Insulin regulation of lipolysis in nondiabetic and IDDM subjects

Michael Dennis Jensen, M. Caruso, V. Heiling, J. M. Miles

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227 Scopus citations

Abstract

To determine whether insulin regulation of lipolysis is abnormal in subjects with poorly controlled insulin-dependent diabetes mellitus (IDDM), free-fatty acid flux ([1-14C]palmitate) was measured under conditions ranging from complete insulin withdrawal to hyperinsulinemia. Seven nondiabetic and seven IDDM subjects were studied with the pancreatic clamp technique to control plasma insulin, growth hormone, and glucagon concentrations at the desired levels. Preliminary studies were performed to validate the experimental design. The palmitate flux response to insulin withdrawal (2.5 ± 0.2 vs. 2.5 ± 0.2 μmol · kg-1 · min-1) and maximally antilipolytic insulin concentrations (0.17 ± 0.02 vs. 0.23 ± 0.03 μmol · kg-1 · min-1) were not different in nondiabetic and IDDM subjects, respectively. In contrast, IDDM subjects required significantly greater plasma free-insulin concentrations to result in equivalent suppression of palmitate flux compared with nondiabetic subjects. Lipolysis was found to be very sensitive to insulin in nondiabetic humans, with half-maximal suppression occurring at plasma free-insulin concentrations of ~12 pM (< 2 μU/ml). We conclude that adipose tissue lipolysis is normally exquisitely sensitive to insulin and that sensitivity, but not responsiveness to insulin, is impaired in poorly controlled IDDM.

Original languageEnglish (US)
Pages (from-to)1595-1601
Number of pages7
JournalDiabetes
Volume38
Issue number12
StatePublished - 1989

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ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Internal Medicine

Cite this

Jensen, M. D., Caruso, M., Heiling, V., & Miles, J. M. (1989). Insulin regulation of lipolysis in nondiabetic and IDDM subjects. Diabetes, 38(12), 1595-1601.