title: Should thyroid-stimulating hormone goals be reviewed in patients with type 1 diabetes mellitus? Results from the Brazilian Type 1 Diabetes Study Group.
abstract: OBJECTIVE
  To investigate if thyroid-stimulating hormone (TSH) levels are associated with any differences in glycaemic control or diabetes-related complications in individuals with Type 1 diabetes.
  
  
  METHODS
  This observational, cross-sectional and multicentre study included patients with Type 1 diabetes for ≥ 5 years, with a recent TSH measurement and without a known previous thyroid disease. Patients were divided into three groups according to TSH levels: 0.4-2.5 mU/l; 2.5-4.4 mU/l; and ≥ 4.5 mU/l.
  
  
  RESULTS
  We included 1205 individuals with a mean ± sd age of 23.8 ± 11.3 years. Seven patients had TSH levels <0.4 mU/l and were excluded from the comparison between groups. HbA1c levels, systolic and diastolic blood pressure, LDL cholesterol and disease duration were similar in all groups (P = 0.893, P = 0.548, P = 0.461, P = 0.575 and P = 0.764, respectively). The rates of diabetic retinopathy and GFR < 60/mL/min/1.73 m(2) differed between groups (P = 0.006 and P < 0.001, respectively) and were lower in those with lower TSH levels. Multivariate analysis confirmed these associations. The frequencies of retinopathy and GFR < 60 mL/min/1.73 m(2) were higher not only in patients with TSH ≥ 4.5 mU/l (odds ratio 1.878 and 2.271, respectively) but also in those with TSH levels of 2.5-4.4 mU/l (odds ratio 1.493 and 2.286, respectively), when compared with patients with TSH levels of 0.4-2.5 mU/l.
  
  
  CONCLUSIONS
  TSH levels of 0.4-2.5 mU/l are associated with a lower risk of diabetic retinopathy and renal failure in individuals with Type 1 diabetes, independently of glycaemic control and duration of the disease.
authors: Diabetes and Nutrition Section, Department of Internal Medicine, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors: M
authors: M
authors: Rodacki
authors: L
authors: L
authors: Zajdenverg
authors: J R
authors: JR
authors: Dantas
authors: J E P
authors: JE
authors: de Oliveira
authors: R R
authors: RR
authors: Luiz
authors: R A
authors: RA
authors: Cobas
authors: C C S
authors: CC
authors: Palma
authors: C A
authors: CA
authors: Negrato
authors: M B
authors: MB
authors: Gomes
mesh_terms: D000293:Adolescent; D000328:Adult; D001938:Brazil; D002648:Child; D003430:Cross-Sectional Studies; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000188:drug therapy / Q000378:metabolism*; D003928:Diabetic Nephropathies / Q000209:etiology / Q000378:metabolism*; D003930:Diabetic Retinopathy / Q000209:etiology / Q000378:metabolism*; D005260:Female; D005919:Glomerular Filtration Rate; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D007037:Hypothyroidism / Q000150:complications / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012307:Risk Factors; D013972:Thyrotropin / Q000378:metabolism*; D055815:Young Adult
chemical_list: D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D013972:Thyrotropin; C517652:hemoglobin A1c protein, human