title: Seasonal variability of glycated hemoglobin in a diabetic population from southern Europe.
abstract: OBJECTIVE
  To analyze the seasonal variations in A1c levels among a southern European diabetic population.
  
  
  METHODS
  We examined all monthly-grouped A1c determinations from diabetic patients during the period 2006-2011, in a region of southern Spain.
  
  
  RESULTS
  There were 61,329 records available. The mean A1c value was 56mmol/mol (7.2%±1.7%) (95% CI, 55-56mmol/mol (7.2%-7.3%), with a range of 0.2%. The highest value was in February and the lowest in July (56mmol/mol (7.3%) and 54mmol/mol (7.1%), respectively) (P<0.01). However, spectral analysis and correlation coefficients did not reach significance, and the series presented no seasonal pattern.
  
  
  CONCLUSIONS
  In our area, although the A1C levels have some monthly fluctuation they show no significant seasonal pattern. Thus, the seasonal fluctuation of HbA1c is not a limitation for decision making in clinical practice.
authors.affiliation: Internal Medicine Department, Hospital Regional Universitario Carlos Haya, Malaga, Spain; Ciber Fisiopatología de la Obesidad y Nutrición (CB06/003) Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Gomez-Huelgas
authors.forename: Sonia
authors.initials: S
authors.lastname: Santamaria-Fernandez
authors.forename: Ricardo
authors.initials: R
authors.lastname: Guijarro-Merino
authors.forename: Federico
authors.initials: F
authors.lastname: Navajas-Luque
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Tinahones
authors.forename: Carlos M San
authors.initials: CM
authors.lastname: Roman-Teran
authors.forename: M Jose
authors.initials: MJ
authors.lastname: Picon
authors.forename: M Rosa
authors.initials: MR
authors.lastname: Bernal-Lopez
mesh_terms: D003920:Diabetes Mellitus / Q000097:blood* / Q000453:epidemiology; D005060:Europe / Q000453:epidemiology; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D008297:Male; D012621:Seasons; D013030:Spain / Q000453:epidemiology; D013696:Temperature
chemical_list: D006442:Glycated Hemoglobin
keywords: Diabetic population; Glycated hemoglobin; Seasonal variability