TY - JOUR
T1 - Familial Risk of Inflammatory Bowel Disease
T2 - A Population-Based Cohort Study in South Korea
AU - Kim, Hyun Jung
AU - Shah, Shailja C.
AU - Hann, Hoo Jae
AU - Kazmi, Sayada Zartasha
AU - Kang, Taeuk
AU - Lee, Jee Hyun
AU - Kim, Kyoung Beom
AU - Kang, Min Ji
AU - Ahn, Hyeong Sik
N1 - Publisher Copyright:
© 2021 AGA Institute
PY - 2021/10
Y1 - 2021/10
N2 - Background & Aims: Despite the rapid increase in inflammatory bowel disease (IBD), population-level familial risk estimates of IBDs still are lacking in Asian-Pacific countries. We aimed to quantify the familial risk of incident IBD among first-degree relatives (FDRs) of individuals with IBD according to age, sex, and familial relationship. Methods: Using the South Korea National Health Insurance database (2002–2017), which has complete population coverage and confirmed accuracy of both FDR information and IBD diagnoses, we constructed a cohort of 21,940,795 study subjects comprising 12 million distinct families. We calculated incidence risk ratios of ulcerative colitis (UC) or Crohn's disease (CD) in individuals of affected FDRs compared with individuals without affected FDRs. Results: Of 45,717 individuals with UC and 17,848 individuals with CD, 3.8% and 3.1% represented familial cases, respectively. Overall, there was a 10.2-fold (95% CI, 9.39–11.1) and a 22.1-fold (95% CI, 20.5–24.5) significantly higher adjusted risk of UC and CD among FDRs of individuals with vs without IBD. Familial risk was highest among twins, followed by nontwin siblings, and then offspring of affected parents. Familial risk generally was higher within generations (sibling–sibling) vs between generations (parent–offspring). Familial risk also increased with the increasing number of affected FDRs. Conclusions: According to this population-based analysis, there is a substantially increased risk of IBD among FDRs of affected individuals, with the highest risk among siblings and for CD. These findings might help with an earlier diagnosis and appropriate therapeutic intervention in FDRs of individuals with IBD. Dedicated studies are needed to evaluate the contributions of shared early-in-life environmental exposures and genetic factors.
AB - Background & Aims: Despite the rapid increase in inflammatory bowel disease (IBD), population-level familial risk estimates of IBDs still are lacking in Asian-Pacific countries. We aimed to quantify the familial risk of incident IBD among first-degree relatives (FDRs) of individuals with IBD according to age, sex, and familial relationship. Methods: Using the South Korea National Health Insurance database (2002–2017), which has complete population coverage and confirmed accuracy of both FDR information and IBD diagnoses, we constructed a cohort of 21,940,795 study subjects comprising 12 million distinct families. We calculated incidence risk ratios of ulcerative colitis (UC) or Crohn's disease (CD) in individuals of affected FDRs compared with individuals without affected FDRs. Results: Of 45,717 individuals with UC and 17,848 individuals with CD, 3.8% and 3.1% represented familial cases, respectively. Overall, there was a 10.2-fold (95% CI, 9.39–11.1) and a 22.1-fold (95% CI, 20.5–24.5) significantly higher adjusted risk of UC and CD among FDRs of individuals with vs without IBD. Familial risk was highest among twins, followed by nontwin siblings, and then offspring of affected parents. Familial risk generally was higher within generations (sibling–sibling) vs between generations (parent–offspring). Familial risk also increased with the increasing number of affected FDRs. Conclusions: According to this population-based analysis, there is a substantially increased risk of IBD among FDRs of affected individuals, with the highest risk among siblings and for CD. These findings might help with an earlier diagnosis and appropriate therapeutic intervention in FDRs of individuals with IBD. Dedicated studies are needed to evaluate the contributions of shared early-in-life environmental exposures and genetic factors.
KW - Epidemiology
KW - Family
KW - IRR
KW - Inherited
UR - http://www.scopus.com/inward/record.url?scp=85099538645&partnerID=8YFLogxK
U2 - 10.1016/j.cgh.2020.09.054
DO - 10.1016/j.cgh.2020.09.054
M3 - Article
C2 - 33010407
AN - SCOPUS:85099538645
SN - 1542-3565
VL - 19
SP - 2128-2137.e15
JO - Clinical Gastroenterology and Hepatology
JF - Clinical Gastroenterology and Hepatology
IS - 10
ER -