Can urinary thyroid hormone loss cause hypothyroidism?
Four patients presented with nephrotic syndrome associated with hypothyroidism; none had thyroid antibodies. Hypothyroidism resolved on remission of nephrotic syndrome in two patients; thyroxine (T4) replacement was ineffective during periods of gross proteinuria in another, and the fourth had had normal thyroid function a year before presentation. Urinary T4 excretion was measured in ten further patients with proteinuria. It was detectable in the urine in five, who had significantly lower serum free T4 (8.5 [95% confidence interval 5.8-11.2] vs 13.9 [11.1-16.7] pmol/l; p less than 0.01) and free triiodothyronine (3.1 [2.2-4.0] vs 4.9 [3.8-6.0] pmol/l; p less than 0.01) concentrations than the five patients without detectable urinary T4.
Fonseca
V
V
Royal Free Hospital, London, UK.
Thomas
M
M
Katrak
A
A
Sweny
P
P
Moorhead
J F
JF
D000368:Aged; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000209:etiology / Q000652:urine*; D008297:Male; D008875:Middle Aged; D009404:Nephrotic Syndrome / Q000097:blood / Q000150:complications / Q000652:urine*; D011507:Proteinuria / Q000150:complications / Q000652:urine; D013972:Thyrotropin / Q000652:urine; D013974:Thyroxine / Q000097:blood / Q000652:urine*; D014284:Triiodothyronine / Q000652:urine
D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine