Table 1. Characteristics of the sons and parents according to quintiles of sons’ BMI.
Subject | Variable | Quintile of sons’ BMI | Mean difference or odds ratio (95% CI) | N | ||||
---|---|---|---|---|---|---|---|---|
1st | 2nd | 3rd | 4th | 5th | ||||
Sons |
BMIa,b (kg/m2) | 18.5 | 20.2 | 21.3 | 22.7 | 26.2 | 2.90 (2.90–2.90) | 1,036,817 |
Heighta,b (cm) | 179.6 | 179.4 | 179.3 | 179.1 | 179.0 | –0.19 (−0.20 to −0.18) | 1,036,817 | |
Smokersb,c (%) | 64% | 61% | 59% | 57% | 56% | 0.91 (0.89–0.93) | 29,508 | |
BMIa,b (kg/m2) | 20.3 | 20.9 | 21.2 | 21.6 | 22.2 | 0.62 (0.60–0.64) | 73,982 | |
Heighta,b (cm) | 178.4 | 178.4 | 178.2 | 178.2 | 178.2 | –0.09 (−0.13 to −0.05) | 74,001 | |
Fathers | Date of birtha | 1936.4 | 1935.3 | 1934.9 | 1934.9 | 1935.8 | 0.003 (−0.02 to 0.03) | 1,025,639 |
Smokersb,c (%) | 62% | 64% | 62% | 64% | 67% | 1.09 (1.06–1.12) | 17,254 | |
Age at sons’ birth (years)a | 30.5 | 30.5 | 30.5 | 30.5 | 30.5 | –0.003 (−0.02 to 0.01) | 1,025,639 | |
Educated >10 yearsc (%) | 57% | 56% | 55% | 53% | 48% | 0.88 (0.88–0.88) | 973,704 | |
In nonmanual workc (%) | 51% | 51% | 50% | 49% | 42% | 0.86 (0.86–0.87) | 858,447 | |
Mothers |
Date of birth | 1939.4 | 1938.4 | 1938.0 | 1938.0 | 1939.0 | 0.05 (0.03–0.07) | 1,035,861 |
Age at sons’ birth (years)a | 27.4 | 27.4 | 27.4 | 27.4 | 27.3 | –0.05 (−0.06 to −0.04) | 1,035,861 | |
Educated >10 yearsc (%) | 56% | 55% | 55% | 53% | 50% | 0.92 (0.91–0.92) | 1,016,365 | |
In nonmanual workc (%) | 50% | 50% | 49% | 47% | 42% | 0.88 (0.88−0.88) | 753,046 |
aContinuous variables are summarised as means in each quintile and linear regression produced mean differences per SD (2.90 kg/m2) of BMI preadjusted for each son’s age at examination, conscription office, and secular trends (date of birth).
bMeasured at preconscription medical examination. Smoking was only recorded at examinations in 1969 through 1970.
cBinary variables are summarised as percentages in each quintile and logistic regression produced odds ratios per SD (2.90 kg/m2) of BMI preadjusted for each son’s age at examination, conscription office, and secular trends (date of birth).
Abbreviations: BMI, body mass index; CI, confidence interval; SD, standard deviation