To examine the associations between hypothyroidism, levothyroxine therapy, and renal impairment, addressing the lack of consolidated research.
Key Findings:
Non-specific hypothyroidism and subclinical hypothyroidism (SHypo) are significantly linked to chronic kidney disease (CKD) (OR 1.94, 95% CI [1.62, 2.32] and 1.87, 95% CI [1.55, 2.27], respectively).
Both forms of hypothyroidism are associated with a decrease in estimated glomerular filtration rate (eGFR) (SMD -0.68, 95% CI [-0.81, -0.55] and -0.99, 95% CI [-1.59, -0.38], respectively).
No significant correlation between hypothyroidism and CKD incidence was found, nor was there a notable improvement in eGFR following levothyroxine therapy.
Interpretation:
The study confirms a cross-sectional relationship between hypothyroidism and renal impairment but does not establish a conclusive prospective relationship, highlighting the need for further research.
Limitations:
The study is based on observational data, which may introduce bias.
The lack of large-scale randomized controlled trials limits the strength of the conclusions, and potential confounding factors were not fully addressed.
Conclusion:
Further large-scale randomized controlled trials are needed to clarify the relationship between hypothyroidism, levothyroxine therapy, and kidney outcomes to avoid overtreatment or undertreatment, emphasizing the clinical implications of these findings.
