Calf circumference is an independent predictor of mortality in older adults: An approach with generalized additive models

Calf circumference was negatively associated with all-cause mortality among the Chinese centenarians: a prospective study with a 5-year follow-up

BACKGROUND

Sarcopenia is an aging-related disorder characterized by a loss of muscle mass and function. Calf circumference (CC) is a useful surrogate marker of muscle mass and function. This prospective study was designed to investigate the association between CC and all-cause mortality during a follow-up for 5 years in the Chinese centenarians.

METHODS

The China Hainan Centenarian Cohort Study (CHCCS) is conducted in 18 cities and counties of Hainan, China.

RESULTS

All 231 centenarians had a mean age of 103.03 years. Survival participants had a longer CC and were often living alone compared with others (P<0.05 for all). Multivariate Cox regression models showed that CC was negatively associated with all-cause mortality (P < 0.05 for all). Participants with a longer CC had a lower mortality risk compared with others [Exp(β): 0.918; 95%confidence interval: 0.863-0.977]. Participants with a longer CC had a lower mortality risk whether they were males or females and lived with family members or alone.

CONCLUSION

CC was negatively associated with all-cause mortality and could be an indicator of future mortality among the Chinese centenarians. Further researches should focus on preventing a decline in the CC in order to promote human longevity.

Measuring calf circumference in frail hospitalized older adults and prediction of in-hospital complications and post-discharge mortality

Background

Sarcopenia, characterized by muscle mass, strength, and performance decline, significantly impacts outcomes in older adults. This study aims to assess the predictive value of calf circumference (CC), in conjunction with SARC-F and hand grip, concerning in-hospital complications and post-discharge mortality among hospitalized frail older adults.

Methods

A cohort of 158 hospitalized patients aged over 65 years underwent Comprehensive Geriatric Assessment and sarcopenia screening, including CC measurement. Multivariable regression analyses, adjusted for confounders, were conducted to assess predictive associations.

Results

The study cohort, comprising 53% males with a median age of 86 years, exhibited significant sarcopenia prevalence based on SARC-F (85% indicating sarcopenia), hand grip strength (probable sarcopenia in 77% of males and 72% of females), and CC (sarcopenia in 83%). Multivariate analysis, adjusting for age, sex, Clinical Frailty Scale (CFS), and Mini Nutritional Assessment-Short Form (MNA-SF), demonstrated associations of CC and SARC-F with in-hospital complications, while CC also showed a significant association with reduced risks of in-hospital mortality (OR 0.441, 95% CI 0.257 to 0.754, p = 0.003) and 90-day mortality (OR 0.714, 95% CI 0.516 to 0.988, p = 0.043).

Conclusion

This study provides insights into the predictive accuracy of sarcopenia screening tools on mortality in real-world hospitalized older adults with frailty. Notably, CC emerges as a robust predictor of mortality outcomes. Further research is warranted to validate and elucidate the respective contributions of CC and frailty to mortality in vulnerable populations.

Dietary advanced glycation end products, body composition, and anthropometric measures: A cross-sectional analysis in women with excess body weight

BACKGROUND AND AIMS

To assess the association between dietary advanced glycation end products (dAGEs) versus body composition and anthropometric variables.

METHODS AND RESULTS

Body composition (dual-energy X-ray absorptiometry), anthropometry, and habitual food intake were cross-sectionally evaluated in women with excess body weight and body fat. Mean dAGEs content was estimated using a database containing the Nԑ-(carboxymethyl)lysine (CML) content of 549 foods, which was adjusted by mean energy intake, and categorized into low, medium, and high dAGEs, by the 10th and 50th percentiles of the sample. Associations were tested by linear regression adjusted for age, education, marital status, and physical activity level. Eighty participants had mean ± standard deviation dAGEs 7.85 ± 2.65 AGEs kU/kcal. Compared with high dAGEs, women with low dAGEs ingested more carbohydrate (62% vs. 50% of calories, p < 0.001) and fiber (≈25 g vs. ≈18 g, p = 0.027) and less protein (13% vs. 17% of calories, p = 0.006) and fat (26% vs. 33% of calories, p = 0.011). Women with low dAGEs had waist/hip ratio 0.05 higher than those with high dAGEs (R2 = 0.256, p = 0.005). Low dAGEs relative to medium (p = 0.009) and high (p = 0.002) dAGEs was associated with a ≈5% gynoid fat reduction (R2 = 0.164).

CONCLUSION

Low dAGEs was associated with a higher waist/hip ratio and lower percentage of gynoid fat in women with excess body weight and excess body fat.

REGISTRATION NUMBER

RBR-7z358j.

Prevalence of low calf circumference in hospitalized patients classified by raw or body mass index-adjusted values

BACKGROUND

Adiposity can influence the estimation of muscle mass using calf circumference (CC) and underestimate the frequency of low CC. An adjustment for CC using body mass index (BMI) was proposed to reduce this effect. We aimed to compare the low CC frequency in hospitalized patients when considering raw and BMI-adjusted values and explore data by sex, age, and race (white and non-white).

METHODS

Secondary analysis from two cohort studies conducted with adult hospitalized patients using BMI and CC data collected in the first 72 h after hospital admission. We classified low CC by two approaches: (1) raw CC; (2) BMI-adjusted CC for patients with BMI ≥ 25. Cutoff values for low CC were ≤34 cm (men) and ≤33 cm (women).

RESULTS

Among 1272 patients (54.1 ± 15.3 years old; 51.7% women; 82.1% White race), low CC frequency was 30.6% and low BMI-adjusted CC was 68.9%. For all elevated BMI categories, the low CC frequency was higher when considering BMI-adjusted values (P < 0.001). Low CC was more frequent (P < 0.001) in older adults (38.7% by raw; 79.1% by BMI-adjusted value) than in younger adults (27.6% by raw; 65.2% by BMI-adjusted value) and it was not associated with race. Low CC by raw values was more frequent in men than in women (35.0% versus 26.4%; P = 0.001), but did not differ between sexes when classified by BMI-adjusted values (70.7% versus 67.1%; P = 0.184).

CONCLUSION

Low CC BMI adjusted was 2.2 times more frequent in comparison with raw CC values, and it was identified in >60% of patients with BMI ≥ 25.

Association of Calf Circumference with Clinical and Biochemical Markers in Older Adults with COVID-19 Admitted at Intensive Care Unit: A Retrospective Cross-Sectional Study

BACKGROUND

COVID-19 is an infectious disease characterized by a severe catabolic and inflammatory state, leading to loss of muscle mass. The assessment of muscle mass can be useful to identify nutritional risk and assist in early management, especially in older adults who have high nutritional risks. The aim of this study was to evaluate the association of calf circumference (CC) with clinical and biochemical markers and mortality in older adults with COVID-19 admitted to the intensive care unit (ICU).

METHODS

A retrospective cross-sectional study was conducted in a public hospital. CC was adjusted for body mass index (BMI), reducing 3, 7, or 12 cm for a BMI of 25-29.9, 30-39.9, and ≥40 kg/m2, respectively, and classified as reduced when <33 cm for women and <34 cm for men. Pearson's correlation between BMI and CC was performed to assess the association between variables. Regression analysis was adjusted for sex, age, and BMI variables. Cox regression was used to assess survival related to CC.

RESULTS

A total of 208 older adults diagnosed with COVID-19 admitted to ICU were included, of which 84% (n = 176) were classified as having reduced CC. These patients were older, with lower BMI, higher nutritional risk, malnourished, and higher concentration of urea and urea-creatinine ratio (UCR) compared with the group with normal CC. There was an association between edematous patients at nutritional risk and malnourished with reduced CC in the Cox regression, either adjusted or not for confounding.

CONCLUSIONS

CC was not associated with severity, biochemical markers, or mortality in older adults with COVID-19 admitted to the ICU, but it was associated with moderately malnourished patients assessed by subjective global assessment (SGA).

Absence of association between low calf circumference, adjusted or not for adiposity, and ICU mortality in critically ill adults: A secondary analysis of a cohort study

BACKGROUND

Despite its correlation with skeletal muscle mass and its predictive value for adverse outcomes in clinical settings, calf circumference is a metric underexplored in intensive care. We aimed to determine whether adjusting low calf circumference for adiposity provides prognostic value superior to its unadjusted measurement for intensive care unit (ICU) mortality and other clinical outcomes in critically ill patients.

METHODS

In a secondary analysis of a cohort study across five ICUs, we assessed critically ill patients within 24 h of ICU admission. We adjusted calf circumference for body mass index (BMI) (25-29.9, 30-39.9, and ≥40) by subtracting 3, 7, or 12 cm from it, respectively. Values ≤34 cm for men and ≤33 cm for women identified low calf circumference.

RESULTS

We analyzed 325 patients. In the primary risk-adjusted analysis, the ICU death risk was similar between the low and preserved calf circumference (BMI-adjusted) groups (hazard ratio, 0.90; 95% CI, 0.47-1.73). Low calf circumference (unadjusted) increased the odds of ICU readmission 2.91 times (95% CI, 1.40-6.05). Every 1-cm increase in calf circumference as a continuous variable reduced ICU readmission odds by 12%. Calf circumference showed no significant association with other clinical outcomes.

CONCLUSION

BMI-adjusted calf circumference did not exhibit independent associations with ICU and in-hospital death, nor with ICU and in-hospital length of stay, compared with its unadjusted measurement. However, low calf circumference (unadjusted and BMI-adjusted) was independently associated with ICU readmission, mainly when analyzed as a continuous variable.

Validity of a video-analysis-based app to detect prefrailty or frailty plus sarcopenia syndromes in community-dwelling older adults: Diagnostic accuracy study

Objectives

Sarcopenia and frailty have been associated with an increased risk of suffering health-related adverse events but the combination of both conditions results in worse health-related outcomes than either condition alone. Since both syndromes are reversible states, their early detection is fundamental. This study aims to validate a video analysis-based App to detect the presence of frailty or prefrailty plus sarcopenia syndromes and to analyze its construct validity with health-related risk factors.

Methods

A total of 686 community-dwelling older adults (median-age: 72, 59% female) were enrolled. Muscle power generated during a sit-to-stand test using the App and calf circumference were considered the index test. The reference standards were the EWGSOP2 criteria (five-chair stand test plus appendicular skeletal mass or skeletal muscle index) and Fried's frailty phenotype. Area under the curve (AUC), sensitivity, specificity, positive and negative predictive values (PPV and NPV) were calculated.

Results

The prevalence of both syndromes varied from 2.9% to 7.2% depending on the diagnostic criteria used for sarcopenia assessment. Excellent-to-outstanding AUC values were observed (range 0.80-0.92). Sensitivity and specificity ranged from 75% to 100% and 81.7% to 87.2%, respectively. PPV and NPV ranged from 12.1% to 37.5% and 97.9% to 100%, respectively. Individuals diagnosed by the App showed an increased risk of polypharmacy, depression, comorbidities, falls, hospitalization, low socioeconomical and educational levels, and smoking and poor self-perceived health compared to their healthy counterparts.

Conclusions

This App seems to be reliable to detect the simultaneous presence of both syndromes in community-dwelling older adults. Individuals diagnosed by the App showed more odds to have health-related risk factors.

Sit-to-Stand Video Analysis-Based App for Diagnosing Sarcopenia and Its Relationship With Health-Related Risk Factors and Frailty in Community-Dwelling Older Adults: Diagnostic Accuracy Study

BACKGROUND

Probable sarcopenia is determined by a reduction in muscle strength assessed with the handgrip strength test or 5 times sit-to-stand test, and it is confirmed with a reduction in muscle quantity determined by dual-energy X-ray absorptiometry or bioelectrical impedance analysis. However, these parameters are not implemented in clinical practice mainly due to a lack of equipment and time constraints. Nowadays, the technical innovations incorporated in most smartphone devices, such as high-speed video cameras, provide the opportunity to develop specific smartphone apps for measuring kinematic parameters related with sarcopenia during a simple sit-to-stand transition.

OBJECTIVE

We aimed to create and validate a sit-to-stand video analysis-based app for diagnosing sarcopenia in community-dwelling older adults and to analyze its construct validity with health-related risk factors and frailty.

METHODS

A total of 686 community-dwelling older adults (median age: 72 years; 59.2% [406/686] female) were recruited from elderly social centers. The index test was a sit-to-stand video analysis-based app using muscle power and calf circumference as proxies of muscle strength and muscle quantity, respectively. The reference standard was obtained by different combinations of muscle strength (handgrip strength or 5 times sit-to-stand test result) and muscle quantity (appendicular skeletal mass or skeletal muscle index) as recommended by the European Working Group on Sarcopenia in Older People-2 (EWGSOP2). Sensitivity, specificity, positive and negative predictive values, and area under the curve (AUC) of the receiver operating characteristic curve were calculated to determine the diagnostic accuracy of the app. Construct validity was evaluated using logistic regression to identify the risks associated with health-related outcomes and frailty (Fried phenotype) among those individuals who were classified as having sarcopenia by the index test.

RESULTS

Sarcopenia prevalence varied from 2% to 11% according to the different combinations proposed by the EWGSOP2 guideline. Sensitivity, specificity, and AUC were 70%-83.3%, 77%-94.9%, and 80.5%-87.1%, respectively, depending on the diagnostic criteria used. Likewise, positive and negative predictive values were 10.6%-43.6% and 92.2%-99.4%, respectively. These results proved that the app was reliable to rule out the disease. Moreover, those individuals who were diagnosed with sarcopenia according to the index test showed more odds of having health-related adverse outcomes and frailty compared to their respective counterparts, regardless of the definition proposed by the EWGSOP2.

CONCLUSIONS

The app showed good diagnostic performance for detecting sarcopenia in well-functioning Spanish community-dwelling older adults. Individuals with sarcopenia diagnosed by the app showed more odds of having health-related risk factors and frailty compared to their respective counterparts. These results highlight the potential use of this app in clinical settings.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05148351; https://clinicaltrials.gov/study/NCT05148351.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.3390/s22166010.

Central adiposity as a predictor of mortality in older adults: Identification of cutoffs using generalized additive models

Background

Obesity is associated with premature mortality in adults; however, this association has been inconsistent in the older adult population. In addition, there is a lack of specific cutoff points for indicators of negative health outcomes in older adults. Methods: This is a prospective study with 796 non-institutionalized older adults. Data on sociodemographic characteristics, lifestyle, food consumption, and nutritional status were obtained at baseline. Generalized additive models were used to identify cutoff points for the waist circumference (WC) and waist-to-height ratio (WHtR) and Cox proportional hazards models to assess the independent association between adiposity and mortality.

Results

Over the 9 years of follow-up, 197 deaths (24.7%) occurred, of which 51.8% were men, with a mean age of 76.1 ± 9.0 years. Older adults at higher risk of death had WHtR of <0.52 or ≥0.63 and WC of <83 cm or ≥101 cm. An increased risk of death was observed in older adults with high WC (HR: 2.03 95% CI: 1.20-3.41) and high WHtR (HR: 1.51 95% CI: 1.01-2.26) in the adjusted models, and an increase in WC was a risk factor for higher CVD mortality (HR: 2.09, 95% CI: 1.12-3.88) in the adjusted models.

Conclusion

Adiposity was associated with an increased risk of death in older adults. In view of these results and considering the lack of cutoff points for anthropometric indices in Brazilian older adults, further studies are needed to confirm the WC and WHtR cutoff values found in this study.

Evaluating the association between anthropometric parameters and successful aging in older adults

This study aimed to determine the relationship between successful aging (SA) and anthropometric parameters in older adults. We used body mass index (BMI), waist circumference, hip circumference, and calf circumference to reflect anthropometric parameters. SA was assessed by the following five aspects: self-rated health, self-rated psychological status or mood, cognitive function, activities of daily life, and physical activity. Logistic regression analyses were employed to examine the relationship between anthropometric parameters and SA. Results showed that larger BMI, waist circumference, and calf circumference are related to a higher prevalence of SA in older women; greater waist circumference and calf circumference are associated with a higher rate of SA in old-old adults. These findings suggest that the greater BMI, waist circumference, hip circumference, and calf circumference are associated with a higher rate of SA in older adults, and the associations are influenced to some extent by the sex and age.

Low calf circumference adjusted for body mass index is associated with prolonged hospital stay

BACKGROUND

Calf circumference (CC) is of emerging importance because of its practicality, high correlation with skeletal muscle, and potential predictive value for adverse outcomes. However, the accuracy of CC is influenced by adiposity. CC adjusted for BMI (BMI-adjusted CC) has been proposed to counteract this problem. However, its accuracy to predict outcomes is unknown.

OBJECTIVES

To evaluate the predictive validity of BMI-adjusted CC in hospital settings.

METHODS

A secondary analysis of a prospective cohort study in hospitalized adult patients was conducted. The CC was adjusted for BMI by reducing 3, 7, or 12 cm for BMI (in kg/m²) of 25-29.9, 30-39.9, and ≥40, respectively. Low CC was defined as ≤34 cm for males and ≤33 cm for females. Primary outcomes included length of hospital stay (LOS) and in-hospital death, and secondary outcomes were hospital readmissions and mortality within 6 mo after discharge.

RESULTS

We included 554 patients (55.2 ± 14.9 y, 52.9% men). Among them, 25.3% presented with low CC, whereas 60.6% had BMI-adjusted low CC. In-hospital death occurred in 13 patients (2.3%), and median LOS was 10.0 (5.0-18.0) d. Within 6 mo from discharge, 43 patients (8.2%) died, and 178 (34.0%) were readmitted to the hospital. BMI-adjusted low CC was an independent predictor of LOS ≥ 10 d (odds ratio = 1.70; 95% confidence interval: 1.18, 2.43], but it was not associated with the other outcomes.

CONCLUSIONS

BMI-adjusted low CC was identified in more than 60% of hospitalized patients and was an independent predictor of longer LOS.

The association between low calf circumference and mortality: a systematic review and meta-analysis

PURPOSE

Low calf circumference is an important indicator of malnutrition and has been widely studied, especially among older adults. However, data on the association between low calf circumference and mortality have been inconsistent. This systematic review was aimed to quantify this association.

METHODS

The internet databases (PubMed, Embase, ScienceDirect and Cochrane Library databases) were systematically searched from inception to November 01, 2021 for studies investigating the association between low calf circumference and mortality. A random effects model was adopted to pool the relevant data.

RESULTS

Low calf circumference was associated with a higher risk of mortality than normal calf circumference, with a pooled HR of 2.42 (95% CI 1.97-2.97, I² = 74.3%). In addition, this association between low calf circumference and morality was still statistically significant in the subgroup analysis across different settings, including hospitals (pooled HR = 2.63, 95% CI 1.93-3.58), nursing homes (pooled HR = 2.49, 95% CI 1.76-3.54), and communities (pooled HR = 2.22, 95% CI 1.60-3.07). Other subgroup analyses based on different cutoffs of calf circumference showed that, compared to individual with normal calf circumference, participants with low calf circumference had an increased risk of mortality (pooled HR = 2.66, 95% CI 2.06-3.43) when using the Asian Working Group for Sarcopenia (AWGS) criterion (≤ 34 cm for males and ≤ 33 cm for females). Similar results were found when the Mini Nutritional Assessment (MNA) criterion (≤ 31 cm) was used, with a pooled HR of 2.11 (95% CI 1.59-2.81).

CONCLUSION

Calf circumference, which is simple and convenient to measure, could be used to stratify the high-risk group, as low calf circumference was significantly associated with mortality among patients. Interventions, including exercise and nutrition programs, could be conducted promptly once low calf circumference is detected.

Calf Circumference and All-Cause Mortality: A Systematic Review and Meta-Analysis Based on Trend Estimation Approaches

OBJECTIVES

To perform a systematic review and meta-analysis and quantify the associations of total mortality with calf circumference (CC) in adults 18 years and older via combining various analyses based on empirical dichotomic CC, continuous CC, and dose-response CC.

METHODS

We conducted a systematic search of relevant studies in PubMed, EMBASE, Cochrane Library, and Web of Science published through April 12, 2022. This systematic review includes longitudinal observational studies reporting the relationships of total mortality with CC. We calculated the pooled relative risk (RR) and 95% confidence interval (CI) of total mortality with CC per 1 cm for each study and combined the values using standard meta-analysis approaches. Newcastle-Ottawa scale (NOS), Grading of Recommendations, Assessment, Development and Evaluations approach (GRADE), and the Instrument for assessing the Credibility of Effect Modification Analyses (ICEMAN) were assessed for meta-analyses.

RESULTS

Our analysis included a total of 37 cohort studies involving 62,736 participants, across which moderate heterogeneity was observed (I2=75.7%, P<0.001), but no publication bias was found. Study quality scores ranged from 6 to 9 (mean 7.7), with only three studies awarded a score of 6 (fair quality). We observed an inverse trend between total death risk and CC per 1 cm increase (RR, 0.95, 95% CI, 0.94-0.96; P<0.001; GRADE quality=high). Only a very slight difference was found among residents of nursing homes (6.9% mortality risk reduction per one cm CC increase), community-dwellers (5.4%), and those living in hospitals (4.8%), respectively (P for meta-regression=0.617). Low credible subgroup difference was found based on the ICEMAN tool.

CONCLUSIONS

Calf circumference is a valid anthropometric measure for mortality risk prediction in a community, nursing home, or hospital.