Rising incidence of pediatric inflammatory bowel disease in Scotland.

BACKGROUND: An accurate indication of the changing incidence of pediatric inflammatory bowel disease (PIBD) within a population is useful in understanding concurrent etiological factors. We aimed to compare the current incidence and other demographic attributes of PIBD in the Scottish population to previous data. METHODS: A national cohort of prospectively and retrospectively acquired incident cases of PIBD diagnosed less than 16 years old in pediatric services in Scotland was captured for the period 2003-2008; historical Scottish data were used for comparison (1990-1995). Age/sex-adjusted incidences were calculated and statistical comparisons made using Poisson regression. RESULTS: During the 2003-2008 study period 436 patients were diagnosed with PIBD in Scotland, giving an adjusted incidence of 7.82/100,000/year. The incidence of Crohn's disease (CD) was 4.75/100,000/year, ulcerative colitis (UC) 2.06/100,000/year, and inflammatory bowel disease-unclassified (IBDU) 1.01/100,000/year. Compared with data from 1990-1995 when 260 IBD patients were diagnosed, significant rises in the incidence of IBD (from 4.45/100,000/year, P < 0.0001), CD (from 2.86/100,000/year, P < 0.0001), and UC (from 1.59/100,000/year, P = 0.023) were seen. There was also a significant reduction in the median age at IBD diagnosis from 12.7 years to 11.9 years between the periods (P = 0.003), with a continued male preponderance. CONCLUSIONS: The number of Scottish children diagnosed with IBD continues to rise, with a statistically significant 76% increase since the mid-1990 s. Furthermore, PIBD is now being diagnosed at a younger age. The reason for this continued rise is not yet clear; however, new hypotheses regarding disease pathogenesis and other population trends may provide further insights in future years.

Validation of dual-energy x-ray absorptiometry and foot-foot impedance against deuterium dilution measures of fatness in children.

OBJECTIVE: To determine the validity of estimation of body fatness by dual-energy x-ray absorptiometry (DXA) and foot-foot bio-electrical impedance (BIA). METHODS: In 176, 11-12-year-olds (84 boys; 92 girls) body fatness was measured using total body water (TBW), derived from deuterium oxide dilution space. Body fatness was also estimated from DXA and BIA. Methods were compared by regression and by Bland-Altman analysis using TBW measures as the reference. RESULTS: In boys, mean fat mass from TBW was 9.8 kg (standard deviation, SD=6.1); bias by DXA estimated fat mass was +0.9 kg (limits of agreement -2.2 to +4.1) and bias for BIA was -5.2 kg (limits of agreement +0.5 to -10.8). In boys, regression analysis indicated significant differences in slope (p<0.001) for DXA, and both slope (p < 0.001) and intercept (p < 0.001) for BIA. In girls, mean fat mass from TBW was 12.1 kg (SD 7.7); bias for DXA was +1.2 kg (limits of agreement -1.9 to +5.1) and bias for BIA was -0.2 kg (limits of agreement -5.4 to +5.1). In girls, regression analysis indicated significant differences for slope and intercept (p<0.001 in all cases) for both DXA and BIA. CONCLUSIONS: Errors in estimation of fat mass using BIA and DXA can be very large, and the direction of error can differ between the sexes.