Growth assessment and risk factors of malnutrition in children with cystic fibrosis

Objectives:

To evaluate the nutritional status, to screen for the presence of malnutrition, and to study the possible risk factors associated with malnutrition in patients with cystic fibrosis (CF).

Methods:

A retrospective cross-sectional review of medical records of all diagnosed CF patients in the Pediatric Department, Salmaniya Medical Complex, Manama, Kingdom of Bahrain, between January 1984 and May 2015 was conducted. Demographic and anthropometric data were collected from records of last visit to CF clinic. Nutritional status and risk factors of malnutrition were assessed.

Results:

All records of 109 CF patients were reviewed. Forty-seven pediatric patients were included in the study. All included patients were on pancreatic enzyme replacement and 42 (89%) received high-calorie supplementation. Growth failure was noted in 34 (72%) patients, 19 (56%) were wasted and stunted, 8 (23.5%) were wasted only, and 7 (20.5%) were stunted. Low birth weight (p=0.032), and the presence of gastroesophageal reflux disease (GERD) (p=0.039) were the significant risk factors for malnutrition.

Conclusion:

Most CF patients in Bahrain (72%) are malnourished. Low birth weight and the presence of GERD are risk factors.

Growth monitoring as an early detection tool: a systematic review

Growth monitoring of apparently healthy children aims at early detection of serious underlying disorders. However, existing growth-monitoring practices are mainly based on suboptimal methods, which can result in delayed diagnosis of severe diseases and inappropriate referrals. We did a systematic review to address two key and interconnected questions underlying growth monitoring: which conditions should be targeted, and how should abnormal growth be defined? We systematically searched for studies reporting algorithms for growth monitoring in children and studies comparing the performance of new WHO growth charts with that of other growth charts. Among 1556 identified citations, 69 met the inclusion criteria. Six target conditions have mainly been studied: Turner syndrome, coeliac disease, cystic fibrosis, growth hormone deficiency, renal tubular acidosis, and small for gestational age with no catch-up after 2 or 3 years. Seven algorithms to define abnormal growth have been proposed in the past 20 years, but their level of validation is low, and their overall sensitivities and specificities vary substantially; however, the Grote and Saari clinical decision rules seem the most promising. Two studies reported that WHO growth charts had poorer performance compared with other existing growth charts for early detection of target conditions. Available data suggest a large gap between the widespread implementation of growth monitoring and its level of evidence or the clinical implications of early detection of serious disorders in children. Further investigations are needed to standardise the practice of growth monitoring, with a consensus on a few priority target conditions and with internationally validated clinical decision rules to define abnormal growth, including the selection of appropriate growth charts.

From lip to lab: salty tasting skin is the main clue that raises clinical suspicion of cystic fibrosis in young infants

AIM

This study developed a clinical decision rule (CDR) to rule in or rule out cystic fibrosis (CF) in the first weeks of life.

METHODS

We combined a two-step nonconcurrent birth cohort and a cross-sectional controlled study in which observers and mothers were blinded to confirmatory sweat test results. Neonates from uncomplicated pregnancies and deliveries, with two subsequent tests for immunoreactive trypsinogen (IRT) higher than 70 ng/mL, were eligible to take part.

RESULTS

We included 49 CF-affected and 177 CF-unaffected infants with an average age of 34 days. CF-affected infants demonstrated statistically significant differences in weight gain, stool frequency and salty tasting skin from birth. Multivariate analysis showed that the main predictors of CF were salty tasting skin (odds ratio 17.2) and weight gain of <10.5 g per day (odds ratio 4.6). Depending on the CDR score, we obtained the following results: sensitivity (42.9-61.2%), specificity (89.6-96.5%), positive (62.5-77.8%) and negative (85.6-89.1%) predictive value and positive (5.8-12.3) and negative (0.4-0.6) likelihood ratio.

CONCLUSION

The CDR could provide a reliable index of clinical suspicion and timely referral for sweat testing in settings without newborn screening programmes and may also be applied to false-negative individuals where such programmes already exist.

Glucose tolerance affects pubertal growth and final height of children with cystic fibrosis

There are few data about the impact of cystic fibrosis-related diabetes (CFRD) on growth. We analyzed 17 children with cystic fibrosis (CF) presenting with newly diagnosed CFRD during puberty, in comparison with a matched control group of 52 CF children with normal glucose tolerance (NGT). Anthropometric evaluation showed that body mass index at CFRD diagnosis was significantly reduced in children with CFRD, in comparison with children with NGT (CFRD: -0.48 ± 1.08 vs. NGT: 0.2 ± 0.99; P=0.01), and the same difference remained evident at the end of follow up (CFRD: -0.49 ± 0.95 vs. NGT: 0.13 ± 0.89; P=0.04). Height standard deviation score (SDS) at baseline was slightly but not significantly lower in CFRD children (CFRD: -0.71 ± 0.83 vs. NGT: -0.25 ± 1.08; P=0.08), while final height SDS was significantly reduced (CFRD: -1.61 ± 1.12 vs. NGT: -0.61 ± 1.15; P=0.003). Mean final height SDS of the whole group was lower than mean target height SDS (final height SDS: -0.86 ± 1.2 vs. target height SDS: -0.3 ± 0.85; P<0.001). Target adjusted final height was lower in CFRD children, although the difference between CFRD and NGT children did not reach statistical significance (CFRD: -0.8 ± 1.03 vs. NGT: -0.47 ± 0.9; P=0.09). Pubertal growth and final height are negatively affected by CFRD. Intensive insulin treatment does not appear to be effective in normalizing growth, even when treatment is started early in the course of the disease, before the onset of clinical deterioration.

Etiologies and early diagnosis of short stature and growth failure in children and adolescents

Accurate measurement of height and weight using standardized techniques is a fundamental component of pediatric medical visits. Calculation of height velocity over time enables comparison with standardized growth charts to identify potential deviations from normal. Growth deviations may be expressed as SD from the normal population mean for children of comparable age and sex; children with heights >2 SD below the mean are generally classified as short stature. In a child with suspected impaired growth, a detailed evaluation should be conducted to identify the cause. Such an evaluation may include a combination of personal, family, and social history; physical examination; general and perhaps specialized laboratory evaluations; radiologic examinations; genetic testing; and consultation with a pediatric subspecialist, such as a pediatric endocrinologist. Variants of normal growth include familial short stature, constitutional delay of growth and puberty, and small for gestational age with catch-up growth. Pathological causes of abnormal growth include many systemic diseases and their treatments, growth hormone deficiency, and a series of genetic syndromes, including Noonan syndrome and Turner syndrome. Children with short stature in whom no specific cause is identified may be diagnosed with idiopathic short stature. Early identification of abnormal growth patterns and prompt referral to specialist care offer children with growth failure and/or short stature the greatest chance for appropriate diagnosis, treatment, and improved clinical outcomes.

Methods to obtain referral criteria in growth monitoring

An important goal of growth monitoring is to identify genetic disorders, diseases or other conditions that manifest themselves through an abnormal growth. The two main conditions that can be detected by height monitoring are Turner’s syndrome and growth hormone deficiency. Conditions or risk factors that can be detected by monitoring weight or body mass index include hypernatremic dehydration, celiac disease, cystic fibrosis and obesity. Monitoring infant head growth can be used to detect macrocephaly, developmental disorder and ill health in childhood. This paper describes statistical methods to obtain evidence-based referral criteria in growth monitoring. The referral criteria that we discuss are based on either anthropometric measurement(s) at a fixed age using (1) a Centile or a Standard Deviation Score, (2) a Standard Deviation corrected for parental height, (3) a Likelihood Ratio Statistic and (4) an ellipse, or on multiple measurements over time using (5) a growth rate and (6) a growth curve model. We review the potential uses of these methods, and outline their strengths and limitations.