Smoking, white blood cell counts, and TNF system activity in Japanese male subjects with normal glucose tolerance.

BACKGROUND: Cigarette smokers have increased white blood cell (WBC) counts and the activation of tumor necrosis factor (TNF). The effect of smoking on WBC counts and TNF system activity, however, has not been separately investigated yet. Subjects and Methods One hundred and forty-two Japanese male subjects with normal glucose tolerance were recruited. They were stratified into two groups based on the questionnaire for smoking: one with current smokers (n=48) and the other with current non-smokers (n=94). Whereas no significant differences were observed in age, BMI, high molecular weight (HMW) adiponectin, and TNF-alpha between the two groups, current smokers had significantly higher soluble TNF receptor 1 (sTNF-R1) (1203+/-30 vs 1116+/-21 pg/ml, p =0.010) and increased WBC counts (7165+/-242 vs 5590+/-163, p <0.001) and lower HDL cholesterol (55+/-2 vs 60+/-1 mg/dl, p =0.031) as compared to current non-smokers. Next, we classified 48 current smokers into two subpopulations: one with high active smoking (Brinkman index>600) and the other with low active smoking (Brinkman index<600). RESULTS: Whereas no significant difference was observed in age, BMI, HMW adiponectin, WBC counts and TNF-alpha, sTNF-R1 and sTNF-R2 were significantly higher in high active smoking group (1307+/-44 vs 1099+/-30 pg/ml, p <0.001; 2166+/-86 vs 1827+/-62 pg/ml, p =0.005) than in low active smoking group, whose sTNF-R1 and sTNF-R2 were similar to non-smokers (sTNF-R1: 1116+/-15 pg/ml, p =0.718, sTNF-R2; 1901+/-32 pg/ml, p =0.437). In contrast, WBC counts were significantly increased in high (7500+/-324/mul, p <0.001) or low (6829+/-352/mul , p =0.001) active smoking group as compared to non-smokers (5590+/-178/mul). There was no significant difference in WBC counts between high and low active smoking group (p =0.158). CONCLUSION: We can hypothesize that low active smoking is associated with an increase in WBC counts, while high active smoking is responsible for TNF activation in Japanese male subjects with normal glucose tolerance. [ABSTRACT FROM AUTHOR]