BACKGROUND: Excessive iron intake can promote biliary cholesterol crystal formation in experimental studies. The absorption of heme iron is more complete than that of non-heme iron in humans; however, the effect of long-term consumption of heme and non-heme iron on the risk of gallstones is unknown. OBJECTIVE: The objective of the study was to examine long-term iron intake in relation to the occurrence of gallstone disease. DESIGN: We prospectively studied intakes of heme and non-heme iron and the risk of gallstone disease in a cohort of 44 758 US men from 1986 to 2002. Iron consumption was assessed by using a validated semiquantitative food-frequency questionnaire. Newly diagnosed gallstone disease was ascertained biennially. RESULTS: We documented 2468 incident cases of symptomatic gallstones during 597 699 person-years of follow-up. The age-adjusted relative risks (RRs) for men with intakes of heme iron and non-heme iron, when the highest and lowest quintiles were compared, were 1.21 (95% CI: 1.06, 1.37; P for trend = 0.0008) and 1.02 (95% CI: 0.90, 1.16; P for trend = 0.45), respectively. After adjustment for multiple potential confounding variables, when extreme quintiles were compared, the multivariate RR of heme iron intake was not significantly changed and remained significant with a dose-response relation (RR = 1.21; 95% CI: 1.03, 1.42; P for trend = 0.01), and that of non-heme iron intake was not significant (RR = 1.14; 95% CI: 0.99, 1.31; P for trend = 0.18). CONCLUSION: Our findings suggest that a higher consumption of heme iron is associated with a greater risk of gallstone disease among men.
BACKGROUND: Excessive iron intake can promote biliary cholesterol crystal formation in experimental studies. The absorption of hemeiron is more complete than that of non-hemeiron in humans; however, the effect of long-term consumption of heme and non-hemeiron on the risk of gallstones is unknown. OBJECTIVE: The objective of the study was to examine long-term iron intake in relation to the occurrence of gallstone disease. DESIGN: We prospectively studied intakes of heme and non-hemeiron and the risk of gallstone disease in a cohort of 44 758 US men from 1986 to 2002. Iron consumption was assessed by using a validated semiquantitative food-frequency questionnaire. Newly diagnosed gallstone disease was ascertained biennially. RESULTS: We documented 2468 incident cases of symptomatic gallstones during 597 699 person-years of follow-up. The age-adjusted relative risks (RRs) for men with intakes of hemeiron and non-hemeiron, when the highest and lowest quintiles were compared, were 1.21 (95% CI: 1.06, 1.37; P for trend = 0.0008) and 1.02 (95% CI: 0.90, 1.16; P for trend = 0.45), respectively. After adjustment for multiple potential confounding variables, when extreme quintiles were compared, the multivariate RR of hemeiron intake was not significantly changed and remained significant with a dose-response relation (RR = 1.21; 95% CI: 1.03, 1.42; P for trend = 0.01), and that of non-hemeiron intake was not significant (RR = 1.14; 95% CI: 0.99, 1.31; P for trend = 0.18). CONCLUSION: Our findings suggest that a higher consumption of hemeiron is associated with a greater risk of gallstone disease among men.
Authors: Janine Wirth; Mingyang Song; Teresa T Fung; Amit D Joshi; Fred K Tabung; Andrew T Chan; Cornelia Weikert; Michael Leitzmann; Walter C Willett; Edward Giovannucci; Kana Wu Journal: Int J Epidemiol Date: 2018-12-01 Impact factor: 7.196
Authors: Janine Wirth; Amit D Joshi; Mingyang Song; Dong Hoon Lee; Fred K Tabung; Teresa T Fung; Andrew T Chan; Cornelia Weikert; Michael Leitzmann; Walter C Willett; Edward Giovannucci; Kana Wu Journal: Am J Clin Nutr Date: 2020-09-01 Impact factor: 7.045