| Autor: |
Johnson, Nathan A., Stannard, Stephen R., Rowlands, David S., Chapman, Phillip G., Thompson, Campbell H., O'Connor, Helen, Sachinwalla, Toos, Thompson, Martin W. |
| Předmět: |
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| Zdroj: |
Experimental Physiology; Jul2006, Vol. 91 Issue 4, p693-703, 11p, 4 Charts, 3 Graphs |
| Abstrakt: |
It is currently believed that intramyocellular triglyceride (IMTG) accumulation and insulin resistance are a consequence of dietary fat ingestion and/or the elevated circulating lipid levels associated with chronic fat surplus. The purpose of this study was to compare the effect of short-term starvation versus low-carbohydrate (CHO)/high-fat diet on IMTG accumulation and the development of insulin resistance in physically fit men. Intramyocellular triglyceride content, measured as intramyocellular lipid (IMCL) by proton magnetic resonance spectroscopy (1H-MRS), and glucose tolerance/insulin sensitivity, assessed by frequently sampled intravenous glucose tolerance test (IVGTT), were determined after 67 h of: (a) water-only starvation (S); and (b) very low-CHO/high-fat diet (LC). These diets had in common significant restriction of CHO availability but large differences in fat content. All results were compared with those measured after a mixed CHO diet (C). Dietary interventions were administered by cross-over design. The level of dietary-induced IMTG accumulation ( P= 0.46), insulin resistance ( P= 0.27) and glucose intolerance ( P= 0.29) was not different between S and LC treatments. Intramyocellular triglyceride content and insulin sensitivity were negatively correlated ( r=−0.63, P < 0.01). Therefore, whilst insulin resistance may be due to fat accumulation at a cellular level, in the integrated human organism this outcome is not exclusively a function of dietary fat intake. The comparable level of IMTG accumulation and insulin resistance following S and LC may suggest that these metabolic perturbations are largely a consequence of the increased lipolytic response associated with CHO restriction. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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