Stature as a prognostic factor in cystic fibrosis survival.

OBJECTIVE/DESIGN: This study provides a longitudinal analysis of the National Cystic Fibrosis Patient Registry to determine if height-for-age percentile would be a useful predictor of survival. SUBJECTS: All patients were selected from the national registry (n = 19,000) maintained by the Cystic Fibrosis Foundation's 115 accredited Cystic Fibrosis Care Centers in the United States. Inclusion in our analysis required that subjects were born between 1980 and 1989; had a minimum of 4 records each; the subject was alive at age 7; and the subject had a recorded height measurement at age 7 to 8 (n = 2,773). STATISTICAL ANALYSIS: The Cox proportional hazards model was used to compare height-for-age with survival. We recorded whether a subject was less than the 5th National Center for Health Statistics (NCHS) percentile at age 5 and then in a separate analysis at age 7. Cohort effect was coded as "1" if they were born before 1982 and "0" otherwise. RESULTS: Stature is a significant prognostic indicator of survival. The relative hazard associated with height below the 5th NCHS percentile for age was significant for both males and females. In males at age 5 the relative hazard was 2.9, [95% confidence interval (CI) 1.23, 6.91; P < .02] and at age 7 it was 6.3 (95% CI 2.1, 18.8; P < .001). The relative hazard in females at age 5 was 4.3 (95% CI 2.4, 7.3; P < .0001) and at age 7 was 5.8 (95% CI 2.5, 13.1; P < .0001). APPLICATION: These highly significant relative hazard values strongly suggest that shorter patients are much more likely to die before taller patients. The dietetic professional should consider using height-for-age as an effective screening tool to identify patients at risk. Based on these data, short stature should not be considered benign to patients with cystic fibrosis. The CF team, clinicians, family, and patients need work together to maximize linear growth through medical and nutritional intervention.

Effect of vitamin K1 supplementation on vitamin K status in cystic fibrosis patients.

BACKGROUND: Patients with cystic fibrosis are at risk for impaired vitamin K status due to fat malabsorption from pancreatic insufficiency. This study was designed to assess vitamin K status and measure the effect of vitamin K1 supplementation in cystic fibrosis patients. METHODS: Eighteen outpatients participated in a crossover study to determine the effect of vitamin K1 (phylloquinone) supplementation. After obtaining initial data, each subject was randomly assigned to either a 4-week study treatment of 5 mg oral vitamin K1 supplementation per week, or no supplementation and then crossed over to the other treatment for a second 4 week period. Plasma, serum and urine samples were collected and analyzed pre-study and at the end of each study period. RESULTS: The mean concentration of plasma vitamin K1 for the supplemented group was significantly higher than the unsupplemented group, [0.34 nmol/L and 0.21 nmol/L, respectively (p < 0.05)]. The percent of undercarboxylated osteocalcin increased on supplementation from 17% to 31%, (p < 0.005). Prothrombin induced in vitamin K absence (PIVKA-II) increased on supplementation from 5 ng/mL to 22 ng/mL, (p < 0.005). The ratio of urinary gamma-carboxyglutamic acid/creatinine was similar for both study periods. CONCLUSIONS: In contrast to other studies in cystic fibrosis, this study demonstrated a need for vitamin K1 supplementation. The carboxylation state of osteocalcin and PIVKA-II were the most sensitive indices of changes in vitamin K1 status. Although the 5 mg vitamin K1/week dose improved these vitamin K parameters, normal levels were not achieved.

Comparison of weight-based dosages of enteric-coated microtablet enzyme preparations in patients with cystic fibrosis.

Twenty-one stable hospitalized cystic fibrosis patients with malabsorption syndrome participated in an open-label crossover clinical trial to evaluate the efficacy of two-period dosing regimens of a pancreatic microtablet enzyme preparation in the treatment of steatorrhea. Standard dosing consisted of 500 U lipase/kg body weight/meal, 250 U lipase/kg body weight/snack; high dosing consisted of 1,500 U lipase/kg body weight/meal, 750 U lipase/kg body weight/snack. Doses were determined by units of lipase/kg body weight to provide dosing consistency among patients of varying size. Each patient was on a regular diet of approximately 100 g of fat per day. Two separate, 72-h stool collections were performed between markers. A significant difference in mean percentage fat absorbed between the standard dose and the high dose was found (86% versus 91%, p < 0.05). Subjects were then stratified into two groups, based on the grams of fecal fat eliminated (GFFE) as follows: Group 1 with < or = 7 GFFE/24 h on both dosages (n = 7) and Group 2 with > 7 GFFE/24 h on either dose (n = 14). A significant difference (p < 0.05) between Group 1 (96%) and Group 2 (88%) was noted in the percentage fat absorbed while on the high dose. Fat absorption improved from 81% to 88%, (p < 0.05) in Group 2. During the study period, the adverse reactions of constipation or elevated serum uric acid levels were not observed. The increased doses of pancreatic enzymes resulted in improved correction of steatorrhea.