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REVIEW ARTICLE

DIETARY ADHERENCE IN CHILDREN WITH CHRONIC KIDNEY DISEASE: A REVIEW OF THE EVIDENCE Aggeliki Apostolou, Thomai Karagiozoglou-Lampoudi Clinical Nutrition Laboratory, Department of Nutrition and Dietetics, Alexander Technological Education Institute, Thessaloniki, Greece

Apostolou A., Karagiozoglou-Lampoudi T. (2014). Dietary adherence in children with chronic kidney disease: A review of the evidence. Journal of Renal Care 40(2), 125–130.

SUMMARY Background: In children with chronic kidney disease (CKD), a nutrition support plan is important to ensure optimal macroand micro-nutrient intake in order to avoid malnutrition, disease-related complications and growth rate reduction. Children with CKD and their families encounter many difficulties in adjusting to the renal diet. Even though adherence to the recommended dietary plan is important in CKD, it is rarely measured partly due to the lack of robust, unbiased assessment methods. Methods: In this review of 22 papers, the techniques used to assess adherence in children with CKD are reviewed, alongside their advantages and disadvantages. Findings: Although dietary surveys, biochemical index assessment and clinician ratings have been found not to be efficient when used as a single tool, they should be used in combination in order to give the opportunity to the health providers to perceive adherence from as many angles as possible.

K E Y W O R D S Adherence score Chronic kidney disease Dietary adherence Paediatric

INTRODUCTION Children with chronic kidney disease (CKD) usually have lower stature than their peers and are at great risk of malnutrition. It is not clear how dietary intake affects renal function in children but its impact (Canepa et al. 1996; Foster et al. 2011) on growth has been initially pointed out by Betts and Magrath (1974) who

noted that reduced growth velocity occurred when energy intake was falling below 80% of recommended energy intake. However, higher energy intake has not been proved to be helpful in restoring growth loss and the opportunity for catch up growth might be lost permanently, especially if growth retardation occurs during infancy. Since then it has been well

BIODATA Aggeliki Apostolou, M.Sc. Nutrition, is a research and teaching assistant at the Clinical Nutrition Laboratory, Department of Nutrition and Dietetics, Alexander Technological Education Institution of Thessaloniki. She is currently working on her PhD under the supervision of her co-author Prof. Thomai Karagiozoglou-Lampoudi.

CORRESPONDENCE

Aggeliki Apostolou, Clinical Nutrition Laboratory, Department of Nutrition and Dietetics, Alexander Technological Education Institute of Thessaloniki, Sindos, P.O. Box 14 561, 54 101 Thessaloniki, Greece Tel.: þ030 2310 791 362 Fax: þ030 2310 791 360 Email: [email protected]

Thomai Karagiozoglou-Lampoudi, Paediatrician, Ph.D., is the Professor of Clinical Nutrition at the Department of Nutrition and Dietetics, Alexander Technological Education Institution of Thessaloniki, Greece. She is the President of the Institution’s Bioethics Committee and also the supervisor of many research protocols that are supported by the Institution and other organisations.

© 2014 European Dialysis and Transplant Nurses Association/European Renal Care Association

Journal of Renal Care 2014

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documented that neither energy nor protein intake increase is effective to counterbalance inflammation catabolic rate and restore growth rate when malnutrition is established (McSherry & Morris 1978; National Kidney Foundation KIDOQI 2009; Mak et al. 2012). Thus, a carefully planned personalised dietetic approach is very important in order to prevent malnutrition if possible. Aggressive medical nutrition therapy is associated with improved growth in young children with CKD (Jones et al. 1983; Rizzoni et al. 1984; Crittenden & Holaday 1986; Polito et al. 1987; Jureidini et al. 1990; Van Renen et al. 1992; Tom et al. 1999; Norman et al. 2004b). Increased caloric and protein intake is required in addition to optimal dialysis to improve nutrition status, especially in children receiving Haemodialysis (HD). However, excessive dietary protein intake, especially when disproportionate to energy intake, seems to negatively affect acid–base status, fat-free mass and growth (Zadik et al. 1998; Azocar et al. 2004). Currently, necessary information to estimate energy, protein and micro-nutrient needs is provided by clear evidence-based guidelines in a way that the diversity of ages, body weight and method of treatment (conservative or receiving renal replacement therapy) are considered (KIDOQI; Ad Hoc European Committee on the assessment of growth and nutritional status in Children on Chronic Peritoneal Dialysis). The dietary plan should be also based on individualised assessment of preferences and limitations set by both the patient and his/her family. Children with CKD, who often suffer from loss of appetite and taste alterations, are often led to impractical, restrictive and unappetising diet plans that are difficult to follow (Tong et al. 2008; Tjaden et al. 2012). When oral intake is inadequate to maintain growth, the use of special dietary products and enteral feeding should be considered (National Kidney Foundation KIDOQI 2009). Dietary management is an integral part of multidisciplinary CKD approach. To ensure optimal outcomes, adherence to renal diet is required and its regular evaluation promotes a more targeted intervention.

DIETARY NON-ADHERENCE IN CHILDREN WITH CKD Only few of the studies that monitored the dietary intake of children with CKD also examined adherence prevalence. One reason for this might be the variety and complexity of the methods used to assess dietary adherence and difficulties in

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describing its extent. Individual measures showed that a substantial proportion of children on dialysis were nonadherent. Using the total adherence scale score, with a median cut-off score of 3, 61% of those on dialysis were non-adherent (Hudson et al. 1987). However, reduction in average weight gain by 45% has been also reported as a result of behaviour modification in maintaining dietary control (Magrab & Papadopoulou 1977). Adherence to protein reduction is poor, mainly due to difficulties encountered by both the parent who has to enforce them and the patient who has to endure them. Reported adherence to dietary protein intake reduction has varied from 66% to 76% of children, and when based on urinary urea nitrogen excretion measurements, researchers found that patients understated the children’s protein intake. All patients exceeded the suggested protein intake (141% of WHO recommendations instead of 100%) while compliance to suggested energy intake was at more acceptable levels at 80% (caloric intake above 70% of WHO recommendations was prescribed) (Wingen et al. 1991, 1997). In children, adherence to the suggested intake of phosphate and calcium reached 39% and 43% of the time when monitored, respectively. Interestingly clinician’s ratings ranged from 33% to 100% (averaged at 83%) in the same study, revealing the multifactorial discrepancies in measuring compliance (Simoni et al. 1997). Longitudinal studies have also supported difficulty in children adhering to reduced phosphorous intake (Norman et al. 2004a).

ASSESSMENT OF DIETARY ADHERENCE Denhaerynck et al. (2007) has identified that the lack of officially adopted renal diet adherence criteria has led mainly to the use of biochemical markers and self-reported scoring (0–6: representing poor to excellent) for this purpose. In the present review, we aim to study the dietary adherence of children with CKD, after they and their parents were provided with guidance regarding nutrition. For this purpose, 22 studies were included, in which dietary intake of children with CKD who were submitted to dietary intake monitoring and its impact on relevant indicators. The methods used to evaluate children’s dietary adherence (Table 1), vary significantly in the studies reviewed, so often the assessment is not conducted in a comprehensive way. Intake recording at home (14/22 of the studies reviewed) and after observation in clinic (2/22), and also biochemical markers such as urea, phosphorus and potassium levels (9/22), scores and


– –

Moreover, all the methods used are reported to have both advantages and disadvantages. Although lacking evidencebased criteria, urea levels in serum and urine have been suggested as indicators of protein intake adherence. Weight and skinfold thickness records have been suggested as markers of energy intake adequacy when patients are under conventional treatment (Giovannetti 1986). It is known though that urea levels may reflect protein intake but are also influenced by deterioration of renal function and nutrition intake. Therefore, urinary urea levels have been proved to be a poor indicator of nitrogen intake and are not considered reliable descriptive markers of dietary compliance (Kist-van Holthe tot Echtenl et al. 1992).

p – – –

Table 1: Dietary prescription and adherence monitoring methods.

NS, not specified; RNI, recommended nutrient intake; KDOQI, Kidney Disease Outcome Quality Initiative.

– – – p – – – – p – – – – –

–

– –

clinicians ratings (5/2), weight gain (3/22) and blood pressure (3/22) have been used to define adherence.

–

– – – – – – – – – – – – – – – – – p – – – – – – – – – – –

p p

– – – – –

– – p – p

– – –

– – –

p

– – –

p p

– – –

– – –

– – –

p p

– p p p – – – p p – – p

–

–

–

–

–

p

–

p

–

p

p – p p p p – p p –

p

p

p

p

–

p

p

p

–

–

p

–

KDOQI NS KDOQI NS %RNI NS %RNI p %RDA p NS p %WH0 p NS NS NS NS NS NS %WH0 NS %RDI NS NS NS RDA NS NS NS NS NS

RDA p

NS NS

RDA p

NS NS

%WH0 p

1993 p 1987 NS 1987 NS 1978 NS 1977 p

1983 p

1984 p

1986 NS

1990 p

1991 p

1992 NS

1994 p

KDOQI –

2010 p 2010 p 1997 p 1997 –

1998 p

2001 NS

1999 NS

2004 p

2005 p

16 16 22 51 12 24 31 191 23

34 (22þ12T) 1996 p 60 56 9 50 6 18 10 21 42 7 10 4

Number of patients included Year Dietitian given instructions Guideline reference Individualised diet prescription Adherence criteria Analysis of food records Assessment of biochemical parameters Adherence ratings Weight gain Intake observation in clinic Blood pressure

Kist-van Van Holthe tot Echten Brownbridge Magrab and McSherry & Jones Rizzoni Crittenden & Polito Hudson Jureidini Wingen Renen et al. et al. and Fielding Papadopoulou Morris et al. et al. Holaday et al. et al. et al. et al. (1993) (1994) (1977) (1978) (1983) (1984) (1986) (1987) (1987) (1990) (1997) (1992)

Davis et al. (1996)

Simoni Wingen Zadik Parekh Tom Norman Blaszak Abercrombie Ahlenstiel et al. et al. et al. et al. et al. et al. et al. et al. et al. (1997) (1991) (1998) (2001) (1999) (2004b) (2005) (2010) (2010)

DIETARY ADHERENCE IN CHILDREN WITH CHRONIC KIDNEY DISEASE: A REVIEW OF THE EVIDENCE

Potassium and phosphate values reflect not only food intake but also residual renal function, dialysis adequacy, time at which blood was obtained for the analysis between dialysis, acid–base and hormonal status as well as adherence with medication (Morduchowicz et al. 1993; Curtin et al. 1999). Food intake and semi-quantitative dietary diaries as well as weighed dietary intake are most commonly used to assess dietary patterns. It has been pointed out, though, that food diaries can be unreliable due to memory lapses, mistaken evaluation of food intake or false report by children and their parents in order to please clinicians or the dietician (Locatelli 1997). The standard deviation for individual errors in energy intake has been estimated to approach 20%, and because of bias and imprecision, it is recommended that self-reported energy intakes should be interpreted with caution, unless independent methods of assessing their validity are also included in the assessment of adherence (Schoeller 1995). However, according to National Kidney Foundation KDOQI (2009), a three-day diet diary or three 24-hour recalls (that might be preferable in adolescents) are considered reliable methods of assessing nutrition intake and allow the treating team to evaluate the adequacy of intake before complications in body composition are established. The use of scores or scales to measure the severity and frequency of problems with adhering to energy, protein, fat, sodium and



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phosphorus has already been tested (Crittenden & Holaday 1986; Hudson et al. 1987; Brownbridge & Fielding 1994; Davis et al. 1996; Simoni et al. 1997). Simoni et al. (1997) have used a 3-point scale that was rated by a physician, a dietician and four nurses to describe adherence to diet, dialysis regimen and medication intake. Crittenden and Holaday (1986) used medical staff’s ratings to assess parents and children’s cooperation with diets, medications, appointments, record keeping and staff, and then used their average to obtain global ratings. Davis et al. (1996), who have chosen to use a different approach, determined non-adherence by adding individual scores for frequency of problems with compliance to fat and sodium intake guidelines in transplanted children and frequency of problems with adhering to calorie, protein and phosphorus intake for non-transplanted children. A score including ratings of pre-dialysis serum potassium, blood urea and systolic blood pressure levels, weight gain between dialysis and self and parental report of difficulties in taking medicine was used in two of the studies reviewed (Hudson et al. 1987; Brownbridge & Fielding 1994). Brownbridge and Fielding (1994) additionally included an overall adherence indicatorl, the mean of the five individual indicators: energy, protein, sodium, potassium and phosphorus intake that were rated with the use of a 4-point scale provided by food diaries analysis.

PSYCHOSOCIAL PROBLEMS RELATED TO DIETARY NON-ADHERENCE Children with CKD often have large changes to make to their diet. They are not able to eat like their peers, as they are advised to exclude many foods from their diet, or replace them with special dietary products that are either enhanced with energy or contain less phosphorus, protein, etc. Therefore, they often feel isolated. According to Davis et al. (1996), who reported maladaptive behaviour for 96% of their patients, adaptive functioning skills are related to the frequency of dietary adherence problems and dietary adherence in general. Adherence to a modified diet is greatly associated with psychological but also socioeconomic factors in children. A few researchers have attempted to detect adherence-related factors in order to improve it. Prolonged dialysis period, age, other health problems and hospitalisations have a negative impact on adherence (Brownbridge & Fielding 1994). Selfreported depression has been associated with negativistic and

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depressogenic thinking but it was not related to adherence. However, the limitations of the study analysed by the authors, who also detected underscoring, pointed out the multidimensional aspect of compliance evaluation (Wingen et al. 1991). Both patients’ and parents’ commonly reported anxiety and depression state is associated with non-adherence to weight maintenance (Brownbridge & Fielding 1994). Family expressiveness, on the contrary, was positively related to dietary adherence and inversely related to the frequency of diet adherence problems. Not living with both natural parents and low socioeconomic status were related to poor dietary compliance, designating socially disadvantaged family’s difficulty in providing a most suitable diet or environment for the patient (Brownbridge & Fielding 1994). More recent studies on adherence to phosphate-binding medication, where dietary intake should be matched to medication dose, highlight that feasibility and comprehension of calculations determine the suitability of such treatments (Laakkonen et al. 2010).

NUTRITION COUNSELLING Evidence is accumulating that intensive nutritional support and adequate dialysis in pre-pubertal children promote normal and even enhanced growth, without the need for recombinant human growth hormone (Coleman et al. 2001). It is pointed out that adequate dietetic time is essential to provide this support, considering food preferences, eating patterns, cultural, psychosocial and economic factors as parameters of a more personalised approach. Regular sessions of dietary counselling aim to improve meal-preparing skills for parents and children. The use of food modules, measuring containers and recipes simplifies quantifying selected options. This educational process is essential as potassium-reducing, flavour-enhancing and energy-boosting techniques can be used to broaden selections. Alternatives for not-recommended foods and planning for eating out should also be taught, so that spontaneous selections are easy, appealing and safe (Raymond et al. 1990; Bellisle et al. 1995; Armstrong et al. 2010). Understanding adaptation problems, encouraging adherence and giving fresh motives are crucial in supporting family (Harvey et al. 1996; Fielding & Duff 1999; Soliday et al. 2000; Pai & Ingerski 2012).


DIETARY ADHERENCE IN CHILDREN WITH CHRONIC KIDNEY DISEASE: A REVIEW OF THE EVIDENCE

Even though the dietician’s role in providing the patient and his family with the plan to meet dietary needs is central, in only 14/22 of the studies reviewed above it is clarified that the instructions were given by a dietitian. Furthermore, only in 7/22 was it specified that a personalised diet plan should be prescribed, and in even fewer studies, the regularity of the sessions was defined.

IMPLICATIONS FOR PRACTICE A score including dietary intake parameters and biochemical markers, enhanced by adherence ratings marked by the dietician and patient’s parents based on frequency of adherence problems, might actually prove to be a more robust assessment tool. However, prolonged evaluation periods are needed to test the validity of such scores. Further investigation in paediatric populations for the establishment of a universally accepted adherence assessment tool is necessary. Since time constraints are often a limitation, it is essential that any dietary adherence tool used is also convenient and brief (Hand et al. 2013).

CONCLUSION In conclusion, concordance to prescribed diet should be monitored regularly in order to resolve dietary decline, redefine goals and enhance the value of dietary intervention. Although dietary surveys, biochemical index assessments and clinician ratings have been found not to be efficient when used as a single tool, they should be used in combination in order to give the opportunity to the clinicians to measure adherence from as many angles as possible.

CONFLICT OF INTEREST No conflict of interest has been declared by the author(s).

AUTHOR CONTRIBUTIONS AA: main author of the manuscript. TKL: conceived study, provided editorial support. Both authors read and approved the final manuscript.

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