Effect of sex and impaired glucose tolerance on organ-specific dietary fatty acid metabolism in humans

Abstract

Oral 14(R,S)-[18F]-fluoro-6-thia-heptadecanoic acid was used to determine whether an increase in cardiac dietary fatty acid (DFA) metabolism in impaired glucose tolerance (IGT) is different in men and women. Myocardial DFA partitioning after 6 h was higher in IGT versus control subjects (P = 0.006) in both men (2.14 [95% CI 1.70-2.18] vs. 1.28 standard uptake value [SUV] units [0.80-1.76]) and women (1.95 [1.57-2.33] vs. 1.64 SUV units [1.32-1.96]) without difference between sexes. Myocardial DFA fractional uptake (Ki) between time 90 and 120 min postprandially was also higher in IGT versus control subjects (P0.001) in men (0.063 [0.032-0.095] vs. 0.016 min21 [0.007-0.025]) and women (0.050 [0.024- 0.077] vs. 0.030 min21 [0.013-0.047]) without significant sex difference. Men had higher netmyocardial DFA uptake between time 90 and 120 min driven by higher chylomicrontriglyceride (TG) levels. IGT-associated increased cardiac DFA partitioning was directly related to obesity in women, whereas it was associated with IGT per se in men. We conclude that early cardiac DFA uptake is higher in men driven by change in postprandial chylomicron- TG level but that increase in 6-h postprandial cardiac DFA partitioning nevertheless occurs with IGT both in men and women.