Luis A Rodriguez1, Alka M Kanaya2, Stephen C Shiboski3, Alicia Fernandez4, David Herrington5, Jingzhong Ding6, Patrick T Bradshaw7. 1. University of California, San Francisco, Department of Epidemiology & Biostatistics, San Francisco, CA; Kaiser Permanente Northern California, Division of Research, Oakland, CA. Electronic address: Luis.Rodriguez@ucsf.edu. 2. University of California, San Francisco, Department of Epidemiology & Biostatistics, San Francisco, CA; University of California, San Francisco, Division of General Internal Medicine, San Francisco, CA. 3. University of California, San Francisco, Department of Epidemiology & Biostatistics, San Francisco, CA. 4. University of California, San Francisco, Department of Medicine, San Francisco, CA. 5. Wake Forest School of Medicine, Department of Internal Medicine, Winston-Salem, NC. 6. Wake Forest School of Medicine, Sticht Center on Aging, Winston-Salem, NC. 7. University of California, Berkeley, School of Public Health, Division of Epidemiology & Biostatistics, Berkeley, CA.
Abstract
PURPOSE: To estimate the effect of obesity on type 2 diabetes (T2DM) risk and evaluate to what extent non-alcoholic fatty liver disease (NAFLD) mediates this association. METHODS: Data came from 4,522 adults ages 45-84 participating in the Multi-Ethnic Study of Atherosclerosis cohort. Baseline obesity was defined using established BMI categories. NAFLD was measured by CT scans at baseline and incident T2DM defined as fasting glucose ≥126 mg/dL or use of diabetes medications. RESULTS: Over a median 9.1 years of follow-up between 2000 and 2012, 557 new cases of T2DM occurred. After adjusting for age, sex, race/ethnicity, education, diet and exercise, those with obesity had 4.5 times the risk of T2DM compared to normal weight (hazard ratio [HR] = 4.5, 95% confidence interval [CI]: 3.0, 5.9). The mediation analysis suggested that NAFLD accounted for ~36% (95% CI: 27, 44) of the effect (direct effect HR = 3.2, 95% CI: 2.3, 4.6; indirect effect through NAFLD, HR = 1.4, 95% CI: 1.3, 1.5). CONCLUSIONS: These data suggest that the association between obesity and T2DM risk is partially explained by the presence of NAFLD. Future studies should evaluate if NAFLD could be an effective target to reduce the effect of obesity on T2DM.
PURPOSE: To estimate the effect of obesity on type 2 diabetes (T2DM) risk and evaluate to what extent non-alcoholic fatty liver disease (NAFLD) mediates this association. METHODS: Data came from 4,522 adults ages 45-84 participating in the Multi-Ethnic Study of Atherosclerosis cohort. Baseline obesity was defined using established BMI categories. NAFLD was measured by CT scans at baseline and incident T2DM defined as fasting glucose ≥126 mg/dL or use of diabetes medications. RESULTS: Over a median 9.1 years of follow-up between 2000 and 2012, 557 new cases of T2DM occurred. After adjusting for age, sex, race/ethnicity, education, diet and exercise, those with obesity had 4.5 times the risk of T2DM compared to normal weight (hazard ratio [HR] = 4.5, 95% confidence interval [CI]: 3.0, 5.9). The mediation analysis suggested that NAFLD accounted for ~36% (95% CI: 27, 44) of the effect (direct effect HR = 3.2, 95% CI: 2.3, 4.6; indirect effect through NAFLD, HR = 1.4, 95% CI: 1.3, 1.5). CONCLUSIONS: These data suggest that the association between obesity and T2DM risk is partially explained by the presence of NAFLD. Future studies should evaluate if NAFLD could be an effective target to reduce the effect of obesity on T2DM.
Authors: Luis A Rodriguez; Yichen Jin; Sameera A Talegawkar; Marcia C de Oliveira Otto; Namratha R Kandula; David M Herrington; Alka M Kanaya Journal: J Nutr Date: 2020-06-01 Impact factor: 4.798