C‘lm~u~l Nurrimn , 1994) 13: 197

0 Longman Group Ltd 1994

Comments on recent literature

Long term effects of early nutritional support with new enterotropic peptide-based formula vs. standard enteral formula in HIV-infected patients: randomised prospective trial.

Chlebowski R T, Beall G, Grovenor M, Lillington L, Weintraub N, Ambler C, Richards E W, Abbruzzese B C, McCamish M A and Cope F 0.

Nutrition 1993; 9 (6): 507412

Abstract

This paper describes a prospective trial of a new peptide based formula (NEF) compared with a standard enteral for- mula (SEF) in the management of weight loss in people with HIV infection. 80 largely asymptomatic patients were randomised to receive 2-3 8 oz cans of either the NEF or SEF supplement. Outcome measures included adherence, weight change, anthropometric measurements, serum bio- chemistry, gastrointestinal symptoms, physical performance and intercurrent health events and were assessed at baseline, 3 and 6 month intervals. For the 56 evaluable patients those receiving the NEF supplement maintained body weight bet- ter (p = 0.04), had more stable triceps skinfold measure- ments (p = 0.03), lower blood urea nitrogen (p = 0.04), and reduced hospitalisation during the 3-6 month evaluation pe- riod (p = 0.02) than those consuming the SEF supplement. The NEF supplement was well tolerated and did not result in untoward clinical effects. These data suggest that the sup- plemental use of a NEF provides superior nutritional man- agement compared to an SEF for patients with early stage HIV infection.

Comment

The conclusion of this paper relies on demonstrating that in two groups of patients consuming similar amounts of en- ergy only those taking the novel peptide-containing supple- ment gained weight. However the reported changes in body weight are relatively small, with an increase of 4 lb in the novel supplement group and a loss of 1.5 lb in the conven- tional supplement group. The difference is only of border- line statistical significance (p = 0.04) and the clinical significance is unclear. Unfortunately the paper contains little information on the clinical course of these patients. A recent paper (Am J Clin Nutr 1993; 58: 417-424) which described patterns of weight change in people with HIV in- fection demonstrated that weight losses and gains are closely correlated with clinical events. In the absence of

more clinical data it is difficult to interpret the clinical significance of the final changes in body weight.

There is also the question as to whether the differences between the two groups simply reflect differences in the energy intake, rather than a specific effect of NEF supple- ment. Although no quantitative data on energy intakes are given the authors comment that energy intakes between the groups were ‘closely comparable’. Assuming that the weight gain in the group taking the NEF supplement con- sists of 40% lean tissue and 60% fat (Arch Int Med 1989; 149: 901-905) this requires an increase in energy intake of only 59 kcals per day for 6 months. This difference is likely to be close to the error of the methods used to measure energy intake since 5day food records are reported to be accurate to only f 10% of the mean (Nutr Abs Rev 1987: 57: 705-742). which would be approximately 200 kcals (although the total energy intake is not given). Furthermore since the volume of supplement consumed each day was equal, but the caloric density of the NEF is higher (see be- low), the NEF group received 78 kcals per day more than the SEF group from the supplement alone. The possibility that the different outcome between the groups is due to dif- ferences in the energy intake cannot be excluded. In order to rule out this possibility it would be useful to evaluate this novel formula against an iso-energetic supplement.

Although the paper suggests that the differences are due to the novel peptide there are several major differences in the two supplements used in this study. The SEF is a 1 kcal/ ml formula with 37.2 g/l protein, whilst the NEF contains 1.3 kcal/ml and 60.0 g/l protein. The NEF contains a novel peptide. MCT oil and fibre. is rich in a-3 fatty acids, and is supplemented with beta-carotene. Care must be taken before attributing any difference in outcome to any single nutrient. However it would be interesting to have further details about this peptide, its properties and its putative mode of action, particularly in this context.

This is an interesting paper which raises many questions about the use of novel nutrients in HIV infection and dem- onstrates the difficulties of finding appropriate endpoints in nutritional intervention studies. Clearly more studies using this product are needed to fully evaluate its use in this patient group.

Christine Baldwin, B SC SRD, Specialist Dietitian, King’s Healthcare,

London, SE5 9RS, UK

Carole Noble, B SC SRD, Specialist Dietitian,

St George’s Hospital, London.

SW17. UK

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