Cystatin C, Vitamin D and Thyroid Function Test Profile in Chronic Kidney Disease Patients

Beyond creatinine: New methods to measure renal function?

Accurate assessment of kidney function is essential for diagnosing and managing chronic kidney disease (CKD) and acute kidney injury (AKI), adjusting drug dosages, and predicting clinical outcomes. Despite its ubiquitous use, serum creatinine has significant limitations, necessitating the exploration of alternative and complementary biomarkers and technologies. This review revisits the benefits and limitations of serum creatinine, explores other kidney function biomarkers such as Cystatin C and ProEnkephalin, and examines traditional gold-standard techniques, including creatinine clearance, radioisotopes, and inulin clearance. Furthermore, it highlights innovations in real-time glomerular filtration rate (GFR) measurement, such as transdermal monitoring using MB-102 and dual fluorescent tracers. We conclude with a discussion on the development, validation, and clinical integration of these advancements, which may redefine renal function assessment in the years to come.

Association of thyroid hormones with the severity of chronic kidney disease: a cross-sectional observational study at Tabuk, Saudi Arabia

Background

The interplay between chronic kidney disease (CKD) and thyroid dysfunction is becoming more evident in the biomedical community. However, the intricacies of their relationship warrant deeper investigation to understand the clinical implications fully.

Objective

This study aims to systematically evaluate the correlation between thyroid hormone levels, including thyroid-stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4), and markers of renal disease severity. These markers include serum creatinine, urea, and parathyroid hormone (PTH) levels in individuals diagnosed with CK).

Methods

We conducted a cross-sectional observational study involving a cohort of 86 participants with CKD recruited from the renal clinic at King Fahad Hospital in Tabuk. Biochemical parameters, encompassing plasma electrolytes and thyroid hormone concentrations, were quantitatively assessed. These measurements were performed with the aid of a Roche Cobas E411 analyzer. The Pearson correlation coefficient was employed to delineate the strength and direction of the associations between the thyroid function markers and renal disease indicators.

Results

The statistical analysis highlighted a generally weak correlation between the concentrations of thyroid hormones and the indicators of renal disease severity, with Pearson correlation coefficients between -0.319 and 0.815. Critically, no significant correlation was found between creatinine and thyroid hormones (TSH, T3, T4), nor was any substantial correlation between urea and thyroid hormones. Conversely, a robust positive correlation was noted between the levels of parathyroid hormone and serum creatinine (r = 0.718, p < 0.001).

Conclusion

The data suggests that thyroid hormone levels have a minimal correlation with the severity of renal disease markers. In contrast, the pronounced correlation between PTH and creatinine underscores the importance of considering PTH as a significant factor in managing and therapeutic intervention of CKD complications. These initial findings catalyze further research to thoroughly investigate the pathophysiological relationships and potential therapeutic targets concerning thyroid dysfunction in patients with renal impairment.

Evaluation of Interactions Between Thyroid Dysfunction in End-Stage Renal Disease Patients: A Cross-Sectional Study

BACKGROUND

Thyroid hormones have a very crucial role in the regulation of metabolism, synthesis of proteins, development, and influencing functions of various other hormones in the human body. While both kidneys play an essential role in the metabolism of thyroid hormone by conversion of thyroxine (T4) to triiodothyronine (T3). In patients with chronic renal failure, frequent abnormal thyroid functions are observed.

AIMS

To evaluate thyroid function in patients of chronic renal failure and to find out their correlation with the severity of the disease.

METHODS

A total of 192 patients were selected for the study after applying inclusion and exclusion criteria. A thyroid function test was done in all enrolled subjects. Serum estimation of T3, T4, and thyroid stimulating hormone (TSH) was done by the chemiluminescent immunoassay (CLIA) method, urea was estimated by the diacetyl monoxide method (DAM, Method), and serum creatinine by Jaffe's method. The results were evaluated for age, sex, and estimated glomerular filtration rate (eGFR) of the patients in view of thyroid dysfunction.

RESULTS

Of all 192 patients enrolled in the study, 124 (64.58%) were male and 68 (35.41%) were females. The observed male-to-female ratio was 1.93:1.18. The mean age of the study group (mean +/- standard deviation, SD) in males was 42+/-18 and in females 38+/-11 years (p value = 0.258). Significant reductions of serum T3, T4, and elevation of TSH were noted in both sexes. A reduced level of T3 was observed in 38.54% (42 males and 32 females) patients, reduced T4 in 34.37% (42 males and 22 females) patients, and subclinical hypothyroidism (SCH) in 16.7% (12 males and 20 females) patients. Biochemical overt hypothyroidism was noted in 7.29% (six males and eight females) of patients.

CONCLUSION

Chronic renal failure is a condition of thyroid hypofunction. A higher prevalence of SCH and clinical hypothyroidism is reported here in chronic kidney disease (CKD) patients. The severity of thyroid hypofunction increases with a progressive reduction in eGFR. Hypothyroidism in CKD patients may be due to different onset mechanisms other than anti-thyroid antibodies.

Assessment of Cystatin-C level in Newly Diagnosed Iraqi Children with Nephritic Syndrome

BACKGROUND: Nephritic syndrome (NS) is a common kidney disease in children that causes protein leakage from the blood into the urine due to glomerular injury. AIM: The aim of this research was to determine the level of Cystatin-C (CysC) and other biochemical parameters in newly diagnosed NS children in Iraq. PATIENTS AND METHODS: Ninety Iraqi children divided into: 50 children with newly diagnosed NS (28 boys and 22 girls) aged between (4 and 16) years, and 40 healthy control children (20 boys and 20 girls) aged between (5 and 16) years, who were attending Al-Yarmouk Teaching Hospital, Baghdad. RESULTS: There was a significant increase in blood urea, serum total cholesterol (S.TC), and serum low density lipoprotein (S.LDL) and a significant decreased of serum creatinine (S. creatinine), protein/creatinine ratio, serum total bilirubin, serum albumin, and serum high density lipoprotein, while a highly significant increased (p < 0.001) of CysC levels in children with newly diagnosed NS when compared with control group. A significant positive correlation between CysC level versus systolic blood pressure, body mass index, diastolic blood pressure, S.TC, S. LDL cholesterol (S.LDL-C), S. Total Bilirubin, S. Albumin, S. Total protein, and B. urea, while a significant negative correlation was found between CysC level versus serum low density lipoprotein cholesterol and estimated glomerular filtration rate in children with newly diagnosed NS. CONCLUSION: It may come to the conclusion that CysC can be the best predictor of overall efficacy than creatinine and in the diagnosis of any damage to the kidney in children with NS.

Prospective Comparison of 24-Hour Urine Creatinine Clearance with Estimated Glomerular Filtration Rates in Chronic Renal Disease Patients of African Descent

BACKGROUND

The 24-hour (24-h) creatinine clearance (CrCl) is the most common method for measuring GFR in clinical laboratories. However, the limitations of CrCl have resulted in the widespread acceptance of mathematically derived estimated glomerular filtration rate (eGFR) using Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD) and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations in predicting eGFR. The aim of the study was to compare 24-h CrCl with eGFR derived from these formulae and to identify which could be the best alternative.

METHOD

A prospective study was conducted involving 140 CKD patients. Creatinine and cystatin C concentrations were determined using the cobas 6000 analyzer. The eGFR was calculated using the CG formula, 4-variable MDRD and CKD-EPI equations, and Bland-Alman plots bias was determined.

RESULTS

The CG and MDRD formulas had mean eGFR values similar to CrCl and correlation coefficients (r) were highest for CG (0.906) and lowest for MDRD (0.799). The CG equation was in agreement with 24-h CrCl in all but stage V CKD while the MDRD equation compared well in all except Stage IV CKD. The CG equation was positively biased (0.9857) while the MDRD had a negative bias (-0.05).

CONCLUSION

The Cockcroft-Gault formula provides a more accurate assessment of GFR than 24-h CrCl and would be recommended as a substitute to provide the best estimate of GFR in our population.