Thyroid atoimmunity and function among children and adolescents with diabetes mellitus at Mulago hospital.

Abstract

Background: Up to 30% of Type-1diabetes mellitus (T1DM) patients have co-existent thyroid autoimmunity and a high prevalence (up to 50%) of thyroid dysfunction which predominantly manifests as hypothyroidism (clinical or subclinical). It is recommended to screen all T1DM patients for thyroid dysfunction. This is not the current practice at the paediatric diabetes clinic at Mulago Hospital. There is also paucity of data regarding thyroid dysfunction in African children and adolescents with diabetes mellitus. Results from this study quantified the magnitude of this problem and can be used to inform the future management of diabetic children and adolescents.

Methods: This was a cross sectional study to determine the prevalence of thyroid autoantibodies and describe thyroid function among children and adolescents aged 1- 19 years with diabetes mellitus attending the paediatric diabetes clinic at Mulago hospital. Out of the 70 children and adolescents who attended the clinic, 69 were enrolled. Information was obtained on clinical history and detailed physical examination. Blood was assayed to determine levels of thyroid autoantibodies (antiTPO), free thyroxine (FT4) and thyrotropin (TSH).

Findings: The prevalence of thyroid autoimmunity in this study was 7.3%. Three of the five subjects with thyroid autoantibodies were female and all the subjects were post pubertal aged between 13 – 17 years. 7.3% of the study subjects had elevated TSH levels and one had elevated FT4. All study subjects were clinically euthyroid. Subjects with thyroid dysfunction had had longer duration of diabetes 4 (3.8-8.0) vs. 2.8 ((1.1 – 4.4) years. Of all study subjects, 35% were stunted and 85% had poor glycaemic control.

Conclusions: The low prevalence (7.3%) of thyroid autoimmunity precludes the routine screening for thyroid autoantibodies in this setting however thyroid function should be assessed in all adolescents especially those with poor glycaemic control.