Incidence of sub clinical thyroid dysfunction among asymptomatic adult population

Background: Patients with subclinical thyroid dysfunction are universally encountered in routine clinical practice. Advanced diagnostic techniques have created new categories of thyroid disorders such as subclinical hypo-and-hyperthyroidism. The management of subclinical thyroid dysfunction is controversial. Patients with subclinical thyroid dysfunction may have vague, nonspecific symptoms that do not aid the clinical apperception. This study aimed to screen the normal adult population for the incidence of subclinical thyroid dysfunction and discuss the optimal management strategy. Materials and methods: Four hundred subjects with no clinical evidence of thyroid dysfunction were included in the present study. Elaborate history in the form of a symptom questionnaire was obtained and clinical examination was performed. Laboratory analysis of thyroid function was done by electro-chemiluminescence immunoassay (ECLIA). Patients with normal free thyroxine (FT4) and tri-iodothyronine levels (T3) were further classified into subclinical hypo/hyperthyroid based on the serum thyroid-stimulating hormone (TSH) levels. The incidence of subclinical thyroid disorder in the sample population was detected and optimal management strategies were followed as per the European thyroid association (ETA) guidelines. Results: The normal TSH value by ECLIA was 0.27 - 4.2μIU/ml. Seventeen (4.25%) out of four hundred subjects included in the present study were found to have subclinical thyroid dysfunction. The Ratio of subclinical hypothyroid cases to subclinical hyperthyroid cases was found to be 12:5. Clustering of the cases was found around the age of 60 years and was significantly more common among females in comparison to males. Cases with subclinical thyroid dysfunction were managed by follow up after a thorough evaluation and treatment of other comorbid conditions. Conclusions: The study provides valuable insight towards understanding the epidemiology and management of subclinical thyroid disorders in the present scenario. Screening is recommended for a high-risk population since there is good evidence that subclinical thyroid dysfunctions may be associated with progression to overt disease in up to 5% of the population.