Place et impact des régimes chez les personnes très âgées

Successful ageing promotion is a major goal of care in geriatrician patients, even in old age. Cardiovascular prevention strategy, diabetes care or kidney protection involve dietary management. However, mortality and morbidity risk factors are modified in the oldest old, and on the other hand, dietary restrictions could impair health status of the older. Studies devoted to the oldest old are scarce. In most situations, exercise training promotion seems to better address the prevention goals than do diets.     

L’évaluation nutritionnelle chez le sujet âgé en 2008

Malnutrition is frequent in elderly patients and results from multifactorial mechanisms, including age-related metabolic alterations, reduction of food intake and intercurrent diseases, especially inflammatory processes, that compromise nutritional status. Nutritional evaluation must be systematically and repeatedly performed and based primarily on clinical parameters such as weight, body mass index, weight loss, anthropometric measurements and dietetic history eventually combined in scores such as the mini-nutritional assessment (MNA). Fat-free mass evaluated by bioimpedance analysis has a prognostic value. Hypoalbuminemia is indicative of bad prognosis and may be combined with weight loss in the geriatric nutritional risk index (GNRI) to assess the nutritional risk. The determination of plasma transthyretin (prealbumin) is especially useful to assess acute malnutrition state and the response to nutritional support. Routine determination of the above criteria may be facilitated by the spreading of simple integrated tools and a better education of health professionals to the screening and active treatment of malnutrition in the elderly.     

Propositions de structuration des commissions de menus en établissements d’hébergement pour personnes âgées dépendantes

Menu Committees (MC) are frequently present in French geriatric institutions like nursing homes, but with variable functioning conditions. Their aims are theoretically to favour communication about food, and to validate menus in each institution. However, statutory frame and bibliography on MC are poor and consequently pragmatic propositions based on daily practice can be made. They give optimal aims of MC, its composition including which role each participant plays and the functioning conditions before, during and after MC. A better satisfaction of residents, medical practitioners and employees, combined with surveys showing improvements in food supply could be signs of a good efficiency for MC.     

Programme de soins communautaires pour les personnes âgées « Des Années à Savourer »

The ageing of population and socioeconomic changes in our societies oblige us to explore other forms of action and geriatrics organizations. Promotion and prevention programs are obvious. Elderly diet in community becomes field of priority interventions for geriatrics teams. The ten years Geneva experiment is recounted in this article.     

Variation de l'équilibre hydrique de la personne âgée

Total body water is the sum of extracellular and intracellular compartments, and is reduced with age. This, together with the difficulties to maintain and fine tune water inflows and outflows make the elderly person highly succeptible to dehydration during acute episodes of disease. Clinical and biogical evaluation are indirect and the only validated tools to estimate hydration status. Measurements of body water spaces by isotope dilution or bioelectrical impedance analysis are possible and technically reliable. However, measured values need to be compared with reference values, which are not yet available. Building reference data base is the necessary fisrt step before progress can be made about optimal hydration and its influence over aging.     

Interventions pour restaurer la masse musculaire du sujet âgé

Resistance exercice training is the most efficient intervention to prevent or limit sarcopenia in elderly. Studies with anabolic treatments have poor results. Because old persons have low energy and protein intakes, increased protein intakes over 0.8–1.0 g/kg of body weight per day could enhance exercice efficacy.     

Effets ventilatoires d'une solution d'acides aminés chez des insuffisants respiratoires chroniques obstructifs

The enhancement of ventilatory drive induced by amino acids (AA) has only been demonstrated in healthy subjects and in patients with nutritional depletion. The ventilatory effects of AA are more pronounced with branched chain amino acid (BCAA)-enriched AA solutions. This study examined the ventilatory effects of AA in patients with chronic obstructive pulmonary disease (COPD). Six hundred and seventy ml (nitrogen intake = 8 g) of BCAA-enriched AA solution (Valinor^®) was infused over a 4-hour period in 5 patients with COPD. Tidal volume, minute-ventilation and the ventilatory response to CO₂ increased in all 5 patients during the AA infusion, while PaCO₂ decreased in three. These results indicate that amino acids enhance ventilatory drive in COPD patients.     

L'altération des fonctions sensorielles et de l'appétit est-elle une fatalité chez le sujet âgé ?

Profound differences of appetite occur in older persons. Appetite correlates poorly with body weight in older persons, leading to failure to increase ingestion of nutrients in response to weight loss. Older persons exhibit less hunger and earlier satiety. Dramatic and poorly understood alterations occur in the physiologic regulation of appetite. The response to social and psychological stimulants is similar to younger adults. The screening for sensory impairment should be included in the comprehensive geriatric assessment. Pharmacologic stimulants of appetite suggest a promising intervention for anorexia.     

Intérêt de l'administration par voie orale d'acides aminés à chaîne ramifiée chez le cirrhotique encéphalopathe chronique

In the past 10 years several controlled studies have been published on the use of oral BCAA supplementation in patients with cirrhosis and chronic encephalopathy. Differences in trial design, end-point and treatment make any meta-analysis of the results impossible. From a review of the literature it appears that BCAA are safe and constitute a useful, non-comagenic source of nitrogen. Their superiority over other nitrogen sources (casein) is doubtful, but in long-term studies there seems to be an advantage in terms of encephalopathy, nutritional parameters and possibly survival. Given their low cost/effectiveness, other studies are justified to identify patients who may benefit most from long-term BCAA treatment.     

Influence des acides gras polyinsaturés n-3 et des antioxydants alimentaires sur les acides gras de la viande et la lipoperoxydation chez le bovin en finition

This study aimed at analysing the impact, on beef lipids and fatty acids and on beef colour, of dietary lipid supplements provided by extruded linseeds (rich in n-3 polyunsaturated fatty acids, n-3 PUFA) alone or with extruded rapeseed (rich in n-6 and n-3 PUFA and in 18:1n-9) in association or not with dietary antioxidants in cull dairy cows in finition. Dietary linseeds increased significantly proportions of 18:3n-3 (+56% and +36% respectively), of total trans 18:1 (+66% and +105%); and of 9cis,11trans 18:2 (CLA) (+50% and +41%) in Longissimus thoracis and Semitendinosus muscles, 18:3n-3 and CLA being known to be beneficial for the human health. Antioxidant supplements (association of vitamin E with plant extracts rich in polyphenols, PERP) reinforced the stimulating effect of lipid supplements on proportions of 18:3 n-3, 18:1trans, and 9cis,11trans 18:2 in lipids of the two muscles. Dietary n-3 PUFA reduced the capacity of plasma to resist against lipoperoxidation (−11%) favouring the formation of peroxides such as conjugated dienes (× 1.75) and malonedialdehyde (MDA, ×2). Intensity of lipoperoxidation tended to increase in beef packaged under modified atmosphere rich in oxygen (O₂/CO₂: 70/30) of the linseed group (2.96 μg/g fresh tissue) when compared to that in the control group (2.19 μg/g, p = 0.1). Combined supply of vitamin E and PERP efficiently protected beef against lipoperoxidation, even in beef packaged under modified atmosphere rich in oxygen. Beef samples packaged under air from cows of the linseed group exhibited a more intense red colour than that of cows of the control group. In cows of the linseed group submitted to an emotional stress 2 hours before slaughtering, beef samples packaged under the air or the O₂-rich atmosphere had a red colour with a lower intensity that beef samples from cows of the linseed plus antioxidants group. In conclusion, feeding strategy for finishing cull cows combining lipid (from linseed rich in n-3 PUFA) and antioxidant (vitamin E + PERP) supplements improve the health value of beef fatty acids avoiding the major risks of beef lipoperoxidation and of alteration of beef colour whatever (i) the conditions of beef ageing and packaging (especially with O₂), (ii) the level of emotional stress of animals just before slaughtering.     

Malnutrition et épilepsie : des liens complexes

A link between malnutrition and epilepsy has been suspected for many years. Several studies which have been performed on animal models or on humans highlighted the adverse effects of malnutrition in the onset of seizures. Proteinoenergetic, electrolytes, vitamine or trace-element deficiencies could be implied. The possible negative effect of epilepsy on nutritional status has also been studied, with several determinants leading to malnutrition: foods which are forbidden during epilepsy in developing countries and probably in France, social exclusion which is common for people with epilepsy, role of antiepileptic diets or treatments on appetite for example. Two different hypotheses exist as a vicious circle: malnutrition predisposing to epilepsy or conversely epilepsy predisposing to malnutrition.     

Effect de l'hGH sur le métabolisme des protéines et des acides aminés chez l'homme

The increased availability of human Growth Hormone (rhGH) as a result of recombinant molecular biology has provided the opportunity to explore its actions and potential utility in humans. rhGH administration is associated with an increase in the resting energy expenditure of GH-deficient adults, but has little effect on the resting energy expenditure of GH-sufficient individuals. By mechanisms which remain to be elucidated, rhGH increases the oxidation of fat, decreases the oxidation of protein, and has little effect on the oxidation of carbohydrate. The net effect of these changes in substrate oxidation is a reduction in fat mass and an increase in muscle mass in GH-deficient adults, and increased linear growth in GH-deficient children. The primary mechanism of rhGH on whole body protein would appear to increase the whole body rate of protein synthesis with little effect on the rates of proteolysis in both the fasting and intracibal conditions. rhGH appears to increase acutely the rates of protein synthesis in forearm tissues, but has little effect on muscle mass or strength following 3 months of treatment in GH-sufficient adults. The effects of rhGH on two experimental models of protein catabolism in humans (caloric restriction and glucocorticosteroid treatment) are reviewed. Our knowledge of the actions and utility of rhGH as a therapeutic agent has increased tremendously over the last decade. However, a great deal remains to be discovered about the specific genes induced or suppressed as a result of rhGH treatment before we will be knowledgeable in all of its potential clinical applications.