Renal function declines over time due to Chronic Kidney Disease, which is a huge public health concern worldwide. Cardiovascular disease, anemia, electrolyte imbalance, and endocrine dysfunction are some of the consequences that can lead to considerable morbidity and mortality. Thyroid dysfunction is one of the endocrine abnormalities seen in chronic kidney disease, and it is becoming more and more acknowledged as a significant but sometimes ignored disorder [1, 2].

The release of the thyroid hormones thyroxine (T4) and triiodothyronine (T3) by the thyroid gland is essential for the regulation of development, metabolism, and energy balance. Ensuring proper cellular metabolism and organ function relies on these hormones. Thyroid hormone levels are aberrant in chronic kidney disease due to multiple causes, including uremia, altered protein binding, chronic inflammation, and reduced peripheral conversion of T4 to T3 [3-5].

"Low T3 syndrome" and hypothyroidism, either subtle or obvious, are common in patients with chronic kidney disease. Although these changes do not always indicate intrinsic thyroid illness, they do have the potential to greatly affect clinical results. Elevated mortality rates, poorer renal function, and an increased risk of cardiovascular disease have all been linked to thyroid dysfunction in chronic kidney disease. Furthermore, thyroid problems are more common in people with advanced kidney disease, especially those on dialysis [6-8].

Thyroid dysfunction is frequently misdiagnosed in patients with chronic kidney disease because of vague symptoms and a lack of regular screenings, even though this link is clinically significant. Patients' overall prognosis and quality of life may be improved if thyroid problems are identified and managed appropriately early on [9-11].

This prospective hospital-based study set out to assess the frequency and pattern of thyroid dysfunction in patients undergoing treatment for Chronic Kidney Disease at a tertiary care hospital.

This prospective hospital-based study was carried out in the department of Biochemistry, Madha Medical College and Research Institute, Kovur, Chennai, between December 2019 to November 2020. 40 patients diagnosed with Chronic Kidney Disease were enrolled following the acquisition of informed consent. Chronic Kidney Disease was classified and staged in accordance with established clinical standards utilizing estimated glomerular filtration rate (eGFR). Inclusion Criteria:  Patients aged ≥18 years diagnosed with Chronic Kidney Disease  Patients in any stage of CKD (Stages 1–5)  Patients willing to participate and provide informed consent Exclusion Criteria:  Patients with known thyroid disorders on treatment  Patients with acute kidney injury  Pregnant women  Patients taking medications affecting thyroid function (e.g., steroids, amiodarone)  Patients with severe systemic illness unrelated to CKD Statistical Analysis: Statistical software was used for data entry and analysis. Categorical variables were shown as frequencies and percentages, whilst continuous variables were shown as mean ± standard deviation (SD). We used appropriate statistical techniques, like a Chi-square test or an ANOVA, to look for correlations between thyroid dysfunction and CKD stages. Statistical significance was determined by a p-value less than 0.05.

The study consisted a total of 40 participants diagnosed with Chronic Kidney Disease. The demographic features, distribution of chronic kidney disease stages, thyroid function status, and their connections are detailed below.

Table 1: Demographic Characteristics of Study Population

Patients aged 41–60 made up the largest age group, with 45% of the total, followed by those aged 60 and higher at 35%. The higher proportion of males (65%) compared to females (35%), suggesting that CKD was more common among male patients in this study.

Table 2: Distribution of CKD Stages among Patients

Patients were more likely to be in severe stages of chronic kidney disease (CKD), with 30% of cases falling into Stage 4 or Stage 5. This indicates that the majority of patients had moderate to severe kidney damage when they arrived.

Table 3: Thyroid Function Status in CKD Patients

The thyroid function was normal in 60% of the 40 individuals and dysfunctional in 40%. Among the abnormalities observed, hypothyroidism accounted for 30% and hyperthyroidism for 10%.

Table 4: Distribution of Subclinical and Overt Thyroid Dysfunction

The majority of thyroid dysfunction cases (20%) were subclinical hypothyroidism, which means that many individuals had early or mild thyroid problems but didn't have any noticeable symptoms.

Table 5: Association between CKD Stage and Thyroid Dysfunction

In Stages 4 and 5, the most advanced stages of CKD, 50% of patients exhibited abnormalities related to the thyroid. This points to a correlation between an increase in the frequency of thyroid problems and a decline in renal function.

The current investigation indicates a significant association between renal impairment and diminished thyroid function, as seen by the finding that 40% of patients with Chronic Kidney Disease exhibited thyroid dysfunction. In accordance with the current study, previous research has demonstrated a notable prevalence of thyroid disorders in individuals with chronic kidney disease [12-14].

Thirty percent of participants in this study exhibited hypothyroidism, the predominant thyroid disorder. The majority of these cases exhibited subclinical hypothyroidism. Subclinical hypothyroidism is the most prevalent thyroid abnormality in persons with chronic kidney disease, as indicated by previous study. Potential etiologies encompass metabolic changes associated with uremia, dysregulation of the hypothalamic-pituitary-thyroid axis, and compromised peripheral conversion of thyroxine (T4) to triiodothyronine (T3) [15-17].

This study revealed that thyroid dysfunction was more prevalent in the advanced stages of chronic kidney disease, particularly in stages 4 and 5. Previous studies have demonstrated a link between severe chronic kidney disease and a heightened prevalence of thyroid problems. This connection may be elucidated by a confluence of factors, such as chronic inflammation, suboptimal hormone metabolism, and the progressive accumulation of uremic toxins as renal function declines [18-20].

No substantial gender bias was observed in thyroid dysfunction, despite men constituting a greater proportion of the research population. Prior studies indicate that thyroid disorders are more prevalent in females, while chronic kidney disease is more prevalent in males. This indicates that gender-specific factors may influence illness trends [21, 22]. This work reveals substantial clinical effects of thyroid dysfunction in people with chronic renal disease. Previous study has established a correlation between thyroid abnormalities and risk factors for cardiovascular disease, renal disease progression, and mortality. Subclinical hypothyroidism, despite being asymptomatic, can adversely affect a patient's prognosis by exacerbating dyslipidemia and endothelial dysfunction [23, 24].

Patients with chronic kidney disease, especially in later stages, should undergo regular thyroid function assessments, as shown by this study's findings. Previous studies have shown that metabolic status and clinical outcomes in patients with chronic renal disease can be enhanced with the early detection and appropriate management of thyroid dysfunction [25].

While the findings may possess significant consequences, it is crucial to acknowledge that this study has several limitations, including a single-center design and a small sample size. The association between chronic kidney disease and thyroid dysfunction has been more thoroughly investigated in larger multicentric investigations [26, 27]. The findings of the current study validate prior research and underscore the necessity of including thyroid function monitoring into the standard therapy for patients with chronic renal disease.

Thyroid dysfunction, especially subclinical hypothyroidism, was frequent in Chronic Kidney Disease patients in this study. Thyroid dysfunction also increased with CKD severity, especially in advanced stages (Stages 4 and 5). In this study, thyroid anomalies in CKD patients show a strong renal-endocrine relationship. These changes may cause kidney disease progression and cardiovascular risk. The current study emphasizes the significance of routine thyroid function assessment in CKD patients, even without symptoms. Early thyroid dysfunction diagnosis and treatment may enhance patient outcomes and quality of life. Due to its small sample size and single-center approach, this study requires larger, multicentric studies to confirm its findings. This study emphasizes the necessity for a complete and integrated approach to CKD care, including thyroid function testing. Funding None Conflict of Interest: None

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