Total parenteral nutrition in the surgical patient: a meta-analysis

OBJECTIVE

To examine the relationship between total parenteral nutrition(TPN) and complication and death rates in surgical patients.

DATA SOURCES

A computer search of published research on MEDLINE, personal files and a review of relevant reference lists.

STUDY SELECTION

A review of 237 titles, abstracts or papers. Primary studies were included if they were randomized clinical trials of surgical patients that evaluated the effect of TPN (compared to no TPN or standard care) on complication and death rates. Studies comparing TPN to enteral nutrition (EN) were excluded.

DATA EXTRACTION

Relevant data were abstracted on the methodology and outcomes of primary studies. Data were independently abstracted in duplicate.

DATA SYNTHESIS

There were 27 randomized trials in surgical patients that compared the use of TPN to standard care (usual oral diet plus intravenous dextrose). When the results of these trials were aggregated, there was no effect on mortality (risk ratio = 0.97, 95% confidence intervals, 0.76 to 1.24). There were fewer major complications in patients who received TPN, although there was significant heterogeneity in the overall estimate (risk ratio = 0.81, 95% CI, 0.65 to 1.01). Because of this significant heterogeneity, several a priori hypotheses were examined. Studies that included only malnourished patients demonstrated a trend to a reduction in complication rates but no difference in death rate when compared with studies of patients who were not malnourished. Studies published in 1988 or earlier and studies with a lower methods score were associated with a significant reduction in complication rates and a trend to a reduction in death rate when compared with studies published after 1988 and studies with a higher methods score. There was no difference in studies that provided lipids as a component of TPN when compared with studies that did not. Studies that initiated TPN preoperatively demonstrated a trend to a reduction in complication rates but no difference in death rate when compared with studies that initiated TPN postoperatively.

CONCLUSIONS

TPN does not influence the death rate of surgical patients. It may reduce the complication rate, especially in malnourished patients, but study results are influenced by methodologic quality and year of publication.

Clinical usefulness of the mini nutritional assessment (MNA) scale in geriatric medicine

OBJECTIVE

This study was undertaken to estimate the prevalence of malnutrition in elderly patients hospitalized with an acute illness, as well as to assess the clinical usefulness of standardized nutritional assessment upon admission by means of the MNA scale.

DESIGN

A prospective study.

SETTING

A large size regional university hospital.

SUBJECTS

There were 175 patients (113 women and 62 men) with a mean age of 79.7 + 8.5 years admitted for an acute problem. Death occurred in 11 patients (6.3%).

METHODS

Upon admission, demographic (age, gender, origin) and medical (disease, drugs) data were recorded for each patient; the MNA questionnaire (score: 0-30) was administered and Katz score (7-28) calculated. At hospital discharge, data included Katz score, outcome (death/survival), and destination.

RESULTS

The mean MNA score was 20.5 + 5.1 and the prevalence of severe malnutrition (MNA <17) was 21.7%. Further, 48.6% of elderly were at risk of malnutrition (MNA between 17 and 24). There was no association between MNA and age or gender, but underweight was a sign of low MNA values (P <.001). MNA scores were inversely related to Katz scores at both admission and hospital discharge (P <.001). Patients originating from nursing homes had a poorer nutritional status than those living at home (MNA: 18.4 against 22.3, P <.001). The number of drugs taken per patient (5.2 + 2.8) was found to be correlated with MNA (P =.049). MNA scores were on average significantly higher (P <.001) in survivors (20.9) than in nonsurvivors (14.1).

CONCLUSIONS

The study clearly demonstrates the high prevalence of malnutrition and the clinical usefulness of the MNA scale in geriatric medicine. The MNA score upon admission reflects the patient's nutritional condition, degree of autonomy (Katz score), living conditions and current treatment. It is also predictive of patient's outcome (death or survival).

Association between nutritional indicators and infectivity of dogs seroreactive for Trypanosoma cruzi in a rural area of northwestern Argentina

The association between the nutritional state of mongrel dogs naturally infected with Trypanosoma cruzi and their infectivity to Triatoma infestans bugs and immune response to Trypanosoma cruzi were studied in the rural village of Amamá, northwestern Argentina. All of the 97 evaluated dogs were classified into one of three categories of external clinical aspect (ECA) based on the degree of muscle development, external evidence of bone structures, state of the hair of the coat, existence of fatty deposits, and facial expression. ECA was significantly associated with two nutritional indicators, hematocrit and skin-fold thickness, but not with total serum proteins. For all dogs, hematocrit was significantly correlated with skin-fold thickness. The 2-year survival probability decreased significantly from 60.7% for dogs with good ECA to 45.9% and 31.2% for those with regular and bad ECA, respectively. The age-adjusted relative odds of infection for Triatoma infestans xeno-diagnosis nymphs that fed once on a dog seroreactive for Trypanosoma cruzi decreased significantly as ECA improved, when tested by multiple logistic regression analysis. A delayed hypersensitivity reaction was observed in all of the seroreactive dogs with good ECA but only in 45-50% of those with regular or bad ECA. Dogs with bad ECA had a 2.6 and 6.3 times greater probability of infecting triatomines after a single full blood meal than dogs with regular or good ECA, respectively. Our study shows that the reservoir competence of dogs for Trypanosoma cruzi was associated with ECA, which is a surrogate and valid index of nutritional state.

Epidemiological study of malnutrition in elderly patients in acute, sub-acute and long-term care using the MNA

MNA is a simple and accurate way to assess the nutritional status in routine practice, and is suitable for systematic use and large epidemiologic studies. The purpose of this study was to evaluate the difference in the nutritional status of elderly patients hospitalized in different types of care in the same hospital, and to evaluate its relationship with risk factors. Nutritional status was evaluated in 918 elderly patients hospitalized in acute care (AC) (n=299), sub-acute care (SAC) (n=196) or long-term care (LTC) (n=423), using the MNA (Mini-Nutritional Assessment), a nutritional assessment tool including 18 items grouped in 4 domains, within the first 48 h after admission (all subjects) and at the end of hospitalization (AC, SAC). More patients were rated in the "malnourished" class in SAC (32.5%) than in AC (24.5%) and LTC (24. 7%). Retrospective analysis showed that the initial nutritional status was linked to the type of care and the nature of underlying pathology. The nutritional status on arrival was worse in patients in SAC, and better in those in LTC (p = 0.005). This is probably due to a difference in the kind of patients hospitalized. The nutritional status was worse in patients suffering from infectious disease, stroke, dementia and traumatic injuries, and, conversely, better in patients suffering from cardiopathy, metabolic and gastro-intestinal (except cancerous) diseases (p < 0.0001). Prospective analysis showed that duration of hospitalization was the only variable found to be linked to an improvement of nutritional status. The MNA is a rapid, effective and cheap tool for the assessment of nutritional status and moreover for evaluation of the mortality risk of patients admitted into AC and SAC.

Evaluating the clinical management of severely malnourished children--a study of two rural district hospitals

BACKGROUND

Severe malnutrition is an important cause of preventable mortality in most South African hospitals. Work recently done in two rural Eastern Cape hospitals supports the literature which shows that many deaths occur as a result of outdated clinical practices and that improving these practices reduces case fatality rates. Rapid assessment of clinical management in paediatric wards is necessary to highlight areas for improvement.

OBJECTIVE

To assess the management of severely malnourished children in two rural district hospitals and to recommend improvements for their care.

METHODS

Based on draft World Health Organisation (WHO) guidelines for inpatient care of children with severe malnutrition, data collection instruments were developed in conjunction with the district nutrition team to assess the quality of care given to malnourished children in two Mount Frere hospitals, Eastern Cape. Data were collected through retrospective review of case records, with detailed studies of selected cases, structured observations of the paediatric wards, and interviews with ward sisters and doctors.

RESULTS

The combined case fatality rate for severe malnutrition was 32%. Inadequate feeding, poor management of rehydration and infection, lack of resources, and a lack of knowledge and motivation among staff were identified as areas that need attention.

CONCLUSION

The clinical management of severely malnourished children can be rapidly assessed to highlight areas for improvement. Involving staff in the assessment process has led to their active involvement in improving the management of malnourished children in their hospitals.

[Malnutrition and mortality in hemodialyzed patients]

BACKGROUND

Due to the ageing of the general population and improved techniques, the acceptance rate of patients starting dialysis has increased. Mortality remains high and the factors involved include nutritional parameters, which also seem to be of value for prognosis in this population.

SCOPE OF THE STUDY

We proposed a prospective study in our haemodialysis population in order to establish the factors with the greatest predictive value for mortality.

PATIENTS AND METHODS

One hundred stabilized patients receiving this technique were included in the study, with registration of any concomitant pathologies, their severity and the presence of HBP; we carried out a clinical assessment measuring nutritional parameters and functional capacity, with anthropometric and analytical measurements with dialysis dosage and protein catabolism rate. The observation period lasted for one year. The statistical analysis compared survivors and dead patients by means of a bivariant analysis, and after selecting the significant variables, log regression was applied.

RESULTS

The annual death rate was 15%. The bivariant analysis highlights the greater age and the prevalence of vascular pathology prior to dialysis, with a greater severity score and prior weight loss, as well as a lessened functional capacity and clinical assessment score among the dead patients. The analytical parameters showed lymphocytes to be significantly lower among the deceased. The log regression analysis revealed the predictive value of severity, followed by initial vascular co-morbidity, lymphocyte levels less than 1,200 and the nutritional clinical assessment score.

CONCLUSIONS

1. Severity was the main factor predicting mortality. 2. The presence of vascular co-morbidity at the start of dialysis increased the likelihood of death by more than ten times. 3. Lymphopenia of less than 1,200 and low scores in the subjective overall assessment were predictors of mortality.

Prevalence and prognostic significance of malnutrition in chronic renal insufficiency

OBJECTIVE

Malnutrition is present in a significant proportion of patients commencing dialysis. However, the prevalence and prognostic significance of malnutrition within the chronic renal insufficiency (CRI) population before the initiation of dialysis is poorly characterized. The aim of this study was to determine the prevalence and prognostic significance of malnutrition in an unselected group of patients with CRI.

DESIGN

Cohort analytic study.

SETTING

Ambulatory care practice of a university teaching hospital.

PATIENTS

Fifty patients with CRI (serum creatinine concentration > or = 1.7 mg/dL) were enrolled. Patients with a recent acute illness, nephrotic syndrome, intercurrent steroid therapy, gastrointestinal disease, or other severe organ failure that may have independently influenced nutritional status were excluded.

INTERVENTION

At baseline, patients had a nutritional assessment consisting of subjective global assessment (SGA), measurement of body mass index (BMI), midarm circumference (MAC), serum albumin concentration, total lymphocyte count, and single frequency bioelectrical impedance analysis. Patients received standard medical care and were followed prospectively at quarterly intervals for 12 months.

RESULTS

At baseline assessment, 28% of patients had evidence of malnutrition by SGA criteria. The malnourished group of patients had a significantly lower creatinine clearance (18.9 +/- 9.8 v 36.5 +/- 14.0 mL/min/1.73 m(2), mean +/- SD, P <.001), glomerular filtration rate (20.7 +/- 10.9 v 28.5 +/- 12.5 mL/min/1.73 m(2), P =.04), BMI (22.7 +/- 2.9 v 29.0 +/- 5.0 kg/m(2)), and MAC (24.3 +/- 4.9 v 30.7 +/- 4.8 cm, P <.001), but there were no differences in serum albumin concentration or total lymphocyte count between the groups. At the 12-month follow-up, there was significantly increased mortality (21% v 3%, P =.04), composite endpoint of death or dialysis (50% v 11%, P =.02), and likelihood of acute hospitalization (78% v 23%, P =.001) in the malnourished group. A significant association was observed between baseline nutritional status and subsequent admission to hospital and baseline glomerular filtration rate and progression to end-stage renal failure.

CONCLUSION

These data suggest that SGA provides a useful means of assessing nutritional status and is helpful in identifying patients with increased risk of morbidity and mortality in the setting of CRI.

Enteral versus parenteral nutrition: a pragmatic study

Controversy persists as to the optimal means of providing adjuvant nutritional support. The aim of this study was to compare enteral nutrition (EN) and parenteral nutrition (TPN) in terms of adequacy of nutritional intake, septic and nonseptic morbidity, and mortality. This was a prospective pragmatic study, whereby the route of delivery of nutritional support was determined by the attending clinician's assessment of gastrointestinal function. Patients considered to have inadequate gastrointestinal function were given TPN (group 1), while those deemed to have a functioning gastrointestinal tract received EN (group 2). Patients in whom there was reasonable doubt as to the adequacy of intestinal function were randomized to receive either TPN (group 3) or EN (group 4). The trial setting was a large district general hospital with a dedicated nutrition team. A total of 562 patients were included in the study (331 males; median age 67 y). Gastrointestinal function on entry into the study was considered inadequate in 267 patients who were given TPN (group 1) and adequate in 231 whom received EN (group 2). There was clinical uncertainty about the adequacy of gut function in 64 patients (11.4%) who were randomized to receive either TPN (group 3, 32 patients) or EN (group 4, 32 patients). The incidence of inadequate nutritional intake was significantly higher in group 4 compared with group 3 (78.1% versus 25%, P < 0.001). Complications related to the delivery system and other feed-related morbidity were significantly more frequent in both EN groups compared with the respective TPN groups. EN was associated with a higher overall mortality in both nonrandomized and randomized patients. There were no significant differences observed in the incidences of septic morbidity between patients receiving TPN and those given EN. EN is associated with a higher incidence of inadequate nutritional intake, complications related to the delivery system, and other feed-related morbidity than TPN. There is no evidence from this study to support a difference between the two modalities in terms of septic morbidity. Patients in whom there is reasonable doubt as to the adequacy of gastrointestinal function should be fed by the parenteral route.

Effect of malnutrition at the time of diagnosis on the survival of children treated for cancer in El Salvador and Northern Brazil

PURPOSE

To investigate the relationship between survival and malnutrition at the time of diagnosis among children treated for cancer in two developing countries.

PATIENTS AND METHODS

We studied 443 children treated for cancer between 1995 and 1998 at two centers in San Salvador, El Salvador, and Recife, Brazil. Median age at diagnosis was 4.9 years; 283 children had leukemia and 160 had solid tumors. Z-scores were calculated for weight for age (WAZ), height for age (HAZ), and weight for height (WHZ) at diagnosis. Z scores <-2 indicated malnutrition. Patients were also stratified by low-risk disease (solid tumors: stage I, stage II, or localized; acute lymphocytic leukemia: white blood cell count <25,000/microL, no central nervous system involvement, no mediastinal mass and age >1 and <10 yrs) and high-risk disease (all other patients, including those with acute or chronic myelocytic leukemia).

RESULTS

Z-scores indicated malnutrition in 23.5% (WAZ), 22.8% (HAZ), and 15.7% (WHZ) of patients. Z-score was not significantly related to overall survival rates, to survival rates analyzed by type of malignancy or risk status, or to survival rates at the end of the first month of treatment.

CONCLUSIONS

We found no relationship between nutritional status and survival in these patients. This implies that future protocols for use in developing countries can be designed to provide optimal treatment intensity despite the high incidence of malnutrition.

Use of subjective global assessment to identify nutrition-associated complications and death in geriatric long-term care facility residents

OBJECTIVE

The primary objective of this study was to assess the use of Subjective Global Assessment to identify nutrition-associated complications and death in a geriatric population. A secondary objective was to evaluate the ability of Subjective Global Assessment to identify geriatric residents of long-term care facilities who were undernourished or at risk for developing undernutrition.

METHODS

Fifty-three consecutive residents who were > or = 65 years of age and had been residing in a long-term care facility for < 2 weeks were enrolled in the study. The Subjective Global Assessment Classification technique was performed according to the procedure outlined by Detsky and colleagues. Residents were classified as well-nourished (A), mild/moderately undernourished (B) or severely undernourished (C). In addition, a Subjective Global Assessment Composite Score was derived. Subjective Global Assessment measures were compared with two traditional objective measurements of nutritional status: serum albumin and serum total cholesterol. Outcome measurements of nutrition-associated complications were determined over a 3-month period by recording the incidence of major infections, decubitus ulcers, nutrition-related hospital readmissions, and mortality.

RESULTS

Sixteen residents (30.2%) were categorized as Subjective Global Assessment class A, 28 residents (52.8%) were class B, and 9 residents (17%) were class C. A significant association was found between nutritional status as determined by Subjective Global Assessment Composite Score and nutrition-associated complications (p<0.05). Subjective Global Assessment Classification was related to death (p<0.05) with severely undernourished residents having the highest mortality rate. Hypoalbuminemia only demonstrated a significant relationship with nutrition-associated complications (p<0.05), whereas hypocholesterolemia was associated with death (p<0.05).

CONCLUSIONS

Subjective Global Assessment of nutritional status appears to be a simple, noninvasive and cost-effective tool for assessing nutritional status of geriatric residents in long-term care facilities. This assessment tool is also beneficial for identifying patients with increased risk of nutrition-associated complications as well as death.

The validity and reproducibility of clinical assessment of nutritional status in the elderly

Malnutrition is an important predictor of morbidity and mortality. In the non-elderly, a subjective global assessment (SGA) has been developed. It has a high inter-rater agreement, correlates with other measures of nutritional status, and predicts subsequent morbidity. The purpose of this study was to determine the validity and reproducibility of the SGA in a group of patients older than 70 y of age. Consecutive patients from four geriatric/rehabilitation units were considered for the study. Each patient underwent independent nutritional assessments by a geriatrician and senior medical resident. At the completion of the assessment, skinfold caliper measurements were obtained and the patient reclassified according to the results, which were then compared with objective measures of nutritional status. Six-month follow-up was obtained on all patients. The agreement between the two clinicians was 0.48 +/- 0.17 (unweighted kappa), which represents moderate agreement and is less than the reported agreement in nonelderly subjects. Skin calipers improved the agreement between clinicians but did not improve the correlation with other nutritional markers or prediction of morbidity and mortality. There was a correlation between a patient's severely malnourished state and mortality. In addition, patients with a body mass index (BMI) of <75% or >150% age/sex standardized norms had an increased mortality. The SGA is a reproducible and valid tool for determining nutritional status in the elderly. The reproducibility is less than in the nonelderly, which may relate to changes in body composition or ability to obtain an accurate nutritional history.

Parenteral nutrition in the critically-ill patient: more harm than good?

While many studies have reported that providing parenteral nutrition (PN) can change nutritional outcomes, there are limited data that demonstrate that PN influences clinically-important end points in critically-ill patients. The purpose of the present paper is to systematically review and critically appraise the literature to examine the relationship between PN and morbidity and mortality in the critically-ill patient. Studies comparing enteral nutrition (EN) with PN and studies comparing PN with no PN were reviewed. The results suggest that EN is associated with reduced infectious complications in some critically-ill subgroups. PN, on the other hand, is associated with increased morbidity and mortality in critically-ill patients. When nutritional support is indicated, EN should be used preferentially over PN. Further studies are needed to define the optimal timing and composition of PN in patients not tolerating sufficient EN. Strategies to optimize EN delivery and minimize PN utilization in critically-ill patients are indicated.

Assessment of hospital morbidity, mortality, and cost-effectiveness of a nutritional program for children under 5 years of age in Pala, Chad

This paper analyses the effectiveness of case management at referral level for malnourished sick children in a rural district health system in the south of Chad (Pala district). The methodology followed was based on a cohort study of malnourished children as well as a cost-effective analysis of alternative options for nutritional rehabilitation strategies. Results show that effective case management at hospital level is possible with few resources as long as the nutritional rehabilitation programme is implemented on an integrated basis including early diagnosis of malnutrition for all children admitted to hospital and not to wait for a normal weight-for-height but discharge when the hospital is no longer the best place to avoid further mortality.

Long-term physiological and economic consequences of growth retardation in children and adolescents

The application of a lifespan perspective in human biology in recent years has shown that a number of early environmental factors influencing human growth and development have long-term biological or psycho-social consequences. Human growth is characterized by prolonged infancy, an extended childhood phase and high rates of growth during the adolescent growth spurt. It is unlikely that these characteristics would have evolved without having advantages, and curtailments have the potential for disadvantage. The present paper examines the evidence for long-term physiological and economic consequences of growth retardation in children and adolescents. The emphasis is the biological and economic imperatives of survival, subsistence, reproduction and production rather than aspects of metabolic competence. Many of the consequences of growth retardation are determined by the direct effect on body size, but many other consequences arise from the conditions that cause the growth retardation. Catch up of retarded growth can occur, but does not usually do so because of the continued presence of the retarding agents. Basal metabolism and physical work capacity are usually commensurate with the size of the individual; mechanical efficiency of physical work is unchanged, but falls in activity levels may occur along with a reduction in the pace of activity. Growth retardation in childhood is associated with a higher disease and mortality risk in adulthood, with decreased productivity and employment and promotion prospects. Studies are showing that relative deprivation and the accumulation of socially patterned exposures are important in some societies. Height and growth retardation have proved invaluable in reflecting these factors, but the next generation of studies may require more discriminating indices.

Global outlook on nutrition and the environment: meeting the challenges of the next millennium

As we enter the new millennium, nearly 800 million of the World's population will remain chronically malnourished. Nearly 200 million children are moderately to severely underweight, while 70 million are severely malnourished. And those who are yet to be born will be faced with the same set of circumstances that predispose them to malnutrition and its consequences. Eradication of nutritional deficiencies among women and children on a global scale are needed to ensure improved quality of life for the next generation of citizens. Primary deficiencies in vitamin A, iron, iodine, calcium, folic acid and trace elements such as zinc are compounded by pollutants caused by human activity. Environmental lead, arsenic, mercury, and other heavy metals that enter the food chain can seriously deplete body stores of iron, vitamin C and other essential nutrients leading to decreased immune defenses, intrauterine growth retardation, impaired psycho-social faculties and other disabilities associated with malnutrition. Increased susceptibilities to communicable diseases, and those provoked by water or insect borne vectors are additional risks encountered by malnourished individuals. Migration of populations from rural to urban centers and the expansion of major metropolitan areas have had a significant and adverse impact on the quality of life of these citizens. In the next 20 years most of the growth in urban populations will be in Asia and Latin America. Urbanization and the resultant burden on limited national resources is a major contributory factor to malnutrition. There are many other lifestyle-associated disabilities such as use of tobacco (cancer) and alcoholism that require active intervention. Within the family unit, socioeconomic factors and the status of women (literacy, economic independence) are major determinants of the quality of life. In the coming century, the World will have to meet these challenges by careful planning and international cooperation.

Hypoglycemia in patients with renal failure

Of a total of 1545 admissions of end stage renal failure (ESRD) patients, fifty-six (3.6%) were admitted during a ten-year period with hypoglycemia. Thirty-eight of them were diabetic while the others were non-diabetic patients. The most common etiology found to be drug-induced hypoglycemia in 26 (46%) patients. In 22 (39%) cases, sepsis was the contributing cause of hypoglycemia. Severe malnutrition caused 7% of hypoglycemic episodes. Of the patients, 18 (32%) with ESRD eventually died, none of them were from the drug induced group. However, mortality rate in the sepsis induced hypoglycemia group was 66%, and of the malnutrition group 17% of the deaths. Thus, hypoglycemia is frequent in ESRD patients, and is fatal if associated with either sepsis or malnutrition.

Nutritional assessment and survival in ALS patients

Malnutrition, present in 16-50% of ALS patients, is an independent prognostic factor for worsened survival. It is caused primarily by swallowing dysfunction, resulting from involvement of the lower sets of cranial nerves, but hypermetabolism is also implicated. Malnutrition itself can produce neuromuscular weakness and adversely affect patients' quality of life, thereby creating a vicious circle. The nutritional status of ALS patients can be assessed with dietary review and measurements of weight (W) and height (H). A body mass index (BMI = W/H2) below 18.5-20 kg/m2 indicates a state of malnutrition. Dietary counselling is important, but rapidly becomes insufficient, particularly in bulbar-onset ALS, where enteral nutritional support is then necessary. Percutaneous endoscopic gastrostomy tube placement is well tolerated, and provides more efficient enteral nutrition than nasogastric tube feeding. Enteral nutrition support can improve the respiratory status of ALS patients. The effect on survival remains to be confirmed.

[Causes of death of German refugee children in 1945]

In the last months of the second World War, 250,000 German refugees landed in Denmark. A third of them were children under the age of 15. Seven thousand German refugee children under the age of five died in Denmark in 1945. Using birth certificates and death certificates from the Danish national archives and burial lists from the German refugee cemetaries I have collected data to reveal causes of death, age distributions and time of the deaths of the 7000 fatal cases among children under the age of five. Three thousand children under the age of one, 2000 children one year old and 2000 children 2-4 years old died. Most of them died just before and after the German surrender, but many died in the months following the German surrender. The infant mortality was extremely high all during 1945. The infants died from diseases due to malnutrition, but the older the children the more likely the causes of death were due to infectious diseases such as pneumonia, measles, diphtheria and gastroenteritis.

Malnutrition, morbidity and mortality in children and their mothers

While being underweight or stunted is recognized as an important risk factor for increased prevalence and severity of infection and high mortality rates, there is increasing evidence for an independent role for micronutrient deficiency. Improving vitamin A status reduces mortality among older infants and young children and reduces pregnancy-related mortality; it also reduces the prevalence of severe illness and clinic attendance among children. Improving Zn status reduces morbidity from diarrhoeal and respiratory infection. Treatment of established infection with vitamin A is effective in measles-associated complications, but is not as useful in the majority of diarrhoeal or respiratory syndromes. Zn supplements, however, have significant benefit on the clinical outcome of diarrhoeal and respiratory infections. Concerns that Fe supplements might increase morbidity if given in malarious populations appear to be decreasing, in the light of new studies on Fe supplements showing improved haemoglobin without an increase in morbidity. Breast-feeding, well known to protect against diarrhoea, is also important in protecting against respiratory infection, especially in the young infant. Transmission of human immunodeficiency virus (HIV) in breast milk is recognized, but new data showing reduced transmission in infants who receive exclusive breast-feeding rather than mixed feeding reinforces the importance of promoting this practice in areas where environmental contamination precludes the safe use of other infant feeding regimens. The presence of subclinical mastitis, now recognized to occur in approximately 20 % of mothers in several developing countries, has been shown to increase the concentration of HIV in breast milk. Preliminary findings suggest that the prevalence of subclinical mastitis is reduced by dietary supplements containing antioxidants. Governments and international agencies now have a strong scientific basis to be much more active and innovative in the introduction of focused nutrition interventions especially micronutrients, for the control of infection.

Natural selection and sex differences in morbidity and mortality in early life

Both morbidity and mortality are consistently reported to be higher in males than in females in early life, but no explanation for these findings has been offered. This paper argues that the sex difference in early vulnerability can be attributed to the natural selection of optimal maternal strategies for maximizing lifetime reproductive success, as modelled previously by Trivers and Willard. These authors theorized that males and females offer different returns on parental investment depending on the state of the environment. Natural selection has therefore favoured maternal ability to manipulate offspring sex in response to environmental conditions in early life, as shown in variation in the sex ratio at birth. This argument can be extended to the whole period of parental investment until weaning. Male vulnerability in response to environmental stress in early life is predicted to have been favoured by natural selection. This vulnerability is most evident in the harsh conditions resulting from pre-term birth, but can also be seen in term infants, and manifests as greater morbidity and mortality persisting into early childhood. Malnutrition, interacting with infection after birth, is suggested as the fundamental trigger mechanism. The model suggests that whatever improvements are made in medical care, any environmental stress will always affect males more severely than females in early life.

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.