Prevalence of Thyroid Dysfunction and Autoimmunity among First Degree Relatives of Patients with Graves' Disease at Aminu Kano Teaching Hospital, Kano, Nigeria.

Background: Graves' disease has a familial predisposition with about 15% of the patients having a close relative with the same disorder, while about 50% of the relatives of patients with Graves' have circulating thyroid autoantibodies. This study determined and compared the prevalence of thyroid dysfunction, and autoimmunity among healthy individuals, and first-degree relatives of patients with Graves' disease at Aminu Kano Teaching Hospital (AKTH), Kano.

Methodology: A cross-sectional descriptive study design was used to study 87 first degree relatives of patients with Graves' disease comprising of 5.7% fathers, 3.4% mothers, 29.9% brothers, 29.9% sisters, 16.1% sons, and 14.9% daughters; as well as 87 age and gender-matched controls selected using a systematic sampling technique. A pretested interviewer-administered questionnaire was administered to the eligible study participants. Anthropometric and clinical parameters were measured, and blood samples were assessed for TSH, fT3, fT4, anti-TPO, and anti-Tg antibodies. Data was analysed using SPSS version 22 for Windows with an α value of ≤0.05.

Results: The mean ±SD age of the study subjects and controls were 29.4±9.0 years, and 31.6±8.8 years respectively. About half 45 (51.7%) of the respondents were males among the study subjects and controls respectively. Up to 12.6% of study subjects had raised thyroid stimulating hormone (TSH). Overt hypothyroidism was observed among 5.7% of study subjects and none among the controls. Anti-thyroid peroxidase (anti-TPO) antibodies were positive among 4.6% of the study subjects while 1.1% of controls had positive anti-TPO antibodies. Anti-thyroglobulin antibody (anti-Tg) positivity was found among 23.0% of study subjects, while 9.2% of controls had positive anti-Tg antibodies.

Conclusion: Primary Hypothyroidism was the predominant thyroid dysfunction found amongst the relatives of patients with Graves' disease. The government and relevant stakeholders should develop a model that will mandate screening and follow-up amongst the first-degree relatives of patients with Graves' disease.