Dissociation of clinical and laboratory diagnosis in hypothyroidism.
OBJECTIVE
To assess the significance of clinical versus biochemical diagnosis of hypothyroidism using a clinical scoring index and optimize the therapeutic dose of levothyroxine in Indian patients.


METHODS
Three hundred and eighty eight cases of primary hypothyroidism (male:female ratio 1:5.8) were clinically classified as hypothyroid, euthyroid or inconclusive by Billewicz score. TSH estimation was repeated at 6-8 week intervals and appropriate adjustments in levothyroxine dosage made till the TSH was within the normal range.


RESULTS
Of 388 biochemically confirmed hypothyroid subjects less than one fourth (21.6%) could be classified as hypothyroid, almost one half were euthyroid (48.4%) and the remaining (29.9%) fell in the inconclusive category according to Billewiz score. Of 227 patients who returned for complete follow up there was a positive correlation of replacement dose with age and initial weight in females, but not in males. Baseline TSH values were not found to have a significant correlation with the initial dose. The mean replacement dose of levothyroxine (T4) in our subjects was 109.4 +/- 24.05 microg/d (range 1.25-3.84 microg/kg).


CONCLUSIONS
Clinical parameters alone fare poorly in establishing an unequivocal diagnosis of hypothyroidism. A biochemical confirmation is mandatory. The replacement done of T4 was found to be independent of the basal TSH level.
Bajaj
Sarita
S
Department of Medicine, MLN Medical College, Allahabad, UP.
Sharma
G P
GP
Kumar
D
D
Mehrotra
R
R
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000175:diagnosis*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D013960:Thyroid Function Tests; D013963:Thyroid Hormones / Q000097:blood*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000627:therapeutic use
D013963:Thyroid Hormones; D013972:Thyrotropin; D013974:Thyroxine