title: High prevalence of antithyroid peroxidase and antiparietal cell antibodies among patients with type 1 diabetes mellitus attending a tertiary diabetes centre in South Africa.
abstract: OBJECTIVE
  Data on the prevalence of autoimmune thyroid disease (AITD) and gastric autoimmunity in type 1 diabetes mellitus (T1DM) in Africa are limited. The aim of this study was to assess the prevalence of antithyroid peroxidase (TPO-A) and antiparietal cell antibody (PCA) in patients with T1DM at a tertiary diabetes clinic in Durban, South Africa.
  
  
  METHODS
  This was a cross-sectional observational study among subjects attending the adult T1DM clinic at Inkosi Albert Luthuli Hospital. Information about history and clinical examination was collected. Blood tests included glutamic acid decarboxylase antibody (GADA), TPO-A, PCA, vitamin B12, folate, ferritin, thyroid stimulating hormone (TSH), free thyroxine, lipids and HbA1c.
  
  
  RESULTS
  A total of 202 (M:F, 90:112) patients were recruited. The ethnic composition was African (black) (56.4%; n=114), Indian (31.7%; n=64), white (4.5%; n=9) and coloured (mixed race) (7.4%; n=15). Mean age and mean duration of diabetes were 26.4±11.4 and 10.7±9.1 years, respectively. Mean body mass index was 21.6±6.3 kg/m2. GADA was positive in 63.37% (n=128). The prevalence of TPO-A was 18.9% (n=39) and PCA 8.9% (n=17). The prevalence of overt hypothyroidism, subclinical hypothyroidism and Graves' disease was 10.9%, 2.5% and 1.5%, respectively; vitamin B12deficiency was noted in 3.5% (n=7) and iron deficiency in 19.3% (n=39).
  
  
  CONCLUSIONS
  Among patients with T1DM in this study, there was a high prevalence of coexistent AITD and gastric autoimmunity. Screening for hypothyroidism and thyroid autoimmunity should be undertaken in all patients at initial presentation. However, to assess the feasibility and optimal timing of subsequent testing in the African setting with limited resources, more collaborative research with longitudinal studies is required.
authors.affiliation: Department of Diabetes and Endocrinology, University of KwaZulu-Natal, Durban, South Africa.
authors.forename: Imran M
authors.initials: IM
authors.lastname: Paruk
authors.affiliation: Department of Paediatrics, University of KwaZulu-Natal, Durban, South Africa.
authors.forename: Yasmeen
authors.initials: Y
authors.lastname: Ganie
authors.affiliation: Department of Diabetes and Endocrinology, University of KwaZulu-Natal, Durban, South Africa.
authors.forename: Sureka
authors.initials: S
authors.lastname: Maharaj
authors.affiliation: Department of Diabetes and Endocrinology, University of KwaZulu-Natal, Durban, South Africa.
authors.forename: Fraser J
authors.initials: FJ
authors.lastname: Pirie
authors.affiliation: Department of Gastroenterology and Hepatology, University of KwaZulu-Natal, Durban, South Africa.
authors.forename: Vasudevan G
authors.initials: VG
authors.lastname: Naidoo
authors.affiliation: Department of Public Health Medicine, University of KwaZulu-Natal, Durban, South Africa.
authors.forename: Ntombifikile M
authors.initials: NM
authors.lastname: Nkwanyana
authors.affiliation: Department of Haematology, Inkosi Albert Luthuli Central Hospital, Durban, South Africa.
authors.forename: Hilary L
authors.initials: HL
authors.lastname: Dinnematin
authors.affiliation: Department of Anatomical Pathology, University of KwaZulu-Natal, Inkosi Albert Luthuli Central Hospital, Durban, South Africa.
authors.forename: Pratistadevi K
authors.initials: PK
authors.lastname: Ramdial
authors.affiliation: Department of Diabetes and Endocrinology, University of KwaZulu-Natal, Durban, South Africa.
authors.forename: Ayesha A
authors.initials: AA
authors.lastname: Motala
mesh_terms: D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000097:blood*; D001327:Autoimmune Diseases / Q000453:epidemiology / Q000208:ethnology; D003430:Cross-Sectional Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000453:epidemiology / Q000208:ethnology; D005260:Female; D006801:Humans; D007453:Iodide Peroxidase / Q000097:blood*; D033862:Iron-Binding Proteins / Q000097:blood*; D008297:Male; D010295:Parietal Cells, Gastric / Q000276:immunology*; D015995:Prevalence; D013019:South Africa / Q000453:epidemiology
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D033862:Iron-Binding Proteins; C056658:TPO protein, human; D007453:Iodide Peroxidase