Plasma free iron: a possible cause of oedema in kwashiorkor

Micronutrient status in children aged 6-59 months with severe wasting and/or nutritional edema: implications for nutritional rehabilitation formulations

Undernutrition remains a global struggle and is associated with almost 45% of deaths in children younger than 5 years. Despite advances in management of severe wasting (though less so for nutritional edema), full and sustained recovery remains elusive. Children with severe wasting and/or nutritional edema (also commonly referred to as severe acute malnutrition and part of the umbrella term "severe malnutrition") continue to have a high mortality rate. This suggests a likely multifactorial etiology that may include micronutrient deficiency. Micronutrients are currently provided in therapeutic foods at levels based on expert opinion, with few supportive studies of high quality having been conducted. This narrative review looks at the knowledge base on micronutrient deficiencies in children aged 6-59 months who have severe wasting and/or nutritional edema, in addition to highlighting areas where further research is warranted (See "Future Directions" section).

Nutritional and other types of oedema, albumin, complex carbohydrates and the interstitium - a response to Malcolm Coulthard's hypothesis: Oedema in kwashiorkor is caused by hypo-albuminaemia

The various types of oedema in man are considered in relation to Starling's hypothesis of fluid movement from capillaries, with the main emphasis on nutritional oedema and the nephrotic syndrome in children. It is concluded that each condition has sufficient anomalous findings to render Starling's hypothesis untenable. The finding that the endothelial glycocalyx is key to control of fluid movement from and into the capillaries calls for complete revision of our understanding of oedema formation. The factors so far known to affect the function of the glycocalyx are reviewed. As these depend upon sulphated proteoglycans and other glycosaminoglycans, the argument is advanced that the same abnormalities will extend to the interstitial space and that kwashiorkor is fundamentally related to a defect in sulphur metabolism which can explain all the clinical features of the condition, including the formation of oedema.

The elephant moves into the sunlight: progress in childhood malnutrition

Beginning with a historical summary of investigative work into protein-energy malnutrition, now termed 'severe acute malnutrition', this review ends by summarizing recent initiatives to tackle the global problem of malnutrition, specifically Scaling-Up Nutrition (SUN). In early years, macronutrient deficiency or imbalance was considered the principal cause of complex metabolic disturbances, including kwashiorkor, whereas, now, micronutrient deficiency infections, including HIV, and a background of deprivation are implicated. Different approaches to management are reviewed. The rehabilitation of individual children by protocolised-phased feeding has largely given way to community-based therapeutic feeding. Despite sporadic successes, the overall impact on morbidity and mortality has been so disappointing that the global community now plans a new initiative, viz. SUN. Its focus on the critical window of 1000 days (from conception to 2 years) is similar to the earlier focus on early childhood vulnerability which inspired the under-5 clinics and their integration into maternal and child health programmes. 'Targeted' interventions, recently more prominent than integrated community-based primary care, often undertaken by NGOs, have been effective, although sometimes imperfectly accountable. Will SUN, aiming for a broad approach, and the participation of recipient communities finally succeed in integrating nutrition into child health?

Proposed Recommended Nutrient Densities for Moderately Malnourished Children

Recommended Nutrient Intakes (RNIs) are set for healthy individuals living in clean environments. There are no generally accepted RNIs for those with moderate malnutrition, wasting, and stunting, who live in poor environments. Two sets of recommendations are made for the dietary intake of 30 essential nutrients in children with moderate malnutrition who require accelerated growth to regain normality: first, for those moderately malnourished children who will receive specially formulated foods and diets; and second, for those who are to take mixtures of locally available foods over a longer term to treat or prevent moderate stunting and wasting. Because of the change in definition of severe malnutrition, much of the older literature is pertinent to the moderately wasted or stunted child. A factorial approach has been used in deriving the recommendations for both functional, protective nutrients (type I) and growth nutrients (type II).

Hierro libre, transferrina y ferritina séricas en desnutrición aguda grave

INTRODUCTION

"Free" serum iron has been associated with the development of edema in Kwashiorkor-type severe acute malnutrition.

MATERIAL AND METHODS

A descriptive, cross sectional study was performed. Twenty-four children with edematous malnutrition, 22 with marasmus and 20 without malnutrition were compared. "Free" iron, transferrin, saturation index and attachment capacity of iron, ferritin, total protein, albumin, total iron, and C-reactive protein (CRP) were determined in serum.

RESULTS

A significant difference was found between malnourished children with "free" serum iron and the control group in which "free" iron was not found. However, no significant differences were found in "free" serum iron levels between marasmatic and edematous children. Transferrin was negatively correlated with "free" iron (r=-0.519; p=0.000). Total proteins, albumin and transferrin were all significantly lower in children with edema than in those with marasmus. A low transferrin level and a high saturation index could be used to estimate the probability of edema in 67.5% of cases (p=0.001).

CONCLUSIONS

Severe acute malnutrition was associated with the presence of "free" serum iron both in children with marasmus and in those with edema. "Free" iron does not explain the presence of edema but, as with severe hypoalbuminemia, the concurrence of a low transferrin level and a high saturation index may contribute to the etiology of edema.

Palm versus soybean oil on intestinal recovery from malnutrition in Guinea pigs

Recent recommendations on feeding malnourished children do not provide indication on the nature of dietary lipids. Our aim was to compare the effect of palm oil (mainly saturated and monounsaturated fatty acids) and soybean oil (mainly polyunsaturated fatty acids) on the recovery from malnutrition in guinea pigs. In a first experiment, guinea pigs received a balanced (control group) or a maize (malnourished group) diet for 7, 12, and 21 d. In a second experiment, after 12 d of malnutrition, guinea pigs received a rehabilitation diet containing palm or soybean oil. Both rehabilitation diets allowed a partial recovery from the severe weight loss induced by malnutrition. Thiobarbituric acid reactive substances content, measured in intestinal homogenates, increased in malnourished guinea pigs compared with control animals (40%, p < 0.05) and returned to near control values after rehabilitation with palm (10%) but not soybean (43%) oil diet. Intestinal short-circuit current, assessed in jejunal segments mounted in Ussing chambers, increased progressively during malnutrition (p < 0.001) and returned to near control values with both rehabilitation diets. Compared with control animals, the cell turnover (Ki-67 index assessed by immunohistochemistry detection of the Ki-67 antigen) decreased after soybean (-60%, p < 0.01) but not after palm oil. These results confirm that experimental polydeficient malnutrition induces oxidative stress and dysfunction in the intestine. They show a differential effect of palm and soybean oil on these intestinal measurements, suggesting that the composition of dietary lipids may be important in the treatment of malnutrition.

The capacity of different infusion fluids to lower the prooxidant activity of plasma iron: an important factor in resuscitation?

BACKGROUND

Prooxidant activity of non-protein-bound iron (NPBI) is an important contributor to reactive oxygen species-induced injury after the resuscitation of critically ill patients. Plasma NPBI occurs in critically ill adults, children, and newborn babies, who often require resuscitation. The ability of the resuscitation fluids to bind iron and lower the patients' NPBI levels in vitro has not previously been studied.

STUDY DESIGN AND METHODS

In an in vitro model, highly iron-saturated cord blood plasma from 10 preterm and 10 term babies was mixed with FFP, pasteurized plasma protein solution, and 0.9-percent saline. Plasma from 10 healthy adult volunteers was used as a control. Before and after the mixing with any resuscitation fluid, NPBI levels and ceruloplasmin iron-oxidizing and transferrin iron-binding antioxidant capacities were measured.

RESULTS

After the in vitro mixing with FFP, the incidence and concentration of NPBI were markedly decreased and the iron-binding antioxidant capacity was increased in the plasma of the preterm and term babies. Being mixed with pasteurized plasma protein solution and 0.9-percent saline did not influence the iron-binding antioxidant capacity of newborn babies' plasma. In the control plasma, results were not changed after the mixing with any resuscitation fluid. In every group, the iron-oxidizing antioxidant capacity was not changed after the mixing with any fluid.

CONCLUSION

Iron-induced oxidative tissue damage may be influenced by resuscitation fluids. In the ongoing debate over the choice of crystalloid or colloid resuscitation fluids, the influence of each fluid on the patient's antioxidant capacity warrants more attention.

New concepts on nutritional management of severe malnutrition: the role of protein

Current guidelines for the management of severe malnutrition are mainly based on new concepts regarding the causes of malnutrition and on advances in our knowledge of the physiological roles of micronutrients. In contrast to the early 'protein dogma', there is a growing body of evidence that severely malnourished children are unable to tolerate large amounts of dietary protein during the initial phase of treatment. Similarly, great caution must be exercised to avoid excessive supply of iron and sodium in the diet, while keeping energy intake at maintenance levels during early treatment. Because severely malnourished children require special micronutrients, a mineral-vitamin mix is added to the milk-based formula diets, which are specially designed for the initial treatment and the rehabilitation phase. To further improve nutritional rehabilitation and reduce cases of relapse, 'ready-to-use therapeutic food' and 'ready-to-eat nutritious supplements' with relatively low protein (10% protein calories) and high fat content (54-59% lipidic calories) have been developed. Although current dietary recommendations do not differentiate between oedematous and nonoedematous forms of malnutrition or between adults and children, there are indications that further clarification is still needed for applying dietary measures for specific target groups.