J Clin Res Ped Endo 2009;1(4):157–163 ISSN: 1308-5727 DOI: 10.4274/jcrpe.v1i4.39 Online ISSN: 1308-5735 Nutrition and Growth Fima Lifshitz President, Pediatric Sunshine Academics, Inc; Director of Pediatrics & Senior Nutrition Scientist, Sansum Medical Research Institute, Santa Barbara, CA, USA and Professor of Pediatrics, Emeritus, Downstate Medical Center, State University of New York, Brooklyn, NY, USA; Former Professor of Pediatrics, Cornell University Medical College, New York, NY & University of Miami, Miami, FL, USA Keywords: ABSTRACT Nutritional growth retardation (NGR), nutrient intake, short stature, growth retardation, Nutrition plays a fundamental role in determining the growth of individuals. An appropri- metabolic rates, erythrocyte ate growth progression is considered a harbinger of adequate nutrient intake and good Na+,K+- ATPase activity. health. On the other hand growth deceleration with or without short stature may indicate inadequate nutrition, even when there is no body weight deficit for height. Nutritional growth Received: 11 November, 2008 Accepted: 04 December, 2008 retardation (NGR) is most prevalent in populations at risk of poverty. However in affluent com- munities patients with NGR are often referred to the specialist because of short stature and Corresponding Author: delayed sexual development. The diagnosis may be overlooked and/or be established after Fima Lifshitz exhaustive evaluations, if the pattern of weight progression over time is not considered. Pediatric Sunshine Academics, Inc. Director of Pediatrics & Patients with so-called idiopathic short stature may present diminished nutrient intake and Senior Nutrition Scientist decreased IGF-I levels, however their nutritional status and body weight progression patterns Sansum Medical Research are usually not addressed by pediatric endocrinologists. NGR patients may cease to gain Institute Santa Barbara, CA, appropriate weight and fail to grow in height, even without exhibiting body weight deficits USA Tel: +805-687 8038 for height. They adapt to decreased nutrient intake by decreasing growth progression and Fax: +805-682 3332 thereby achieve equilibrium by decreasing the nutrient demands. This occurs by diminishing E-mail: [email protected] their metabolic rates and erythrocyte Na+,K+- ATPase activity, however they may not present alterations in other clinical biochemical markers of malnutrition. Therefore accurate weights and heights plotted on the growth chart over time are necessary to detect NGR. Nutritional rehabilitation is accompanied with catch up growth, though it may be difficult to change the dietary habits of adolescents who exhibit NGR. Conflict of interest: None declared Growth is the fundamental physiologic time and compares it to expected norms. process that characterizes childhood. It The norms are usually provided by the gen- should be closely monitored by pediatri- eral population as depicted in growth charts cians and families alike as a benchmark of (www.cdc.gov/growthcharts).2 Short stature a child’s health. Similarly, secular trends in and growth failure frequently, but not growth patterns are followed as indicators always, occur together. For example, a of children’s health on a population level. healthy child of short parents will have Growth can be worrisome along two vari- short stature but not growth failure; he or ables: height (short stature) and velocity she will grow at normal velocity towards a (growth failure).1 Height involves a meas- lower genetic potential. Conversely, a REVIEW urement of linear stature at a single point in child of very tall parents can have growth © 2008 Journal of Turkish Pediatric Endocrinology and Diabetes Society This is an open-access article distributed under the terms of the 157 Pubbiz/Probiz Ltd. fiti. Creative Commons Attiribution License which permits unrestricted use distribution and reprodiction in any medium prov ided the original work is prope rly cited Nutrition and Growth failure, but still be taller than the cut-off for be over-emphasized, carefully assessing the short stature of the general population. progression of body weight is equally rele- Multiple diseases can present solely with vant to be able to recognize NGR. growth failure, not necessarily with short Longitudinal assessment of both height and stature. Included are non-endocrine diseases weight is required.6-9 i.e. as celiac disease, cystic fibrosis, renal An increasing number of children on disease and HIV infection.1 These alterations stimulant medications are being referred to share a common pathophysiological process the pediatric endocrinologist for short stature in regards to growth failure, namely malnu- evaluation. Stimulant medication for the trition. Non organic causes leading to treatment of attention deficit hyperactivity decreased food intake may also result in disorder (ADHD) has long been suspected of poor growth and short stature. Failure to adversely affecting linear growth, since it is asses a patients’ nutritional intake can lead well known that these medications produce to unnecessarily delayed or missed NGR anorexia and poor nutrient intake. A cooper- diagnoses. The clinical outcome of many ative growth paper reviewed 29 cohort stud- nutritional alterations depends on the timeli- ies of children treated with methylphenidate ness of diagnosis and treatment.3,4 or dexamphetamine.10 The most sensitive The single most important cause of studies measured growth progression before growth retardation worldwide is poverty- and after the period of treatment, and eight related malnutrition. When suboptimal nutri- of these 16 studies showed an attenuation of tion is continued for prolonged periods of growth on stimulants. In the most rigorous time, growth stunting occurs as the main study, 540 children, 7-9 yr old, with ADHD clinical phenotype.3,4 However nutritional were randomly assigned to different treat- growth retardation (NGR) is a frequently ment groups for up to 24 months. The under-appreciated entity in pediatric behavioral effectiveness of medication use endocrine practices in the United States. was greatest among children who ingested Poverty-related malnutrition is less common medications throughout the 24-month obser- than in developing nations, and if anything, vation period. Those who stopped taking the current major health crisis is the obesity their medication and those who did not epidemic. Partly in response to the obesity ingest them consistently showed increasing around them, a subset of American youths, behavioral problems. However, there was many from suburban upper middle class, significant growth deterioration among chil- restrict their nutrient intake and develop dren who took the medication for the NGR and delayed sexual development.1 This longest periods. After 2 years’ treatment, decreased intake is on the continuum of height was suppressed by a mean of –1.94 weight gain problems; it is insufficient to cm and deficits in weight gain were even support normal growth but it does not larger. The authors concluded that consistent include a distorted body image as occurs in treatment with stimulant medication was eating disorders.5 associated with maintenance of behavioral Children with NGR are generally referred effectiveness but continued growth suppres- to the pediatric endocrinologist because of sion.11 The somewhat larger deterioration short stature or delayed puberty. Therefore, observed in body weight may be due to the pediatricians and pediatric endocrinologists anorexic effects of these medications. need to recognize NGR and become familiar Suboptimal nutrition appears to be an under- with its causes and treatment. Although the lying cause of stimulant-mediated growth fal- importance of evaluating the pattern of tering. stature increments throughout life in the The classic anthropometric criteria for differential diagnosis of short stature cannot NGR stipulate low weight for age with min- 158 © 2009 Journal of Turkish Pediatric Endocrinology and Diabetes Society Lifshitz F. imal deficits in weight for height. By these retinol-binding protein, pre-albumin, albu- cross-sectional criteria, it may be difficult to min, transferrin, and triiodothyronine (T3) differentiate NGR children from those with levels, do not differentiate NGR patients familial short stature or constitutional from those with familial or constitutional growth delay.6-9 Only the longitudinal pro- short stature. Other indices of malnutrition, gression of body weight and height can such as the urinary creatine-height index or more clearly reveal NGR, which may occur urinary nitrogen/creatinine ratio, do not usu- even when there is weight-for-height ally demonstrate abnormalities. The reason excess.12 The distinguishing feature is a is that NGR patients have adapted to their delay in linear growth and puberty resulting suboptimal nutritional intake and they main- from inadequate weight gain. Thus, tain homeostasis by decreasing growth, although concern is intensified when weight thereby reaching equilibrium with preserva- or height measurements fall below the 5th tion of biochemical nutritional markers.13 percentile, growth failure expressed as dete- Although fasting and protein-calorie mal- rioration across percentiles of weight and nutrition have been shown to lower circulat- height may also indicate NGR even when ing IGF-I levels in humans and rodents, the child is still above the 5th percentile. IGF-I levels may not differentiate NGR With nutritional rehabilitation, catch-up patients from those