TABLE 3.

Differences in lipid levels from prepregnancy to after first birth by breastfeeding length for parous HUNT2 and HUNT3 study participants (n = 22,047 women)

	Model 1a			Model 2b
	Estimate	95% CI	P	Estimate	95% CI	P
HDL-C (mg/dl)
All parous women	−4.2	−5.0, −3.3	<0.001	−3.0	−4.2, −1.8	<0.001
By breastfeeding length
Did not breastfeed	−6.2	−7.3, −5.1	<0.001	−3.9	−5.3, −2.5	<0.001
Breastfed <3 months	−5.2	−6.1, −4.3	<0.001	−3.5	−4.7, −2.2	<0.001
Breastfed 3-6 months	−4.0	−4.9, −3.1	<0.001	−2.7	−3.9, −1.5	<0.001
Breastfed >6 months	−3.8	−4.6, −2.9	<0.001	−2.9	−4.1, −1.7	<0.001
Non-HDL-C (mg/dl)
All parous women	−0.4	−2.8, 2.1	0.77	1.1	−2.3, 4.5	0.53
By breastfeeding length
Did not breastfeed	5.6	2.3, 8.8	<0.001	3.7	−0.3, 7.7	0.07
Breastfed <3 months	2.2	−0.5, 5.0	0.11	2.1	−1.5, 5.7	0.25
Breastfed 3-6 months	0.5	−2.0, 3.1	0.67	1.5	−2.0, 5.0	0.39
Breastfed >6 months	−1.9	−4.4, 0.5	0.13	0.3	−3.1, 3.8	0.85
Triglycerides (mg/dl)
All parous women	−3.6	−7.8, 0.7	0.10	1.8	−3.8, 7.5	0.52
By breastfeeding length
Did not breastfeed	9.7	4.1, 15.4	<0.001	7.5	0.8, 14.2	0.03
Breastfed <3 months	1.9	−2.9, 6.7	0.43	3.8	−2.2, 9.8	0.22
Breastfed 3-6 months	−2.6	−7.1, 1.9	0.25	1.8	−4.0, 7.7	0.54
Breastfed >6 months	−6.6	−10.9, −2.3	0.003	0.7	−5.1, 6.4	0.82
TC/HDL-C ratio
All parous women	0.18	0.11, 0.25	<0.001	0.16	0.06, 0.25	<0.001
By breastfeeding length
Did not breastfeed	0.43	0.33, 0.52	<0.001	0.27	0.16, 0.39	<0.001
Breastfed <3 months	0.29	0.21, 0.37	<0.001	0.21	0.11, 0.31	<0.001
Breastfed 3-6 months	0.19	0.12, 0.26	<0.001	0.15	0.06, 0.25	0.002
Breastfed >6 months	0.12	0.06, 0.19	<0.001	0.13	0.04, 0.23	0.006

Models include all parous women without restricting to participants born between 1940 and 1974, as in Fig. 2 and Table 2 comparisons with nulliparous women.

^aAdjusted for participant’s age at measurement, HUNT survey, time since last meal, education, smoking initiation by the age of 20 years, and family history of CVD.

^bAdditionally adjusted for updated BMI, updated alcohol use, updated physical activity, updated oral contraceptive use, maternal age at first birth, and preterm first birth.