title: White blood cell counts as risk markers of developing metabolic syndrome and its components in the PREDIMED study.
abstract: BACKGROUND
  The Metabolic Syndrome (MetS) is a cluster of metabolic abnormalities that includes hyperglucemia, hypertension, dyslipidemia and central obesity, conferring an increased risk of cardiovascular disease. The white blood cell (WBC) count has been proposed as a marker for predicting cardiovascular risk. However, few prospective studies have evaluated the relationship between WBC subtypes and risk of MetS.
  
  
  METHODS
  Participants were recruited from seven PREDIMED study centers. Both a baseline cross-sectional (n = 4,377) and a prospective assessment (n = 1,637) were performed. Participants with MetS at baseline were excluded from the longitudinal analysis. The median follow-up was 3.9 years. Anthropometric measurements, blood pressure, fasting glucose, lipid profile and WBC counts were assessed at baseline and yearly during the follow-up. Participants were categorized by baseline WBC and its subtype count quartiles. Adjusted logistic regression models were fitted to assess the risk of MetS and its components.
  
  
  RESULTS
  Of the 4,377 participants, 62.6% had MetS at baseline. Compared to the participants in the lowest baseline sex-adjusted quartile of WBC counts, those in the upper quartile showed an increased risk of having MetS (OR, 2.47; 95%CI, 2.03-2.99; P-trend<0.001). This association was also observed for all WBC subtypes, except for basophils. Compared to participants in the lowest quartile, those in the top quartile of leukocyte, neutrophil and lymphocyte count had an increased risk of MetS incidence. Leukocyte and neutrophil count were found to be strongly associated with the MetS components hypertriglyceridemia and low HDL-cholesterol. Likewise, lymphocyte counts were found to be associated with the incidence of the MetS components low HDL-cholesterol and high fasting glucose. An increase in the total WBC during the follow-up was also associated with an increased risk of MetS.
  
  
  CONCLUSIONS
  Total WBC counts, and some subtypes, were positively associated with MetS as well as hypertriglyceridemia, low HDL-cholesterol and high fasting glucose, all components of MetS.
  
  
  BACKGROUND
  Controlled-Trials.comISRCTN35739639.
authors.affiliation: Human Nutrition Unit, Sant Joan Hospital, IISPV, Universitat Rovira i Virgili, Reus, Spain.
authors.forename: Nancy
authors.initials: N
authors.lastname: Babio
authors.forename: Núria
authors.initials: N
authors.lastname: Ibarrola-Jurado
authors.forename: Mònica
authors.initials: M
authors.lastname: Bulló
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: Martínez-González
authors.forename: Julia
authors.initials: J
authors.lastname: Wärnberg
authors.forename: Itziar
authors.initials: I
authors.lastname: Salaverría
authors.forename: Manuel
authors.initials: M
authors.lastname: Ortega-Calvo
authors.forename: Ramón
authors.initials: R
authors.lastname: Estruch
authors.forename: Lluís
authors.initials: L
authors.lastname: Serra-Majem
authors.forename: Maria Isabel
authors.initials: MI
authors.lastname: Covas
authors.forename: José Vicente
authors.initials: JV
authors.lastname: Sorli
authors.forename: Jordi
authors.initials: J
authors.lastname: Salas-Salvadó
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002318:Cardiovascular Diseases / Q000097:blood / Q000209:etiology / Q000517:prevention & control; D003430:Cross-Sectional Studies; D038441:Diet, Mediterranean; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D018655:Lymphocyte Count; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood* / Q000209:etiology*; D008875:Middle Aged; D009504:Neutrophils; D011446:Prospective Studies; D012307:Risk Factors