Serum creatinine/cystatin C ratio is a systemic marker of sarcopenia in patients with gastrointestinal stromal tumours

Association of low skeletal muscle mass and radiodensity with clinical outcomes in patients undergoing robotic radical gastric cancer surgery: a population-based retrospective cohort study

BACKGROUND

Sarcopenia (defined as low skeletal muscle index - SMI) and myosteatosis (defined as low skeletal muscle radiodensity - SMD) associate with poor outcomes in gastric cancer, but their impact after robotic surgery is unknown.

METHODS

This retrospective cohort study analyzed 381 gastric cancer patients undergoing robotic surgery from December 2019 to October 2022. Sarcopenia and myosteatosis were assessed on preoperative CT scans. Outcomes were postoperative complications, mortality, survival, and recurrence. Multivariable regression and propensity score matching examined associations.

RESULTS

The mean age at diagnosis was 58.5 ± 10.8 years, and 69.3% (262/381) were male. Low SMI or Low SMD independently associated with more complications (odds ratio[OR] = 3.36, 95%CI: 2.08-5.43; OR = 2.49,95%CI: 1.48-4.19, respectively), unplanned ICU admission (OR = 1.51, 95%CI: 1.22-8.44; OR = 2.00; 95%CI: 1.23-8.89, respectively) or 30-day mortality (OR = 5.89, 95%CI: 1.80-14.23; OR = 7.34; 95%CI: 2.43-18.67, respectively). Concurrent sarcopenia and myosteatosis heightened risks of complications (OR = 7.29, 95%CI: 1.62-42.30), severe complications (OR = 6.67, 95%CI: 2.22-12.68), 30-day mortality (OR = 9.55, 95%CI: 2.67-33.89), and reduced survival (hazard ratio[HR] = 3.09, 95%CI: 1.77-8.60).

CONCLUSIONS

Sarcopenia and myosteatosis independently and additively associate with increased postoperative complications, mortality, and worse prognosis after robotic gastric cancer surgery. Identifying sarcopenia and myosteatosis preoperatively could inform risk assessments and guide management to improve surgical outcomes.

Sex differences in the association between sarcopenia index and sarcopenia: a cross-sectional study from a Chinese community-based population

PURPOSE

The sarcopenia index (SI) is a convenient method to screen for sarcopenia, but few studies have analysed whether there are sex differences. The aim of this study was to analyse sex differences in the relationship between SI and sarcopenia in a Chinese community-based population.

METHODS

This cross-sectional study included participants from 2011 China Health and Retirement Longitudinal Study. The SI was defined as 100 × creatinine / cystatin C. Diagnosis of sarcopenia based on the Asian Working Group for Sarcopenia 2019 consensus. Logistic regression model, linear regression model, and natural spline model were used to analyze the association between SI and sarcopenia.

RESULTS

A total of 7,118 participants with a mean age of 60.6 ± 10.1 were included, 53.4% females. In males, the prevalence of sarcopenia decreased by 25% for every 10 increase in SI, and skeletal muscle mass index (SMI) increased by 0.04, odds ratio (OR), β, and 95% confidence interval (CI) were 0.75 (0.65-0.87), 0.04 (0.02-0.05), both P < 0.001. In females, the SI was not significantly associated with sarcopenia, OR and 95% CI were 0.99 (0.9 ~ 1.08), P = 0.775; for every 10 increase in SI, the SMI in females decreased by 0.03, β and 95% CI were -0.03 (-0.04 ~ -0.01), P = 0.001.

CONCLUSION

In the Chinese community, the SI is negatively associated with sarcopenia in males and has moderate diagnostic test performance. It was not associated with sarcopenia in females, and using the SI to screen for sarcopenia in females may not be a reliable method.

Serum creatinine- and cystatin C-based indices are associated with the risk of subsequent sarcopenia: evidence from the China Health and Retirement Longitudinal Study

Background

Serum creatinine (Cr)- and cystatin C (CysC)-based indices have been suggested as alternative markers for sarcopenia, but their predictive value for sarcopenia risk is uncertain, which was investigated in the present study in the Chinese population with the middle and older ages.

Methods

Data from the China Health and Retirement Longitudinal Study (CHARLS) were collected in the 2011 and 2015 waves. All participants were free of sarcopenia at the baseline. Sarcopenia was diagnosed when low muscle mass and grip strength or low physical performance were present. Four indices were computed: predictive skeletal muscle mass index (pSMI), total-body muscle mass (TBMM), creatinine-to-cystatin C ratio (CCR), and sarcopenia index (SI). Restricted cubic splines and logistic regression models were used to assess the effects of these indices on sarcopenia risk.

Results

Among 4,527 participants without sarcopenia at the baseline (2011), the median age was 58 year-old (IQR: 52-65), with 52.7% women. Followed up in year 2015, the incidence of sarcopenia was 20.8 per 1,000 person-years (376/4,527). Neither CCR nor SI showed linear or non-linear associations with the risk of subsequent sarcopenia. However, a decrease in pSMI and TBMM was significantly associated with an increased risk of sarcopenia [adjusted per-SD decrease OR, 2.93; 95% CI, 2.09-4.13, p < 0.001; adjusted per-SD decrease OR: 2.38, 95% CI: 1.80-3.16, p < 0.001, respectively].

Conclusion

In the middle and older age of Chinese population, decreased pSMI and TBMM were associated with an increased risk of subsequent sarcopenia, whereas CCR and SI showed no such correlation. Thus, pSMI and TBMM may serve as potential biological indicators for predicting the risk of sarcopenia, and decreased pSMI and TBMM may be the early biomarkers for diagnosis and intervention of sarcopenia.

Pre-donation assessment of cystatin C to improve prediction of pre- and post-donation GFR in potential living kidney donors

BACKGROUND

Accurate estimation of glomerular filtration rate (GFR) is crucial in living kidney donation. While most estimated GFR (eGFR) equations are based on plasma creatinine, its levels are strongly influenced by muscle mass. Application of cystatin C (cysC)-based estimates before donation may improve both estimation of current GFR and prediction of post-donation GFR.

METHODS

We assessed the performance of Chronic Kidney Disease Epidemiology Collaboration equations based on creatinine (eGFRcreat-2009, eGFRcreat-2021), cysC (eGFRCysC-2012) or both (eGFRcombined-2012, eGFRcombined-2021) for estimating pre- and post-donation (mGFR) GFR in 486 living kidney donors. We subsequently focused on a subgroup of individuals with high/low muscle mass (25% highest/lowest 24-hour urinary creatinine excretion, sex stratified and height indexed).

RESULTS

Pre-donation eGFRcombined-2012 and eGFRcombined-2021 showed the strongest associations with pre- and post-donation mGFR. Pre-donation eGFRcombined-2021 was most accurate for estimating both pre-donation (bias 0.01 ± 11.9 ml/min/1.73 m2) and post-donation mGFR (bias 1.3 ± 8.5 ml/min/1.73 m2). In donors with high/low muscle mass, cysC-based equations (with or without creatinine) performed better compared with equations based on only creatinine.

CONCLUSIONS

Combined eGFR equations yielded a better estimate of pre- and post-donation mGFR compared with estimates based on creatinine or cysC only. The added value of cysC seems particularly pronounced in donors with high or low muscle mass.

Creatinine-to-cystatin C ratio and frailty in older adults: a longitudinal cohort study

BACKGROUND

Creatinine-to-cystatin C ratio (CCR) has been associated with multiple adverse outcomes. However, little is known about its relationship with frailty. We aimed to explore the association between CCR and frailty among older adults.

METHODS

A total of 2599 participants aged ≥ 60 years (mean age 67.9 ± 6.0 years, 50.4% males) were included from the China Health and Retirement Longitudinal Study (2011-2015). Baseline CCR was calculated as plasma creatinine (mg/dL) / cystatin C (mg/L) × 10 and was grouped by quartiles. Frailty was evaluated by the validated physical frailty phenotype (PFP) scale and was defined as PFP score ≥ 3. The generalized estimating equations model was used to explore the relationship between CCR and frailty.

RESULTS

The frailty risk decreased gradually with increasing CCR in the quartiles (P for trend = 0.002), and the fourth CCR quartile was associated with a significantly lower risk of frailty compared with the lowest quartile (odds ratio [OR] 0.37, 95% confidence interval [CI] 0.19-0.70). When modeling as a continuous variable, per 1-unit increase in CCR was related to 17% decreased odds of frailty (OR 0.83, 95% CI 0.74-0.93). The association was consistent in male and female participants (P for interaction = 0.41). Poisson models revealed that frailty score was negatively associated with CCR (β= -0.11, 95% CI= -0.19 to -0.04), and sex did not significantly moderate the associations (P for interaction = 0.22). The results were not affected by further adjusting for high-sensitivity C-reactive protein. Similar results were observed by analyses with multiple imputation technique and analyses excluding participants with baseline frailty.

CONCLUSIONS

Higher CCR was associated with a lower frailty risk. CCR may be a simple marker for predicting frailty in older adults.

Serum creatinine and serum cystatin C as an index of muscle mass in adults

PURPOSE OF REVIEW

Serum creatinine reflects both muscle mass and kidney function. Serum cystatin C has recently been recommended as an additional marker for estimating kidney function, and use of both markers together may provide an index of muscle mass. This review aims to describe the biological basis for and recent research examining the relationship of these markers to muscle mass in a range of adult populations and settings.

RECENT FINDINGS

This review identified 67 studies, 50 of which had direct measures of muscle mass, and almost all found relationships between serum creatinine and cystatin C and muscle mass and related outcomes. Most studies have been performed in older adults, but similar associations were found in general populations as well as in subgroups with cancer, chronic kidney disease (CKD), and other morbid conditions. Creatinine to cystatin C ratio was the measure examined the most often, but other measures showed similar associations across studies.

SUMMARY

Measures of serum creatinine and cystatin C together can be an index of muscle mass. They are simple and reliable measures that can be used in clinical practice and research. Further study is needed to determine actionable threshold values for each measure and clinical utility of testing and intervention.

Myosteatosis predicts postoperative complications and long-term survival in robotic gastrectomy for gastric cancer: A propensity score analysis

BACKGROUND

Robotic gastrectomy is increasingly utilized for gastric cancer, but high morbidity remains a concern. Myosteatosis or low skeletal muscle density reflecting fatty infiltration, associates with complications after other cancer surgeries but has not been evaluated for robotic gastrectomy.

METHODS

This retrospective study analysed 381 patients undergoing robotic gastrectomy for gastric cancer from September 2019 to October 2022. Myosteatosis was quantified on preoperative computed tomography (CT) images at lumbar 3 (L3). Propensity score matching addressed potential confounding between myosteatosis and non-myosteatosis groups. Outcomes were postoperative complications, 30 days mortality, 30 days readmissions and survival.

RESULTS

Myosteatosis was present in 33.6% of patients. Myosteatosis associated with increased overall (47.7% vs. 26.5%, p < 0.001) and severe complications (12.4% vs. 4.9%, p < 0.001). After matching, myosteatosis remained associated with increased overall complications, major complications, intensive care unit (ICU) transfer and readmission (all p < 0.05). Myosteatosis independently predicted overall [odds ratio (OR) = 2.86, 95% confidence interval (CI): 1.57-5.20, p = 0.001] and severe complications (OR = 4.81, 95% CI: 1.51-15.27, p = 0.008). Myosteatosis also associated with reduced overall (85.0% vs. 93.2%, p = 0.015) and disease-free survival (80.3% vs. 88.4%, p=0.029). On multivariate analysis, myosteatosis independently predicted poorer survival [hazard ratio (HR) = 2.83, 95% CI: 1.32-6.08, p=0.012] and disease-free survival (HR = 1.83, 95% CI: 1.01-3.30, p=0.032).

CONCLUSION

Preoperative CT-defined myosteatosis independently predicts increased postoperative complications and reduced long-term survival after robotic gastrectomy for gastric cancer. Assessing myosteatosis on staging CT could optimize preoperative risk stratification.

Association between preoperative sarcopenia and postoperative delirium in older patients undergoing gastrointestinal cancer surgery

Background

Postoperative delirium (POD) is a usual neurological complication, often leading to poor prognoses. Early identification of high-risk patients is crucial for preventing POD. Sarcopenia is an age-related geriatric syndrome characterized by the loss of skeletal muscle mass and function, and previous studies indicated that preoperative low muscle mass might be a predictor for POD. However, the association between preoperative sarcopenia and POD remains to be fully elucidated. This study was to explore the correlation between preoperative sarcopenia and POD following gastrointestinal cancer surgery in older patients.

Methods

Older patients (≥60 years) undergoing gastrointestinal cancer surgery were enrolled. Sarcopenia was defined based on the Special Interest Group on sarcopenia of the International Society of Physical and Rehabilitation Medicine (ISarcoPRM), which combined the loss of muscle mass (evaluated by ultrasound) and function (assessed by chair stand test and handgrip strength) before surgery. POD assessment was performed using the Confusion Assessment Method (CAM) or CAM for the intensive care unit (CAM-ICU) during the first 7 days after surgery or before discharge. Multivariate logistic regression analysis examined the correlation between preoperative sarcopenia and POD. Moreover, the receiver operator characteristic (ROC) curve was applied to analyze the predictive effect of the preoperative sarcopenia in POD.

Results

One hundred and thirty patients were finally included, of which 43 patients presented with sarcopenia before surgery. Twenty-four patients ultimately developed POD, and the incidence was 18.5%. The results of the multivariate analyses demonstrated that preoperative sarcopenia was still independently associated with POD after adjusting for age ≥70 years, preoperative Mini-Mental State Examination score, and intraoperative blood transfusion. The area under the ROC curve of preoperative sarcopenia in predicting POD was 0.680 (95% confidence interval 0.557-0.804).

Conclusion

Preoperative sarcopenia defined by ISarcoPRM criteria was independently associated with POD in geriatric patients after gastrointestinal cancer surgery.

Low serum creatinine levels are associated with major post-operative complications in patients undergoing surgery with gynecologic oncologists

OBJECTIVE

Serum creatinine is a byproduct of muscle metabolism, and low creatinine is postulated to be associated with diminished muscle mass. This study examined the association between low pre-operative serum creatinine and post-operative outcomes.

METHODS

This retrospective cohort study utilized the 2014-2021 National Surgical Quality Improvement Program to identify patients undergoing surgery with gynecologic oncologists. Patients with missing pre-operative creatinine, end-stage renal disease, sepsis, septic shock, dialysis, or pregnancy were excluded. Pre-operative creatinine was categorized into markedly low (≤0.44 mg/dL), mildly low (0.45-0.64 mg/dL), normal (0.65-0.84 mg/dL), and four categories of elevated levels (0.85-1.04, 1.05-1.24, 1.25-1.44, and ≥1.45 mg/dL). Outcomes included major (≥Grade 3) 30-day complications, categorized into any complications, wound, cardiovascular and pulmonary, renal, infectious, and thromboembolic complications. Also examined were 30-day readmissions, reoperations, and mortality. Logistic regressions assessed the association between creatinine and complications, with stratification by albumin and sensitivity analysis with propensity score matching.

RESULTS

Among 84 786 patients, 0.8% had markedly low, 19.6% mildly low, and 50.2% normal creatinine; the remainder had elevated creatinine. As creatinine decreased, the risks of major complications increased in a dose-dependent manner on univariable and multivariable analyses. A total of 9.6% (n=63) markedly low patients experienced major complications, second to creatinine ≥1.45 mg/dL (9.9%, n=141). On multivariable models, both markedly and mildly low creatinine were associated with higher odds of major complications (OR 1.715, 95% CI 1.299 to 2.264 and OR 1.093, 95% CI 1.001 to 1.193) and infections (OR 1.575, 95% CI 1.118 to 2.218 and OR 1.165, 95% CI 1.048 to 1.296) versus normal. Markedly low creatinine had similar ORs to creatinine ≥1.45 mg/dL and was further associated with higher odds of cardiovascular and pulmonary complications (OR 2.301, 95% CI 1.300 to 4.071), readmissions (OR 1.403, 95% CI 1.045 to 1.884), and mortality (OR 2.718, 95% CI 1.050 to 7.031). After albumin stratification, associations persisted for markedly low creatinine. Propensity-weighted analyses demonstrated congruent findings.

CONCLUSIONS

Low creatinine levels are associated with major post-operative complications in gynecologic oncology in a dose-dependent manner. Low creatinine can offer useful information for pre-operative risk stratification, surgical counseling, and peri-operative management.

Impact of preoperative sarcopenia on postoperative complications and prognosis in patients undergoing robotic gastric cancer surgery: A propensity score matching study

BACKGROUND

Sarcopenia, defined as decreased muscle mass and function, correlates with postoperative morbidity and mortality in cancer surgery. However, sarcopenia's impact specifically following robotic gastrectomy for gastric cancer has not been clearly defined. This study aimed to determine the influence of sarcopenia on short- and long-term clinical outcomes after robotic gastrectomy for gastric cancer.

METHODS

This retrospective study analyzed 381 gastric cancer patients undergoing robotic gastrectomy. Sarcopenia was diagnosed by preoperative computed tomography (CT) body composition analysis. Propensity score matching created 147 pairs of sarcopenia and nonsarcopenia patients for comparison. Outcomes included postoperative complications, survival, inflammatory markers, length of stay, intensive care unit (ICU) transfer, and readmissions.

RESULTS

Sarcopenia patients exhibited significantly higher rates of overall (53.7% versus 21.1%, P < 0.001), serious (12.9% versus 4.1%, P = 0.007), and grade III-IV complications compared to nonsarcopenia pairs after matching. Sarcopenia independently predicted reduced 3-years overall (HR = 2.53, 95% CI: 1.19-5.40, P = 0.016) and disease-free survival (HR = 1.99, 95% CI: 1.09-3.66, P = 0.026). Sarcopenia patients also showed heightened postoperative leukocyte, neutrophil, platelet, platelet to lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and monocyte to lymphocyte ratio (MLR) levels alongside suppressed lymphocytes, monocytes, and neutrophil to lymphocyte ratio (NLR).

CONCLUSION

Preoperative sarcopenia is correlated with increased postoperative complications and poorer long-term survival in gastric cancer patients undergoing robotic gastrectomy. Sarcopenia assessment can optimize preoperative risk stratification and perioperative management in this population.

Muscle-origin creatinine-cystatin C ratio is an osteoporosis marker in individuals with normal renal function: evidence from observational and Mendelian randomization analysis

Background

Creatinine-cystatin C ratio (CCR) has been demonstrated as an objective marker of sarcopenia in clinical conditions but has not been evaluated as an osteoporosis marker in individuals with normal renal function.

Methods

We selected 271,831 participants with normal renal function from UK Biobank cohort. Multivariable linear/logistic regression and Cox proportional hazards model were used to investigate the phenotypic relationship between CCR and osteoporosis in total subjects and gender-stratified subjects. Based on the genome-wide association study (GWAS) data, linkage disequilibrium regression (LDSC) and Mendelian randomization (MR) analysis were performed to reveal the shared genetic correlations and infer the causal effects, respectively.

Results

Amongst total subjects and gender-stratified subjects, serum CCR was positively associated with eBMD after adjusting for potential risk factors (all P<0.05). The multivariable logistic regression model showed that the decrease in CCR was associated with a higher risk of osteoporosis/fracture in all models (all P<0.05). In the multivariable Cox regression analysis with adjustment for potential confounders, reduced CCR is associated with the incidence of osteoporosis and fracture in both total subjects and gender-stratified subjects (all P<0.05). A significant non-linear dose-response was observed between CCR and osteoporosis/fracture risk (P non-linearity < 0.05). LDSC found no significant shared genetic effects by them, but PLACO identified 42 pleiotropic SNPs shared by CCR and fracture (P<5×10-8). MR analyses indicated the causal effect from CCR to osteoporosis/fracture.

Conclusions

Reduced CCR predicted increased risks of osteoporosis/fracture, and significant causal effects support their associations. These findings indicated that the muscle-origin serum CCR was a potential biomarker to assess the risks of osteoporosis and fracture.

The coexistence of myosteatosis and the creatinine/cystatin C ratio are determinants of outcomes in cholangiocarcinoma patients undergoing curative surgery

Background

Myosteatosis is a well-established predictor of poor prognosis in many types of cancer, and a decreased Creatinine/Cystatin C ratio (CCR) is a known indicator of unfavorable outcomes in patients with metabolic disorders and cancer. Despite this knowledge, the significance of concurrent CCR and myosteatosis in predicting the prognosis of patients with cholangiocarcinoma (CCA) who undergo radical surgery remains uncertain.

Method

Data from 757 patients with cholangiocarcinoma who underwent the first radical resection in the Affiliated Hospital of Qingdao University from January 2017 to March 2022 were collected. According to the inclusion and exclusion criteria, 149 patients were finally included in the retrospective study cohort. Various clinicopathological, serological, and radiological data were collected at admission. Myosteatosis was evaluated using sliceOmatic software on computed tomography (CT) images. The study used receiver operating characteristic (ROC) curve analysis to determine the critical value of CCR, which predicts overall survival (OS) based on the Kaplan-Meier method. Univariate and multivariate Cox regression analyses were employed to identify the risk factors associated with OS and RFS confidently.

Results

The group identified as the myosteatosis cohort consisted of 79 patients with an average age of 64.3 ± 7.8 years. The ROC curve analysis revealed an optimal critical CCR value of 10.834. A low CCR ≤ 10.834 and myosteatosis were found to be associated with poor OS and RFS outcomes (P = 0.022; P = 0.017; P = 0.038; P = 0.030 respectively). Moreover, patients with myosteatosis and a CCR ≤ 10.834 had the worst OS and RFS outcomes (P = 0.035; P = 0.027).

Conclusion

After radical excision in CCA patients, the presence of myosteatosis and CCR had a negative correlation with prognosis. A more accurate prediction of OS and RFS was possible by combining CCR and myosteatosis, compared to CCR alone.

Creatinine-to-cystatin C ratio and body composition predict response to PD-1 inhibitors-based combination treatment in metastatic gastric cancer

Background

Creatinine-to-cystatin C ratio (CCR) and body composition (BC) parameters have emerged as significant prognostic factors in cancer patients. However, the potential effects of CCR in gastric cancer (GC) remains to be elucidated. This multi-center retrospective study explored the predictive and prognostic value of CCR and BC-parameters in patients with metastatic GC receiving PD-1 inhibitors-based combination therapy.

Methods

One hundred and thirteen GC patients undergoing PD-1 inhibitors-based combination therapy were enrolled at three academic medical centers from January 2021 to July 2023. A deep-learning platform based on U-Net was developed to automatically segment skeletal muscle index (SMI), subcutaneous adipose tissue index (SATI) and visceral adipose tissue index (VATI). Patients were divided into two groups based on the median of CCR or the upper tertile of BC-parameters. Logistic and Cox regression analysis were used to determine the effect of CCR and BC-parameters in predicting response rates and survival rates.

Results

The CCR was positively correlated with SMI (r=0.43; P<0.001), but not with SATI or VATI (P>0.05). Multivariable logistic analysis identified that both low CCR (OR=0.423, P=0.066 for ORR; OR=0.026, P=0.005 for DCR) and low SATI (OR=0.270, P=0.020 for ORR; OR=0.149, P=0.056 for DCR) were independently associated with worse objective response rate (ORR) and disease control rate (DCR). Patients with low CCR or low SATI had significantly lower 8-month progression-free survival (PFS) rate and 16-month overall survival (OS) rate than those with high CCR (PFS rate, 37.6% vs. 55.1%, P=0.011; OS rate, 19.4% vs. 44.9%, P=0.002) or those with high SATI (PFS rate, 37.2% vs. 53.8%, P=0.035; OS rate, 8.0% vs. 36.0%, P<0.001). Multivariate Cox analysis showed that low CCR (HR=2.395, 95% CI: 1.234-4.648, P=0.010 for PFS rate; HR=2.528, 95% CI: 1.317-4.854, P=0.005 for OS rate) and low SATI (HR=2.188, 95% CI: 1.050-4.560, P=0.037 for PFS rate; HR=2.818, 95% CI: 1.381-5.752, P=0.004 for OS rate) were both independent prognostic factors of poor 8-month PFS rate and 16-month OS rate. A nomogram based on CCR and BC-parameters showed a good performance in predicting the 12- and 16-month OS, with a concordance index of 0.756 (95% CI, 0.722-0.789).

Conclusions

Low pre-treatment CCR and SATI were independently associated with lower response rates and worse survival in patients with metastatic GC receiving PD-1 inhibitors-based combination therapy.

Diagnostic test accuracy of serum creatinine and cystatin C-based index for sarcopenia: a systematic review and meta-analysis

BACKGROUND

Sarcopenia is an important prognostic factor, but its optimal screening methods remain challenging. Several new indices developed based on serum creatinine (Cr) and cystatin C (CysC) have been proposed to be diagnostic biomarkers for sarcopenia screening.

OBJECTIVE

This review aimed to evaluate the diagnostic accuracy of serum Cr- and CysC-based indices for sarcopenia diagnosis.

METHODS

We systematically searched MEDLINE, EMBASE, SCIE and SCOPUS from inception to 2 April 2023. Methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. A bivariate random-effects model was used to synthesise the pooled sensitivity, specificity and area under the curves of the summary receiver operating characteristic (SROC-AUC).

RESULTS

We retrieved 936 publications and included 16 studies with 5,566 participants (mean age ranged: 51.0-78.4 years, 50.2% men). The prevalence of sarcopenia ranged from 7.8 to 69.5%. All included studies presented a moderate to high risk of bias. The serum Cr- and CysC-based indices showed moderate diagnostic accuracy for sarcopenia (pooled sensitivity: 0.67, 95% CI 0.57-0.75; pooled specificity: 076, 95% CI 0.67-0.83; pooled SROC-AUC: 0.78, 95% CI 0.74-0.81). The Cr/CysC ratio is the most widely studied index, followed by the Cr × eGFRcys index. Overall, both indicators had satisfactory and comparable performance in screening sarcopenia.

CONCLUSION

Serum Cr- and CysC-based indices showed moderate diagnostic accuracy for sarcopenia. The most studied indices-the Cr/CysC ratio and Cr × eGFRcys index-had comparable diagnostic accuracy for evaluating sarcopenia and may serve as surrogate markers for sarcopenia. However, further validation is required to verify these findings.

Blood biomarkers for sarcopenia: A systematic review and meta-analysis of diagnostic test accuracy studies

Biomarkers are emerging as a potential tool for screening or diagnosing sarcopenia. We aimed to summarize the current evidence on the diagnostic test accuracy of biomarkers for sarcopenia. We comprehensively searched Ovid MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials up to January 2023 and only included diagnostic test accuracy studies. We identified 32 studies with 23,840 participants (women, 58.26%) that assessed a total of 30 biomarkers. The serum creatinine to cystatin C ratio (Cr/CysC) demonstrated a pooled sensitivity ranging from 51% (95% confidence interval [CI] 44-59%) to 86% (95% CI 70-95%) and a pooled specificity ranged from 55% (95% CI 38-70%) to 76% (95% CI 63-86%) for diagnosing sarcopenia defined by five different diagnostic criteria (11 studies, 7240 participants). The aspartate aminotransferase to alanine aminotransferase ratio demonstrated a pooled sensitivity of 62% (95% CI 56-67%) and a pooled specificity of 66% (95% CI 60-72%) (3 studies, 11,146 participants). The other 28 blood biomarkers exhibited low-to-moderate diagnostic accuracy for sarcopenia regardless of the reference standards. In conclusion, none of these biomarkers are optimal for screening or diagnosing sarcopenia. Well-designed studies are needed to explore and validate novel biomarkers for sarcopenia.

The Association between Serum Creatinine/Cystatin C Ratio and Cardiovascular Morbidity and Mortality: Insights from NHANES

Background

The Serum creatinine/cystatin C ratio (Cr/CysC ratio) is an emerging alternative index for muscle mass loss, a risk factor for cardiovascular diseases (CVDs). However, the association between the Cr/CysC ratio and CVD morbidity and mortality remains unknown.

Methods

A total of 11,150 participants of the National Health and Nutrition Examination Survey (NHANES) were included in this study. Univariable and multivariable logistic regression models were employed to assess the association between the Cr/CysC ratio and self-reported CVD morbidity. Cox proportional hazard models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI) of the Cr/CysC ratio for CVD mortality.

Results

At baseline, 1181 (7.90%) participants had self-reported CVDs. Lower Cr/CysC ratios were found in participants with CVDs (1.18 ± 0.30 vs. 1.05 ± 0.23, p < 0.001). In the multivariable logistic regression model, the Cr/CysC ratio was inversely linked to CVD morbidity (odds ratio: 0.65, 95% CI: 0.52-0.81, p < 0.001, per standard deviation [SD] increase). 997 (8.94%) CVD deaths were documented during a median follow-up of 16.9 years. A higher Cr/CysC ratio was associated with a decreasing risk of CVD mortality (adjusted HR: 0.54, 95% CI: 0.46-0.65, p < 0.001, per SD increase).

Conclusions

In NHANES participants, the Cr/CysC ratio had an inverse correlation with CVD morbidity and mortality.

Serum creatinine/cystatin C ratio as a prognostic indicator for patients with colorectal cancer

Background

This study aimed to explore the relationship between creatinine/cystatin C ratio and progression-free survival (PFS) and overall survival (OS) in colorectal cancer (CRC) patients undergoing surgical treatment.

Methods

A retrospective analysis was conducted on 975 CRC patients who underwent surgical resection from January 2012 to 2015. Restricted three-sample curve to display the non-linear relationship between PFS/OS and creatinine-cystatin C ratio. Cox regression model and Kaplan-Meier method were used to evaluate the effect of the creatinine-cystatin C ratio on the survival of CRC patients. Prognostic variables with p-value ≤0.05 in multivariate analysis were used to construct prognostic nomograms. The receiver operator characteristic curve was used to compare the efficacy of prognostic nomograms and the traditional pathological stage.

Results

There was a negative linear relationship between creatinine/cystatin C ratio and adverse PFS in CRC patients. Patients with low creatinine/cystatin C ratio had significantly lower PFS/OS than those with high creatinine/cystatin C ratio (PFS, 50.8% vs. 63.9%, p = 0.002; OS, 52.5% vs. 68.9%, p < 0.001). Multivariate analysis showed that low creatinine/cystatin C ratio was an independent risk factor for PFS (HR=1.286, 95%CI = 1.007-1.642, p=0.044) and OS (HR=1.410, 95%CI=1.087-1.829, p=0.010) of CRC patients. The creatinine/cystatin C ratio-based prognostic nomograms have good predictive performance, with a concordance index above 0.7, which can predict the 1-5-year prognosis.

Conclusion

Creatinine/cystatin C ratio may be an effective prognostic marker for predicting PFS and OS in CRC patients, aid in pathological staging, and along with tumour markers help in-depth prognostic stratification in CRC patients.