. 2010 Oct 22;22(6):1809–1819. doi: 10.1007/s00198-010-1415-y

Table 3.

Sex-specific associations of maternal and paternal smoking with spinal bone outcomes at age 9.9 years in multiple imputation analysis (boys N = 2,772; girls N = 2,715)

		Mean difference	95% CI	P value	Mean difference	95% CI	P value	Mean difference	95% CI	P value
Boys		Spine BMC (SD score: 1 SD = 14.8 g)			Spine BA (SD score: 1 SD = 11.7 cm²)			Spine BMD (SD score: 1 SD = 0.076 g/cm²)
Maternal smoking in any trimester
Model 1		0.03	−0.06–0.12	0.501	0.00	−0.09–0.09	0.918	0.05	−0.04–0.14	0.304
Model 2		0.07	−0.02–0.16	0.153	0.05	−0.04–0.14	0.289	0.07	−0.03–0.16	0.171
Model 3		0.01	−0.05–0.07	0.683	0.01	−0.04–0.07	0.640	0.01	−0.07–0.09	0.829
Maternal smoking in all trimesters
Model 1		0.06	−0.06–0.18	0.301	0.04	−0.08–0.15	0.534	0.07	−0.05–0.20	0.245
Model 2		0.11	−0.01–0.23	0.063	0.10	−0.02–0.21	0.100	0.10	−0.03–0.22	0.122
Model 3		−0.02	−0.09–0.06	0.640	−0.01	−0.09–0.06	0.745	−0.01	−0.12–0.09	0.792
Paternal smoking
Model 1		0.03	−0.06–0.11	0.535	0.03	−0.05–0.11	0.404	0.00	−0.08–0.09	0.950
Model 2		0.03	−0.05–0.11	0.421	0.04	−0.04–0.12	0.283	0.01	−0.08–0.09	0.884
Model 3		−0.01	−0.06–0.04	0.634	0.01	−0.04–0.05	0.834	−0.03	−0.10–0.04	0.346
Combined models
Model 1	Maternal smoking^a	0.05	−0.05–0.14	0.344	0.01	−0.08–0.11	0.802	0.07	−0.03–0.17	0.166
Model 1	Paternal smoking	0.02	−0.07–0.10	0.706	0.03	−0.05–0.11	0.458	−0.01	−0.10–0.08	0.797
Model 2	Maternal smoking^a	0.07	−0.02–0.17	0.127	0.05	−0.05–0.14	0.311	0.08	−0.02–0.19	0.106
Model 2	Paternal smoking	0.01	−0.07–0.09	0.774	0.03	−0.05–0.11	0.526	−0.01	−0.10–0.08	0.767
Model 3	Maternal smoking^a	0.02	−0.04–0.08	0.537	0.02	−0.05–0.08	0.642	0.03	−0.06–0.11	0.557
Model 3	Paternal smoking	−0.02	−0.07–0.04	0.548	0.00	−0.05–0.05	0.997	−0.04	−0.11–0.04	0.330
Girls		Spine BMC (SD score: 1 SD = 16.7 g)			Spine BA (SD score: 1 SD = 12.3 cm²)			Spine BMD (SD score: 1 SD = 0.086 g/cm²)
Maternal smoking in any trimester
Model 1		0.13	0.03–0.23	0.013	0.12	0.03–0.22	0.012	0.10	0.00–0.21	0.049
Model 2		0.15	0.05–0.25	0.002	0.16	0.06–0.25	0.001	0.12	0.01–0.22	0.025
Model 3		0.02	−0.03–0.07	0.444	0.05	−0.00–0.10	0.065	−0.01	−0.08–0.06	0.799
Maternal smoking in all trimesters
Model 1		0.13	0.01–0.25	0.035	0.12	−0.00–0.23	0.055	0.11	−0.01–0.24	0.081
Model 2		0.18	0.06–0.30	0.004	0.17	0.06–0.29	0.004	0.14	0.01–0.26	0.035
Model 3		0.04	−0.02–0.11	0.210	0.07	−0.00–0.13	0.054	0.01	−0.09–0.10	0.859
Paternal smoking
Model 1		0.10	0.02–0.18	0.014	0.08	−0.01–0.16	0.066	0.12	0.04–0.20	0.005
Model 2		0.11	0.03–0.19	0.009	0.08	0.00–0.16	0.043	0.12	0.04–0.20	0.004
Model 3		0.01	−0.03–0.06	0.580	0.00	−0.04–0.05	0.951	0.03	−0.03–0.09	0.288
Combined models
Model 1	Maternal smoking^a	0.11	0.01–0.21	0.040	0.11	0.02–0.21	0.020	0.07	−0.04–0.18	0.186
Model 1	Paternal smoking	0.07	−0.01–0.16	0.089	0.05	−0.04–0.13	0.293	0.10	0.01–0.18	0.025
Model 2	Maternal smoking^a	0.13	0.03–0.23	0.013	0.14	0.05–0.24	0.003	0.08	−0.02–0.19	0.130
Model 2	Paternal smoking	0.07	−0.01–0.15	0.101	0.04	−0.04–0.13	0.337	0.10	0.01–0.18	0.027
Model 3	Maternal smoking^a	0.02	−0.04–0.07	0.545	0.06	−0.00–0.11	0.058	−0.02	−0.10–0.06	0.546
Model 3	Paternal smoking	0.01	−0.04–0.06	0.681	−0.01	−0.06–0.03	0.598	0.04	−0.02–0.11	0.197

Reference category for maternal smoking variables is “Never smoked during pregnancy” and for paternal smoking variable is “Non-smoking”

Model 1 is adjusted for the child’s age, mother’s parity, household social class and maternal/paternal factors (age, height, pre-pregnancy BMI, education).

Model 2 is adjusted additionally for the child’s gestational age and birth weight

Model 3 is adjusted for all these plus the child’s height and weight at age 9.9 years

BA bone area, BMC bone mineral content, BMD bone mineral density

^aMaternal smoking in any trimester