Associations between serum cystatin C and fall reports in an Elderly population.

Fall is common in the elderly, and chronic kidney disease is considered a major risk factor. Serum creatinine (Cre) and cystatin C (Cys C) are commonly used biomarkers for renal function, while the ratio of Cre to Cys C, known as the sarcopenia index (SI), provides insights into muscle health. This study investigates the relationships between Cre, Cys C, estimated glomerular filtration rates (eGFR), SI, and self-reported falls using National Health and Nutrition Examination Survey (NHANES) data. We included 4,272 older adults with eGFR > 30mL/min/1.73m2 from NHANES (1999 to 2004) and divided them into the fall and non-fall groups based on the questionnaires. Correlations were assessed using restricted cubic spline, weighted generalized linear regression models. Multi-factor logistic regression analysis identified serum Cys C as significantly associated with falls (all participants: OR 1.16, 95% CI: 1.09 to 1.23, p < 0.001; participants with eGFR > 75 mL/min/1.73m2: OR 1.17, 95% CI: 1.05 to 1.30, p < 0.001,). In contrast, Cre and eGFR were not significant after adjustments; SI showed marginal significance (p = 0.045). Cys C is significantly associated with fall risk in older adults, demonstrating a positive linear relationship with self-reported falls.

Prognostic Value of Systemic Inflammation, Nutritional Status and Sarcopenia in Patients With Amyotrophic Lateral Sclerosis.

BACKGROUND: Nutritional status, systemic inflammatory responses and muscle mass are associated with the prognosis of patients with amyotrophic lateral sclerosis (ALS). However, the optimal biomarker for predicting prognosis remains unclear. This study aimed to identify the optimal indicators of survival among the nutrition-based, inflammation-based and muscle mass-related markers for ALS patients. METHODS: We enrolled ALS patients from January 2014 to December 2019. Experienced neurologists followed up with the participants until January 2022. This study included a total of 17 nutritional, systemic inflammatory or muscle mass-related indicators. Maximally selected rank statistics determined the cut-off points for these indicators. Kaplan-Meier estimation was used to assess survival. Uni- and multivariate Cox proportional hazards models were used to determine the effects of indicators on survival. Finally, time-dependent receiver operating characteristic (time-ROC) curves and the C-index were calculated to evaluate the predictive efficacy of different indicators. RESULTS: A total of 506 patients with ALS were enrolled in this study, including 288 males (56.9%) and 218 females (43.1%), with a mean age of 54.2 ± 10.5 years. Among these ALS patients, 334 cases (68.0%) either died or underwent tracheotomy. In univariate Cox proportional hazards regression, 11 indicators were significantly associated with ALS survival (p < 0.05). And systemic immune inflammation (SII), platelet-to-lymphocyte ratio (PLR), modified geriatric nutritional risk index (mGNRI), creatinine and sarcopenia index (SI, (creatinine/cystatin C) × 100) were determined as independent predictors (p < 0.05) in multivariate Cox proportional hazards regression. A higher SI predicted longer survival (hazard ratio, 0.59; 95% confidence interval [CI], 0.46-0.76; p < 0.001). The results of time-ROC and C-index analyses indicated that SI had the best predictive efficacy for ALS survival, with a C-index of 0.65 (95% CI, 0.54-0.75) for 1-year, 0.61 (95% CI, 0.57-0.65) for 3-year and 0.59 (95% CI, 0.55-0.62) for 5-year survival. Across different subgroups, SI had the highest C-index in men and women, limb onset and aged < 60 year ALS patients, compared with other indicators. However, cystatin C was the best indicator for predicting the survival of ALS patients with bulbar onset, whereas the prognostic nutritional index (PNI) was the best for those aged ≥60 years. CONCLUSIONS: The serum SI demonstrates superior prognostic ability compared to other inflammation-based, nutrition-based and muscle mass-related indicators for patients with ALS. Given its simplicity and availability, it is well suited for clinical use in evaluating the prognosis of ALS patients.

Cystatin C and sarcopenia index are associated with cardiovascular and all-cause death among adults in the United States.

OBJECTIVES: This study aimed to investigate the association of cystatin C, serum creatinine and sarcopenia index with cardiovascular and all-cause death in general population. METHODS: Data of participants from the National Health and Nutrition Examination Surveys (NHANES) from 1999 to 2004 were used and all participants were followed up regularly until December 31, 2019. Multivariable Cox analysis was used to investigate the association of cystatin C, serum creatinine and sarcopenia index with cardiovascular and all-cause death. Restricted cubic spline was conducted to evaluate the nonlinear association. RESULTS: A total of 9894 participants with a mean age of 45.64 years were enrolled and followed up for a mean duration of 15.62 ± 4.68 years. Approximately 50.3% were male and there were a total of 2681 all-cause deaths and 691 cardiovascular deaths recorded during the follow-up period. In final adjusted model, compared with the first quartile of cystatin C (< 0.659 mg/L), the risk of cardiovascular and all-cause death increased 2.36-fold and 1.71-fold for participants in the fourth quartile (≥ 0.877 mg/L) (HR: 3.36, 95% CI: 2.06-5.46, P < 0.001; HR: 2.71, 95% CI: 2.17-3.38, P < 0.001; respectively). Furthermore, a higher sarcopenia index (< 88.41 vs. ≥125.52) was associated with the reduced risk of cardiovascular death (HR: 0.41, 95% CI: 0.31-0.53, P < 0.001) as well as all-cause death (HR: 0.41, 95% CI: 0.35-0.49, P < 0.001). Additionally, restricted cubic splines showed that there was a nonlinear relationship between sarcopenia index levels and all-cause death while there was a linear relationship between sarcopenia index levels and cardiovascular death. CONCLUSIONS: Higher sarcopenia index was associated with the decreased risk of cardiovascular and all-cause death in general population in the United States. Elevated cystatin C was positively associated with cardiovascular and all-cause death.

Association between sarcopenia and sleep disorders: a cross-sectional population based study.

Objective: Sleep disorders is a worldwide public health problem. We sought to examine the association between sarcopenia, a decline in skeletal muscle mass and function, and sleep disorders within the adult demographic of the United States during the period spanning 2011 to 2018. Methods: Diagnosis of sarcopenia and sleep disorders was ascertained through appropriate calculations and a structured questionnaire. The primary correlation analysis was conducted using a weighted multivariate logistic regression model. Furthermore, to confirm the presence of a potential non-linear association between sarcopenia and sleep disorders, additional analyses were performed using multivariate logistic regression and restricted cubic spline (RCS) regression with dose-response curve analysis. Subgroup analyses were also conducted to explore the influence of relevant socio-demographic factors and other covariates. Results: The final analysis encompassed 5,616 participants. Model 4, inclusive of all pertinent covariates, revealed a positive correlation between sarcopenia and sleep disorders, yielding an odds ratio (OR) of 1.732 (95% CI: 1.182-2.547; P = 0.002). Further analysis, utilizing the restricted cubic spline model, indicated a decreasing trend in sleep disorders as sarcopenia indices rose. Stratified analyses across diverse variables underscored the significant impact of sarcopenia on sleep disorders prevalence in several subgroups. Specifically, males, individuals aged 40 and above, non-Hispanic whites, those with high school education or equivalent, unmarried individuals, obese individuals (BMI ≥ 30), alcohol drinkers, former smokers, diabetics, and those engaging in less rigorous recreational activities exhibited a more pronounced association between sarcopenia and sleep disorders. The incidence of sleep disorders exhibited an upward trend as the incidence of sarcopenia declined among study participants. Conclusions: In summary, our study provides evidence of an association between sarcopenia and the prevalence of sleep disorders, with a negative correlation observed between the sarcopenia index and the odds ratio of sleep disorders. These findings suggest that maintaining optimal muscle mass may have a beneficial impact on sleep-related issues. In terms of exploring the mechanisms underlying the relationship between sarcopenia and sleep disorders, more in-depth research is warranted to ascertain the definitive causal relationship.

The Impact of Reduced Skeletal Muscle Mass on Patients with Knee Osteoarthritis.

Although several studies have suggested a possible association between sarcopenia and knee osteoarthritis (OA) in the elderly, there remains no definitive evidence. Recently, however, the serum creatinine/cystatin C ratio (sarcopenia index: SI) was reported to correlate with skeletal muscle mass. The present retrospective study therefore investigated the impact of reduced skeletal muscle mass on advanced knee OA using SI. In 55 individuals scheduled for knee osteotomy or knee arthroplasty, correlations between SI and patient-reported outcomes such as the Knee Society Score (KSS), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Oxford Knee Score (OKS) were explored. Significant associations were found between SI and the KSS functional activity score (ß=0.37; p=0.022), KOOS subscale for activities of daily living (ß=0.42; p=0.0096), and OKS (ß=0.42; p=0.0095). This study underscores the role of reduced muscle mass in functional outcomes and introduces SI as a valuable marker for assessing muscle loss in knee OA patients.

Association of the sarcopenia index with cognitive impairment in a middle-aged to older patients with acute ischemic stroke or transient ischemic attack: A multicenter cohort study.

OBJECTIVES: The sarcopenia (SI) index, defined as the serum creatinine to cystatin C ratio, is considered a predictor of poor muscle health and malnutrition, which is related to major adverse cardiovascular events. However, the effect of the SI index on cognitive function in stroke patients remains unknown. In this study, we aimed to examine the association between the SI and longitudinal cognitive impairment in patients with acute ischemic stroke or transient ischemic attack. RESEARCH DESIGN AND METHODS: Participants who met the inclusion criteria in this national, multicenter, prospective cohort study were enrolled from the Impairment of Cognition and Sleep (ICONS) study of the China National Stroke Registry-3 (CNSR-3). They were categorized into four groups according to the quartile of the SI index. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA) scale. Multivariable-adjusted logistic regression models were performed to evaluate the association between the SI index and post-stroke cognitive impairment (PSCI) at the 3-month follow-up. Moreover, discrimination tests were used to evaluate the incremental predictive value of the SI index beyond the potential risk factors. Furthermore, we performed subgroup analyses to test interactions. RESULTS: Among the enrolled participants, the lower the SI index was, the worse the cognitive performance. At the 3-month follow-up, participants in the lowest SI quartile group exhibited a 42% increase in the risk of cognitive impairment relative to the highest quartile group [OR 0.58 (95% CI 0.37-0.90)]. Moreover, after applying the discrimination test, adding the SI index into the potential risk factors resulted in a slight improvement in predicting the risk of cognitive impairment [NRI 14% (P = 0.01)]. CONCLUSION: This study demonstrated that a lower sarcopenia index was positively associated with a higher prevalence of PSCI. Monitoring the SI index in stroke patients and early identification and treatment of individuals with low SI level may be helpful to reduce the risk of cognitive impairment.

Association between macro- and microvascular damage and sarcopenia index in individuals with type 2 diabetes mellitus.

Sarcopenia was recently reported to be relevant to an increased macro-and microvascular disease risk. Sarcopenia index (SI) has been identified as a surrogate marker for sarcopenia. The aim of the present study was to investigate the association between macro- and microvascular disease and SI in patients with type 2 diabetes mellitus (T2DM). A total of 783 patients with T2DM were enrolled in this cross-sectional study. The SI was calculated by (serum creatinine [mg/dL]/cystatin C [mg/L]) × 100. The subjects were divided into three groups according to SI tertiles: T1 (41.27-81.37), T2 (81.38- 99.55), and T3 (99.56-192.31). Parameters of macro- and microvascular complications, including diabetic retinopathy (DR), micro- and macroalbuminuria (MAU), diabetic peripheral neuropathy (DPN), and lower extremity peripheral artery disease (LEAD) were evaluated. Multivariate logistic regression analysis revealed that when taking the top tertile of SI as a reference, an increasing trend of the prevalence of DR, MAU, DPN, and LEAD were presented (all P for trend  < 0.05), where the OR (95% CI) for DR prevalence was 1.967 (1.252-3.090) in T2, 2.195 (1.278-3.769) in T1, for MAU was 1.805 (1.149-2.837) in T2, 2.537 (1.490-4.320) in T1, for DPN was 2.244 (1.485-3.391) in T2, 3.172 (1.884-5.341) in T1, and for LEAD was 2.017 (1.002-4.057) in T2, 2.405 (1.107-5.225) in T1 (all P < 0.05). Patients with lower SI were more inclined to have an increased risk of macro- and microvascular damage in T2DM population, which may be related to sarcopenia.

Novel equations incorporating the sarcopenia index based on serum creatinine and cystatin C to predict appendicular skeletal muscle mass in patients with nondialysis CKD.

BACKGROUND & AIMS: Skeletal muscle mass measurements are important for customizing nutritional strategies for patients with chronic kidney disease (CKD). The serum creatinine-to-cystatin C ratio (Cr/CysC) is a potential indicator of sarcopenia. We developed simple equations to predict the appendicular skeletal muscle mass (ASM) of patients with CKD using readily available parameters and Cr/CysC. METHODS: Overall, 573 patients with nondialysis CKD stages 3-5 were included for developing and validating the equations. The participants were randomly divided into development and validation groups in a 2:1 ratio. ASM was measured using the Body Composition Monitor (BCM), a multifrequency bioelectrical impedance spectroscopy device. The height, weight, anthropometric data, and handgrip strength (HGS) of the participants were obtained. Equations were generated using stepwise multiple linear regression models. The prognostic significance of the predicted ASM was evaluated in a CKD registry comprising 1043 patients. RESULTS: The optimal equation without anthropometric data and HGS (Equation 1) was as follows: ASM (kg) = -7.949 - 0.049 × Age (years) - 2.213 × Woman + 0.090 × Height (cm) + 0.210 × Weight (kg) + 1.141 × Cr/CysC. The modified equation (Equation 2) with anthropometric data and HGS was as follows: ASM (kg) = -4.468 - 0.050 × Age (years) - 2.285 × Woman+ 0.079 × Height (cm) + 0.228 × Weight (kg) - 0.127 × Mid-arm muscular circumference (cm) + 1.127 × Cr/CysC. Both equations exhibited strong correlations with the ASM measured via BCM in the validation cohort (r = 0.944 and 0.943 for Equations 1 and 2, respectively) with minimal bias. When Equation 1 was applied to the CKD registry, the estimated ASM index (ASM/Height2) significantly predicted overall mortality over a median of 54 months. CONCLUSIONS: Novel ASM equations offer a simple method for predicting skeletal muscle mass and can provide valuable prognostic information regarding patients with nondialysis CKD.

Association between the sarcopenia index and abnormal liver function in the adult population in the United States: a cross-sectional study.

Background: The objective of this study was to explore the association between the sarcopenia index and abnormal liver function in adult individuals in the United States. Methodology: This study employed a rigorous cross-sectional analysis of data derived from the National Health and Nutrition Examination Survey (NHANES) conducted between 2017 and 2018. The primary objective was to investigate the correlation between the sarcopenia index and abnormal liver function. To achieve this, an advanced multivariate regression model was utilized, allowing for comprehensive analysis and meticulous adjustment of relevant variables. To ensure the robustness of the findings, a visually appealing smooth curve was constructed, and a two-stage regression model was applied for validation. Additionally, a detailed gender-stratified analysis was conducted to further explore the association between the sarcopenia index and abnormal liver function within distinct subgroups. Results: Through our rigorous participant selection process, a total of 1756 individuals were included in the study. The meticulously adjusted multivariate regression model revealed a significant negative association between the sarcopenia index and abnormal liver function, with an adjusted odds ratio (OR) of 0.73 and a 95% confidence interval (CI) ranging from 0.63 to 0.86. The robustness of this association was further supported by the visually appealing smooth curve plot. Moreover, in the gender-stratified subgroup analysis, after meticulous adjustment for confounding factors, notable differences in this association emerged (males: OR = 0.8, 95% CI: 0.66-0.98; females: OR = 0.61, 95% CI: 0.47-0.79). Conclusion: This cross-sectional study yields robust evidence indicating a negative correlation between the sarcopenia index and abnormal liver function, predominantly observed among females.

A baseline sarcopenia index based on creatinine/cystatin C for the prediction of stroke recurrence and mortality in older survivors of first ischemic strokes.

Objective: Older adults individuals have a higher risk of stroke recurrence, leading to high mortality and disability rates, which, in turn, hinders the achievement of healthy aging. This study aimed to assess the utility of a baseline sarcopenia index (SI) based on serum creatinine (Cr)/cystatin C (CysC) as a prognostic marker for the risk of stroke recurrence and mortality in first-ever ischemic stroke older survivors (ISOS). Materials and methods: Data were obtained from an ischemic stroke cohort study. The baseline information was collected from medical records and face-to-face interviews with patients admitted between January 2010 and June 2016. Follow-up information was obtained from telephone interviews every 3 months to determine stroke recurrence and survival status. The SI was calculated from the Cr and CysC values in the medical records as Cr/CysC × 100. Using the first quantile of the SI as the cut-off value, the study participants were divided into the low muscle-mass group (low SI) and the high muscle-mass group (high SI). Cox regression analysis was used to assess the association between SI and recurrence and mortality. Results: A total of 415 first-ever ISOS were enrolled, including 242 (58.31%) male and 173 (41.69%) female participants. In the high-SI group, the relapse and mortality rates were lower than those in the low-SI group (relapse: 20.58% vs. 30.77%; mortality:13.5% vs. 29.81%). After adjusting for confounding factors, the high-SI group was found to have a lower risk of relapse and mortality than the low-SI group (relapse: HR = 0.571; mortality: HR = 0.294). Conclusion: The SI was predictive of the long-term prognosis of IS recurrence and mortality in first-ever ISOS. After discharge, in addition to conventional medication, it is recommended that patients with low SI values actively receive treatment for sarcopenia to reduce the risk of stroke recurrence and mortality and promote healthy aging.

Serum creatinine/cystatin C ratio is a predictor of all-cause mortality for older adults over 80 years.

Objective: Sarcopenia is a prevalent condition in the senior population and has been related to adverse outcomes. This study aimed to investigate the performance of the serum creatinine/cystatin C ratio (Cr/CysC) in predicting all-cause mortality in elders over 80 years. Methods: A total of 486 older patients over 80 were enrolled in this study. Calf circumference (CC) and handgrip strength (HGS) were carried out for each patient. All the participants accepted serum creatinine and cystatin C test. The primary clinical outcome was all-cause mortality during an over-4-year follow-up. Results: During an over 4-year follow-up, 200 participants died. The non-survivors had a significantly lower baseline Cr/CysC level than the survivors (62.6 ± 13.1 vs. 71.4 ± 14.5 P < 0.001). The lowest Cr/CysC quartile group (Q1) had a significantly higher mortality rate than their counterparts (Q1 vs. Q2-4, 62.8% vs. 33.2%, P < 0.001). The Cr/CysC level was positively correlated with CC (R2 = 0.17, P < 0.001) and HGS (R2 = 0.19, P < 0.001). Moreover, survival curve was significantly worse in the lowest Cr/CysC quartile (Log-rank test χ2 = 21.09, P < 0.001). After adjustment for potential confounders, age (HR, 1.10; 95% CI, 1.06-1.14, P < 0.001), coronary heart disease (HR, 1.49; 95% CI, 1.01-2.21, P = 0.045), and lowest Cr/CysC (HR, 1.59; 95% CI, 1.12-2.24, P = 0.009) were independent factors of all-cause mortality during the over-4-year follow-up. Conclusion: Cr/CysC, also known as Sarcopenia Index, could be used as a predictor of all-cause mortality in older adults over 80 years.

Association between the sarcopenia index and the risk of stroke in elderly patients with hypertension: a cohort study.

The purpose of this study was to investigate the relationship between the sarcopenia index (SI) and stroke risk in elderly patients with hypertension. This study included 5145 stroke-free elderly hypertensive patients. We used Cox regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of incident stroke. Over a median follow-up of 38 months, we identified 607 (11.80%) individuals with total stroke, of whom 507 (9.85%) had ischemic stroke and 93 (1.81%) had hemorrhagic stroke. The risk of developing stroke decreased with each quartile of SI; after adjustment for multiple confounders, the HRs for the Q4 group versus the Q1 group were 0.46 (95% CI, 0.35-0.59) for total stroke, 0.46 (95% CI, 0.35-0.61) for ischemic stroke, and 0.33 (95% CI, 0.17-0.64) for hemorrhagic stroke. Restricted cubic spline analysis also demonstrated a cumulative increase in the risk of total stroke with decreases in the SI. The addition of SI to the conventional model for total stroke improved (ΔC-statistics = 0.02), an integrated discrimination improvement of 0.03 (95% CI, 0.02-0.04), and a net reclassification improvement of 0.17 (95% CI, 0.10-0.23). Similar results were observed for ischemic stroke and hemorrhagic stroke. This study found that elevated SI was negatively associated with the risk of stroke in elderly patients with hypertension. Uncovering the causality behind the relationship requires further prospective study.

Association between sarcopenia and kidney stones in United States adult population between 2011 and 2018.

Purpose: To investigate the relationship between kidney stones and sarcopenia in United States adult population between 2011 and 2018. Materials and methods: We conducted a cross-section study based on the National Health and Nutrition Examination Survey (NHANES) including 39,156 individuals. Sarcopenia was assessed by the sarcopenia index. Association between kidney stones and sarcopenia verified by multiple logistic regression analysis and dose-response curves analysis using restricted cubic spline (RCS) regression. Meanwhile, propensity score matching (PSM) was performed to exclude the effect of confounding variables. Results: There were 9,472 participants in the study by our accurate enrollment screening process. The odds of kidney stones decreased significantly with the increase of sarcopenia index. Logistic regression analysis showed that sarcopenia expressed significant differences in the participants which suffered kidney stone before PSM (p < 0.001). In model 4, adjusting all relevant covariates shown that adjusted odds ratio (aOR) of the 95% confidence intervals for kidney stones in all participants, age <39 years and age ≥40 years, were, respectively, 1.286 (1.006-1,643), 1.697 (1.065-2.702), and 0.965 (0.700-1.330) for sarcopenia, and p values were 0.044, 0.026, and 0.827. After performing PSM, the aOR of the 95% in modal 4 for kidney stones in all participants and age <40 year were 2.365 (1.598-3.500) and 6.793 (2.619-17.6180), respectively (p < 0.01), and especially the aOR in participants (age ≥40) was 1.771(1.138-2.757) with p value being 0.011. Conclusion: Sarcopenia was positively related to the potential risk of kidney stones in the United States adult population.

Pneumonia risk prediction in patients with acute alcohol withdrawal syndrome through evaluation of sarcopenia index as a prognostic factor.

OBJECTIVE: This study aimed to explore the relationship between the sarcopenia index (SI) and the risk of pneumonia in hospitalized patients with acute alcohol withdrawal syndrome (AWS). STUDY DESIGN: We have performed a retrospective study of individuals with AWS from a teaching hospital in western China. Patients' data were retrieved from the medicinal record databases. Patients' primary (upon admission) blood serum creatinine (Cr) and cystatin C (CysC) levels were incorporated into the records. Participants were separated into low and high SI cohorts based on the three-quarter digit of SI (SI = serum Cr/serum CysC ratio × 100). The association between SI and the risk of pneumonia in hospitalized patients with AWS was assessed by logistic regression analysis. RESULT: Three hundred and twelve patients with acute AWS were included in this retrospective analysis. Among hospitalized patients with acute AWS, the incidence of pneumonia was 13.78%. The average median age of acute AWS patients with pneumonia was 55.28 (10.65) years, and the mean age of acute AWS individuals without pneumonia was 51.23 (10.08) years. In the univariate analysis, the high SI group (SI > 87.91) had a lower incidence of pneumonia than the low SI group (SI ≤ 87.91) (high SI vs. low SI, 6.41% vs. 16.24%, p = 0.029). Further logistic regression analysis showed that the high SI group demonstrated a poorer risk of pneumonia (OR = 0.353, 95%CI: 0.134-0.932, p = 0.036). After adjusting for possible confounders, the risk of pneumonia remained low in the high SI group (OR = 0.358, 95%CI: 0.132-0.968, p = 0.043). CONCLUSION: Our results showed that SI was linked with the risk of pneumonia in hospitalized individuals with acute AWS. We further suggest that it could be a pneumonia risk factor, especially in medical centers where sarcopenia diagnosis is unavailable.

Sarcopenia index as a predictor of clinical outcomes among older adult patients with acute exacerbation of chronic obstructive pulmonary disease: a cross-sectional study.

BACKGROUND: Sarcopenia is a geriatric syndrome with progressive loss of skeletal muscle mass and function and has a negative impact on clinical outcomes associated with chronic obstructive pulmonary disease (COPD). Recently, the sarcopenia index (SI) was developed as a surrogate marker of sarcopenia based upon the serum creatinine to cystatin C ratio. We aimed to assess the value of SI for predicting clinically important outcomes among elderly patients with acute exacerbation of COPD (AECOPD). METHODS: This cross-sectional study included elderly patients with AECOPD in China from 2017 to 2021. Clinical data were collected from medical records, and serum creatinine and cystatin C were measured. Outcomes included respiratory failure, heart failure, severe pneumonia, invasive mechanical ventilation, and mortality. Binary logistic regression was used to analyze the association between SI and clinical outcomes. RESULTS: A total of 306 patients (260 men, 46 women, age range 60-88 years) were enrolled in this study. Among the total patients, the incidence of respiratory failure and severe pneumonia was negatively associated with SI values. After adjusting for potential confounding factors, binary logistic regression analyses showed that a higher SI was still independently associated with a lower risk of respiratory failure (odds ratio [OR]: 0.27, 95% confidence interval [CI]: 0.13-0.56, P < 0.05). In subgroup analysis, the incidence of respiratory failure was negatively associated with SI values in groups with both frequent exacerbation and non-frequent exacerbation. After adjustment for potential confounders, binary logistic regression analyses showed that a higher SI was also independently associated with a lower risk of respiratory failure in both groups (OR: 0.19, 95% CI: 0.06-0.64 and OR: 0.31, 95% CI: 0.11-0.85). However, there were no significant differences in the correlations between SI and the risk of heart failure, invasive mechanical ventilation, and mortality in all groups. CONCLUSION: The SI based on serum creatinine and cystatin C can predict respiratory failure in patients with AECOPD and either frequent or infrequent exacerbations. This indicator provides a convenient tool for clinicians when managing patients with AECOPD in daily clinical practice.

The effectiveness of the sarcopenia index in predicting septic shock and death in elderly patients with community-acquired pneumonia.

BACKGROUND: Community-acquired pneumonia (CAP) causes high morbidity and mortality in all age groups worldwide. Lower muscle radiodensity was associated with worse clinical outcomes (including shock) and higher in-hospital mortality. Prompt detection of sarcopenia in older adults with CAP is important. The measurement of muscle mass often involves specialized and expensive techniques. A relatively simple and inexpensive method such as the sarcopenia index (SI) to measure muscle mass would be helpful. Therefore, we performed a retrospective cohort study to assess the association between SI and septic shock risk and mortality in older patients with CAP. STUDY DESIGN: In this retrospective cohort study, information on hospitalized CAP patients, including general information and septic shock, were obtained from the medical record database of the Southwest Medical University Zigong Affiliated Hospital, China. Data on patient survival and mortality (all-cause) were acquired from government authorities and telephonic follow-up. Serum creatinine (Cr) and cystatin-C (CysC) levels on admission were included in the database. The SI was determined as the serum Cr/CysC ratio × 100 and the participants were assigned to low and high SI groups. The association between SI and septic shock was evaluated by logistic regression, and that between SI and mortality by Cox regression analysis. RESULTS: In total, 769 older adults (≥ 60 years) with CAP were included, of which 480(62.4%) were male and 289(37.6%)were female. We found that the total prevalence of septic shock in older adults with CAP was 16.0%. In the female group, septic shock was more prevalent in the low SI group than in the high SI group (low SI vs. high SI, 22.22% vs. 11.52%, p = 0.024). Following adjustment for confounders, there was a significant association between high SI and a lower risk of septic shock in female patients (OR = 0.38, 95%CI: 0.16-0.94; p < 0.05). The total death toll of older adults with CAP was 332(43.2%). Irrespective of sex, there was a higher risk of mortality in the low SI group (total group: low SI vs. high SI, 63.02% vs. 36.57%, p < 0.001; male group: low SI vs. high SI, 63.03% vs. 39.34%, p < 0.001; female group: low SI vs. high SI, 73.61% vs. 28.57%, p < 0.001) and, after adjustment for confounding factors and irrespective of sex, high SI was a protective factor for mortality in older adults with CAP (total group: HR = 0.64, 95%CI: 0.48-0.84; p < 0.05; male: HR = 0.69, 95%CI: 0.49-0.97; p < 0.05; female: HR = 0.39, 95%CI: 0.24-0.62; p < 0.05). CONCLUSION: While the SI effectively predicts mortality in older adults with CAP, it was only found to be associated with septic shock in older females.

Serum creatinine/cystatin C ratio as a screening tool for sarcopenia and prognostic indicator for patients with esophageal cancer.

BACKGROUND & AIMS: Sarcopenia is associated with poor clinical outcomes of patients who underwent esophagectomy. The current diagnostic criteria for sarcopenia are complex and laborious. We aimed to employ the simple and economic indicator sarcopenia index (SI = creatinine/cystatin C ×100) to screen for sarcopenia and to evaluate its prognostic value in patients with esophageal cancer (EC). METHODS: Older participants in the National health and nutrition examination survey (NHANES) database (1999-2002) were divided into three groups according to tertiles of the SI value to explore the feasibility of SI in the diagnosis of sarcopenia. Restricted cubic spline (RCS) was utilized to show the non-linear relationship between all-cause mortality and SI. Patients with EC admitted to Jinling Hospital were enrolled to validate the efficacy and prognostic value of SI. Cut-off values of SI were determined using receiver operating characteristic curves. Multivariable logistic analyses and Cox analyses were used to identify the independent factors of postoperative complications and long-term survival, respectively. RESULTS: A total of 989 participants were identified from the NHANES database. SI showed the diagnostic value of sarcopenia (tertile 1 vs. tertile 3: odds ratio [OR]=3.67, 95% confidence interval [CI]: 1.52-8.87, p=0.004; tertile 2 vs. tertile 3: OR=1.79, 95% CI: 0.75-4.28, p=0.191) adjusted for race, gender, and body mass index (BMI). Individuals with SI ≤ 68 had a poorer overall survival (OS) (hazard ratio [HR]=2.14, 95% CI: 1.71-2.68, p<0.001), and the RCS plot showed that the all-cause mortality risk gradually decreased with the increase in SI. Then, 203 patients with EC were enrolled, of which 76 patients were diagnosed with sarcopenia. There was a linear correlation between SI and skeletal muscle index and prealbumin, indicating that SI was reliable for diagnosing sarcopenia. Patients in the high sarcopenia risk group (Male: SI < 62; Female: SI < 55) showed a higher incidence of complications (OR=3.50, 95% CI: 1.85-6.61, p<0.001) and poorer long-term survival (HR=2.62, 95% CI: 1.02-6.77, p=0.046). CONCLUSION: SI could be used to identify sarcopenia in patients with EC, and it is a useful prognostic factor of postoperative complications and long-term survival.

Serum creatinine to cystatin C ratio reflects preoperative and early postoperative walking ability in older patients with hip fracture.

BACKGROUND: The sarcopenia index (SI), calculated as the ratio of serum creatinine to cystatin C levels, reflects skeletal muscle mass and strength. Patients with hip fracture (HF) and sarcopenia have poor functional outcomes, and many require long-term care after surgery. We hypothesized that the SI can predict preoperative and early postoperative functional outcomes. METHODS: Preoperative serum creatinine and cystatin C were measured to calculate the SI for patients with surgically treated HF (n = 130, mean age: 87.8 ± 6.9 years). Walking ability before and 2 weeks after surgery was assessed, and patients were dichotomized into independent and assistance groups. To assess the validity of the SI, we examined its correlation with the quality [computed tomography (CT) value] and quantity (cross-sectional area) of the muscles around the hip on the non-operated side, which were preoperatively measured using CT. Receiver operating characteristic (ROC) analysis was performed to evaluate the prognostic value of the SI. RESULTS: The SI of the preoperative independent (n = 77) and assistance groups (n = 53) significantly differed (70.2 ± 12.4 and 60.1 ± 9.8, respectively, P < 0.000001). At 2 weeks after surgery, the SI was significantly higher in the independent group (n = 31, 73.0 ± 14.9) than in the assistance group (n = 99, 64.0 ± 10.7, P = 0.0003). In the preoperative independent group, 28 could walk independently after surgery (SI: 74.8 ± 14.0) while 49 required assistance (SI: 67.7 ± 10.6, P = 0.01). For patients with femoral neck fracture (FNF), the SIs were significantly higher in the postoperative independent group (78.6 ± 15.7) than in the postoperative assistance group (63.2 ± 10.9, P = 0.002). Logistic regression analysis showed that the odds ratio (95% confidence interval) of the SI for postoperative walking ability was 0.95 (0.91-0.99, P = 0.03). The correlations of SIs with CT values and cross-sectional areas were as follows: iliopsoas at the apex of the femoral head, r = 0.40, P < 0.001 and r = 0.49, P < 0.001, respectively; rectus femoris at the level of the lessor trochanter, r = 0.26, P = 0.007 and r = 0.37, P < 0.001, respectively. ROC analysis for predicting postoperative walking ability in preoperative independent patients with HF and FNF revealed areas under the curve (95% confidence interval) of 0.63 (0.50-0.76) and 0.80 (0.65-0.96), respectively. CONCLUSIONS: In patients with HF, the SI correlated with preoperative walking ability and could predict postoperative walking ability. Among patients who could walk independently before surgery, those with high SIs could walk independently early in the postoperative period. The SI is beneficial for estimating walking ability in patients with HF.

Sarcopenia index based on serum creatinine and cystatin C predicts the risk of postoperative complications following hip fracture surgery in older adults.

OBJECTIVE: To assess the utility of the preoperative Sarcopenia index (SI) as a predictive marker of the risk of postoperative complications following hip fracture surgery in older adults. STUDY DESIGN: This observational study enrolled older adults with hip fracture who were hospitalized in the Department of Orthopedics of West China Hospital, Sichuan University, from December 7, 2010 - June 14, 2017, and who underwent hip fracture surgery. PRIMARY OUTCOME AND MEASURES: Clinical data were collected from medical records and serum creatinine and cystatin C were measured before surgery. Outcomes included postoperative complications such as pneumonia, urinary tract infection, respiratory failure, heart failure, and non-grade A healing. Binary logistic regression analyses were used to analyze association between SI and postoperative complications. RESULTS: A total of 897 patients aged 60 years and over were enrolled in this study (age range: 60 - 100 years), of whom 306(34.1%)were male, and 591(65.9%)were female. Postoperative complications included pneumonia (12%), urinary tract infections (1.8%), respiratory failure (1.5%), heart failure (1.6%), and non-A- grade healing (3.6%). In the patient group that received joint replacements, the incidence of pneumonia was negatively associated with SI values. After adjusting for potential confounding factors, binary logistic regression analyses showed that a higher SI was independently associated with a lower risk of pneumonia after joint replacement surgery (OR:0.39, 95% CI:0.18-0.89, P<0.05). However, we did not find statistically significant association between SI and the risk of postoperative complications other than pneumonia among patients with two types of hip fracture surgery. CONCLUSION: The SI based on serum creatinine and cystatin C can predict pneumonia rather than other postoperative complications among older patients with hip fracture after joint replacement surgery.

The Role of Baseline Sarcopenia Index in Predicting Chemotherapy-Induced Undesirable Effects and Mortality in Older People with Stage III or IV Non-Small Cell Lung Cancer.

OBJECTIVES: To assess the predictability value of Sarcopenia index( (SI, serum creatinine value/cystatin C value×100) in determining potential chemotherapy-induced undesirable reactions and eventual death of older patients diagnosed with stage III or IV of non-small cell lung cancer (NSCLC). METHODS: General information was retrieved from health records and mortality data was obtained by phone interview. Serum Cr and CysC levels were measured before chemotherapy. The endpoints recorded were chemotherapy-induced undesirable reactions and mortality from any causes. Logit regression analysis was employed for the analysis of correlation between the SI and short-term adverse reactions to chemotherapy. Cox regression analysis was employed to analyze correlation between the SI and mortality. RESULTS: In this study, 664 NSCLC patients were enrolled. Among them, 83.13% were diagnosed with adenocarcinoma lung cancer and 16.87% with squamous cell carcinoma lung cancer. As of March 1, 2019, 486 patients died, including 361(74.28%) males and 125 (25.72%) females. After the first course of chemotherapy, the proportion of short-term adverse reactions, including bone marrow suppression, digestive reactions, all infection, liver function impairment, and other adverse reactions (non-infectious fever or rashes) was 16%, 4.7%, 7.4, %, 6.6%, and 2.11%, respectively. After adjusting for confounding factors, there was no association between the SI and adverse reactions. We found that high SI was independently associated with a lower risk of mortality after adjusting for confounding factors in females (HR=0.593,95% CI: 0.382-0.92; p=0.02). There was no marked association existed between the SI and mortality in males. CONCLUSION: Among patients with stage III or IV non-small cell lung cancer, the SI is associated with mortality in females, but not in males.