title: Age at menarche and the risk of diabetic microvascular complications in patients with type 1 diabetes.
abstract: OBJECTIVE
  The aim of this study was to evaluate the relationship among age at onset of diabetes, age at onset of menarche and risk of diabetic nephropathy and laser-treated retinopathy in type 1 diabetes.
  
  
  METHODS
  Data related to age at menarche were collected through questionnaires and were available for 1,304 women who participated in the Finnish Diabetic Nephropathy Study (FinnDiane). A possible association between age at menarche and diabetic nephropathy and retinopathy was investigated.
  
  
  RESULTS
  There was an inverse relationship between the age at onset of diabetes and age at menarche: the younger the age at onset of diabetes, the higher the age at menarche (p < 0.0001). A non-linear relationship between the age of menarche and risk of diabetic microvascular complications was found in patients with diabetes onset before menarche, but there was no such association in patients with diabetes onset after menarche. Women with delayed menarche (> mean age + 2 years) had a 2.30 (95% CI 1.27, 4.17; p < 0.006) times higher risk of nephropathy compared with the women who underwent menarche at the mean age ± 2 years. Delayed menarche also increased the risk of retinopathy (OR 2.34 [95% CI 1.36, 4.01]). After excluding patients with nephropathy, the OR for retinopathy was 2.11 (95% CI 1.15, 3.90). Earlier menarche (< mean age - 2 years) did not have any effect on this risk.
  
  
  CONCLUSIONS
  Delayed menarche was associated with an increased risk of diabetic nephropathy and retinopathy, whereas early menarche was not. Delayed menarche may be used as a new tool to identify women at risk of diabetic microvascular complications.
authors.affiliation: Folkhälsan Research Center, Biomedicum Helsinki, University of Helsinki, PO Box 63, 00014, Helsinki, Finland.|Abdominal Center Nephrology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.|Research Program Unit, Diabetes and Obesity, University of Helsinki, Helsinki, Finland.|The Chronic Disease Prevention Unit, National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Valma
authors.initials: V
authors.lastname: Harjutsalo
authors.affiliation: Vascular Biology and Hypertension Branch, Division of Cardiovascular Sciences, National Institute of Heart, Lung and Blood, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Christine
authors.initials: C
authors.lastname: Maric-Bilkan
authors.affiliation: Folkhälsan Research Center, Biomedicum Helsinki, University of Helsinki, PO Box 63, 00014, Helsinki, Finland.|Abdominal Center Nephrology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.|Research Program Unit, Diabetes and Obesity, University of Helsinki, Helsinki, Finland.
authors.forename: Carol
authors.initials: C
authors.lastname: Forsblom
authors.affiliation: Folkhälsan Research Center, Biomedicum Helsinki, University of Helsinki, PO Box 63, 00014, Helsinki, Finland. per-henrik.groop@helsinki.fi.|Abdominal Center Nephrology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland. per-henrik.groop@helsinki.fi.|Research Program Unit, Diabetes and Obesity, University of Helsinki, Helsinki, Finland. per-henrik.groop@helsinki.fi.|Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia. per-henrik.groop@helsinki.fi.
authors.forename: Per-Henrik
authors.initials: PH
authors.lastname: Groop
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000150:complications*; D003928:Diabetic Nephropathies / Q000097:blood / Q000209:etiology; D003930:Diabetic Retinopathy / Q000097:blood / Q000209:etiology; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008297:Male; D008572:Menarche / Q000502:physiology*; D008875:Middle Aged; D012307:Risk Factors; D055815:Young Adult
chemical_list: D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
keywords: Age at menarche; Age at onset of diabetes; Delayed menarche; Diabetic nephropathy; Diabetic retinopathy; Puberty; Type 1 diabetes