Determinants of lung disease progression measured by lung clearance index in children with cystic fibrosis.

The lung clearance index (LCI) measured by the multiple breath washout (MBW) test is sensitive to early lung disease in children with cystic fibrosis. While LCI worsens during the preschool years in cystic fibrosis, there is limited evidence to clarify whether this continues during the early school age years, and whether the trajectory of disease progression as measured by LCI is modifiable.A cohort of children (healthy and cystic fibrosis) previously studied for 12 months as preschoolers were followed during school age (5-10 years). LCI was measured every 3 months for a period of 24 months using the Exhalyzer D MBW nitrogen washout device. Linear mixed effects regression was used to model changes in LCI over time.A total of 582 MBW measurements in 48 healthy subjects and 845 measurements in 64 cystic fibrosis subjects were available. The majority of children with cystic fibrosis had elevated LCI at the first preschool and first school age visits (57.8% (37 out of 64)), whereas all but six had normal forced expiratory volume in 1 s (FEV1) values at the first school age visit. During school age years, the course of disease was stable (-0.02 units·year-1 (95% CI -0.14-0.10). LCI measured during preschool years, as well as the rate of LCI change during this time period, were important determinants of LCI and FEV1, at school age.Preschool LCI was a major determinant of school age LCI; these findings further support that the preschool years are critical for early intervention strategies.

Lung Clearance Index to Track Acute Respiratory Events in School-Age Children with Cystic Fibrosis.

Rationale: The lung clearance index (LCI) is responsive to acute respiratory events in preschool children with cystic fibrosis (CF), but its utility to identify and manage these events in school-age children with CF is not well defined.Objectives: To describe changes in LCI with acute respiratory events in school-age children with CF.Methods: In a multisite prospective observational study, the LCI and FEV1 were measured quarterly and during acute respiratory events. Linear regression was used to compare relative changes in LCI and FEV1% predicted at acute respiratory events. Logistic regression was used to compare the odds of a significant worsening in LCI and FEV1% predicted at acute respiratory events. Generalized estimating equation models were used to account for repeated events in the same subject.Measurements and Main Results: A total of 98 children with CF were followed for 2 years. There were 265 acute respiratory events. Relative to a stable baseline measure, LCI (+8.9%; 95% confidence interval, 6.5 to 11.3) and FEV1% predicted (-6.6%; 95% confidence interval, -8.3 to -5.0) worsened with acute respiratory events. A greater proportion of events had a worsening in LCI compared with a decline in FEV1% predicted (41.7% vs. 30.0%; P = 0.012); 53.9% of events were associated with worsening in LCI or FEV1. Neither LCI nor FEV1 recovered to baseline values at the next follow-up visit.Conclusions: In school-age children with CF, the LCI is a sensitive measure to assess lung function worsening with acute respiratory events and incomplete recovery at follow-up. In combination, the LCI and FEV1 capture a higher proportion of events with functional impairment.

The cost of thinking about false beliefs: evidence from adults' performance on a non-inferential theory of mind task.

Much of what we know about other people's beliefs comes non-inferentially from what people tell us. Developmental research suggests that 3-year-olds have difficulty processing such information: they suffer interference from their own knowledge of reality when told about someone's false belief (e.g., [Wellman, H. M., & Bartsch, K. (1988). Young children's reasoning about beliefs. Cognition, 30, 239-277.]). The current studies examined for the first time whether similar interference occurs in adult participants. In two experiments participants read sentences describing the real colour of an object and a man's false belief about the colour of the object, then judged the accuracy of a picture probe depicting either reality or the man's belief. Processing costs for picture probes depicting reality were consistently greater in this false belief condition than in a matched control condition in which the sentences described the real colour of one object and a man's unrelated belief about the colour of another object. A similar pattern was observed for picture probes depicting the man's belief in most cases. Processing costs were not sensitive to the time available for encoding the information presented in the sentences: costs were observed when participants read the sentences at their own pace (Experiment 1) or at a faster or a slower pace (Experiment 2). This suggests that adults' difficulty was not with encoding information about reality and a conflicting false belief, but with holding this information in mind and using it to inform a subsequent judgement.

A randomized, controlled study of insulin pump therapy in diabetic preschoolers.

OBJECTIVE: To compare glycemic control, safety, and parental satisfaction in preschool-aged diabetic children randomized to treatment either with continuous subcutaneous insulin infusion (CSII) or intensive insulin injection therapy. STUDY DESIGN: This clinical trial enrolled 42 patients <5 years of age who had been diagnosed with diabetes for at least 12 months. Children were randomly assigned to CSII (n = 21) or intensive insulin injection therapy (n = 21). Hemoglobin A1c (HbA1c) level was measured at baseline, 3, and 6 months. Secondary outcomes included severe hypoglycemic events, meter-detected hypoglycemia, blood sugar variability, body mass index (BMI), and satisfaction with therapy. RESULTS: Thirty-seven patients completed 6 months of therapy. There was a significant decrease in HbA1c during the study period for both groups (from 8.9% +/- 0.6% to 8.6% +/- 0.6% at 3- and 6-month visits). At 3 months, children using pumps had a significantly lower HbA1c than the injection group (8.4% vs 8.8%); however, by 6 months the two groups were similar (8.5% vs 8.7%). No differences in pre-meal blood sugar variabilities were seen between groups. Children on pumps had increases in the number of meter-detected episodes of hypoglycemia. Pump therapy was safe and well tolerated. No episodes of ketoacidosis occurred in either group, whereas one hypoglycemic seizure occurred in each group. Parents reported satisfaction with CSII, with 95% of families continuing on CSII beyond the 6-month study period. CONCLUSION: Pump therapy in preschool-aged children was not associated with clinically significant differences in glycemic control as compared with intensive injection therapy. The rationale for initiating CSII in this age group should be based on patient selection and lifestyle preference.