n | Months of exclusive lactation | P^{†} | |||||
---|---|---|---|---|---|---|---|

None | >0 to <1 | 1 to <3 | 3 to <6 | ≥6 | |||

Mean (95% CI) | Mean (95% CI) | Mean (95% CI) | Mean (95% CI) | Mean (95% CI) | |||

Leptin (ng/mL) (n) | 55 | 121 | 81 | 151 | 30 | ||

Unadjusted | 438 | 12.8 (10.2–15.3) | 10.2 (8.9–11.6) | 8.8 (7.2–10.4) | 9.0 (7.4–10.6) | 9.3 (6.5–12.1) | 0.03 |

Multivariable adjusted | 438 | 11.4 (9.5–13.3) | 8.8 (7.5–10.1) | 7.8 (6.4–9.2) | 8.5 (7.1– 9.8) | 9.0 (6.9–11.1) | 0.006 |

Adiponectin (μg/mL) (n) | 56 | 120 | 81 | 153 | 30 | ||

Unadjusted | 440 | 19.8 (16.2–23.4) | 21.5 (19.6–23.5) | 21.4 (19.1–23.7) | 20.7 (18.4–22.9) | 24.5 (20.6–28.5) | 0.26 |

Multivariable adjusted | 440 | 20.4 (16.9–24.0) | 23.6 (21.1–26.1) | 23.3 (20.7–25.9) | 21.9 (19.4–24.4) | 25.9 (21.9–29.9) | 0.05 |

Ghrelin (pg/mL) (n) | 11 | 39 | 22 | 50 | 14 | ||

Unadjusted | 136 | 665.1 (422.9–907.4) | 721.5 (602.2–840.9) | 728.7 (585.1–872.2) | 794.6 (646.6–942.6) | 1,034 (811.9–1,257) | 0.05 |

Multivariable adjusted | 136 | 706.3 (484.8–927.8) | 754.4 (617.9–890.9) | 865.0 (723.1–1,007) | 810.0 (667.9–952.1) | 920.9 (710.5–1,131) | 0.2 |

PYY (pg/mL) (n)^{‡} | 11 | 39 | 21 | 50 | 14 | ||

Unadjusted | 135 | 61.0 (47.1–78.9) | 55.5 (48.8–63.0) | 56.9 (48.6–66.6) | 62.0 (52.9–72.6) | 53.5 (42.2–67.9) | 0.46 |

Multivariable adjusted | 135 | 57.0 (42.6–76.2) | 56.7 (47.4–67.9) | 56.4 (46.5–68.4) | 60.2 (50.0–72.6) | 51.2 (38.8–67.4) | 0.63 |

Data from 570 participants in Project Viva who presented for follow-up at 3 years postpartum without an intervening birth.

*For the multivariate-adjusted model, data presented are mean predicted values for a participant with a prepregnancy BMI of 25.1 kg/m

^{2}, the mean for the study population, modeled using a three-knot quadratic spline model for BMI. This participant continued to breastfeed for up to 3 months after introducing formula or solid foods and is a white woman aged 35–40 years, has two children, has no parental history of diabetes, had normal glucose tolerance, is a nonsmoker, and gained 15 kg during the index pregnancy.†Partial

*F*test*P*values for differences among categories.‡Results presented for PYY are geometric means. Because this outcome was not normally distributed, it was modeled on the log scale. Predicted values are exponentiated for presentation to improve interpretability.