What question should the nurse ask in order to assess an adolescents risk factors for obesity and deficient nutritional status?

Summary

Nutritional assessment is an essential component of the evaluation of children with gastrointestinal diseases because their clinical course frequently is complicated by undernutrition, growth failure, overweight, and micronutrient deficiencies. Although a complete nutritional assessment includes a review of the diet history, physical examination, growth and anthropometric measurements, and selected laboratory testing, accurate height and weight measurements and their transformation to relative indices of undernutrition or overnutrition serve as the mainstay of the nutritional assessment of the child with gastrointestinal disorders. The maintenance of a favorable nutritional status is essential to minimize disease-associated morbidity and maximize the child’s quality of life.

Goals and Importance of Nutritional Assessment

Nutritional assessment in clinical medicine has three primary goals: to identify the presence and type of malnutrition, to define health-threatening obesity, and to devise suitable diets as prophylaxis against disease later in life. The focus of this chapter is on the diagnosis of protein-energy malnutrition because of its wide prevalence and major impact on disease outcome. Other deficiency diseases are of much less relevance in that most occur in conjunction with protein-energy malnutrition or in specific disease states, such as thiamine deficiency in alcoholic liver disease and fat-soluble vitamin deficiency in malabsorptive states. The classic deficiency diseases, whether primary or secondary, are considered elsewhere in those chapters specifically dealing with the diseases mentioned here. The widespread availability of parenteral and enteral therapeutic measures since the mid-1980s that can provide adequate feeding regimens for virtually any disease condition makes a rudimentary knowledge of the pathophysiology of protein-energy malnutrition and its nutritional assessment essential for all primary care practitioners (Chapter 220).

Biomarkers Used in Combination with Dietary Assessment

Despite ongoing improvements in dietary assessment methods, errors inherent in these tools persist. The search for more objective measures of intake is leading researchers to utilize biomarkers that reflect dietary intake in combination with those that predict disease outcome or status. Such biomarkers ideally should (see Pearce et al., 1995; Consensus Group for Biomarkers in Cancer Chemoprevention, 2001)

be inexpensive to collect and analyze,

be present in small amounts of a biological specimen that can be obtained using a minimally invasive collection method,

persist for an extended period and reflect all routes of exposure,

be specific and highly predictive of the exposure of interest,

be measurable using a sensitive, specific, and reliable assay, and

be present in low concentrations in unexposed populations at baseline.

Although it is difficult to meet all of these criteria, there are several promising biomarkers of intake. For example, tissue and serum long-chain n-3 and n-6 polyunsaturated fatty acids have been reported to be reflective of dietary intake of fish, n-3, and n-6 fatty acids (Lands, 1995; Marckmann et al., 1995; Andersen et al., 1996; Connor, 1996; Bagga et al., 1997; Kohlmeier, 1997) and may be indicative of risk for breast (Kohlmeier, 1997) and prostate (Godley et al., 1996) cancers. Serum levels of β-carotene have been positively associated with intake of carotenoid-rich fruits and vegetables (Mangels et al., 1993; Campbell et al., 1994; Drewnowski et al., 1997). Several studies also corroborate the use of vitamin E (α-tocopherol) concentrations in serum and adipose tissue as measures of external intake (both dietary and supplemental) of that nutrient (Riemersma et al., 1991; Rimm et al., 1993).

A convincing body of evidence similarly suggests a direct relationship between consumption of a variety of soy-based products, lignans, isoflavones, isoflavonoid phytoestrogens, and plasma and urinary concentrations (Adlercreutz et al., 1993; Morton et al., 1994; Hutchins et al., 1995a,b; Kelly et al., 1995; Gross et al., 1996). Wu et al. (2004) showed a direct correlation between self-reported soy isoflavone intake from a FFQ and plasma isoflavone levels drawn from a subset of both cases and controls in a population-based study of breast cancer among Asian American women living in Los Angeles County. These findings suggested that, in this instance, breast cancer cases and controls were reliably able to recall their usual soy intake without selective recall biases (Wu et al., 2004).

Although biomarkers appear to be a promising method that could replace food frequency methods, it is important to understand that not all foods have biomarkers of intake. Moreover, several studies have shown a weak association between dietary intake and biological markers of intake (Polsinelli et al., 1998; Crews et al., 2001; El-Sohemy et al., 2002; IARC Working Group on the Evaluation of Cancer-Preventive Strategies, 2003). Well-designed studies of dietary intake and cancer risk ought to include both dietary recall methods and specific biomarkers of intake.

Body Composition and Outcomes

Although the above methods of body composition can accurately assess different components, they are difficult to apply in the clinical setting except in special units. The only methods of nutritional assessment available for wide application in populations are BIA and BIS. There are few data to show that these methods can predict outcome in hospital patients. In patients on renal dialysis, it has been shown that a reduction of the reactance from 70 to 43 Ω increased morbidity by 9% and a reduction of reactance to 31 Ω increased morbidity by 14%. In cancer patients, a lean body mass below the normal range as indicated by BIA was associated with increased morbidity.

MNA Procedure

Currently, several screening instruments are utilized for evaluating malnutrition in older people, together with clinical diagnostic tests, anthropometry, bioelectrical impedance analysis, or biochemical markers. The MNA is a rapid assessment tool designed and validated to quickly assess the nutritional status in healthy and frail older people as part of a CGA [8–12,14–16]. Up to now it has been translated in over 20 languages, and it is internationally used in several geriatric settings (free living, home care, institutionalized, and hospitalized), both in clinical practice and in clinical research. The MNA was originally developed in the 1990s by the Centre for Internal Medicine and Clinical Gerontology of Toulouse (France), together with the Clinical Nutrition Program at the University of New Mexico (United States) and the Nestlè Research Centre in Lausanne (Switzerland). As claimed by its developers, it was designed to represent “a reliable scale, usable by a generalist assessor, inexpensive and well acceptable to patients, with clearly defined thresholds and minimal opportunity for bias dependent on data collector” [10,14]. The MNA two-step procedure, including a nutritional screening (MNA-SF), which takes less than 5 min, and an assessment for patients at risk of malnutrition (full MNA), which can be completed in approximately 10–15 min, represent a reproducible and inexpensive tool, with high sensitivity (96%), specificity (98%), positive predictive value (97%), and a level of reliability equal to 0.89 [9,17] (Table 110.1).

Table 110.1. Validity of the Three Versions of the MNA

The MNA procedure evolved over the years via three steps:

The original version of the MNA (full MNA or version 1) [8–12,14], validated in the 1990s for a thorough nutritional evaluation, measures 18 items grouped in four sections (Table 110.2). Different sections of MNA assess different components of nutritional status: (1) MNA-1=anthropometric measurements (4 items), including weight and height to calculate body mass index (BMI), arm and calf circumferences, and weight loss (score: 0–8 points); (2) MNA-2=general assessment (6 items), including residential status, psychological problems, mobility, medications, and skin ulcers (score: 0–9 points); (3) MNA-3=assessment of dietetic habits (6 items), including number of meals, food and fluid intake, and autonomy of feeding (score: 0–9 points); (4) MNA-4=subjective assessment (2 items), including self-perception quality of health and nutrition (score: 0–4 points). Each item has a numerical value and contributes to the final score, which has a maximum of 30 points. The MNA score is used to classify subjects as well nourished (score of 24–30), at risk for malnutrition (score of 17–23.5), or malnourished (score less than 17), according to the original cut-off point of the MNA full test [9,14].

Table 110.2. The MNA 18 Items [8–14] Grouped in Four Sections

The MNA two-step procedure, which incorporated within the full MNA the short form of MNA (MNA-SF, or version 2) [13], was validated in 2001 for screening of malnutrition in low-risk patients. It comprises BMI measurement and the assessment of five other MNA items including questions related to food intake, weight loss, mobility, psychological stress, and neuropsychological problems such as dementia or depression (Table 110.2), with a maximum score of 14 (step 1—screening). The MNA-SF can distinguish subjects well nourished (score of 12–14), requiring no further investigation from those at risk for malnutrition (score of 8–11), or malnourished (score less than 8), in which diagnostic confirmation by completing the full MNA is required (step 2—assessment), with a similar validity and accuracy of the full MNA (Table 110.1).

The revised MNA-SF (newest MNA-SF, or version 3) [18] was validated as a stand-alone tool in 2009, including the same six MNA-SF questions, with the option to substitute calf circumference if BMI is not available.

MNA-SF

The MNA-SF consists of only six questions from the full MNA that showed the strongest correlation to the original MNA. Its validity as an isolated tool was demonstrated in 2009, comparing the score obtained from the six items to the score obtained from the full MNA [14]. Despite the fact that its test-retest reliability has not been checked, it is considered the tool of choice in clinical practice at present, as it reduces the screening time to less than 5 min (compared to the up to 15 min required to complete the full MNA).

This new version includes an option to substitute BMI for calf circumference (CC) for patients for whom height or weight measurements are difficult to obtain [15]. Another advantage of the MNA-SF is that among these six items there are no subjective questions, which strengthens its applicability in patients with cognitive impairment and dementia [16]. Nonetheless, the main disadvantage of MNA-SF is that, like the full MNA, it was not designed to be applied in demented patients.

A Different Purposes of Dietary Assessment

Dietary assessment is needed in many types of dietary studies, such as nutritional epidemiology, national or regional food consumption surveys, experimental or dietary intervention studies, and methodological studies. Interest can be in a group of persons or in the individual. The individual or group may consist of one or various age groups such as infants, toddlers, children, adolescents, adults, or older adults. Also, interest may be focused on specific population groups such as immigrants, persons with disabilities or illnesses, persons with low or high socioeconomic status, or persons in low- and middle-income countries.

The reason to collect dietary data can also vary greatly. There can be interest in intake of individual foods, food groups, nutrients, potentially toxic or healthy compounds, or on dietary patterns, meal patterns, environmental impact of diets, overall health profiles, etc. Moreover, the interest may be in the actual intake, in the habitual intake, or intake in a specific period of time. These different purposes are important for determining which dietary assessment method is most appropriate. After describing the main types of dietary assessment methods in the next paragraph, the considerations for choosing an appropriate dietary assessment method will be discussed.

3 Nutritional Assessment

Nutrition assessment that includes dietary and clinical history, physical exams, and laboratory measurements is the key part in nutritional management of IBD patients. It needs to be noted that many biomarkers of nutrients status, which are positive or negative acute phase reactants, are influenced by inflammatory responses of disease and do not reflect correctly the status of nutrients. For example, in inflammation, albumin, prealbumin, transferrin, zinc, folate, and selenium decrease and ferritin increases.25,44 In consideration of this, it has been suggested that nutrients status is evaluated in remission stage of disease or the cutoffs for determining nutrients deficiency are considered differently from usual conditions.11,25,45 Moreover, food avoidance should be considered in nutritional assessment. It has been reported that most food avoidance was observed in during of active disease, in CD compared with UC, and in structuring CD compared with nonstructuring CD.46,47

Nutrition Assessment

Nutritional assessment should commence at diagnosis and then be carried out longitudinally during treatment as well as during survivorship. Body mass index is the simplest, normalized value to follow in children ≥2 years of age. Basic laboratory assessment of nutritional status should include liver and renal function, glucose measurement, and lipids. The practitioner should be cognizant of direct chemotherapeutic effects which can affect nutritional status such as hyperglycemia secondary to steroids or decreased liver protein synthesis after asparaginase administration. Chemotherapy, RT, and periods of infection all lead to a catabolic state with nutrient depletion, exacerbated by decreased oral intake and subsequent micronutrient deficiencies.

NUTRITION ASSESSMENT

Nutrition assessment is the final critical factor in patient selection. Complying with postoperative nutrition requirements is crucial for successful outcomes. At our center, all prospective patients are evaluated by a dietitian experienced with eating disorders and specifically bariatric surgery patients. Diagnosis of the eating disorders discussed earlier often occurs during this nutrition-assessment process. Patients are evaluated in multiple areas, including diet attempts, general nutrition knowledge, understanding of the diet after surgery, food logs, support, and motivation.

All prospective patients are sent a preoperative information packet that contains the basic explanation of the nutrition requirements for surgery. Patients are required to keep a detailed dietary log for the 7 days preceding the initial clinic visit. The initial clinic visit involves a detailed 30-minute nutrition assessment during which the dietitian first looks at the number and types of previous diet attempts as well as the successes, if any, of those attempts and the associated duration of success (Table 12-2). Patients are tested on their general nutrition knowledge and on aspects of the diet after surgery that they can recall based on their reading of the information that was previously mailed to them. They are asked to list various foods that contain protein and foods that are high in sugar and carbohydrates. If patients are unable to answer appropriately, nutrition knowledge is rated as poor. Detailed food logs, appropriate support, and motivation for surgery are other items the dietitian may use to assess appropriateness for weight-reduction surgery. An ideal candidate for surgery would meet the following criteria: numerous previous diet attempts, including structured weight-loss programs; good general knowledge of nutrition; well-researched and informed awareness of the diet after surgery; 7 days of detailed food logs that are free of the suggestion of a major eating disorder; a display of good motivation; and adequate support from family and friends.