Nocturnal regulation of free fatty acids in healthy young and elderly men

Metabolism. 1988 Jul;37(7):645-8. doi: 10.1016/0026-0495(88)90083-2.

Abstract

To determine the effects of age on nocturnal fuel regulation, we measured spontaneous plasma glucose and free fatty acid (FFA) levels as well as counterregulatory hormones in healthy young (n = 9, mean age 26 +/- 3 years) and old (n = 10, mean age 69 +/- 3 years) men from midnight to 8 AM. FFA levels rose from midnight (660 +/- 80 mEq/L for young subjects, 545 +/- 55 mEq/L for old) to a peak mean level of 866 +/- 110 mEq/L at 3 AM in young and 713 +/- 120 mEq/L at 1:30 AM in old (P less than .05). FFA levels declined thereafter for both groups. FFA levels were lower in older subjects (P less than .05) but integrated glucose (P less than .05) and insulin (P less than .05) levels were higher. FFA levels were inversely related to integrated insulin (r = -0.46, P less than .05) and glucose concentrations (r = -0.66, P less than .05). Integrated insulin levels were significantly higher in older subjects, which may explain the lower FFA levels as may lower growth hormone levels in the older subjects. While fasting glucose responsivity to endogenous insulin is impaired in healthy older men, the FFA response appears to be preserved.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aging*
  • Blood Glucose / analysis
  • Catecholamines / blood
  • Circadian Rhythm*
  • Energy Metabolism
  • Fatty Acids, Nonesterified / blood*
  • Growth Hormone / blood
  • Humans
  • Hydrocortisone / blood
  • Insulin / blood
  • Male
  • Time Factors

Substances

  • Blood Glucose
  • Catecholamines
  • Fatty Acids, Nonesterified
  • Insulin
  • Growth Hormone
  • Hydrocortisone