Schooling et al. BMC Public Health 2011, 11:345 http://www.biomedcentral.com/1471-2458/11/345 Table 1 Participant Characteristics by Recalled Childhood Meat Eating in 9,867 Older Chinese Men (2,498) and Women (7,369) in Phase 3 Of The Guangzhou Biobank Cohort Study (2006-8) Men Women Recalled childhood meat eating Recalled childhood meat eating <1/week About once a Almost <1/week About once a Almost (n = week daily (n = week daily 1337) (n = 878) (n = 283) 3686) (n = 2714) (n = 969) Age (yrs): mean (standard deviation (SD)) 64.3 (7.6) 61.6 (7.3) 62.5 (7.9) 60.7 (7.9) 57.5 (6.8) 57.9 (7.4) Height (cm): mean (SD) 163.9 164.8 (5.9) 165.2 (6.3) 153.4 154.5 (5.4) 154.5 (5.4) (6.0) (5.5) Body mass index: mean (SD) 23.4 (3.2) 23.5 (3.0) 23.9 (3.3) 24.1 (3.5) 23.7 (3.3) 24.0 (3.2) Waist-hip ratio: mean (SD) 0.90 0.90 (0.06) 0.91 (0.07) 0.86 0.84 (0.07) 0.85 (0.06) (0.07) (0.07) Childhood socio-economic position (parental Low 81.2 53.0 35.0 73.6 41.2 23.3 possessions) # Highest educational attainment Smoking status Medium High Unknown < primary Primary Junior middle Senior middle Junior college College Never Ex-smoker Current Unknown 10.0 7.1 1.7 4.0 32.3 32.0 20.4 7.0 4.4 34.0 29.1 35.9 1.0 21.6 23.6 1.8 0.5 20.3 33.0 29.1 11.2 5.9 41.5 22.3 33.9 0.3 16.6 46.6 1.8 0.7 17.3 24.7 33.2 12.0 12.0 38.5 26.5 34.3 0.7 13.9 9.9 2.6 17.9 38.6 23.0 17.0 2.7 0.8 96.1 1.8 1.5 0.5 23.6 32.3 3.0 4.1 22.8 30.3 34.6 6.8 1.4 97.4 0.6 1.4 0.6 Page 4 of 6 20.6 53.2 2.9 3.5 18.6 29.0 38.5 8.0 2.6 96.7 1.0 0.9 1.3 # These correspond to parental possession of none (low), 1 to 2 (medium) and 3 (high) of: sewing machine, watch and bicycle. Alternatively, we could place these observations within a theoretical hypothesis driven framework [15,37]. Speci- fically, pubertal sex-steroids are nutritionally driven [38-40], either by meat eating or some other aspect of a less limited diet, with potentially long-term effects. Testosterone suppresses immune responsiveness, while estrogen may promote it [19-21]. Higher sex-steroids might be expected to result in a more pro-inflammatory state among men but not women. Whether a greater impact would be expected on lymphocytes than Table 2 Akaike Information Criterion values‡ for Models with and without Interactions by Sex and Age in 9,867 Older Chinese Men (2,498) and Women (7,369) in Phase 3 of the Guangzhou Biobank Cohort Study (2006-8) All Men Women Model † Interaction by sex Interaction by age Interaction by age with without with without with without White blood cell count 1 36632 36634 9662 9656 26958 26946 2 35981 35980 9565 9558 26417 26404 Lymphocyte count Granulocyte count 1 2 1 2 17899 17360 31907 31545 17901 17365 31905 31542 4779 4700 8610 8568 4774 4692 8603 8561 13130 12681 23251 22947 13111 12663 23241 22936 †Model 1 adjusted for age, smoking, parental possessions and education. Model 2 additionally adjusted for body mass index and waist-hip ratio. ‡A lower Akaike Information Criterion value indicates a better fitting model.