Table 3.
Associations between higher BMI and five measures of socioeconomic, using linear or logistic regression and instrumental variable analysis
| Socioeconomic status measures and subcategories | No | Observational* | Genetic† | Genetic: Egger‡ | |||||
|---|---|---|---|---|---|---|---|---|---|
| Change in socioeconomic status (95%CI) per SD higher BMI | P value | Change in socioeconomic status (95%CI) per SD higher BMI | P value | Change in socioeconomic status (95%CI) per SD higher BMI | P value | ||||
| Age completed full time education: | |||||||||
| All | 82 543 | −0.08 (−0.08 to −0.07) | <1×10−15 | −0.01 (−0.07 to 0.04) | 0.63 | – | |||
| Men only | 38 342 | −0.07 (−0.08 to −0.06) | <1×10−15 | 0.00 (−0.09 to 0.09) | 0.98 | – | |||
| Women only | 44 201 | −0.08 (−0.09 to −0.07) | <1×10−15 | −0.02 (−0.09 to 0.05) | 0.56 | – | |||
| Degree level education: | |||||||||
| All | 118 565 | OR: 0.83 (0.82 to 0.84) | <1×10−15 | 0.94 (0.85 to 1.03) | 0.18 | – | |||
| Men only | 56 111 | OR: 0.82 (0.81 to 0.84) | <1×10−15 | 0.94 (0.81 to 1.09) | 0.43 | – | |||
| Women only | 62 454 | OR: 0.83 (0.82 to 0.84) | <1×10−15 | 0.93 (0.82 to 1.06) | 0.28 | – | |||
| Job class (skilled/unskilled): | |||||||||
| All | 76 404 | OR: 0.91 (0.89 to 0.92) | <1×10−15 | 0.90 (0.79 to 1.02) | 0.10 | – | |||
| Men only | 37 608 | OR: 0.93 (0.91 to 0.95) | 8×10−9 | 0.88 (0.73 to 1.08) | 0.22 | – | |||
| Women only | 38 796 | OR: 0.89 (0.87 to 0.91) | <1×10−15 | 0.91 (0.76 to 1.08) | 0.29 | – | |||
| Annual household income: | |||||||||
| All | 103 327 | −0.06 (−0.06 to −0.05) | <1×10−15 | −0.05 (−0.10 to −0.00) | 0.041 | −0.03 (−0.11 to 0.05) | 0.58 | ||
| Men only | 50 862 | −0.01 (−0.02 to −0.00) | <1×10−15 | 0.06 (−0.02 to 0.14) | 0.15 | – | |||
| Women only | 52 465 | −0.09 (−0.10 to −0.08) | <1×10−15 | −0.14 (−0.20 to −0.08) | 1×10−5 | −0.17 (−0.25 to −0.05) | 0.004 | ||
| Townsend deprivation index: | |||||||||
| All | 119 519 | 0.08 (0.07 to 0.08) | <1×10−15 | 0.05 (0.01 to 0.10) | 0.024 | −0.00 (−0.08 to 0.08) | 0.96 | ||
| Men only | 56 582 | 0.05 (0.04 to 0.05) | <1×10−15 | −0.01 (−0.08 to 0.06) | 0.78 | – | |||
| Women only | 62 937 | 0.10 (0.09 to 0.11) | <1×10−15 | 0.10 (0.04 to 0.16) | 0.001 | 0.10 (−0.01 to 0.21) | 0.08 | ||
BMI=body mass index; OR=odds ratio.
For age completed full time education, annual household income, and Townsend deprivation index, changes reported are standard deviation. For degree and job class, odds ratios are shown, representing odds of higher socioeconomic status per SD higher BMI.
*Age, assessment centre, and sex adjusted associations.
†Uses instrumental variable analysis, via ivreg2 command in Stata for continuous variables and two step approach for binary outcomes, using BMI genetic risk score. F statistic for all participants is ≥1257 for each socioeconomic status measure; in men only, F statistic is ≥591 for each socioeconomic status measure; in women only, F statistic is ≥666 for each socioeconomic status measure.
‡Alternative genetic approach detailed in Bowden et al 2015,24 used as sensitivity analysis when instrumental variable was P<0.05.