Stefan N, Wahl H G, Fritsche A, Häring H, Stumvoll M
Medizinische Klinik, Abteilung für Endokrinologie, Stoffwechsel und Pathobiochemie, Eberhard-Karls-Universität, Tübingen, Germany.
Horm Metab Res. 2001 Jul;33(7):432-8. doi: 10.1055/s-2001-16231.
In order to investigate whether the pattern of elevated free fatty acids (FFAs) has any effect on insulin sensitivity and insulin secretion in humans, we produced 2 distinct serum FFA patterns (PT 1 and 2) by infusing 6 healthy volunteers with 2 different lipid emulsions plus heparin for 24 hours. A hyperglycemic clamp (approx. 8 mM, 140 min) was performed before and 5 and 24 hours after both lipid infusions to determine insulin sensitivity and insulin secretion simultaneously. Total FFAs had increased comparably by 24 hours (2020+/-268 microM in PT 1) and (1812+/-154 microM in PT 2, p =0.24). Serum PT 1 contained 66% saturated FFAs plus monoenes and 34% polyenes, while PT 2 contained 80% saturated FFAs plus monoenes and 20% polyenes. Thus, the ratio of polyunsaturated to saturated plus monoenes was about 0.5 in PT 1 vs. 0.25 in PT 2. In PT 1, the insulin sensitivity index (ISI) decreased by 20 +/- 7% and 27 +/- 10% from basal after 5 and 24 hours, respectively. In PT 2, the ISI decreased significantly more after 5 (41+/-7%, p = 0.008) and 24 hours (52+/-6%, p = 0.005). In contrast, different phases of insulin secretion did not change during the lipid infusion and did not vary between the two FFA profiles. In conclusion, these findings provide preliminary evidence that the composition of elevated serum FFAs influenced insulin sensitivity in humans. The FFA pattern low in polyunsaturated FFAs reduced insulin sensitivity more than the pattern high in polyunsaturated FFAs. In contrast, no effect on insulin secretion was observed.
为了研究游离脂肪酸（FFA）升高模式是否对人类胰岛素敏感性和胰岛素分泌有任何影响，我们通过给6名健康志愿者输注两种不同的脂质乳剂加肝素24小时，产生了2种不同的血清FFA模式（PT 1和2）。在两种脂质输注前、输注后5小时和24小时进行高血糖钳夹（约8 mM，140分钟），以同时测定胰岛素敏感性和胰岛素分泌。到24小时时，总FFA水平相对升高（PT 1中为2020±268 μM）和（PT 2中为1812±154 μM，p = 0.24）。血清PT 1含有66%的饱和FFA加单烯和34%的多烯，而PT 2含有80%的饱和FFA加单烯和20%的多烯。因此，PT 1中多不饱和脂肪酸与饱和脂肪酸加单烯的比例约为0.5，而PT 2中为0.25。在PT 1中，胰岛素敏感性指数（ISI）在5小时和24小时后分别比基础值降低了20±7%和27±10%。在PT 2中，ISI在5小时（41±7%，p = 0.008）和24小时（52±6%，p = 0.005）后显著降低更多。相比之下，在脂质输注期间胰岛素分泌的不同阶段没有变化，并且在两种FFA谱之间也没有差异。总之，这些发现提供了初步证据，表明升高的血清FFA组成影响了人类的胰岛素敏感性。多不饱和FFA含量低的FFA模式比多不饱和FFA含量高的模式更能降低胰岛素敏感性。相比之下，未观察到对胰岛素分泌的影响。
