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

Usefulness of the serum creatinine/cystatin C ratio as a blood biomarker for sarcopenia components among age groups in community-dwelling older people: The SONIC study

AIM

The serum creatinine/cystatin C ratio (CCR) or sarcopenia index is considered a useful marker of muscle mass. However, its usefulness in late-stage older adults remains unclear. We aimed to determine the usefulness of CCR as an indicator of sarcopenia in community-dwelling Japanese adults aged >75 years.

METHODS

Our study recruited participants aged 70, 80, and 90 ± 1 years during the baseline years, and included a 3-year follow-up in the Septuagenarians, Octogenarians, Nonagenarians, Investigation with Centenarians study. From 2015 to 2018, 955 participants were eligible: 367 in their 70s, 304 in their 80s, and 284 in their 90s. The diagnostic components of sarcopenia, including "low muscle mass, plus low muscle strength, and/or low physical performance," were evaluated using the bioelectrical impedance analysis-measured skeletal muscle mass index (SMI), handgrip strength, and short physical performance battery (SPPB) score, respectively, in accordance with the Asia Working Group for Sarcopenia 2019 criteria. Separate analyses were performed between each component and CCR, adjusting for sex, body mass index, and other blood biomarkers in each group.

RESULTS

The relationship between CCR and sarcopenia components was significant for handgrip strength (β = 0.21, 0.13, 0.19, and P < 0.0001, =0.0088, <0.0001, for the 70s, 80s, and 90s age groups, respectively); however, it was limited for SMI (β = 0.14; P = 0.0022, only for the 90s) and not significant for the SPPB score.

CONCLUSION

CCR is a limited indicator of sarcopenia in late-stage older adults. Although its association with muscle strength was significant, its relationship with muscle mass and physical performance was less pronounced. Geriatr Gerontol Int 2024; 24: 529-536.

Association of comorbidities with postoperative walking independence in patients with hip fractures: a single-center, retrospective, observational study

Hip fractures (HFs) are common in the elderly and lead to decreased walking independence. Although comorbidities may be associated with gaining walking independence, few studies have comprehensively examined baseline and preoperative clinical factors. We aimed to evaluate the effects of comorbidities on the postoperative walking independence of patients with HFs. This single-center, retrospective, observational study included patients with HFs admitted to an acute care hospital between 1 May 2022 and 1 March 2023, who before the incident were able to walk independently [functional independence measure (FIM) walk score ≥6 points]. Postoperative walking independence was evaluated using the walk item of the FIM. The Charlson comorbidity index (CCI) was used to evaluate comorbidities at admission, and the patients were divided into two categories with CCI scores of 0 points and ≥1 point. The effect of comorbidities, assessed using the CCI, on postoperative walking independence was evaluated using Cox proportional hazards analysis. Ninety-four participants were included in the analysis. The Cox proportional hazards model adjusted for potential confounders (age, operative delay and nutritional status) revealed that the CCI was significantly associated with postoperative walking independence ( P < 0.05). The hazard ratio and 95% confidence interval (CI) for the CCI for postoperative walking independence were 0.40 (95% CI, 0.189-0.865). Preoperative assessment of comorbidities using the CCI may aid in predicting the postoperative walking independence of patients with HFs.

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.

Correlation between preoperative CT scan of the paraspinal, psoas, and gluteus muscles and postoperative ambulatory status in patients with femoral neck fractures

BACKGROUND

This study aimed to investigate the relationship between femoral neck fractures and sarcopenia.

METHODS

This was a retrospective analysis of 92 patients with femoral neck fractures, from September 2017 to March 2020, who were classified into high ambulatory status (HG) and low ambulatory status (LG) groups. Ambulatory status was assessed before surgery, one week after surgery, at discharge, and during the final follow-up. To evaluate sarcopenia, muscle mass and fatty degeneration of the muscles were measured using preoperative CT. An axial slice of the superior end of the L5 vertebra was used to evaluate the paraspinal and psoas muscles, a slice of the superior end of the femoral head for the gluteus maximus muscle, and a slice of the inferior end of the sacroiliac joint for the gluteus medius muscle. The degeneration of the muscles was evaluated according to the Goutallier classification.

RESULTS

The cross-sectional area of the gluteus medius and paraspinal muscles was significantly correlated with ambulatory status before the injury, at discharge, and during the final follow-up.

CONCLUSIONS

Measurement of the gluteus medius and paraspinal muscles has the potential to evaluate sarcopenia and predict ambulatory status after femoral neck fractures.

Association of preoperative nutritional status evaluated by the controlling nutritional status score with walking independence at 180 days postoperatively: a prospective cohort study in Chinese older patients with hip fracture

BACKGROUND

Malnutrition is significantly associated with unfavorable outcomes, but there is little high-level evidence to elucidate the association of malnutrition with losing walking independence (LWI) after hip fracture surgery. This study aimed to assess the association between preoperative nutritional status evaluated by the Controlling Nutritional Status (CONUT) score and walking independence at 180 days postoperatively in Chinese older hip fracture patients.

METHODS

This prospective cohort study included 1958 eligible cases from the SSIOS database. The restricted cubic spline was used to assess the dose-effect relationship between the CONUT score and the recovery of walking independence. Propensity score matching was performed to balance potential preoperative confounders, and multivariate logistic regression analysis was applied to assess the association between malnutrition and LWI with perioperative factors for further adjustment. Furthermore, inverse probability treatment weighting and sensitivity analyses were performed to test the robustness of the results and the Fine and Gray hazard model was applied to adjust the competing risk of death. Subgroup analyses were used to determine potential population heterogeneity.

RESULTS

The authors found a negative relationship between the preoperative CONUT score and recovery of walking independence at 180 days postoperatively, and that moderate-to-severe malnutrition evaluated by the CONUT score was independently associated with a 1.42-fold (95% CI, 1.12-1.80; P =0.004) increased risk of LWI. The results were overall robust. And in the Fine and Gray hazard model, the result was still statistically significant despite the apparent decrease in the risk estimate from 1.42 to 1.21. Furthermore, significant heterogeneities were observed in the subgroups of age, BMI, American Society of Anesthesiologists score, Charlson's comorbidity index, and surgical delay ( P for interaction < 0.05).

CONCLUSION

Preoperative malnutrition is a significant risk factor for LWI after hip fracture surgery, and nutrition screening on admission would generate potential health benefits.

Serum creatinine/cystatin C ratio as a muscle mass evaluating tool and prognostic indicator for hospitalized patients: A meta-analysis

Objective

Sarcopenia is a syndrome of decreased muscle mass and deficits in muscle strength and physical function. We aimed to investigate the relationship between creatinine/cystatin C ratio (CCR) and sarcopenia and the prognostic value of CCR in hospitalized patients.

Materials and methods

We searched for relevant studies in PubMed, EMBASE, and the Cochrane Database up to August 25, 2022. Meta-analyses were performed to evaluate the relationship between CCR and skeletal muscle [computed tomography-assessed skeletal muscle (CTASM), muscle strength, and physical performance], prognosis and important clinical outcomes in hospitalized adults. The pooled correlation coefficient, the area under the receiver operating characteristic (ROC) curves, and hazard ratio (HR) together with their 95% confidence intervals (CIs) were calculated. We also conducted subgroup analyses to explore the sources of heterogeneity.

Results

A total of 38 studies with 20,362 patients were eligible. These studies were of moderate to high quality. Our results showed that CCR was significant correlations with all CTASM types (Fisher's Z ranged from 0.35 to 0.5; P values ranged from < 0.01 to 0.01), handgrip strength (Fisher's Z = 0.39; 95% CI, 0.32-0.45; P < 0.001) and gait speed (Fisher's Z = 0.25; 95% CI, 0.21-0.30; P < 0.001). The ROC curves suggested that CCR had good diagnostic efficacy (0.689; 95% CI, 0.632-0.746; P < 0.01) for sarcopenia. CCR can reliably predict mortality in hospitalized patients, which was confirmed by regression analysis of CCR as both continuous (HR 0.78; 95% CI, 0.72-0.84; P < 0.01) and categorical variables (HR 2.05; 95% CI, 1.58-2.66; P < 0.0001). In addition, less evidence showed that higher CCR was independently associated with a shorter duration of mechanical ventilation, reduced length of stay in the intensive care unit and hospital, less nutritional risk, and decreased complications in hospitalized patients.

Conclusion

CCR could be a simple, economical, and effective screening tool for sarcopenia in hospitalized patients, and it is a helpful prognostic factor for mortality and other important clinical outcomes.

Systematic review registration

https://inplasy.com/inplasy-2022-9-0097/, identifier INPLASY202290097.

Serum creatinine to cystatin C ratio and cognitive function among middle-aged and older adults in China

Background

The sarcopenia index (SI, serum creatinine/serum cystatin C × 100) is recently suggested to be a reliable marker for sarcopenia. It has been reported that sarcopenia is associated with poorer cognition. The purpose of this study was to evaluate the correlation between SI and cognitive function among middle-aged and older adults from the China Health and Retirement Longitudinal Study (CHARLS).

Materials and methods

A total of 6,442 participants ≥45 years of age were enrolled in this study from CHARLS between 2011 and 2012. Cognitive function was assessed by interview-based measurements, including orientation and attention, episodic memory, visuo-construction, and the total cognitive function. SI was calculated by serum creatinine (mg/dL)/cystatin C (mg/L) × 100. One-way analysis of variance (ANOVA) was used to compare the differences among groups divided according to SI quartiles by gender. Both linear and logistic regression models were applied to investigate the relationship between SI and cognitive function.

Results

After adjustment for potential confounders, we found SI was significantly and positively correlated with total cognitive function scores both in males and females [β = 0.014, 95% confidence interval (CI) 0.007 to 0.021, P < 0.001; β = 0.011, 95 CI% 0.003 to 0.018, P = 0.004; respectively]. Similarly, when the total cognitive function score was treated as a categorical variable according to quartiles in males and females, higher SI was related to better total cognitive function scores in both males and females [odds ratio (OR) = 1.147, 95% CI 1.028 to 1.279, P = 0.014; OR = 1.219, 95% CI 1.106 to 1.344, P < 0.001; respectively] following adjustment for confounders.

Conclusions

Lower sarcopenia index was correlated with a higher prevalence of cognitive impairment among middle-aged and older adults in China.

Relationship between serum creatinine to cystatin C ratio and subclinical atherosclerosis in patients with type 2 diabetes

INTRODUCTION

Sarcopenia index (SI), calculated by (serum creatinine/cystatin C)×100, is reported to be associated with sarcopenia. Few studies reported the association between SI and subclinical atherosclerosis. We evaluated the association between SI and subclinical atherosclerosis, assessed by brachial-ankle pulse wave velocity (baPWV).

RESEARCH DESIGN AND METHODS

One hundred seventy-four patients with type 2 diabetes were included in this cross-sectional study. The relationship between SI and baPWV was assessed by Pearson's correlation coefficient. To calculate area under the receiver operator characteristic (ROC) curve (AUC) of SI for the presence of subclinical atherosclerosis, which was defined as baPWV >1800 cm/s, ROC analysis was performed. Logistic regression analyses were performed to assess the effect of SI on the prevalence of subclinical atherosclerosis adjusting for covariates.

RESULTS

Mean age, duration of diabetes, baPWV, and SI were 66.9 (10.1) years, 17.7 (11.6) years, 1802 (372) cm/s, and 77.6 (15.8), respectively. There was an association between SI and baPWV (men; r=-0.25, p=0.001, and women; r=-0.37, p=0.015). The optimal cut-off point of SI for the presence of subclinical atherosclerosis was 77.4 (sensitivity=0.72, specificity=0.58, p<0.001, AUC 0.66 (95% CI: 0.57 to 0.74)). In addition, SI was associated with the prevalence of subclinical atherosclerosis (adjusted OR 0.95, 95% CI: 0.91 to 0.99, p=0.015).

CONCLUSIONS

SI is associated with the prevalence of subclinical atherosclerosis in patients with type 2 diabetes.

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.

Bilateral Incomplete Atypical Femur Fractures with Severe Bowing Treated Using Elastic Intramedullary Nails: A Case Report

CASE

A 77-year-old woman with bilateral symptomatic atypical femoral fractures (AFFs) and severe anterolateral bowing due to long-term bisphosphonate administration was treated using stainless elastic intramedullary nails. Weight-bearing pain disappeared immediately after surgery. Radiographs obtained 1 year postoperatively showed fracture healing.

CONCLUSION

Although intramedullary nail insertion has been recommended for symptomatic incomplete AFFs, in cases of severe bowing, rigid nail insertion was often challenging, and the complication rates were higher than those with mild bowing. The advantage of our method is easy insertion, suggesting effective treatment.