The effect of lactation on insulin sensitivity and lipolysis in women

Aim 1: Does lactation improve insulin sensitivity and increase lipolysis in women? 

In this Aim, we will assess whether lactation amongst women with a history of GDM will improve whole body insulin sensitivity as well as increase whole body lipid turnover by using hyperinsulinemic-euglycemic clamps combined with [6,6-2H]-glucose and [2H5]-glycerol infusions. These stable, non-radiating isotopes have been used extensively and safely to study the mechanisms of insulin resistance amongst non-pregnant as well as pregnant humans; however, these techniques have not previously been applied to the study of insulin sensitivity during lactation. Our goals will be two-fold: 1) to determine whether lactation induces similar changes in insulin sensitivity in humans as in mice and 2) to pilot the feasibility of performing larger, more detailed metabolic studies in this population of women post-partum.

Aim 2: Retrospective chart review of women with a history of GDM who had an OGTT 6-8 weeks post-partum as part of standard of care at Yale Medicine’s Maternal-Fetal Medicine Clinic.

Exclusion criteria:

• Currently lactating or lactation within the past 1 month at the time of the screening visit
• Diagnosis of diabetes (T1D or T2D) prior to pregnancy
• Current use of any glucose-lowering agents
• Pregnancy related medical problems including preeclampsia
• Major congenital fetal anomalies
• Creatinine > 1.5mg/dL, Hematocrit < 35%, ALT and AST > 2.5X upper limit of normal
• Known psychiatric disorders, alcohol abuse, HIV, hepatitis, renal disease, hepatic disease,
• Untreated heart disease, untreated thyroid disease, active systemic infection or malignancy
• Illicit drug use (by the participant’s self-report)
• History of post-partum depression
• Use of weight loss supplements or dieting 6 months prior to study
• Corticosteroid or opiate use within 6 months of study