title: Platelet mean volume, distribution width, and count in type 2 diabetes, impaired fasting glucose, and metabolic syndrome: a meta-analysis.
abstract: BACKGROUND
  Platelet activation contributes to cardiovascular disease (CVD), the main complication of type 2 diabetes mellitus (T2DM) and pre-diabetic conditions. Mean platelet volume is an easy-to-measure platelet parameter that has been associated with CVD. We sought to assess mean platelet volume, platelet distribution width, and platelet count in T2DM, impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and metabolic syndrome.
  
  
  METHODS
  Web-based literature search (PubMed, EMBASE, and Web of Science) of studies published in English through June 2014 was performed to select case-control and cross-sectional studies that reported data on mean platelet volume, platelet distribution width, or platelet count in cases (subjects with T2DM, IFG, IGT, or metabolic syndrome) and noncases. Descriptive and quantitative information was extracted, and within-study standardized mean difference was estimated from means and standard deviations. Standardized mean differences across studies were synthesized using a random random-effects model, and subgroup analyses were performed on pre-specified study-level characteristics.
  
  
  RESULTS
  Thirty-nine studies were included. Compared with controls, mean platelet volume was significantly higher in T2DM (standardized mean difference, 95% confidence interval: 0.70, 0.50-0.91; N = 24,245), IFG (0.14, 0.02-0.26; N = 17,389) but not in metabolic syndrome (0.15, -0.24 to 0.55; N = 14,990). Platelet distribution width was wider in T2DM (0.93, 0.09-1.76; N = 471). Platelet count resulted higher in IFG (0.18, 0.12-0.24; N = 3960) and metabolic syndrome (0.39, 0.01-0.78; N = 4070). Only two studies included IGT.
  
  
  CONCLUSIONS
  Available data suggest that T2DM subjects tend to have higher mean platelet volume and platelet distribution width values, but nondifferent platelet count as compared with subjects without T2DM. Whether and how these morphometric changes contribute to CVD of T2DM or can be used as CVD biomarker awaits further investigation.
authors.affiliation: Internal Medicine and Diabetes Care Unit, Catholic University School of Medicine, Rome, Italy; Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK.
authors.forename: Francesco
authors.initials: F
authors.lastname: Zaccardi
authors.forename: Bianca
authors.initials: B
authors.lastname: Rocca
authors.forename: Dario
authors.initials: D
authors.lastname: Pitocco
authors.forename: Luigi
authors.initials: L
authors.lastname: Tanese
authors.forename: Alessandro
authors.initials: A
authors.lastname: Rizzi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Ghirlanda
mesh_terms: D015415:Biomarkers / Q000097:blood; D001792:Blood Platelets / Q000473:pathology; D002318:Cardiovascular Diseases / Q000150:complications / Q000453:epidemiology*; D048429:Cell Size; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000150:complications / Q000473:pathology; D003925:Diabetic Angiopathies / Q000453:epidemiology; D058065:Diabetic Cardiomyopathies / Q000453:epidemiology; D019317:Evidence-Based Medicine; D018149:Glucose Intolerance / Q000097:blood* / Q000150:complications / Q000473:pathology; D006801:Humans; D024821:Metabolic Syndrome / Q000097:blood* / Q000150:complications / Q000473:pathology; D015539:Platelet Activation; D010976:Platelet Count; D011236:Prediabetic State / Q000097:blood* / Q000150:complications / Q000473:pathology; D012307:Risk Factors
chemical_list: D015415:Biomarkers
keywords: meta-analysis; platelet; pre-diabetic state; review; type 2 diabetes mellitus