Normalized Creatinine-to-Cystatin C Ratio and Risk of Diabetes in Middle-Aged and Older Adults: The China Health and Retirement Longitudinal Study

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.

Sex difference in the association between creatinine-to-cystatin C ratio and metabolic syndrome among Chinese adults

Background

Metabolic syndrome (MetS), characterized by central obesity, insulin resistance, dyslipidemia, and hypertension, affects 20-25% of the global population. The creatinine-to-cystatin C ratio (CCR) is an indicator of skeletal muscle mass. While CCR may play a role in MetS development, sex differences in these associations are not fully understood. Therefore, this study aimed to investigate how CCR levels are associated with MetS in a Chinese adult population, focusing on possible sex disparities.

Method

We conducted a retrospective cross-sectional analysis of 9,376 adults from Xiamen Chang Gung Hospital between 2014 to 2016. We examined the relationship between CCR and MetS, adjusting for cardiometabolic risk factors.

Results

The prevalence of MetS was 24.7% in males and 18.0% in females. Interestingly, we observed significant sex differences in the association between CCR quartiles and MetS. Females in the lowest CCR quartile had a significantly higher risk of MetS (odds ratio=1.84). Receiver operating characteristic curve analysis revealed acceptable diagnostic power of CCR for MetS in females (area under the curve=0.65) but not in males.

Conclusion

Our findings suggest that CCR is an independent risk factor for MetS in females, highlighting the importance of sex-specific assessments when evaluating MetS risk.

Lower serum creatinine to cystatin C ratio associated with increased incidence of frailty in community-dwelling elderly men but not in elderly women

BACKGROUND

Sarcopenia has been reported to play an important role in frailty syndrome. The serum creatinine/serum cystatin C ratio (Scr/Cys C ratio) has recently been recognized as a valuable indicator for assessing sarcopenia. However, few studies have examined the association between serum creatinine/serum cystatin C ratio and frailty. The objective of this study is to investigate the relationship between the serum creatinine/serum cystatin C ratio and frailty among older adults residing in the community.

METHODS AND MATERIALS

A Total of 1926 community-dwelling older adults aged ≥ 60 years in the 2011 waves of the China Health and Retirement Longitudinal Study (CHARLS) were included. The participants' frailty status was determined using a 39 item frailty index (FI), which classified individuals as "robust" (FI ≤ 0.1), "pre-frailty" (0.1 < FI < 0.25), or "frailty" (FI ≥ 0.25). The Scr/Cys C ratio was determined by dividing the serum creatinine level (mg/dL) by the cystatin C level (mg/L). The one-way analysis of variance(ANOVA) and Chi-squared test (χ2)were applied to compare the differences between the 3 groups. Both linear regression and logistic regression models were used to further investigate the relationship between Scr/Cys C ratio and frailty.

RESULTS

After adjusting for potential confounding factors, the study revealed that participants in the Q1 quartile of Scr/Cys C ratio had increased odds of frailty (Q1vs.Q4: OR = 1.880, 95% CI 1.126-3.139, p = 0.016) compared with those in the Q4 quartile group. In fully adjusted logistic regression models, male participants in the Q2 quartile of Scr/Cys C ratio were significantly correlated with higher odds of pre-frailty (Q2 vs.Q4: OR = 1.693, 95%CI 1.040-2.758, p = 0.034). However, this correlation was not observed in females (OR = 0.984, 95% CI 0.589-1.642, p = 0.950,). Additionally, the study observed an increase in both the frailty index and the incidence of frailty as age increased in both males and females.

CONCLUSION

Among community-dwelling older adults, lower Serum creatinine to cystatin C ratio were found to be associated with increased odds of frailty prevalence in males.

Associations of muscle mass and strength with new-onset diabetes among middle-aged and older adults: evidence from the China health and retirement longitudinal study (CHARLS)

BACKGROUND

The associations of muscle mass and strength with new-onset Type 2 diabetes mellitus (T2DM) remain controversial. We aimed to longitudinally evaluate muscle mass and strength in predicting T2DM among Chinese middle-aged and older adults.

METHODS

We enrolled 6033 participants aged ≥ 45 years from the China Health and Retirement Longitudinal Study (CHARLS), a cohort survey, between 2011 and 2012. The appendicular skeletal muscle mass (normalized by weight, ASM/BW%), relative hand grip strength (normalized by weight, HGS/BW), and five-repetition chair stand test (5CST). were all categorized into tertiles (lowest, middle, and highest groups) at baseline, respectively. Individuals were followed up until the occurrence of diabetes or the end of CHARLS 2018, whichever happened first. Cox proportional hazards models to calculate hazard ratios with 95% confidence intervals (CI) and mediation analysis were used.

RESULTS

During follow-up, 815 (13.5%) participants developed T2DM. After adjusting for covariates, lower ASW/BW% was not associated with a higher risk of diabetes. Compared with individuals in the highest tertile of HGS/BW, those in the lowest tertile had 1.296 (95%CI 1.073-1.567) higher risk of diabetes. Compared with individuals in the lowest tertile of 5CST, those in the highest tertile had 1.329 times (95%CI 1.106-1.596) higher risk of diabetes. By subgroup, both the lowest HGS/BW and highest 5CST were risk factors for diabetes among obesity. The mediation analysis revealed that the effect of HGS/BW on the risk of diabetes is mainly mediated by insulin resistance.

CONCLUSIONS

Lower muscle strength is associated with an increased risk of diabetes, especially in obese populations.

Sex-specific associations between skeletal muscle mass and incident diabetes: A population-based cohort study

AIMS

To investigate the sex-specific associations between predicted skeletal muscle mass index (pSMI) and incident type 2 diabetes in a retrospective longitudinal cohort of Chinese men and women.

MATERIALS AND METHODS

We enrolled Chinese adults without diabetes at baseline from WATCH (West chinA adulT health CoHort), a large health check-up-based database. We calculated pSMI to estimate skeletal muscular mass, and measured blood glucose variables and assessed self-reported history to identify new-onset diabetes. The nonlinear association between pSMI and incident type 2 diabetes was modelled using the penalized spline method. The piecewise association was estimated using segmented linear splines in weighted Cox proportional hazards regression models.

RESULTS

Of 47 885 adults (53.2% women) with a median age of 40 years, 1836 developed type 2 diabetes after a 5-year median follow-up. In women, higher pSMI was associated with a lower risk of incident type 2 diabetes (Pnonlinearity  = 0.09, hazard ratio [HR] per standard deviation increment in pSMI: 0.79 [95% confidence interval {CI} 0.68, 0.91]). A nonlinear association of pSMI with incident type 2 diabetes was detected in men (Pnonlinearity  < 0.001). In men with pSMI lower than 8.1, higher pSMI was associated with a lower risk of incident type 2 diabetes (HR 0.58 [95% CI 0.40, 0.84]), whereas pSMI was not significantly associated with incident diabetes in men with pSMI equal to or greater than 8.1 (HR 1.08 [95% CI 0.93, 1.25]).

CONCLUSIONS

In females, a larger muscular mass is associated with a lower risk of type 2 diabetes. For males, this association is significant only among those with diminished muscle mass.

Muscle Quality in Relation to Prediabetes Phenotypes: A Population-Based Study With Mediation Analysis

CONTEXT

Prediabetes is associated with an increased risk of physical disability, yet no studies have assessed the extent to which muscle quality, a measure reflecting muscle functionality, was altered in prediabetes and its specific phenotype.

OBJECTIVE

We evaluated their associations in a general US population with mediation analysis.

METHODS

This was a cross-sectional study based on the National Health and Nutrition Examination Survey 2011-2014. Participants with prediabetes were stratified as having an isolated defect (impaired fasting glucose [IFG], impaired glucose tolerance [IGT], or impaired hemoglobin A1c [IA1c]), 2 defects (IFG + IGT, IFG + IA1c, or IGT + IA1c), or all defects (IFG + IGT + IA1c). Muscle quality was calculated as dominant grip strength divided by dominant arm muscle mass measured by dual-energy X-ray absorptiometry.

RESULTS

We included 2351 participants (938 with prediabetes and 1413 with normoglycemia). Despite higher grip strength and larger arm muscle mass, arm muscle quality was lower in prediabetes and all prediabetes phenotypes (except for IGT) than normoglycemia (all P < .04), and was unrelated to prediabetes awareness. Arm muscle quality was decreased and the odds of low arm muscle quality was increased in prediabetes with increasing numbers of glucometabolic defects (both P < .001), with insulin resistance being the predominant mediator. HbA1c-defined prediabetes (IA1c) had lower arm muscle quality and higher odds of low arm muscle quality than blood glucose-defined prediabetes (IFG, IGT, or IFG + IGT).

CONCLUSION

Muscle quality was impaired in prediabetes and its specific phenotype. Relative to blood glucose, elevated HbA1c might be a better predictor of reduced muscle quality.

Diabetes Mellitus Should Be Considered While Analysing Sarcopenia-Related Biomarkers

Sarcopenia is a chronic, progressive skeletal muscle disease characterised by low muscle strength and quantity or quality, leading to low physical performance. Patients with type 2 diabetes mellitus (T2DM) are more at risk of sarcopenia than euglycemic individuals. Because of several shared pathways between the two diseases, sarcopenia is also a risk factor for developing T2DM in older patients. Various biomarkers are under investigation as potentially valuable for sarcopenia diagnosis and treatment monitoring. Biomarkers related to sarcopenia can be divided into markers evaluating musculoskeletal status (biomarkers specific to muscle mass, markers of the neuromuscular junction, or myokines) and markers assuming causal factors (adipokines, hormones, and inflammatory markers). This paper reviews the current knowledge about how diabetes and T2DM complications affect potential sarcopenia biomarker concentrations. This review includes markers recently proposed by the expert group of the European Society for the Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) as those that may currently be useful in phase II and III clinical trials of sarcopenia: myostatin (MSTN); follistatin (FST); irisin; brain-derived neurotrophic factor (BDNF); procollagen type III N-terminal peptide (PIIINP; P3NP); sarcopenia index (serum creatinine to serum cystatin C ratio); adiponectin; leptin; insulin-like growth factor-1 (IGF-1); dehydroepiandrosterone sulphate (DHEAS); C-reactive protein (CRP); interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α). A better understanding of factors influencing these biomarkers' levels, including diabetes and diabetic complications, may lead to designing future studies and implementing results in clinical practice.

Associations of sarcopenia with peak expiratory flow among community-dwelling elderly population: based on the China Health and Retirement Longitudinal Study (CHARLS)

PURPOSE

To cross-sectionally and longitudinally investigate the correlations of sarcopenia and its components with peak expiratory flow (PEF) among Chinese community-dwelling elderly people.

METHODS

The data were extracted from the China Health and Retirement Longitudinal Study (CHARLS). A total of 4053 participants aged ≥ 60 years were enrolled from CHARLS 2011, and 2810 were followed up until 2015. Participants were classified into no-sarcopenia, non-severe sarcopenia, and severe sarcopenia groups based on skeletal muscle mass index (SMI), hand grip strength (HGS), and physical performance [gait speed, five-repetition chair stand test (5CST) and short physical performance battery (SPPB)]. Multivariate linear and logistic regression analyses were used to evaluate the associations of sarcopenia and its components with PEF cross-sectionally and longitudinally.

RESULTS

In the cross-sectional analysis, the prevalence of non-severe sarcopenia was 14.6% and severe sarcopenia was 4.9%. The results of linear regression analysis revealed that sarcopenia and its components were all correlated with PEF and PEF%pred. In the longitudinal analysis, compared with non-sarcopenia, subjects with severe sarcopenia were associated with a higher risk of PEF (OR = 2.05, 95%CI = 1.30-3.26) and PEF%pred (OR = 1.83, 95%CI = 1.17-2.86) decline. The changes in physical performance were correlated with changes in PEF and PEF%pred. No associations were observed between changes in SMI and PEF as well as PEF%pred.

CONCLUSIONS

We demonstrated the associations of baseline sarcopenia status with PEF and longitudinal PEF decline. Also, the changes in physical performance were associated with changes in PEF during a 4-year follow-up. It indicates that improving sarcopenia, especially physical performance may increase PEF.

Additive impact of diabetes and sarcopenia on all-cause and cardiovascular mortality: A longitudinal nationwide population-based study

OBJECTIVE

Diabetes mellitus (DM) and sarcopenia (SP) are growing public health concerns in an aging society, which share common pathophysiological mechanisms and are associated with serious health consequences. We investigated the impact of DM and SP on all-cause and cardiovascular mortalities in a longitudinal nationwide population-based study.

METHODS

The study analyzed data from the Korea National Health and Nutrition Examination Survey conducted between 2008 and 2011, including information on appendicular skeletal muscle mass data. Mortality data up to December 2020 were retrieved from the National Death Registry.

RESULTS

Among the 17,920 participants, 14,737 (82.2 %) had neither DM nor SP (DM-/SP-), 1349 (7.5 %) had only DM (DM+/SP-), 1425 (8.0 %) had only SP (DM-/SP+), and 409 (2.3 %) had both DM and SP (DM+/SP+). Compared to the DM-/SP- group, the DM-/SP+ and DM+/SP+ groups demonstrated increased all-cause mortality with adjusted hazard ratios (HRs) of 1.47 (95 % confidence interval [CI]: 1.14-1.89) and 1.85 (95 % CI: 1.28-2.69), respectively, while the DM+/SP- group did not (HR 1.29, 95 % CI: 0.97-1.74). The DM+/SP+ group demonstrated the highest risk of overall mortality (p-for-trend <0.001). Compared to the DM-/SP- group, only the DM+/SP+ group demonstrated increased cardiovascular mortality with HRs of 2.10 (95 % CI: 1.11-4.00) while the DM+/SP- (HR 1.35, 95 % CI: 0.79-2.30) and DM-/SP+ (HR 1.42, 95 % CI: 0.84-2.43) groups did not.

CONCLUSIONS

The coexistence of DM and SP additively increased the risk of all-cause and cardiovascular mortality. Individuals with either disease may require more careful management to prevent the development of the other disease to reduce mortality.

The serum creatinine to cystatin C to waist circumference ratios predicts risk for type 2 diabetes: A Chinese cohort study

BACKGROUND

There is a lack of research regarding the relationship between creatinine to cystatin C to waist circumference ratio (CCR/WC ratios) and the development of type 2 diabetes mellitus (T2DM). We aimed to evaluate the association between CCR/WC ratios and incident T2DM in Chinese adults.

METHODS

This prospective study was from the China Health and Retirement Longitudinal Study (2011, 2013, 2015, and 2018). The participants were divided into three groups by tertiaries of the CCR/WC ratios. Cox proportional-hazards models were used to identify the relationship between CCR/WC and T2DM.

RESULTS

Overall, 5938 participants were included for analysis, 766 of whom developed T2DM between 2011 and 2018. Risk of incident T2DM was decreased with tertiaries 2, 3 versus tertiary 1 of the CCR/WC index (adjusted hazard ratio [HR] 0.772 [95% confidence interval 0.647-0.921] and 0.724 [0.596-0.880], p for trend = .001 across tertiaries of the CCR/WC index). The results were consistent excluding participants with T2DM in the first 2 years.

CONCLUSIONS

This study demonstrated that CCR/WC was negatively correlated with the risk of T2DM in Chinese adults. Early detection is necessary to control the development of T2DM in Chinese with low CCR/WC levels.