Body mass index and biliary tract disease: a systematic review and meta-analysis of prospective studies.
OBJECTIVE
To evaluate the association between body mass index (BMI, kg/m(2)) and incidence of biliary tract disease.


METHODS
We performed a systematic review and a meta-analysis of prospective studies by searching the database of PubMed and EMBASE published up to December 31, 2013. Outcome of interest was disease of biliary tract system (gallbladder, extrahepatic bile duct and Ampullar of Vater). We used a random-effects model to combine the study-specific relative risks (RRs) and 95% confidence intervals (95% CIs) from 22 prospective studies. We examined whether BMI was associated with a higher risk of biliary tract disease in a combined analysis.


RESULTS
The positive association was stronger for non-cancer biliary tract disease than biliary tract cancer; combined RRs (95% CIs) comparing the top with bottom categories were 1.40 (1.15-1.65) for biliary tract cancer and 2.75 (2.35-3.15) for non-cancer biliary tract disease (P for difference<0.001). For non-cancer biliary tract disease, combined RRs (95% CIs) comparing the top with bottom categories were 3.21 (2.48-3.93) for women and 2.01 (1.66-2.37) for men (P for difference=0.04).


CONCLUSIONS
Obesity is associated with higher risks of biliary tract cancer and, to a greater extent, non-cancer biliary tract disease.
Department of Food and Nutrition, Sookmyung Women's University, Seoul 140-742, Republic of Korea. Electronic address: shiningms@sm.ac.kr.
Myungsook
M
Park
Division of Cancer Prevention, National Cancer Control Institute, National Cancer Center, 323 Ilsan-ro, Ilsandong-gu, Goyang-si, Gyeounggi-do 410-769, Republic of Korea. Electronic address: hanasdy@gmail.com.
Da Young
DY
Song
Department of Food and Nutrition, Kyung Hee University, Seoul 130-701, Republic of Korea. Electronic address: youjinje@khu.ac.kr.
Youjin
Y
Je
Department of Food and Nutrition, Sookmyung Women's University, Seoul 140-742, Republic of Korea. Electronic address: junglee@sm.ac.kr.
Jung Eun
JE
Lee
D001660:Biliary Tract Diseases / Q000453:epidemiology*; D001661:Biliary Tract Neoplasms / Q000453:epidemiology; D015992:Body Mass Index; D015897:Comorbidity; D016001:Confidence Intervals; D016206:Databases, Bibliographic; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009765:Obesity / Q000453:epidemiology*; D011446:Prospective Studies; D012307:Risk Factors; D017678:Sex Distribution
Biliary tract diseases; Biliary tract neoplasms; Body mass index; Cholecystitis; Cholelithiasis; Gallbladder; Neoplasms; Obesity