Elevations in systemic free fatty acids (FFA) contribute to insulin resistance. To determine the effects of an acute elevation in FFA on insulin action with aging, we infused saline or intralipid (IL) during a hyperinsulinemic-euglycemic clamp in three groups of rats: young ad libitum-fed (YAL), old ad libitum-fed (OAL), and old on lifelong calorie restriction (OCR). The OCR group was included to distinguish between aging per se and age-related changes in body fat distribution. IL induced marked insulin resistance in both YAL and OCR, but the onset of insulin resistance was approximately two to three times more rapid in OCR as compared with YAL. In response to IL infusion, plasminogen-activating inhibitor-1 (PAI-1) expression was increased in subcutaneous fat from OAL animals. In visceral fat, a marked increase in PAI-1 and interleukin-6 expression was observed in OAL and OCR rats, but not YAL, in response to IL treatment. Thus, aging per se increases the inflammatory response to excess nutrients and vulnerability to FFA-induced insulin resistance with aging.
|Number of pages||9|
|Journal||Journals of Gerontology - Series A Biological Sciences and Medical Sciences|
|State||Published - Aug 2010|
Bibliographical noteFunding Information:
This work was supported by grants from the National Institutes of Health (AG21654 and AG18381 to N.B. and K08 AG027462 to R.H.M.), the Core laboratories of the Albert Einstein Diabetes Research and Training Center (DK20541), and the American Association of Obstetricians and Gynecologists Foundation with the Society of Maternal-Fetal Medicine (to F.H.E). D.M.H. is supported by a T32 Training Grant (T32AG23475).
- Calorie restriction
- Insulin resistance
ASJC Scopus subject areas
- Geriatrics and Gerontology