Bergman BC, Howard D, Schauer IE, Maahs DM, Snell-Bergeon JK, Clement TW, Eckel RH, Perreault L, Rewers M. The importance of palmitoleic acid to adipocyte insulin resistance and whole-body insulin sensitivity in type 1 diabetes.
J Clin Endocrinol Metab 2013;
98:E40-50. [PMID:
23150678 PMCID:
PMC3537110 DOI:
10.1210/jc.2012-2892]
[Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT
Type 1 diabetes is an insulin-resistant state, but it is less clear which tissues are affected. Our previous report implicated skeletal muscle and liver insulin resistance in people with type 1 diabetes, but this occurred independently of generalized, visceral, or ectopic fat.
OBJECTIVE
The aim of the study was to measure adipose tissue insulin sensitivity and plasma triglyceride composition in individuals with type 1 diabetes after overnight insulin infusion to lower fasting glucose.
DESIGN, PATIENTS, AND METHODS
Fifty subjects (25 individuals with type 1 diabetes and 25 controls without) were studied. After 3 d of dietary control and overnight insulin infusion, we performed a three-stage hyperinsulinemic/euglycemic clamp infusing insulin at 4, 8, and 40 mU/m(2) · min. Infusions of [1,1,2,3,3-(2)H(2)]glycerol and [1-(13)C]palmitate were used to quantify lipid metabolism.
RESULTS
Basal glycerol and palmitate rates of appearance were similar between groups, decreased more in control subjects during the first two stages of the clamp, and similarly suppressed during the highest insulin dose. The concentration of insulin required for 50% inhibition of lipolysis was twice as high in individuals with type 1 diabetes. Plasma triglyceride saturation was similar between groups, but palmitoleic acid in plasma triglyceride was inversely related to adipocyte insulin sensitivity. Unesterified palmitoleic acid in plasma was positively related to insulin sensitivity in controls, but not in individuals with type 1 diabetes.
CONCLUSIONS
Adipose tissue insulin resistance is a significant feature of type 1 diabetes. Palmitoleic acid is not related to insulin sensitivity in type 1 diabetes, as it was in controls, suggesting a novel mechanism for insulin resistance in this population.
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