Submitted on February 17, 2005
Accepted on October 19, 2005
Whole body leucine flux in HIV-infected patients treated with or without protease inhibitors
Magali Prod'homme1, Cecile Rochon1, Michele Balage1*, Henri Laurichesse2, Igor Tauveron3, Claude Champredon1, Philippe Thieblot3, Jean Beytout2, and Jean Grizard1
1 Unite de Nutrition et Metabolisme Proteique, Centre de Recherche en Nutrition humaine , INRA, Clermont-Ferrand, France
2 Service des Maladies Infectieuses et Tropicales, Centre Hospitalier et Universitaire, Clermont-Ferrand, France
3 Service d'Endocrinologie et Maladies Metaboliques, Centre Hospitalier et Universitaire, Clermont-Ferrand, France
* To whom correspondence should be addressed. E-mail: balage{at}clermont.inra.fr.
The present study was carried out to assess the effects of protease inhibitor (PIs) therapy on both basal whole body protein metabolism and its response to an acute amino acid-glucose infusion in 14 human immunodeficiency virus (HIV)-infected patients. Patients treated with PIs (PI+, 7 patients) or without PIs (PI-, 7 patients) were studied after an overnight fast during a 180-min basal period followed by a 140-min period of amino acid-glucose infusion. Protein metabolism was investigated by a primed constant infusion of L- [1-13C]leucine. Dual X-ray absorptiometry (DEXA) for determination of fat free mass (FFM) and body fat mass (BFM) measured body composition.
In the postabsorptive state whole body leucine balance was 2.5 times (P < 0.05) less negative in the PI+ than in PI- group. In HIV-infected patients treated with PIs, the oxidative leucine disposal during an acute amino acid-glucose infusion was lower (0.58 ±0.09 vs 0.81 ±0.07 µmol.kg FFM -1.min-1 using plasma 13C-leucine enrichment, P = 0.06 or 0.70 ± 0.10 vs 0.99 ± 0.08 µmol.kg FFM -1.min-1 using plasma 13C-KIC enrichment, P = 0.04 in PI+ and PI- groups respectively) than in patients treated without PIs. Consequently, whole body nonoxidative leucine disposal (an index of protein synthesis) (+19-24 %, P < 0.05) and leucine balance (0.50 ± 0.10 vs 0.18 ± 0.06 µmol.kg FFM -1.min-1 in PI+ and PI- groups respectively, P < 0.05) were significantly improved during amino acid-glucose infusion in patients treated with PIs. However, whereas the response of whole body protein anabolism to an amino acid-glucose infusion was increased in HIV-infected patients treated with PIs, any improvement in lean body mass was detected.
