There are two aims that this research will address.~In Aim 1, the research question is Does lactation improve insulin sensitivity and increase lipolysis in women? In this Aim, researchers will assess whether lactation amongst women with a history of gestational diabetes mellitus (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. Therefore, the 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.~The second aim (Aim 2) will use a retrospective chart review of women with a history of GDM who had an oral glucose tolerance test (OGTT) 6-8 weeks post-partum as part of standard of care.~The focus of this protocol registration will be Aim 1.
This purpose of this study is to investigate whether lactation improves insulin sensitivity and increases lipolysis in women.