Relationships of plasma leptin levels to changes in plasma free fatty acids in women who are lean and women who are abdominally obese

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22 Scopus citations

Abstract

Regulation of leptin production by the hormonal and metabolic milieu is poorly understood. Because abdominal obesity is commonly associated with elevated plasma free fatty acid (FFA) flux, we examined the effects of augmenting FFA on plasma leptin levels in women who were lean and of suppressing FFA in women with abdominal obesity. In study 1, nine subjects who were lean, after a 12-hour overnight fast, received either intravenous saline or Intralipid plus heparin to increase the plasma FFA concentration to approximately 1000 μmol/ L. After 3 hours of additional fasting, subjects underwent 3-hour hyperglycemic clamps. In study 2, seven subjects with abdominal obesity were evaluated by a similar protocol, but lipolysis and plasma FFA flux were instead maximally suppressed by acipimox. In the individuals who were lean, leptin levels were unchanged during clamping. Increasing plasma FFA reduced plasma leptin from 7.66 ± 0.66 to 7.05 ± 0.66 (p=0.03), but 3 hours of hyperglycemia plus hyperinsulinemia had no additional effect on leptin levels (7.15 ± 0.71). Basal leptin levels, 4-fold higher in the subjects with obesity, were reduced from 34.6 ± 2.4 μg/L to 32.3 ± 1.1 μg/L (p=0.004) during the clamp period. When plasma FFA flux was suppressed, however, plasma leptin levels after clamped hyperglycemia/hyperinsulinemia were increased to 38.9 ± 1.2 μg/L (p=0.014 vs. time 0 and 0.001 vs. saline protocol). Changes in leptin concentrations are not correlated with changes in FFA. These results suggest that plasma FFA concentration does not regulate plasma leptin levels in basal, extended fasting, or hyperglycemic/hyperinsulinemic states.

Original languageEnglish (US)
Pages (from-to)442-446
Number of pages5
JournalObesity research
Volume5
Issue number5
DOIs
StatePublished - 1997

Keywords

  • Abdominal obesity
  • Free fatty acids
  • Insulin
  • Leptin

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Food Science
  • Endocrinology, Diabetes and Metabolism
  • Endocrinology
  • Public Health, Environmental and Occupational Health

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