T. L. Holt

Nutritional rehabilitation in cystic fibrosis : a 5 year follow-up study

Summary Previously, we reported catch-up weight gain, growth, and improved lung function in a group of malnourished cystic fibrosis (CF) children receiving aggressive nutritional supplementation for 1 year compared with a forced expiratory volume in 1 s (FEV1)-, height-, and sex-matched comparison group receiving standard therapy. To evaluate long-term effects, the clinical progress of both groups has been studied over a 5 year period. The supplemented group (n = 10) received supplements for a median of 1.35 years to achieve nutritional rehabilitation. Compared with the nonsupplemented group (n = 14), the previously supplemented group had lower mortality (2 vs. 4, N.S.) and significantly greater weight and height z scores at 4 and 5 years. The progression of pulmonary function abnormalities as measured by FEV1 and forced vital capacity (FVC) slopes was greater at 3 years in the nonsupplemented group (FEV1, p < 0.05) but no significant differences in rates of deterioration of pulmonary function were seen after 5 years in the two groups of survivors. We conclude that intensive nutritional support for 1 year has both short- and long-term effects on nutrition and growth, still evident some years after the cessation of this therapeutic modality. Supplementation for periods of longer than 1 year may produce greater gains and possibly prolong the improvement in pulmonary function observed in the earlier study.

Longitudinal study of the body composition of weight gain in exclusively breast-fed and intake-measured whey-based formula-fed infants to age 3 months

Body composition and the composition of weight gain in 82 healthy infants during the first 3 months of life were measured in relation to the type of feeding and nutrient intakes by serial measurements of total body potassium (TBK), anthropometry, and formula intake. Infants were exclusively fed either breast milk (n = 34, B fed) or whey-based formula (n = 48, F fed). Formula intakes were substantially lower than WHO-FAO recommendations (although serial weights paralleled standards), and were significantly greater in male infants, who had greater gains in weight and lean tissue than females. In both sexes, tissues low in K (fat and extracellular water) were added faster to the body weight than lean tissue. Overall, compared with B fed infants, F fed infants gained less weight between birth and 10 days and more weight between 10 and 90 days, although mean actual weights at 90 days were similar; formula feeding caused greater fat deposition in males and greater daily gains in lean mass in females. Differences in both quantity and quality of ingested nutrients account for these differences although the biological importance of these findings is speculative. These studies further elucidate the nature of growth in relation to modern feeding practices and the question of optimal versus maximal nutrient intake and growth in early life.

Total body potassium in cystic fibrosis

To further evaluate the nature of malnutrition, define at-risk groups, and confirm the efficacy of nutritional supplementation on body composition in cystic fibrosis (CF), we have conducted longitudinal and cross-sectional studies of total body potassium (TBK) in 161 unselected CF subjects aged 1 month to 17 years. TBK was determined by measurement of 40K in a whole body counter, reflecting body cell mass (BCM), the vital work-performing and growing cellular component of the body. Compared with normal TBK data for age and sex from pooled measurements of 1,629 healthy children aged 1 week to 17 years, CF infants (n = 12) diagnosed by newborn screening were depleted in TBK at diagnosis and showed catch-up with therapy by 1 year; CF children aged 2–17 years (n = 140) showed a tendency for inadequate accretion of TBK (and thus BCM) with increasing age, although the normal correlation between TBK and weight and height was maintained in the majority suggesting a pattern of nutritional stunting of growth; and malnourished CF children (n = 9) showed significant catchup in TBK with long-term nutritional rehabilitation (85–98% of TBK predicted for weight and height). These studies suggest that potentially serious, but possibly correctable deficits, in the growth of the body cell mass as measured by TBK occur commonly in CF. These deficits may be established very early in life and if not corrected lead to progressive nutritional growth retardation with increasing age.

Evaluation of bioelectrical impedance for prospective nutritional assessment in cystic fibrosis

We have compared the use of bioelectrical impedance analysis (BIA) with anthropometry for the prediction of changes in total body potassium (TBK) in a group (n = 31) of children with cystic fibrosis. Linear regression analysis showed that TBK was highly correlated (r > 0.93) with height2/impedance, weight, height, and fat-free mass (FFM) estimated from skin-fold measurements. Changes in TBK were also correlated, but less well, with changes in height2/impedance, weight, height, and FFM (r = 0.69, 0.59, 0.44, and 0.40, respectively). The children were divided into two groups: those who had normal accretion of TBK (> 5%/y) and those who had suboptimal accretion of TBK (< 5%/y). Analysis of variance showed that the significant difference in the change in TBK between the groups was detectable by concomitant changes in impedance and weight but not by changes in height, FFM, or weight and height Z scores. The results of this study suggest that serial BIA measures may be useful as a predictor of progressive undernutrition and poor growth in children with cystic fibrosis.

Nutrition in cystic fibrosis

BACKGROUND Cystic fibrosis (CF) is the most common autosomal recessive disorder leading to chronic disease in individuals with Caucasian ethnicity, although other ethnicities are susceptible to this disease as well. The underlying pathogenic mechanism is due to a mutation of the CF transmembrane conductance regulator (CFTR) which decreases chloride secretion and subsequent water transport across the apical surface of epithelial cells (1,2). Abnormal water transport leads to fluid hyperviscosity causing classic pulmonary, intestinal, hepatic, and pancreatic manifestations of the disease (Figure 1). Approximately 1000 known CFTR mutations are associated with CF (2). Currently, CF affects 30,000 individuals in the United States (3). Although progressive and life-threatening lung disease is a well-known complication in CF patients, 90% of CF patients have exocrine pancreatic insuffiency (PI) and subsequent fat malabsorption by one year of age. CF-related diabetes (CFRD), distal intestinal obstruction syndrome (DIOS), and various hepatobiliary diseases (cholelithiasis, fibrosis, and cirrhosis) also can occur as a result of impaired water A SPECIAL ARTICLE

Body composition studies in cystic fibrosis and myelomeningocele.

One of the major considerations of improving the management of many chronic diseases has been the realisation of the importance of nutrition, and, in children, the maintenance of normal growth. Cystic Fibrosis (CF) and Myelomeningocele (MMC) are two such disease states in which nutritional status has a significant effect on morbidity.