Endocrine Abstracts

Background

With the availability of sensitive and accurate TSH assays, the entity of Mild Subclinical hypothyroidism (SCH) is being diagnosed more frequently in clinical practice. A variety of neuropsychiatric and cognitive complications have been noted in hypothyroid patients but there is a dearth of literature on the psychopathology associated with mild SCH.

Objective-

This study was undertaken to determine the prevalence of depression, anxiety in Indian subjects with recently diagnosed mild SCH.

Methods

Participants were 112 subjects recently diagnosed with mild SCH and a similar number of age matched euthyroid controls. Mild SCH was defined as serum TSH level more than 4.0 mIU/l but less than 10 mIU/l with normal FT3 and FT4. All participants underwent clinical and anthropometric evaluation along with relevant investigations. The patients were administered the Hamilton Rating Scale for Depression (HAM-D) and Hamilton Rating Scale (HAM-A) for Anxiety. The data was analysed statistically using SPSS software.

Results

Females constituted 65% of the sample. The mean age of patient group was 47.4 ± 8.9 years and BMI 26.7± 5.6 kg/m² which were comparable to controls. Mean TSH value was 7.1 ± 2.7 mIU/l in patients and 2.4 ± 1.3 mIU/l in controls (P–0.001). Among all the participants, based on HAM-D, some degree of depression was present in 17.8% of patients (males- 15.6% and females- 19.2%) and 8.9% of controls (P–0.03), whereas based on HAM-A, some degree of anxiety was present in 43.7% of patients (males-35.6% and females-49.7%) and 11.6% of controls (P–0.012). Prevalence of anxiety or depression was not affected by age, BMI and TPO antibody level.

Discussion-

Mild SCH is a unique entity often considered separate from hypothyroidism and higher degrees of SCH in respect to clinical implications and treatment criteria. In this study we found anxiety and depression to be more prevalent in subjects with mild SCH compared to the euthyroid subjects. Among the subjects with mild SCH, anxiety was more common than depression (P–0.001). These findings suggest that the cognitive aspects in mild SCH subjects are different from the patients with frank hypothyroidism and higher degree of SCH, who are reported to be having higher prevalence of depression along with a spectrum of other emotional and cognitive problems. Mood changes especially anxiety in mild SCH may have an important impact on the patient’s quality of life. Further studies in larger populations are needed to validate these findings.