Risk of idiopathic nephrotic syndrome among children with asthma: a nationwide, population-based cohort study.
BACKGROUND
Although clinical and immunological studies have shown a possible link between allergy and idiopathic nephrotic syndrome (INS), the nature of the relationship remains unclear. Asthma is the most common chronic allergic airway inflammation. However, no study has used a longitudinal design with a population cohort to investigate INS in children with asthma.


METHODS
Using nationwide claims data from 2000 through 2007, we randomly selected 251,698 asthma cases and 1,006,791 frequency-matched controls. Incidence rates of INS and hazard ratios (HRs) were calculated.


RESULTS
The INS incidence was 3.36-fold greater in the asthma cohort than in the nonasthma control (9.26 vs. 2.76 per 100,000 person-years; 95% confidence interval (CI): 2.65-4.26). The HR for INS increased for those with more asthma-related medical visits per year, from 1.49 (95% CI: 1.06-2.11) for <3 visits to 15.7 (95% CI: 11.5-21.5) for ≥6 visits (trend test, P < 0.0001). The HR for INS slightly decreased during the follow-up period, from 3.41 (95% CI: 2.66-4.38) for ≤5.5 y to 2.90 (95% CI: 1.33-6.30) for >5.5 y.


CONCLUSIONS
We conclude that children with asthma had an increased incidence rate of INS, and increased incidence rate correlated with asthma-related medical visits.
1] Department of Nephrology, Children's Hospital, China Medical University Hospital, Taichung, Taiwan [2] College of Medicine, China Medical University, Taichung, Taiwan.
Chang-Ching
CC
Wei
1] Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan [2] Institute of Biostatistics, China Medical University, Taichung, Taiwan.
Cheng-Li
CL
Lin
1] College of Medicine, China Medical University, Taichung, Taiwan [2] Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan.
Te-Chun
0000000294271068
TC
Shen
Institute of Biostatistics, China Medical University, Taichung, Taiwan.
Yu-Fen
YF
Li
D001249:Asthma / Q000150:complications*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009404:Nephrotic Syndrome / Q000150:complications*