Abstract B135: Mortality risks and life-shortening effect of hepatitis C virus infection: A prospective cohort study of 487,369 adults in Taiwan
Authors: Wen Chi-Pang , Chang Yen Chen , Tsai Min Kwang , Chan Hui Ting , Chung Isabella W.S. , Cheng Ting Yuan David , Tsai Shan Pou , Chiang Po-Huang 
Published: May 2012

Background: There has been emerging knowledge on the serious burden of diseases attributable to Hepatitis C carriers (HCV). However, the extent of the life time risk of HCV, when independently assessed, is as yet fully understood, particularly regarding associated risk factors that are amenable to reductions.

Objectives: We assessed the mortality risks and life-shortening effect of HCV, along with its associated risk factors, based on following up a large healthy cohort in Taiwan.

Methods: The cohort, consisting of 487,369 subjects, participated in a standardized medical screening program since 1994. Based on the hepatitis carrier status (either HBV or HCV or both), three sub-cohorts were created. As of 2007, 16,920 deaths were identified, including 1,383 liver cancer and 631 cirrhosis, with average follow up of 8.5 years. Hazard ratio (RR) was calculated using Cox proportionate hazard model. National prevalence was arrived at by standardizing age and educational status, a surrogate for socioeconomic status (SES) to those in Taiwan. Glomerular Filtration Rate (GFR) was calculated by MDRD equation.

Results: National Prevalence for HCV: 3.6% above age 20, and 6.6% above age 40 (male 6.0% and female 7.3%) increased with age and with lower SES. Rates of diabetes, hypertension, obesity, and HDL among HCV+ participants were significantly higher, but total cholesterol and triglycerides were lower. They had 35% more chronic kidney disease (CKD), with 54% more proteinuria and 13% more reduced GFR (13%). Cohort mortality results: HCV+ male participants had 7.37 years shorter than the total cohort at age 20, compared to 3.36 years for HBV+. In contrast to one out of 7 deaths (13.7%) in the total cohort was liver related, one out of two in the HCV+ sub-cohort. With HR for all-cause being 2.42, 58.7% of the deaths were HCV-related, larger than HBV counterparts (36.7%). The number of HCV related cirrhosis was 1/4 (28%) that of HCC, and HCV related risk, 10.74, was slightly smaller than that for HCC, 14.56. Nearly one out of 10 HCV+ coexisted with HBV (8.9%), and the risk became synergistic, with 2/3 of them dying from liver-related causes. Kidney cancer (5.46), diabetes (2.31), and stroke (1.91) were also significantly increased. In the order of ranking All Cause mortality risks among HCV+ subjects, diabetes (4.5), proteinuria (4.1), smoking (3.5), obesity (3.3), drinking (3.2) and hypertension (2.9) were all significantly increased.

Conclusion: The life expectancy of HCV+ carriers was shortened by 7.37–8.45 years. While the main effect was liver cancer and cirrhosis, HCV also involved kidney damage, producing proteinuria and reduced GFR, and led to an increased mortality from diabetes and stroke. The ranking order of reducible HCV risks were diabetes, CKD including proteinuria, smoking, obesity, drinking and hypertension.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B135.