Iatrogenic hyperthyroidism secondary to weight loss medication. Predictive factors for their precocious detention

OBJECTIVE: To establish the differential clinical characteristics between the Iatrogenic hyperthyroidism for not conventional medication for obesity treatment (weight losers) and the endogenous by Graves Basedow disease. PATIENT AND METHODS: Observational and analytical study, populational based, in the one which prospectively were compared cases with Iatrogenic hyperthyroidism (secondary to weight losers) with those with endogenous hyperthyroidism (Graves Basedow disease) as controls. Consisted of the variable clinical record of 100 correlative patients that consulted in specialized attention of endocrinology for Iatrogenic hyperthyroidism secondary to weight losers and for Graves Basedow disease. RESULTS: The differences observed between Iatrogenic hyperthyroidism (secondary to weight losers) (n = 43) as compared to endogenous hyperthyroidism (Graves Basedow disease) (n = 57) were: smaller age (31.8 +/- 10 as compared to 37.8 +/- 12.6 years), greater body mass index (27.6 +/- 7.2 as compared to 23.4 +/- 3.1), smaller goiter frequency (16.3% as compared to 84.2%) as well as absence of signs of ophthalmopathy (0% as compared to 57.9%). Both groups had low levels of TSH, and the difference rests in the values of free T4, low in the first group and increased in the endogenous hyperthyroidism. The odds ratio were: IMC > 27: 3.92 (0.91-16.72), age < 33 years: 5.58 (1.42-21.99), absence of goiter: 23.29 (6.39-84.85). The precedent of weight losers use was not selective of the first group, being detected in a 12.3% of cases of endogenous hyperthyroidism, though in periods of time remoter in relationship to the beginning of the clinic. CONCLUSIONS: In the differential diagnosis of a case of hyperthyroidism, it can be suspected Iatrogenic hyperthyroidism (secondary to weight losers) for medication for the obesity in patients of the feminine sex with overweight, without previous or familiar history of thyroid disease, and in those which in the physical exploration is not verified goiter neither ophthalmopathy.