title: Mechanism of insulin resistance in normal pregnancy.
abstract: Normal pregnancy is associated with insulin resistance although the mechanism is not understood. Increased intramyocellular lipid is closely associated with the insulin resistance of type 2 diabetes and obesity, and the aim of this study was to determine whether this was so for the physiological insulin resistance of pregnancy. Eleven primiparous healthy pregnant women (age: 27-39 years, body mass index 24.0±3.1 kg/m2) and no personal or family history of diabetes underwent magnetic resonance studies to quantify intramyocellular lipid, plasma lipid fractions, and insulin sensitivity. The meal-related insulin sensitivity index was considerably lower in pregnancy (45.6±9.9 vs. 193.0±26.1; 10(-4) dl/kg/min per pmol/l, p=0.0002). Fasting plasma triglyceride levels were elevated 3-fold during pregnancy (2.3±0.2 vs. 0.8±0.1 mmol/l, p<0.01) and the low-density density lipoprotein fraction, responsible for fatty acid delivery to muscle and other tissues, was 6-fold elevated (0.75±0.43 vs. 0.12±0.09 mmol/l; p=0.001). However, mean intramyocellular lipid concentrations of the soleus muscle were not different during pregnancy (20.0±2.3 vs. 19.1±3.2 mmol/l, p=0.64). The pregnancy effect on muscle insulin resistance is distinct from that underlying type 2 diabetes.
authors.affiliation: Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK. kenneth.hodson@ncl.ac.uk
authors.forename: K
authors.initials: K
authors.lastname: Hodson
authors.forename: C Dalla
authors.initials: CD
authors.lastname: Man
authors.forename: F E
authors.initials: FE
authors.lastname: Smith
authors.forename: P E
authors.initials: PE
authors.lastname: Thelwall
authors.forename: C
authors.initials: C
authors.lastname: Cobelli
authors.forename: S C
authors.initials: SC
authors.lastname: Robson
authors.forename: R
authors.initials: R
authors.lastname: Taylor
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D005260:Female; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance; D008077:Lipoproteins, LDL / Q000378:metabolism; D009132:Muscles / Q000378:metabolism; D011247:Pregnancy / Q000378:metabolism*; D014280:Triglycerides / Q000378:metabolism
chemical_list: D001786:Blood Glucose; D007328:Insulin; D008077:Lipoproteins, LDL; D014280:Triglycerides