Table 3

Lightest participants (body-weight < 60 kg) initiating smoking at ≤ 20 years: relative risk of hospital-treated pneumonia by vitamin E supplementation


Intervention
 Effect of vitamin E


Vitamin E
 No vitamin E

Subgroup
 No. of participants
 No. of cases
 No. of cases
 RR (95% CI)*
 P-value for interaction
All
 935
 41
 25
 1.84 (1.11–3.0)
BMI †




     < median
 467
 25
 17
 1.87 (0.99–3.5)
 0.8
     ≥ median
 468
 16
 8
 2.12 (0.90–5.0)
Height †




     < median
 461
 16
 10
 1.91 (0.85–4.3)
 0.9
     ≥ median
 474
 25
 15
 1.86 (0.97–3.6)
Dietary vitamin E †




     < median
 467
 15
 15
 1.30 (0.63–2.7)
 0.2
     ≥ median
 468
 26
 10
 2.70 (1.30–5.6)
Dietary vitamin C †




     < median
 467
 15
 16
 0.98 (0.48–2.0)
 0.026
     ≥ median
 468
 26
 9
 3.48 (1.61–7.5)
Residual of fruit, vegetables, berries †




     < median
 467
 19
 15
 1.53 (0.76–3.1)
 0.6
     ≥ median
 468
 22
 10
 2.27 (1.06–4.9)
β-Carotene supplementation




     No
 476
 23
 12
 2.20 (1.06–4.5)
 0.7
     Yes
 459
 18
 13
 1.62 (0.78–3.4)

* Proportional hazards regression model comparing participants who received vitamin E with those who did not. The regression models were adjusted for age, baseline smoking, intake of coffee and alcohol, BMI and employment. Participants with missing data on confounders (n = 119) are excluded from this table. The sizes of all compared intervention groups are the same within 25% accuracy. RR, risk ratio; CI, confidence interval.

† The medians for the light-weight group are: weight 57.0 kg; BMI 20.0 kg/m2; height 168 cm; dietary vitamin E intake 9.1 mg/day; dietary vitamin C intake 75.3 mg/day; residual of fruit, vegetable, and berry intake -2.9 g/day.

Hemilä and Kaprio Nutrition Journal 2008 7:33   doi:10.1186/1475-2891-7-33

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