title: Glucose series complexity at the threshold of diabetes.
abstract: BACKGROUND
  One of the earliest signs of dysfunction in a complex system is the simplification of its output. A well-accepted method to measure this phenomenon is detrended fluctuation analysis (DFA). Herein, we evaluated the usefulness of DFA at the threshold of type 2 diabetes mellitus (T2DM).
  
  
  METHODS
  We report on the clinical and glucometric characteristics of a sample of 103 patients at increased risk of developing T2DM. All patients had HbA1c levels 5%-6.4% and met at least one of the following criteria: body mass index (BMI) > 30 kg/m2, essential hypertension or a first-degree relative with T2DM. For each patient, a 24-h glucose time series was obtained, and the clinical and glucometric variables were compared.
  
  
  RESULTS
  There was a significant correlation between the number of National Cholesterol Education Program--Adult Treatment Panel (ATP III) metabolic syndrome (MS)-defining criteria and DFA (ρ = 0.231, P = 0.019), and DFA differed significantly between patients meeting or not the ATP III definition of MS (1.443 vs. 1.399, respectively; P = 0.018). The DFA was not correlated with HbA1c. Depending on how it was calculated, the area under the log(Fn)∼log(n) curve correlated with HbA1c levels or the number of MS criteria. Conventional variability metrics (mean amplitude of glycemic excursions) did not differ between patients complying or not with the definition of MS.
  
  
  CONCLUSIONS
  Complexity analysis is capable of detecting differences in variables related to the risk of developing T2DM and could be a useful tool to study the initial phases of glucoregulatory dysfunction leading to T2DM.
authors.affiliation: Department of Internal Medicine, University Hospital of Mostoles, Madrid, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Varela
authors.forename: Carmen
authors.initials: C
authors.lastname: Rodriguez
authors.forename: Luis
authors.initials: L
authors.lastname: Vigil
authors.forename: Eva
authors.initials: E
authors.lastname: Cirugeda
authors.forename: Ana
authors.initials: A
authors.lastname: Colas
authors.forename: Borja
authors.initials: B
authors.lastname: Vargas
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis*; D001794:Blood Pressure; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis*; D005260:Female; D005500:Follow-Up Studies; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D011379:Prognosis; D012307:Risk Factors
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
keywords: blood glucose; metabolic syndrome X; type 2 diabetes mellitus; 关键词：血糖，X代谢综合征，2型糖尿病