Clinical factors increasing discrepancies of renal function assessment with MDRD and Cockcroft-Gault equations in old individuals

A Comparative Study on the Efficacy Between Cystatin C and Creatinine-Based Equations for Early Detection of Renal Damage in Patients of Eastern India

Chronic kidney disease (CKD) is one of the leading causes of mortality across the globe. Early diagnosis of the disease is important in order to prevent the adverse outcome related to CKD. Many laboratories adopt creatinine-based e-GFR equations which yields imprecise results leading to misdiagnosis of CKD. Emerging studies indicated cystatin C as a better renal marker than creatinine. The aim of the study is to compare the efficacy of CKD epidemiology collaboration (CKD-EPI) creatinine e-GFR equations with (CKD EPI) cystatin-based e-GFR equations alone and in combination with creatinine for early detection of CKD. A cross-sectional study employing 473 patients was conducted. Three estimating GFR equations were calculated based on creatinine and cystatin C. Pearson Correlation study was done to assess the correlation of creatinine and cystatin C with their respective GFRs. A predictive model was developed, and ROC curve was constructed to compare efficacy, sensitivity and specificity of the creatinine and cystatin C based equations. Cystatin C exhibited better negative correlation with GFR than creatinine in correlation study performed with three commonly employed eGFR equations including  CKD EPI Creatine cystatin C combined  equation (2021), cys C alone and CKD EPI  creatinine (2021)  equations respectively[r=(-) 0.801 vs. r=(-)0.786 vs. r=(-)0.773]. Predictive model demonstrated highest efficiency, sensitivity and specificity for creatinine-cystatin C combined equation (88%, 81% and 93%) followed by cystatin C alone equation (73%,63% and 82%) and creatinine-based equation  (61%, 56% and 66% respectively). The study showed better performance of cystatin C based equations for early detection of advance stages in chronic kidney disease as compared to creatinine-based e-GFR equation.

A synergistic effect of variability in estimated glomerular filtration rate with chronic kidney disease on all-cause mortality prediction in patients with type 2 diabetes: a retrospective cohort study

Background

The combination of diabetes mellitus (DM) and chronic kidney disease (CKD) is associated with a high risk of mortality. Annual assessment of the estimated glomerular filtration rate (eGFR) is recommended for patients with DM. We investigated the effect of variability in annual eGFR values on all-cause mortality in patients with type 2 DM.

Methods

In this retrospective cohort study, we enrolled patients with eGFR data between 01 Aug 2017 and 31 July 2018. We defined the index eGFR as the first available eGFR value within the enrollment year and collected additional annual eGFR data from the previous three years. A total of 3592 patients with type 2 DM were enrolled, including 959 patients with CKD (index eGFR < 60 mL/min/1.73 m²) and 2633 patients without CKD. We assessed eGFR variability by using the standard deviation (SD) of the three annual eGFR and index eGFR values. We divided patients into subgroups according to the median SD of their annual eGFR (7.62 mL/min/1.73 m²). The primary endpoint was all-cause mortality after the index eGFR was assessed.

Results

During a median follow-up of 19 months (interquartile range: 18‒20 months), 127 (3.5%) deaths occurred among all 3592 enrolled patients. The highest mortality risk was observed in the high SD with CKD group, with a hazard ratio (HR) of 2.382 [95% confidence interval (CI) 1.346‒4.215] in comparison to the low SD without CKD group after adjusting for the associated factors. In patients without CKD, a high SD was an independent risk factor for mortality (HR = 2.105, 95% CI 1.256‒3.528). According to the C-index, the mortality prediction ability was better for the index eGFR + SD model than for the index eGFR alone model (0.671 vs. 0.629, P < 0.001).

Conclusion

There was a synergistic effect of eGFR variability with single-measured eGFR for the prediction of mortality in patients with type 2 DM. The SD of the annual eGFR values was also an independent predictor of mortality in patients with an eGFR > 60 mL/min/1.73 m².

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01399-z.

Quality of Sleep in Elderly Patients with Diabetes Mellitus from Turkey: A Cross-Sectional Observational Study

BACKGROUND

Elderly patients frequently experience poor sleep quality. We aimed to determine its prevalence and risk factors in diabetic elderly patients from Turkey.

METHODS

An observational cross-sectional study of 220 diabetic elderly patients with a mean age of 70.4 ± 5.9 was conducted between June 2019 and December 2019. Pittsburgh Sleep Quality Index (PSQI) questionnaire was used. Patients were divided based on sleep quality into poor (PSQI> 5) and good (PSQI≤ 5) sleep quality groups. Geriatric Depression Scale, Beck Anxiety Inventory, and Hendrich II Fall Risk Model were adopted. The prevalence of poor sleep quality and risk factors were evaluated.

RESULTS

Prevalence of poor sleep quality was 58.6%. Poor sleepers were significantly older, were more likely to be divorced, had more comorbidities, and used more medicines (ps<0.05). Longer duration of diabetes, higher incidence of hypoglycemic events, and diabetic complications were significantly associated with poor sleep quality (ps<0.05). Poor sleepers had higher levels of blood glucose and HbA1c levels (ps<0.05). PSQI was significantly correlated with age, HbA1c, duration of diabetes, higher depression, anxiety, and falling risk (ps<0.05). Severe depression, anxiety, and higher falling risk were independent risk factors.

CONCLUSION

Most patients experienced poor sleep quality. It was associated with a longer duration of diabetes, chronic diabetes-related complications, and higher HbA1c levels. Severe depression, anxiety, and higher falling risk were risk factors for poor sleep quality.

Comparison of Different Hydration Strategies in Patients with Very Low-Risk Profiles of Contrast-Induced Nephropathy

Background

Hydration remains the mainstay of contrast-induced nephropathy (CIN) prevention, and new biomarkers of cystatin C (Cys C) and neutrophil gelatinase-associated lipocalin (NGAL) have been suggested. This study aimed to explore whether hydration is essential in patients with very low-risk profiles of CIN who are undergoing coronary angiography.

Material/Methods

A total of 150 patients were enrolled and randomly distributed to 3 groups: the Preventive Group (n=50, saline hydration was given 6 h before the procedure until 12 h after the procedure), the Remedial Group (n=50, saline hydration was given after procedure for 12 h), and the No Hydration (NH) group (n=50, saline was only given during the procedure). Serum creatinine (Cr), Cys C, and urinary NGAL were tested 3 times at different times.

Results

Six patients were excluded because of Mehran risk score >2. There was no CIN among 144 individuals. At 24 h and at 72 h after the procedure, we found no significant differences in the levels of Cr and Cys C (0.72±0.11 mg/L for the Preventive Group, 0.67±0.14 mg/L for the Remedial Group, and 0.70±0.1 6 mg/L for the NH Group) among the 3 groups. Urinary NGAL also did not differ significantly among the 3 groups at 6 h or at 48 h (6.31±6.60 ng/ml for the Preventive Group, 5.00±5.86 ng/ml for the Remedial Group, and 6.97±6.37 ng/ml for the NH Group) after the procedure. Subgroup analysis in patients who underwent percutaneous coronary intervention (PCI) showed that there was no significant difference in serum Cr, Cys C, or urinary NGAL at different time points among the 3 groups.

Conclusions

Saline hydration during the perioperative period might be unnecessary in patients with very low-risk profiles of CIN.

Use of renal risk drugs in a nation-wide Polish older adult population: an analysis of PolSenior database

BACKGROUND

Numerous medications should be avoided, or require dose adjustment in subjects with impaired kidney function. We aimed to assess the prevalence of potentially inappropriate use of renal risk drugs in a nation-wide, community-dwelling Polish older adult population.

METHODS

We analysed regular intake of 38 medications that should be avoided, requiring dose modification, increase the risk of pre-renal kidney injury, or may cause potassium retention in subjects with moderately to severely impaired renal function in the PolSenior data base (N = 4514, mean age 76 ± 11 yrs). Kidney function was assessed with short Modification of Diet in Renal Disease formula estimated glomerular filtration rate (sMDRD) and Cockcroft-Gault creatinine clearance (CC).

RESULTS

There were 855 (19%) individuals with sMDRD < 60 ml/min/1.73m2, and 1734 (38%) with CC <  60 ml/min. Among drugs that should be avoided, spironolactone (20.4% of patients as classified by sMDRD and 17.5% by CC), non-steroidal anti-inflammatory drugs (13.4 and 11.3%), hydrochlorothiazide (11.1 and 11.0%), and metformin (6.9 and 8.2%) were most frequently used. The most frequently used drugs requiring dose modification were piracetam (13.9% by sMDRD, and 11.9% by CC), digoxin (8.3 and 8.8%), and gliclazide (6.8 and 5.9%). Classification of a drug use as 'appropriate' or 'inappropriate' was discordant depending on the method of kidney function assessment (sMDRD or CC) in up to 30%. Subgroups with sMDRD < 60 ml/min/1.73m2 and with CC <  60 ml/min were taking ≥2 drugs increasing the risk of pre-renal kidney injury more frequently than individuals with better kidney function (46.6 vs. 23.1 and 33.0% vs. 24.4%, respectively). There were 24.7% of individuals with sMDRD < 60 ml/min/1.73m2 and 18.0% with CC <  60 ml/min taking 2 or more drugs increasing serum potassium level. The proportion of subjects with hyperkalaemia increased with the number of such drugs.

CONCLUSIONS

Use of drugs that should be avoided or require dose adjustment due to renal impairment, and potentially inappropriate drug combinations is a common problem in older adults in Poland. Assessment of kidney function with sMDRD may result in overlooking of requirements for dose adjustment formulated based on creatinine clearance.

TRIAL REGISTRATION

Not applicable.