Investigation of thyroid function and mortality predictors in patients receiving dialysis: a cross-sectional study

Various studies have assessed the link between the thyroid and kidney and concluded that dysfunction in one organ can disrupt the other. Thyroid dysfunction is more prevalent in individuals with end-stage renal disease (ESRD) compared to the general population. Hypothyroid ESRD patients have higher mortality than euthyroid patients. In this study, we evaluated the prevalence of hypothyroidism in dialysis-dependent ESRD patients and assessed the association of possible prognostic factors with mortality.

Patients who were undergoing dialysis in centers affiliated with the Mashhad University of Medical Sciences were enrolled and followed for a year to obtain survival rates. Lab parameters including thyroid stimulating hormone (TSH), parathyroid hormone (PTH), and magnesium (Mg) were recorded at baseline, and the relationship between these values and mortality was assessed.

The prevalence of hypothyroidism was 23% and 32.5% in hemodialysis and peritoneal dialysis patients, respectively. Blood urea was meaningfully higher in hemodialysis patients, while hypocalcemia and hyponatremia were more common in peritoneal dialysis patients. Higher ages (P=0.006), lower baseline Mg (P=0.044) and PTH (P=0.01), and diabetes (P=0.037) were all linked to a higher risk of mortality.

Hypothyroidism was notably prevalent in our study population. As hypothyroidism is associated with higher mortality, proper screening and intervention in this group are essential. We recommend the prescription of supplementary Mg in dialysis patients as baseline Mg and PTH levels are associated with better outcomes in this group. Diabetes was also associated with higher mortality. Maintaining glycated hemoglobin between 6%-8% is therefore suggested to increase the survival of diabetic patients.