Patients undergoing peritoneal dialysis with hypothyroidism or hyperthyroidism may have a higher risk for mortality, study data show.

Connie M. Rhee, MD, MSc, of the Harold Simmons Center for Kidney Disease Research and Epidemiology, division of nephrology and hypertension at the University of California, Irvine Medical Center in Orange, California, and colleagues evaluated data from a large national dialysis organization on 1,484 adults undergoing peritoneal dialysis who underwent one or more thyroid-stimulating hormone measurements from 2007 to 2011.

Thyroid status was divided into five categories: overt-hyperthyroid (TSH, < 0.1 mIU/L), subclinical-hyperthyroid (TSH, 0.1 mIU/L to < 0.5 mIU/L), low-normal (TSH, 0.5 mIU/L to < 3 mIU/L), high-normal (TSF, 3 mIU/L to < 5 mIU/L), subclinical-hypothyroid (TSH, mIU/L 5 to < 10 mIU/L) and overt-hypothyroid (TSH, 10 mIU/L)

Seven percent of participants had hyperthyroidism, 18% had hypothyroidismand 75% were euthyroid as defined by baseline TSH levels.

Through a total of 1,953 person-years of follow-up, there were 258 deaths for a rate of 132 deaths per 1,000 person-years. A higher risk for death was associated with TSH levels less than 0.1 mIU/L and 5 mIU/L or more.

Compared with participants who were euthyroid, participants with hyperthyroidism (adjusted HR = 1.69; 95% CI, 1.09-2.62) and hypothyroidism (adjusted HR = 2.08; 95% CI, 1.56-2.78) had a higher risk for mortality.

“Our study found that both hypothyroidism and hyperthyroidism were independently associated with higher mortality in a national [peritoneal dialysis] cohort, consistent with data in the hemodialysis population,” the researchers wrote. “Given the high prevalence of thyroid functional disease and exceedingly high mortality of the dialysis population, further studies are needed to determine the underlying mechanisms by which thyroid functional disease impacts mortality, whether thyroid hormone modulating therapies ameliorates mortality risk, and the precise TSH targets associated with improved outcomes in the dialysis population.” – by Amber Cox