Association of lymphocyte sub-populations with clustered features of metabolic syndrome in middle-aged Japanese men

To examine the relationship between altered cellular immune status and clustered features of the metabolic syndrome, we measured body mass index (BMI), serum concentrations of high-density lipoprotein–cholesterol, triglycerides, fasting plasma glucose, and blood pressure levels as well as differential leukocyte counts and lymphocyte sub-populations among 439 apparently healthy Japanese men aged 35–60 years. The components of the metabolic syndrome were defined based on the following criteria: BMI ≥25.0 kg/m2, fasting plasma glucose ≥6.11 mmol/l, systolic blood pressure ≥130 mmHg and/or diastolic blood pressure ≥85 mmHg, high-density lipoprotein (HDL)–cholesterol <1.03 mmol/l, and fasting triglyceride ≥1.69 mmol/l. Counts of total leukocyte, total lymphocyte, CD3+T cell, CD4+T cell, and CD4+CD45RO+T cell significantly correlated with the number of components of the metabolic syndrome (0, 1, 2, and 3+) after adjustment for age and smoking status. These findings were more evident among smokers than among non-smokers. The counts of total leukocytes, total lymphocytes and more specifically memory (CD4+CD45RO+T) cells were elevated with clustered features of the metabolic syndrome in middle-aged men, which suggest the involvement of altered cellular immune status in the pathogenesis of atherosclerosis.