Thyroid Resistance Ups Mortality in Euthyroid CKD Patients

TOPLINE:
An impaired central sensitivity to thyroid hormone may be associated with an increased risk for death in patients with chronic kidney disease (CKD) and normal thyroid function.
METHODOLOGY:
Previous studies have shown that abnormal levels of thyroid-stimulating hormone (TSH) are associated with a higher mortality risk in patients with CKD, but whether the risk extends to those with normal thyroid function remains controversial.
Researchers investigated the association between central sensitivity to thyroid hormone and the risk for all-cause mortality in 1303 euthyroid patients with CKD (mean age, 60 years; 59% women) from the National Health and Nutrition Examination Survey database (2007-2012).
All participants had CKD stages I-IV, defined as an estimated glomerular filtration rate < 60 mL/min/1.73 m2 and/or a urinary albumin to urinary creatinine ratio ≥ 30 mg/g.
The central sensitivity to thyroid hormone was primarily evaluated using a new central thy­roid hormone resistance index, the Thyroid Feedback Quantile–based Index (TFQI), using free thyroxine and TSH concentrations.
The participants were followed for a median duration of 115 months, during which 503 died.
TAKEAWAY:
Patients with CKD who died during the follow-up period had a significantly higher TFQI (P < .001) than those who survived.
The rates of all-cause mortality increased from 26.61% in the lowest TFQI tertile to 40.89% in the highest tertile (P = .001).
A per unit increase in the TFQI was associated with a 40% increased risk for all-cause mortality (hazard ratio, 1.40; 95% CI, 1.10-1.79).
This association between TFQI level and all-cause mortality persisted in all subgroups stratified by age, gender, race, body mass index, hypertension, diabetes, cardiovascular diseases, and CKD stages.
IN PRACTICE:
“Our study demonstrates that impaired sensitivity to thyroid hormone might be associated with all-cause mortality in CKD patients with normal thyroid func­tion, independent of other traditional risk factors and comorbidities,” the authors wrote.
SOURCE:
This study was led by Qichao Yang and Ru Dong, Department of Endocrinology, Affiliated Wujin Hospital of Jiangsu University, Changzhou, China, and was published online on August 6, 2024, in BMC Public Health.
LIMITATIONS:
Thyroid function was measured only at baseline, and the changes in thyroid function over time were not measured. The study excluded people on thyroid hormone replacement therapy but did not consider other medication use that might have affected thyroid function, such as beta-blockers, steroids, and amiodarone. Thyroid-related antibodies, metabolic syndrome, and nonalcoholic fatty liver disease were not included in the analysis as possible confounding factors. The US-based sample requires further validation.
DISCLOSURES:
The study was supported by the Changzhou Health Commission. The authors declared no competing interests.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.
 
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