anthropometric prediction equation for fat-free mass estimation by using Bioelectrical Impedance Analysis (BIA) as a reference method in patients with chronic hepatitis C (CHC).

METHODS

We prospectively, included 209 CHC patients, randomly allocated into two groups, 158 patients in a development model (derivation sample) and 51 patients in a validation group (validation sample). Predictive equations were developed using backward stepwise multiple regression and the most adequate and simplest derived predictive equation was further explored for agreement and bias in the validation sample. The accuracy of the predictive equation was evaluated using the coefficient of determination (R²).

RESULTS

The predictive equation with an optimal R² was Fat-Free Mass (Kg) = Sex × 0.17 + Height (m) × 16.83 + Weight (Kg) × 0.62 + Waist Circumference (cm) × (-0.15) + Weight (Kg) × Sex × (-0.30) + Sex × Waist Circumference (cm) × 0.14-6.23; where sex = 1 for female and 0 for male. R² = 0.93, standard error of the estimate = 2.6 Kg and coefficient of variation = 20.0%, p < 0.001.

CONCLUSIONS

Our developed and cross-validated anthropometric prediction equation for fat-free mass estimation by using BIA attained a high coefficient of determination, a low standard error of the estimate, and lowermost coefficient of variation. This study indicates that predictive equations may be reliable and useful alternative methods for clinical evaluation of fat-free mass in patients with CHC.

Development and validation of prediction equations for the assessment of muscle or fat mass using anthropometric measurements, serum creatinine level, and lifestyle factors among Korean adults

BACKGROUND/OBJECTIVES

The measurement of body composition, including muscle and fat mass, remains challenging in large epidemiological studies due to time constraint and cost when using accurate modalities. Therefore, this study aimed to develop and validate prediction equations according to sex to measure lean body mass (LBM), appendicular skeletal muscle mass (ASM), and body fat mass (BFM) using anthropometric measurement, serum creatinine level, and lifestyle factors as independent variables and dual-energy X-ray absorptiometry as the reference method.

SUBJECTS/METHODS

A sample of the Korean general adult population (men: 7,599; women: 10,009) from the Korean National Health and Nutrition Examination Survey 2008–2011 was included in this study. The participants were divided into the derivation and validation groups via a random number generator (with a ratio of 70:30). The prediction equations were developed using a series of multivariable linear regressions and validated using the Bland–Altman plot and intraclass correlation coefficient (ICC).

RESULTS

The initial and practical equations that included age, height, weight, and waist circumference had a different predictive ability for LBM (men: R² = 0.85, standard error of estimate [SEE] = 2.7 kg; women: R² = 0.78, SEE = 2.2 kg), ASM (men: R² = 0.81, SEE = 1.6 kg; women: R² = 0.71, SEE = 1.2 kg), and BFM (men: R² = 0.74, SEE = 2.7 kg; women: R² = 0.83, SEE = 2.2 kg) according to sex. Compared with the first prediction equation, the addition of other factors, including serum creatinine level, physical activity, smoking status, and alcohol use, resulted in an R² that is higher by 0.01 and SEE that is lower by 0.1.

CONCLUSIONS

All equations had low bias, moderate agreement based on the Bland–Altman plot, and high ICC, and this result showed that these equations can be further applied to other epidemiologic studies.

Rising prevalence of BMI ≥40 kg/m2 : A high-demand epidemic needing better documentation

Whilst previously rare, some surveys indicate substantial increases in the population with body mass index (BMI) ≥40 kg/m2 since the 1980s. Clinicians report emerging care challenges for this population, often with high resource demands. Accurate prevalence data, gathered using reliable methods, are needed to inform health care practice, planning, and research. We searched digitally for English language sources with measured prevalence data on adult BMI ≥40 collected since 2010. The search strategy included sources identified from recent work by NCD-RisC (2017), grey sources, a literature search to find current sources, and digital snowball searching. Eighteen countries, across five continents, reported BMI ≥40 prevalence data in surveys since 2010: 12% of eligible national surveys examined. Prevalence of BMI ≥40 ranged from 1.3% (Spain) to 7.7% (USA) for all adults, 0.7% (Serbia) to 5.6% (USA) for men, and 1.8% (Poland) to 9.7% (USA) for women. Limited trend data covering recent decades support significant growth of BMI ≥40 population. Methodological limitations include small samples and data collection methods likely to exclude people with very high BMIs. BMI ≥40 data are not routinely reported in international surveys. Lack of data impairs surveillance of population trends, understanding of causation, and societal provision for individuals living with higher weights.

Simple Skeletal Muscle Mass Estimation Formulas: What We Can Learn From Them

One century ago Harris and Benedict published a short report critically examining the relations between body size, body shape, age, and basal metabolic rate. At the time, basal metabolic rate was a vital measurement in diagnosing diseases such as hypothyroidism. Their conclusions and basal metabolic rate prediction formulas still resonate today. Using the Harris-Benedict approach as a template, we systematically examined the relations between body size, body shape, age, and skeletal muscle mass (SM), the main anatomic feature of sarcopenia. The sample consisted of 12,330 non-Hispanic (NH) white and NH black participants in the US National Health and Nutrition Survey who had complete weight, height, waist circumference, age, and dual-energy X-ray (DXA) absorptiometry data. A conversion formula was used to derive SM from DXA-measured appendicular lean soft tissue mass. Weight, height, waist circumference, and age alone and in combination were significantly correlated with SM (all, p < 0.001). Advancing analyses through the aforementioned sequence of predictor variables allowed us to establish how at the anatomic level these body size, body shape, and age measures relate to SM much in the same way the Harris-Benedict equations provide insights into the structural origins of basal heat production. Our composite series of SM prediction equations should prove useful in modeling efforts and in generating hypotheses aimed at understanding how SM relates to body size and shape across the adult lifespan.

Secular trends in adiposity and musculoskeletal dimensions of elite heavyweight boxers between 1889 and 2019

Purpose

With improving nutrition and health, athletes have grown taller and heavier over the past century. Since there is no weight restriction in the heavyweight class, secular changes in anthropometric measurements of heavyweight boxers may mirror those of contemporary general populations.

Objectives

We aimed to (1) examine secular trends in adiposity and musculoskeletal measurements in heavyweight boxers, (2) determine anthropometric differences between champions and unsuccessful challengers.

Methods

Detailed demographics taken at time of contest (first official World Championship to current contest: 1889–2019) were collected from media archives.

Results

All 237 boxers (83 champions, 154 challengers) contesting a recognised heavyweight World Championships were identified. They had mean (± SD) age = 28.9 ± 4.1 years, height = 187.3 ± 6.5 cm, reach = 195.2 ± 9.4 cm, weight = 97.5 ± 11.5 kg, BMI = 27.8 ± 2.4 kg/m2 and waist = 87.9 ± 6.2 cm. Contest years explained 25.9% (p < 0.001) of the variance in BMI for champions and 30.9% (p < 0.001) for challengers, 9.1% (p < 0.071) in WC for champions and 19.9% (p < 0.001) for challengers. Contest years correlated with height (r = 0.531, p < 0.001), reach (r = 0.341, p < 0.001), weight (r = 0.603, p < 0.001) and BMI (r = 0.370, p = 0.001) among all documented boxers, and with waist only in challengers (r = 0.349, p < 0.001) but not in champions (r = 0.078, p = 0.509). Compared with challengers, champions had greater stature by + 3.4 cm (p < 0.001), reach + 3.6 cm (p = 0.005) and weight + 3.7 kg (p = 0.017), with similar BMI and waist. Champions had larger biceps and forearms but did not differ from challengers in other musculoskeletal dimensions.

Conclusions

Over 130 years elite heavyweight boxers have increased in size (BMI) and reach but waists in champions have remained static. Being heavier, taller with longer and bigger arms, but with similar in BMI and waist, appear to be differentiating factors between champions and challengers.

Estimation of appendicular skeletal muscle: Development and validation of anthropometric prediction equations in Chinese patients with knee osteoarthritis

OBJECTIVE

To develop anthropometric prediction equations for estimating appendicular skeletal muscle (ASM) in Chinese knee osteoarthritis patients.

METHODS

Subjects were divided into the model development group (MD group: 104 cases, 47 men and 57 women) and cross-validation group (CV group: 69 cases, 38 men and 31 women). Stepwise multiple linear regression analyses were undertaken in the MD group to identify the best equations. Agreement between the estimated ASM and ASM measured by dual-energy X-ray absorptiometry (DXA) was tested in the CV group.

RESULTS

Two models were developed in the MD group. Validation in the CV group showed that our models (R²  = 0.83 and R²  = 0.90) had a high coefficient of determination. The mean bias of ASM estimated by the two models from the ASM measured by DXA in the CV group showed no significant difference (P > 0.05).

CONCLUSION

These models could be useful for older Chinese patients with knee osteoarthritis to estimate ASM.

Associations of BMI, waist circumference, body fat, and skeletal muscle with type 2 diabetes in adults

AIMS

Type 2 diabetes (T2D) is known to be associated with high BMI and waist circumference (WC). These measures do not discriminate well between skeletal muscle (SM) and body fat (BF), which may have opposite influences.

METHODS

We conducted a secondary analysis of population-based data from 58,128 aged 18-85 yrs from Scottish Health Surveys (2003, 2008-2011) and Health Surveys for England (2003-2006, 2008-2013), excluding pregnant women and insulin-treated diabetes. Logistic regression was used to assess associations of known T2D, and of screened HbA1c > 48 mmol/mol (> 6.5%), with sex-specific quintiles of BMI, WC, and BF% and SM% estimated by validated anthropometric equations, adjusted for age, sex, smoking, ethnicity, country, and survey year.

RESULTS

As expected, ORs for having known T2D rose with quintiles of BMI (1, 1.5, 2.3, 3.1, and 6.5) and WC (1, 1.8, 2.5, 3.5, and 8.7). Compared to the lowest BF% quintile, OR for having T2D in highest BF% quintile was 11.1 (95% CI = 8.4-14.6). Compared to the highest SM% quintile, OR for having T2D in lowest SM% quintile was 2.0 (1.7-2.4). Of 72 adults with T2D/HbA1c > 6.5% in the lowest quintile of BF%, 27 (37.5%) were in quintile 1 of SM%. Similar patterns of OR were observed for having HbA1c > 6.5% in those without known T2D.

CONCLUSIONS

Estimated BF% associates strongly with T2D. Low SM% also has a significant association, suggesting a neglected aspect of aetiology within T2D. These two simple measures with biological relevance, available from data collected in most health surveys, may be more useful than the purely statistical terms BMI.

[Early prevention and nutritional education]

To be effective, prevention must not remain a theoretical concept and its implementation must not be perceived negatively. Ignorance and prejudices need to be overcome. From conception to adolescence, simple and easy-to-follow nutritional education measures, as well as practical and concrete advice, can be easily applied. Caregivers have an important role to play in communicating these guidelines.

Establishment of Prediction Equations of Lean Body Mass Suitable for Chinese Adults

Aim

To develop predictive equations of lean body mass (LBM) suitable for healthy southern Chinese adults with a large sample. LBM measured by dual-energy X-ray absorptiometry (DXA) are considered as the standard ones.

Methods

Retrospective analysis was conducted on the consecutive people who did total body measurement with DXA from July 2005 to October 2015. People with diseases that might affect LBM were excluded and overall 12,194 subjects were included in this study. Information about the 10,683 subjects (2,987 males and 7,696 females) from July 2005 to November 2014 was used to establish equations. These subjects were grouped by sex and then subdivided according to their body mass index (BMI). The female group was divided into another two subgroups: the premenopausal and postmenopausal subgroups. Equations were developed through stepwise multilinear regression analysis of height, weight, age, and BMI. Information about the 1,511 subjects (395 males and 1116 females) from December 2014 to October 2015 was used to verify the established equations.

Results

BMI, height, weight, and age were introduced into the equations as independent variables in the male group, while age was proved to have no influence on LBM in the female group. Regrouping according to BMI or menopause did not increase the predictive ability of equations. Good agreement between LBM evaluated by equation (LBM_PE) and LBM measured by DXA (LBM_DXA) was observed in both the male and female groups.

Conclusion

Predictive equations of LBM suitable for healthy southern Chinese adults are established with a large sample. BMI was related to LBM content; however, there is no need for further group based on BMI or menopause while developing LBM questions.

Frailty assessment: from clinical to radiological tools

Frailty is a syndrome of cumulative decline across multiple physiological systems, which predisposes vulnerable adults to adverse events. Assessing vulnerable patients can potentially lead to interventions that improve surgical outcomes. Anaesthesiologists who care for older patients can identify frailty to improve preoperative risk stratification and subsequent perioperative planning. Numerous clinical tools to diagnose frailty exist, but none has emerged as the standard tool to be used in clinical practice. Radiological modalities, such as computed tomography and ultrasonography, are widely performed before surgery, and are therefore available to be used opportunistically to objectively evaluate surrogate markers of frailty. This review presents the importance of frailty assessment by anaesthesiologists; lists common clinical tools that have been applied; and proposes that utilising radiological imaging as an objective surrogate measure of frailty is a novel, expanding approach for which anaesthesiologists can significantly contribute to broad implementation.

Associations of body fat and skeletal muscle with hypertension

Hypertension is known to be associated with obesity, while its relationship to skeletal muscle, SM (SM; a marker of general health and body function), remains uncertain. We analyzed population-based data of 22 591 men (mean age: 51.6 ± 16.9 years) and 27 845 nonpregnant women (50.6 ± 16.9 years) from Scottish Health Surveys (2003, 2008-2011) and Health Surveys for England (2003-2006, 2008-2013) including 2595 non-insulin- and 536 insulin-treated diabetic patients. Compared with normotensive individuals (no hypertension history with normal systolic [SBP < 140 mm Hg] and diastolic blood pressure [DBP < 90 mm Hg]), percent body fat (BF%) was significantly higher and percent SM lower (P < 0.001) in undetected (no hypertension history with raised SBP ≥ 140 and/or DBP ≥ 90 mm Hg), controlled (hypertension history with normal BP), uncontrolled (hypertension history with raised BP), and untreated hypertension. The prevalences of hypertension within BF% quintiles were 11.8%, 24.8%, 41.4%, 56.8%, and 71.6% and SM% quintiles were 67.5%, 53.3%, 39.5%, 27.4%, and 18.5%. Compared to referent groups (lowest BF% quintile or highest SM% quintile), odds ratio (age, sex, smoking, ethnicity, country, survey year, and diabetes adjusted) for having all types of hypertension in the highest BF% quintile was 5.5 (95% confidence interval = 5.0-5.9) and lowest SM% quintile was 2.3 (2.2-2.5). Compared with those without diabetes, individuals with diabetes had a 2.3-fold-2.6-fold greater risk of hypertension, independent of confounding factors and BF% or SM%. The associations of hypertension with BF% were higher than those with body mass index (BMI). In conclusion, both BF and SM should be considered when analyzing results from health surveys, rather than relying on BMI which does not discriminate between the two.

Overweight Without Central Obesity, Cardiovascular Risk, and All-Cause Mortality

OBJECTIVE

To assess the association of overweight without central obesity with risks of mortality.

PATIENTS AND METHODS

We included 14,299 participants in the Third National Health and Nutrition Examination Survey (from October 18, 1988, through October 15, 1994). According to their body mass index and waist circumference, participants were categorized into 7 anthropometric groups. Logistic regression models were used to assess the relation of cardiovascular risk factors (hypertension, diabetes, or hypercholesterolemia) and 10-year cardiovascular risk to anthropometric groups. Cox proportional hazards models were used to assess the risk of all-cause mortality, and competing-risks regression models were used for calculating cardiovascular and noncardiovascular mortality.

RESULTS

Compared with those with normal body mass index and waist circumference, overweight men without central obesity were more likely to have all 3 cardiovascular risk factors and a high cardiovascular risk, whereas women in this anthropometric group were more likely to have hypercholesterolemia. In proportional hazards models, overweight without central obesity was associated with lower all-cause mortality among men in the population with cardiovascular risk factors (hazard ratio, 0.71; 95% CI, 0.56-0.89; P=.004) and the general population (hazard ratio, 0.72; 95% CI, 0.60-0.87; P=.001), whereas results of these comparisons among women were not significant (P>.05). In competing risk analyses, overweight men without central obesity had a lower risk of noncardiovascular mortality, but not cardiovascular mortality.

CONCLUSION

Although overweight without central obesity was associated with cardiovascular risk factors and a high cardiovascular risk among men, men in this anthropometric group had a lower mortality risk.

Attenuation of the association between sugar-sweetened beverages and diabetes risk by adiposity adjustment: a secondary analysis of national health survey data

Purpose

While weight gain and obesity are the dominant factors, dietary sugar and specifically sugar-sweetened beverages (SSB) has been implicated in causing type 2 diabetes (T2DM). We assessed how much of the apparent effect of SSB is explained by adiposity, but not captured by adjustment for BMI, which is a poor index of body fat.

Methods

We examined data from 5187 adults (mean age 50.8 years, SD = 16.4, 172 (3.3%) T2DM), from the Scottish Health Survey 2003 and 2008–2010 databases. Logistic regression was used to assess the association between SSB consumption and T2DM (non-insulin treated) and its attenuation (reduction in odds ratios, ORs), after entering published anthropometric indices of adiposity into the regression model, adjusted for age, sex, social class, education, smoking, alcohol consumption and physical activity.

Results

Compared with low SSB categories (“less often/never”, once/week or 1–3 times/month), the OR without adiposity adjustment for having T2DM in high SSB consumers (2–3, 4–5, ≥ 6/day) was 2.56 (95% CI 1.12–5.83; p = 0.026). That OR was marginally changed by adjusting for BMI (+ 4.3%), WC (+ 5.5%) or total body fat (− 4.3%), but greatly attenuated by adjusting for estimated %body fat (− 23.4%). These indices had similar influences on the associations between SSB and T2DM combining known T2DM patients with unknown HbA_1c > 6.5%, > 48 mmol/mol.

Conclusions

Associations between SSB and T2DM are attenuated more markedly by adjustment with estimated %body fat than with BMI, indicating an adiposity effect not captured using BMI. Future research should employ best available estimates of adiposity.

Reliability of repeated arm-crank cardiopulmonary exercise tests in patients with small abdominal aortic aneurysm

Arm-crank ergometry may be useful in patients unable to pedal, for instance due to peripheral arterial disease. Twenty participants with small abdominal aortic aneurysm undertook two serial arm-crank tests and then a pedal test, four of whom had indeterminate anaerobic thresholds, precluding analysis. The mean (SD) peak arm and leg oxygen consumptions in 16 participants were 13.71 (2.62) ml.kg^-1 .min^-1 and 16.82 (4.44) ml.kg^-1 .min^-1 , with mean (SD) individual differences of 3.11 (2.48) ml.kg^-1 .min^-1 , p = 0.0001. The respective values at the anaerobic thresholds were 7.83 (1.58) ml O₂ .kg^-1 .min^-1 and 10.09 (3.15) ml O₂ .kg^-1 .min^-1 , with mean (SD) individual differences of 2.26 (2.34) ml O₂ .kg^-1 .min^-1 , p = 0.0001. The correlation coefficients (95%CI) for peak oxygen consumption and anaerobic threshold were 0.88 (0.62-1.0) and 0.70 (0.32-1.0). There were no significant differences in serial arm-crank tests, with intracluster correlations (95%CI) of 0.87 (0.86-0.88) and 0.65 (0.61-0.69) for peak oxygen consumption and anaerobic threshold, respectively.

Validation of equations and proposed reference values to estimate fat mass in Chilean university students

OBJECTIVES

(i) To propose regression equations based on anthropometric measures to estimate fat mass (FM) using dual energy X-ray absorptiometry (DXA) as reference method, and (ii)to establish population reference standards for equation-derived FM.

MATERIAL AND METHODS

A cross-sectional study on 6,713 university students (3,354 males and 3,359 females) from Chile aged 17.0 to 27.0years. Anthropometric measures (weight, height, waist circumference) were taken in all participants. Whole body DXA was performed in 683 subjects. A total of 478 subjects were selected to develop regression equations, and 205 for their cross-validation. Data from 6,030 participants were used to develop reference standards for FM. Equations were generated using stepwise multiple regression analysis. Percentiles were developed using the LMS method.

RESULTS

Equations for men were: (i) FM=-35,997.486 +232.285 *Weight +432.216 *CC (R²=0.73, SEE=4.1); (ii)FM=-37,671.303 +309.539 *Weight +66,028.109 *ICE (R2=0.76, SEE=3.8), while equations for women were: (iii)FM=-13,216.917 +461,302 *Weight+91.898 *CC (R²=0.70, SEE=4.6), and (iv) FM=-14,144.220 +464.061 *Weight +16,189.297 *ICE (R²=0.70, SEE=4.6). Percentiles proposed included p10, p50, p85, and p95.

CONCLUSION

The developed equations provide valid and accurate estimation of FM in both sexes. The values obtained using the equations may be analyzed from percentiles that allow for categorizing body fat levels by age and sex.

Functional Capacity and Levels of Physical Activity in Aging: A 3-Year Follow-up

Over the last decades, the world elderly population has increased exponentially and this tendency will continue during the coming years; from 2000 to 2050, people over 60 will double and those over 80 will quadruple. Loss of independence occurs as people age due to mobility restrictions, frailty, and decreased functional fitness and cognitive abilities. Evidence has shown that appropriate programs and policies contribute to keep older adults healthy and independent over time. The purpose of this chapter is to report the results of our 3-year follow-up study designed to characterize functional physical fitness in a sample of Portuguese community-dwelling older adults to propose a set of functional parameters that decline the most. We studied a group of 43 elderly people, aged 60 and over. Variables assessed on the participants were anthropometric measurements, functional capacity with the Senior Fitness Test battery (muscle strength, aerobic endurance, flexibility, agility, and dynamic balance), handgrip strength, levels of physical activity, and balance. Three years after the first assessment, a second assessment of the same variables was conducted. We analyzed what were the variables that, for this group, were related with a healthier aging and the relation with different physical activity levels. Our study showed that the distance covered in 6-min walk test and handgrip strength seem to explain a great amount of variability on functional variables that have changed on this period (68% of balance, lower and upper functional strength, respectively) and the active participants showed less decrements with aging in anthropometric and functional variables than those inactive or insufficiently active (p < 0.05). Greater importance should be given to prescription of exercise targeting older adults and, specifically, walking and manual activities should be given more attention as components of a community exercise program.

Development and validation of anthropometric prediction equations for lean body mass, fat mass and percent fat in adults using the National Health and Nutrition Examination Survey (NHANES) 1999-2006

Quantification of lean body mass and fat mass can provide important insight into epidemiological research. However, there is no consensus on generalisable anthropometric prediction equations to validly estimate body composition. We aimed to develop and validate practical anthropometric prediction equations for lean body mass, fat mass and percent fat in adults (men, n 7531; women, n 6534) from the National Health and Nutrition Examination Survey 1999-2006. Using a prediction sample, we predicted each of dual-energy X-ray absorptiometry (DXA)-measured lean body mass, fat mass and percent fat based on different combinations of anthropometric measures. The proposed equations were validated using a validation sample and obesity-related biomarkers. The practical equation including age, race, height, weight and waist circumference had high predictive ability for lean body mass (men: R 2=0·91, standard error of estimate (SEE)=2·6 kg; women: R 2=0·85, SEE=2·4 kg) and fat mass (men: R 2=0·90, SEE=2·6 kg; women: R 2=0·93, SEE=2·4 kg). Waist circumference was a strong predictor in men only. Addition of other circumference and skinfold measures slightly improved the prediction model. For percent fat, R 2 were generally lower but the trend in variation explained was similar. Our validation tests showed robust and consistent results with no evidence of substantial bias. Additional validation using biomarkers demonstrated comparable abilities to predict obesity-related biomarkers between direct DXA measurements and predicted scores. Moreover, predicted fat mass and percent fat had significantly stronger associations with obesity-related biomarkers than BMI did. Our findings suggest the potential application of the proposed equations in various epidemiological settings.

Estimating Gestational Age From Ultrasound Fetal Biometrics

OBJECTIVE

To compare the accuracy of a new formula with one developed in 1984 (and still in common use) and to develop and compare racial and ethnic-specific and racial and ethnic-neutral formulas.

METHODS

The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies-Singletons was a prospective cohort study that recruited women in four self-reported racial-ethnic groups-non-Hispanic black, Hispanic, non-Hispanic white, and Asian-with singleton gestations from 12 U.S. centers (2009-2013). Women with a certain last menstrual period confirmed by first-trimester ultrasonogram had longitudinal fetal measurements by credentialed study ultrasonographers blinded to the gestational age at their five follow-up visits. Regression analyses were performed with linear mixed models to develop gestational age estimating formulas. Repeated cross-validation was used for validation. The estimation error was defined as the mean squared difference between the estimated and observed gestational age and was used to compare the formulas' accuracy.

RESULTS

The new formula estimated the gestational age (±2 SD) within ±7 days from 14 to 20 weeks of gestation, ±10 days from 21 to 27 weeks of gestation, and ±17 days from 28 to 40 weeks of gestation. The new formula performed significantly better than a formula developed in 1984 with an estimation error of 10.4 compared with 11.2 days from 21 to 27 weeks of gestation and 17.0 compared with 19.8 days at 28-40 weeks of gestation, respectively. Racial and ethnic-specific formulas did not outperform the racial and ethnic-neutral formula.

CONCLUSION

The NICHD gestational age estimation formula is associated with smaller errors than a well-established historical formula. Racial and ethnic-specific formulas are not superior to a racial-ethnic-neutral one.

Nutritional status and body composition by bioelectrical impedance vector analysis: A cross sectional study in mild cognitive impairment and Alzheimer's disease

AIMS

Analysis of nutritional status and body composition in Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI).

METHODS

A cross-sectional study was performed in a University-Hospital setting, recruiting 59 patients with AD, 34 subjects with MCI and 58 elderly healthy controls (HC). Nutritional status was assessed by anthropometric parameters (body mass index; calf, upper arm and waist circumferences), Mini Nutritional Assessment (MNA) and body composition by bioelectrical impedance vector analysis (BIVA). Variables were analyzed by analysis of variance and subjects were grouped by cognitive status and gender.

RESULTS

Sociodemographic variables did not differ among the three groups (AD, MCI and HC), except for females' age, which was therefore used as covariate in a general linear multivariate model. MNA score was significantly lower in AD patients than in HC; MCI subjects achieved intermediate scores. AD patients (both sexes) had significantly (p<0.05) higher height-normalized impedance values and lower phase angles (body cell mass) compared with HC; a higher ratio of impedance to height was found in men with MCI with respect to HC. With BIVA method, MCI subjects showed a significant displacement on the RXc graph on the right side indicating lower soft tissues (Hotelling's T2 test: men = 10.6; women = 7.9;p < 0,05) just like AD patients (Hotelling's T2 test: men = 18.2; women = 16.9; p<0,001).

CONCLUSION

Bioelectrical parameters significantly differ from MCI and AD to HC; MCI showed an intermediate pattern between AD and HC. Longitudinal studies are required to investigate if BIVA could reflect early AD-changes in body composition in subjects with MCI.

Changing guards: time to move beyond body mass index for population monitoring of excess adiposity

With the obesity epidemic, and the effects of aging populations, human phenotypes have changed over two generations, possibly more dramatically than in other species previously. As obesity is an important and growing hazard for population health, we recommend a systematic evaluation of the optimal measure(s) for population-level excess body fat. Ideal measure(s) for monitoring body composition and obesity should be simple, as accurate and sensitive as possible, and provide good categorization of related health risks. Combinations of anthropometric markers or predictive equations may facilitate better use of anthropometric data than single measures to estimate body composition for populations. Here, we provide new evidence that increasing proportions of aging populations are at high health-risk according to waist circumference, but not body mass index (BMI), so continued use of BMI as the principal population-level measure substantially underestimates the health-burden from excess adiposity.

A clinical perspective of obesity, metabolic syndrome and cardiovascular disease

The metabolic syndrome is a condition characterized by a special constellation of reversible major risk factors for cardiovascular disease and type 2 diabetes. The main, diagnostic, components are reduced HDL-cholesterol, raised triglycerides, blood pressure and fasting plasma glucose, all of which are related to weight gain, specifically intra-abdominal/ectopic fat accumulation and a large waist circumference. Using internationally adopted arbitrary cut-off values for waist circumference, having metabolic syndrome doubles the risk of cardiovascular disease, but offers an effective treatment approach through weight management. Metabolic syndrome now affects 30-40% of people by age 65, driven mainly by adult weight gain, and by a genetic or epigenetic predisposition to intra-abdominal/ectopic fat accumulation related to poor intra-uterine growth. Metabolic syndrome is also promoted by a lack of subcutaneous adipose tissue, low skeletal muscle mass and anti-retroviral drugs. Reducing weight by 5-10%, by diet and exercise, with or without, anti-obesity drugs, substantially lowers all metabolic syndrome components, and risk of type 2 diabetes and cardiovascular disease. Other cardiovascular disease risk factors such as smoking should be corrected as a priority. Anti-diabetic agents which improve insulin resistance and reduce blood pressure, lipids and weight should be preferred for diabetic patients with metabolic syndrome. Bariatric surgery offers an alternative treatment for those with BMI ≥ 40 or 35-40 kg/m(2) with other significant co-morbidity. The prevalence of the metabolic syndrome and cardiovascular disease is expected to rise along with the global obesity epidemic: greater emphasis should be given to effective early weight-management to reduce risk in pre-symptomatic individuals with large waists.

Calf circumference predicts mobility disability: A secondary analysis of the Mexican health and ageing study

INTRODUCTION

Calf circumference is a surrogate measurement of muscle mass. However, there is scarce evidence on its validity in predicting adverse outcomes such as mobility disability. The aim of this report is to determine if calf circumference could predict incident mobility disability in Mexican 60-year or older adults.

METHODS

This is a secondary analysis of the Mexican Health and Aging Study and in particular of its two first waves. Sixty-year or older adults without mobility disability in the first assessment were included and followed-up for two years. Calf circumference quartile groups were compared to test the difference of incident mobility disability. Logistic regression models were fitted to test the independent association when including confounding variables.

RESULTS

A total of 745 older adults were assessed, from which 24.4% of the older adults developed mobility disability at follow-up. A calf circumference > 38 cm was associated with a higher risk of developing mobility disability, even after adjustment in the multivariate model, with an odds ratio 0.55 (95% confidence interval 0.31-0.99, P = 0.049).

CONCLUSIONS

High calf circumference in Mexican older adults is independently associated with incident mobility disability. This could reflect the impact of adverse health conditions such as obesity (with high fat tissue) or edema. Further research should aim at testing these results in different populations.

Sarcopenia prevalence using simple measurements and population-based cutoff values

OBJECTIVE

To estimate the prevalence of sarcopenia in Mexican older adults using simple measurements and tailored cutoff values for the components of the European Working Group on Sarcopenia in Older People algorithm.

MATERIAL AND METHODS

This study used cross-sectional data from the third wave (2012) of the Mexican Health and Aging Study. Gait speed and handgrip strength cutoff values were tailored for Mexican older adults. Muscle mass was estimated by a formula, which uses simple anthropometry and demographic characteristics.

RESULTS

From the total of 1,238 older adults included in our study, sarcopenia prevalence was 11% (n = 137). When categorizing sarcopenia, 39.1% (n = 484) had pre-sarcopenia, 8.3% (n = 103) moderate sarcopenia, and 2.75% (n = 34) had severe sarcopenia.

CONCLUSIONS

Sarcopenia is a common problem in Mexican older adults, and its frequency along with its severity increases with age. Tailored cutoff values could help in identifying those subjects that could have benefited from intervention.