Oral sodium bicarbonate improves thyroid function in predialysis chronic kidney disease.
OBJECTIVE
metabolic acidosis (MA) in chronic kidney disease (CKD) associates with protein energy malnutrition, osteoporosis, abnormal endocrine function and increased mortality. Oral sodium bicarbonate has been shown to improve nutritional status and preserve renal function in CKD. Depressed thyroid function has been described in CKD and was believed to be related to MA. This is a prospective randomized study that examined the effect of oral sodium bicarbonate on thyroid function in predialysis CKD with MA.


METHODS
predialysis CKD patients with serum total CO(2) ≤ 22 mM were randomized into two groups. The treatment group received increasing dose of oral sodium bicarbonate until serum total CO(2) was ≥ 24 mM. Control patients were kept on the same medications. Thyroid function tests were measured at baseline and again after 8-12 weeks.


RESULTS
all patients had a glomerular filtration rate <35 ml/min/1.73 m(2). Serum total CO(2) increased significantly in the treatment group and was unchanged in the control group. At baseline, over half of the patients had T3 below the lower limit of normal. At study completion, free T3 declined further in the control group, whereas free T3, total T3, free T4 and TSH rose significantly in the treatment group. Percentage changes of total CO(2) from baseline were strongly associated with the changes of T3 parameters. Glomerular filtration rate was maintained in the treatment group but declined significantly in the control group.


CONCLUSIONS
oral sodium bicarbonate, through correction of MA, improved thyroid function in predialysis CKD.
Division of Nephrology, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand. sineemd@hotmail.com
Sinee
S
Disthabanchong
Akarapong
A
Treeruttanawanich
D000138:Acidosis / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001639:Bicarbonates / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000503:physiopathology*; D017693:Sodium Bicarbonate / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D013961:Thyroid Gland / Q000187:drug effects*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
D001639:Bicarbonates; D014284:Triiodothyronine; D017693:Sodium Bicarbonate; D013972:Thyrotropin; D013974:Thyroxine