Use of white blood cell counts to predict metabolic syndrome in the elderly: a 4 year longitudinal study

Background: The white blood cell (WBC) count was one of the first inflammatory markers associated with metabolic syndrome (MetS). Recently, two longitudinal studies have demonstrated a cause and effect relationship between MetS and WBC counts among middle-aged adults. However, no study has used WBC cutoff values to predict MetS in the elderly.

Methods: Subjects who underwent routine health checkups, and were above 60 years of age, were enrolled. All subjects were followed-up until they developed MetS or until 4 years from the date of entry, whichever came earlier. Of the 4539 subjects eligible for enrollment, 3428 subjects comprised the study group and 1111 subjects comprised the validation group.

Results: WBC counts were significantly different between subjects with and without MetS in both genders. Using the ROC curve, WBC cutoff values of 5.7 × 10(3)/µl in males and 5.0 × 10(3)/µl in females were associated with the increased risk of developing MetS (all p values <0.001). Using these WBC cutoff values, the hazard ratio (HR) for females was significant in both the study group and validation group. However, the HR for males failed significance in the validation group. Kaplan-Meier plots and κ coefficients confirmed that the WBC cutoff value could predict development of MetS in women but not in men.

Conclusions: The association between WBC count and MetS was gender specific. A WBC cutoff value greater than 5.0 10(3)/µl may predict the development of MetS in elderly women.