Cumulative Lactation and Clinical Metabolic Outcomes at Mid-Life among Women with a History of Gestational Diabetes

Abstract

Lactation is associated with a lower risk of subsequent cardiometabolic disease among parous women; however, the underlying mechanisms are unknown. Further, the potential protective effects of lactation on cardiometabolic risk markers at mid-life among high-risk women with past gestational diabetes (GDM) are not established. Using data from the Diabetes & Women’s Health Study (2012–2014; n = 577), a longitudinal cohort of women with past GDM from the Danish National Birth Cohort (1996–2002), we assessed associations of cumulative lactation duration (none, < 6 months, 6–12 months, ≥ 12–24 months, and ≥ 24 months) with clinical metabolic outcomes (including type 2 diabetes [T2D], prediabetes, and obesity) and cardiometabolic biomarkers (including biomarkers of glucose/insulin metabolism, fasting lipids, inflammation, and anthropometrics) 9–16 years after enrollment when women were at mid-life. At follow-up, women were 43.9 years old (SD 4.6) with a BMI of 28.7 kg/m2 (IQR 24.6, 33.0); 28.6% of participants had T2D, 39.7% had prediabetes, and 41.2% had obesity. Relative risks (95% CI) of T2D for 0–6, 6–12, 12–24, and ≥ 24 months of cumulative lactation duration compared to none were 0.94 (0.62,1.44), 0.88 (0.59,1.32), 0.73 (0.46,1.17), and 0.71 (0.40,1.27), respectively. Cumulative lactation duration was not significantly associated with any other clinical outcome or continuous biomarker. In this high-risk cohort of middle-aged women with past GDM, T2D, prediabetes, and obesity were common at follow-up, but not associated with history of cumulative lactation duration 9–16 years after the index pregnancy. Further studies in diverse populations among women at mid-age are needed to understand associations of breastfeeding with T2D.

Prospective associations between breast feeding, metabolic health, inflammation and bone density in women with prior gestational diabetes mellitus

“… 55 Our results are in agreement with previous studies in women without GDM, 17 18 but not with two studies in women after GDM. 20 21 The small sample size (n=26), early evaluation after only 3 months, 21 as well as the differences in GDM criteria resulting in a population with an advanced glucose intolerance in these studies 20 21 might explain the differences.…”

“…Associations between breastfeeding duration and lower weight, weight retention, body fat, and FMI during the postpartum are consistent with a previous meta-analysis showing that a longer breastfeeding duration of any intensity is associated with lower BMI among women with prior GDM, 7 but is in contrast to more recent studies. 20 25 …”

“…Variations in study designs, dietary advice, and the cultural and ethnic backgrounds of participants can influence differences in weight loss after GDM. 20 25 The beliefs and practices regarding breastfeeding and concomitant or compensatory increases in food intake in this period may vary significantly. Our multiethnic participants received consistent dietary messages advising against substantial increases in food intake during breastfeeding.…”

“…Although some studies have associated breastfeeding with a reduction in visceral adipose tissue (VAT), 17 18 this has not been shown in women with prior GDM. 20 21 Regarding insulin secretion (assessed by the disposition index), the impact of breastfeeding after GDM has shown a beneficial association in some, 21 22 but not all studies. 23 24 Similar inconsistency is observed regarding the association between breastfeeding and inflammatory parameters, 20 23 25 26 which tend to be higher in women with GDM compared with controls.…”

“… 20 21 Regarding insulin secretion (assessed by the disposition index), the impact of breastfeeding after GDM has shown a beneficial association in some, 21 22 but not all studies. 23 24 Similar inconsistency is observed regarding the association between breastfeeding and inflammatory parameters, 20 23 25 26 which tend to be higher in women with GDM compared with controls. 27 Studying the impact of breastfeeding on metabolic health parameters and inflammation in this population is important, since the underlying mechanism through which breastfeeding mitigates cardiometabolic risk remains unclear.…”