Serum Cystatin C and Arterial Stiffness in Middle-Aged and Elderly Adults without Chronic Kidney Disease: A Population-Based Study

Aortic Stiffness Can be Predicted From Different eGFR Formulas With Long Follow-Up in the Malmö Diet Cancer Study

We studied the impact of estimated glomerular filtration rate (eGFR) based on either creatinine or cystatin C, or in combination, on vascular aging (aortic stiffness) and central hemodynamics (central systolic blood pressure) in a Swedish urban population with median 17 years of follow-up. Participants (n = 5049) from the population-based Malmö Diet and Cancer Study that underwent baseline examination and later participated in the prospective cardiovascular arm were selected. Of these, 2064 with measured carotid-femoral pulse wave velocity (cfPWV) and central blood pressure at follow-up were enrolled. eGFR was calculated using cystatin C (eGFRCYS) and creatinine (eGFRCR) equations: Caucasian, Asian, pediatric, and adult cohorts (CAPA), the Lund-Malmö revised (LMrev), and the European Kidney Function Consortium (EKFC) equations. Lower adjusted eGFRCR, but not eGFRCYS, were independently associated with higher cfPWV (P < .001, respectively). eGFR <60 mL/min/1.73 m2 determined higher cfPWV except when using the EKFC equation. Conversely, CAPA/LMrev and CAPA/EKFC ratios were not associated with aortic stiffness. Lower eGFRCR is associated with higher future aortic stiffness independently of age, sex, heart rate, mean blood pressure, body mass index, and antihypertensive treatment. The ratio of eGFRCYS and eGFRCR equations could not predict aortic stiffness at all.

Relationship of Frailty with Kidney Function in Adults More Than 60-Years-Old: Effect of Using Different Formulas to Estimate Glomerular Filtration Rate

Objective

Determine the relationship of renal function with frailty using different formulas for estimated glomerular filtration rate (eGFR).

Methods

Individuals who were 60-years-old or more (n=507) were recruited from August 2020 to June 2021, and the FRAIL scale was used to classify them as non-frail or frail. The three equations used to compute the eGFR were based on serum creatinine (eGFRcr), cystatin C (eGFRcys), or SCr+CysC (eGFRcr-cys). Renal function was classified using eGFR and defined as normal (≥90 mL/min/1.73m²), mild damage (59-89 mL/min/1.73m²), or moderate damage (≤60 mL/min/1.73m²). The relationship of frailty with renal function was analyzed. A subset of participants (n=358) was used to analyze changes in eGFR from 1 January 2012 to 31 December 2021 according to frailty and using the different eGFR equations.

Results

There were significant differences between the eGFRcr-cys and eGFRcr values in the frail group (P<0.05), but not the non-frail group; however, the differences between the eGFRcr-cys and eGFRcys values were significant in the frail and non-frail groups (P<0.001). Based on each eGFR equation, the prevalence of frailty increased as eGFR decreased (P<0.001), but there was no significant relationship after adjusting for age or the age-adjusted Charlson co-morbidity index. There were temporal declines in eGFR in all three frailty groups (robust, pre-frail, and frail), especially in the frail group (2.226 mL/min/1.73m² per year; P<0.001).

Conclusion

For older individuals who are frail, the eGFRcr value may not provide accurate estimates of renal function. Frailty is associated with a rapid decline in kidney function.

Serum Cystatin C is Associated with Peripheral Artery Stiffness in Patients with Type 2 Diabetes Mellitus Combined with Chronic Kidney Disease

OBJECTIVE

Cystatin C (CysC) is associated with arterial stiffness. However, its suitability for evaluating patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD) remains unclear. We aimed to investigate the relationship between CysC levels and peripheral arterial stiffness (PAS) in patients with T2DM combined with CKD.

METHODS

Participants' arterial stiffness was assessed using brachial-ankle pulse wave velocity (baPWV), and those with a baPWV ≥ 1800 cm/s were included in the PAS group. Additionally, patients were divided into young (18-44 years old), middle-aged (45-59 years old), and older (≥ 60 years old) groups.

RESULTS

Of 200 patients, 94 (47%) were diagnosed with PAS. Multivariate logistic regression revealed that age, pulse pressure, and CysC levels (odds ratio = 1.525, 95% confidence interval: 1.072-2.168, P = 0.019) were independently correlated with PAS in patients with T2DM combined with CKD. The levels of CysC in different age groups were positively correlated with baPWV, and the correlation was significantly higher in the young group (r = 0.739, P < 0.001) than in the middle-aged (r = 0.329, P < 0.001) and older (r = 0.496, P < 0.001) groups. The multifactor linear regression analysis revealed that CysC was significantly correlated with baPWV in the young group (β = 0.455, P = 0.002).

CONCLUSION

CysC was an independent predictor of PAS in patients with T2DM combined with CKD and was more significantly associated with baPWV in young patients than in middle-aged and older patients. CysC may may be an early predictor of peripheral arteriosclerosis in patients with T2DM combined with CKD.

Metabolically healthy obesity is associated with higher risk of both hyperfiltration and mildly reduced estimated glomerular filtration rate: the role of serum uric acid in a cross-sectional study

BACKGROUND

The impact of metabolically healthy obesity (MHO) on kidney dysfunction remains debatable. Moreover, few studies have focused on the early stages of kidney dysfunction indicated by hyperfiltration and mildly reduced eGFR. Thus, we aimed to investigate the association between the MHO and early kidney dysfunction, which is represented by hyperfiltration and mildly reduced estimated glomerular filtration rate (eGFR), and to further explore whether serum uric acid affects this association.

METHODS

This cross-sectional study enrolled 1188 residents aged ≥ 40 years old from Yonghong Communities. Metabolically healthy phenotypes were categorized based on Adult Treatment Panel III criteria. Obesity was defined as body mass index (BMI) ≥ 25 kg/m². Mildly reduced eGFR was defined as being in the range 60 < eGFR ≤ 90 ml/min/1.73m². Hyperfiltration was defined as eGFR > 95th percentile after adjusting for sex, age, weight, and height.

RESULTS

Overall, MHO accounted for 12.8% of total participants and 24.6% of obese participants. Compared to metabolically healthy non-obesity (MHNO), MHO was significantly associated with an increased risk of mildly reduced eGFR (odds ratio [OR] = 1.85, 95% confidence interval [CI]  1.13-3.01) and hyperfiltration (OR = 2.28, 95% CI 1.03-5.09). However, upon further adjusting for uric acid, the association between the MHO phenotype and mildly reduced eGFR was reduced to null. Compared with MHNO/non-hyperuricemia, MHO/non-hyperuricemia was associated with an increased risk of mildly reduced eGFR (OR = 2.04, 95% CI  1.17-3.58), whereas MHO/hyperuricemia was associated with an observably increased risk (OR = 3.07, 95% CI  1.34-7.01).

CONCLUSIONS

MHO was associated with an increased risk of early kidney dysfunction, and the serum uric acid partially mediated this association. Further prospective studies are warranted to clarify the causality.

Metabolic profile predicts incident cancer: A large-scale population study in the UK Biobank

BACKGROUND AND AIMS

Analyses to predict the risk of cancer typically focus on single biomarkers, which do not capture their complex interrelations. We hypothesized that the use of metabolic profiles may provide new insights into cancer prediction.

METHODS

We used information from 290,888 UK Biobank participants aged 37 to 73 years at baseline. Metabolic subgroups were defined based on clustering of biochemical data using an artificial neural network approach and examined for their association with incident cancers identified through linkage to cancer registry. In addition, we evaluated associations between 38 individual biomarkers and cancer risk.

RESULTS

In total, 21,973 individuals developed cancer during the follow-up (median 3.87 years, interquartile range [IQR] = 2.03-5.58). Compared to the metabolically favorable subgroup (IV), subgroup III (defined as "high BMI, C-reactive protein & cystatin C") was associated with a higher risk of obesity-related cancers (hazard ratio [HR] = 1.26, 95 % CI = 1.21 to 1.32) and hematologic-malignancies (e.g., lymphoid leukemia: HR = 1.83, 95%CI = 1.44 to 2.33). Subgroup II ("high triglycerides & liver enzymes") was strongly associated with liver cancer risk (HR = 5.70, 95%CI = 3.57 to 9.11). Analysis of individual biomarkers showed a positive association between testosterone and greater risks of hormone-sensitive cancers (HR per SD higher = 1.32, 95%CI = 1.23 to 1.44), and liver cancer (HR = 2.49, 95%CI =1.47 to 4.24). Many liver tests were individually associated with a greater risk of liver cancer with the strongest association observed for gamma-glutamyl transferase (HR = 2.40, 95%CI = 2.19 to 2.65).

CONCLUSIONS

Metabolic profile in middle-to-older age can predict cancer incidence, in particular risk of obesity-related cancer, hematologic malignancies, and liver cancer. Elevated values from liver tests are strong predictors for later risk of liver cancer.

Arterial Stiffness Determinants for Primary Cardiovascular Prevention among Healthy Participants

Background: Arterial stiffness (AS), measured by arterial stiffness index (ASI), can be considered as a major denominator in cardiovascular (CV) diseases. Thus, it remains essential to highlight the risk factors influencing its increase among healthy participants. Methods: According to European consensus, AS is defined as ASI > 10 m/s. The purpose of this study was to investigate the determinants of the arterial stiffness (ASI > 10 m/s) among UK Biobank normotensive and healthy participants without comorbidities and previous CV diseases. Thus, a cross-sectional study was conducted on 22,452 healthy participants. Results: Participants were divided into two groups, i.e., ASI > 10 m/s (n = 5782, 25.8%) and ASI < 10 m/s (n = 16,670, 74.2%). All the significant univariate covariables were included in the multivariate analysis. The remaining independent factors associated with AS were age (OR = 1.063, threshold = 53.0 years, p < 0.001), BMI (OR = 1.0450, threshold = 24.9 kg/m2, p < 0.001), cystatin c (OR = 1.384, threshold = 0.85 mg/L, p = 0.011), phosphate (OR = 2.225, threshold = 1.21 mmol/L, p < 0.001), triglycerides (OR = 1.281, threshold = 1.09 mmol/L, p < 0.001), mean BP (OR = 1.028, threshold = 91.2 mmHg, p < 0.001), HR (OR = 1.007, threshold = 55 bpm, p < 0.001), Alkaline phosphate (OR = 1.002, threshold = 67.9 U/L, p = 0.004), albumin (OR = 0.973, threshold = 46.0 g/L, p < 0.001), gender (male, OR = 1.657, p < 0.001) and tobacco use (current, OR = 1.871, p < 0.001). Conclusion: AS is associated with multiple parameters which should be investigated in future prospective studies. Determining the markers of increased ASI among healthy participants participates in the management of future CV risk for preventive strategies.

Association Cystatin C and Risk of Stroke in Elderly Patients With Obstructive Sleep Apnea: A Prospective Cohort Study

Background: Few prospective cohort studies have assessed the relationship between Cystatin C (Cys-C) and risk of stroke in elderly patients with obstructive sleep apnea (OSA). The study sought to examine the association between baseline serum Cys-C and long-term risk of stroke among elderly OSA patients.

Methods: A total of 932 patients with OSA, no history of stroke, ≥60 years of age, and complete serum Cys-C records were included in this study. All patients had completed polysomnography (PSG). OSA was defined as an apnea-hypopnea index (AHI) of ≥5 events per hour. Participants were categorized into four groups according to baseline serum Cys-C concentration, split into quartiles. Multivariate Cox regression were used to evaluate the association between Cys-C and the incidence of new-onset stroke.

Results: Stroke occurred in 61 patients during the median 42-month follow-up period. The cumulative incidence rate of stroke was 6.5%, which included 54 patients with ischemic stroke and 7 patients with hemorrhagic stroke. The cumulative incidence of stroke was higher among patients with baseline serum Cys-C concentration of ≥1.15 mg/L when compared with other groups (P_Log–rank < 0.001). After adjusting for potential confounding factors in the Cox regression model, patients with a serum Cys-C concentration of ≥1.15 mg/L had a 2.16-fold higher risk of developing stroke compared with patients with serum Cys-C ≤ 0.81 mg/L (HR, 2.16, 95%CI, 1.09–6.60; P = 0.017). Additionally, there was a higher risk in those of age ≥70 years (HR, 3.23, 95%CI, 1.05–9.24; P = 0.010). The receiver-operating characteristic curves showed that the capability of Cys-C to identify elderly patients with OSA who had a long-time risk of stroke was moderate (AUC = 0.731, 95% CI: 0.683–0.779, P = 0.001).

Conclusion: Increased Cys-C concentration was identified as a risk factor in the incidence of stroke in elderly patients with OSA, independent of gender, BMI, hypertension and other risk factors. Additionally, it conferred a higher risk in patients of age ≥70 years.

The predict value of serum/urocystatin C on acute kidney injury in elderly patients with sepsis

OBJECTIVE

To evaluate the predict value of serum/urocystatin C in acute kidney injury (AKI) in elderly patients with sepsis.

METHODS

A retrospective study was performed and 80 senile patients with sepsis in ** hospital of China was included. According to the diagnosis of AKI, all patients were divided into non-AKI group and AKI group. The clinical characteristics, laboratory and physiological indicators of the two groups were compared. The receiver operating characteristic curve (ROC) was used to analyze the accuracy of the variables, including serum cystatin C, urocystatin C, and serum creatinine, to predict the occurrence of AKI in patients with sepsis.

RESULTS

Of the 80 elderly patients with sepsis in China, 29 patients had AKI. Compared with the non-AKI group, patients in the AKI group had higher APACHE II scores, higher SOFA scores, higher procalcitonin, and lower mean arterial pressure (P < 0.05). The levels of serum cystatin C, urocystatin C, and serum creatinine in the AKI group were significantly higher than those in the non-AKI group (P < 0.05), while the difference in intensive care unit (ICU) mortality rate between the two groups was not significantly different (P > 0.05). The ROC curve showed that the area under the curve of serum cystatin C was 0.893, the area under the curve of urocystatin C was 0.898, and the area under the curve of serum creatinine was 0.652.

CONCLUSION

Serum cystatin and urocystatin could be used to predict the occurrence of AKI in elderly patients with sepsis.