Serum thyrotropin is a better predictor of future thyroid dysfunction than thyroid autoantibody status in biochemically euthyroid patients with diabetes: implications for screening.
OBJECTIVE
To ascertain the predictive values of thyroid autoantibodies and thyrotropin (TSH) levels for subsequent thyroid dysfunction in patients with diabetes.


METHODS
Review of records of 467 patients who had attended diabetes clinics for a mean of 6.1 years. Baseline autoantibody and TSH results and thyroid status at annual review were determined.


RESULTS
Thyroid disorders were known in 29 patients (6.2%), and newly identified in 32 (6.9%), at presentation. Of 406 patients with normal baseline thyroid status, 24 (5.9%) developed thyroid dysfunction during 6.1 years of mean follow-up. Higher baseline TSH concentration was associated with subsequent hypothyroidism; a threshold of 1.53 mU/L, approximately defining the top quartile, provided 75% sensitivity and specificity. Both TSH greater than 1.53 mU/L and positive autoantibody status predicted thyroid dysfunction, but only TSH was significant in multivariable analysis (odds ratio, 7.74, p < 0.001). No overt thyroid dysfunction developed in 293 patients with baseline TSH levels less than 1.53 mU/l.


CONCLUSIONS
Baseline TSH level may be a better predictor of thyroid dysfunction than thyroid autoantibodies in people with diabetes. Patients with TSH levels below the top quartile have a risk of thyroid dysfunction similar to the general population. It may be appropriate to stop annual thyroid screening in this group, although confirmation is required.
Warren
Roderick E
RE
Department of Diabetes, Royal Infirmary of Edinburgh, Edinburgh, United Kingdom.
Perros
Petros
P
Nyirenda
Moffat J
MJ
Frier
Brian M
BM
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood*; D048909:Diabetes Complications / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013959:Thyroid Diseases / Q000175:diagnosis*; D013961:Thyroid Gland / Q000276:immunology*; D013972:Thyrotropin / Q000097:blood*
D001323:Autoantibodies; D013972:Thyrotropin