Perceived dietary salt intake and the risk of primary liver cancer: a population-based prospective study

Background: Although a high-salt diet is associated with high risk of chronic diseases such as hypertension, stroke and cardiovascular disease, little is known about the relationship between a high-salt diet and the risk of primary liver cancer (PLC). Consequently, we prospectively assessed the association of high perceived salt intake with the risk of PLC in the Kailuan Study.

Methods: In total, 97 006 participants who were healthy adults or free living adults at the baseline (2006) were included in the present study. The data of perceived salt intake were collected via questionnaire and classified into three categories: <6 g day^-1 for low salt intake, 6-10 g day^-1 for intermediate salt intake, >10 g day^-1 for high-salt intake. PLC including hepatocellular carcinoma and intrahepatic cholangiocarcinoma (excluding liver metastasis), and was confirmed by review of medical records. We used a Cox proportional hazards model to analyse the association between high perceived salt diet and the risk of PLC after adjusting for possible confounders, including age, gender, body mass index, high sensitivity-C-reactive protein, low-density lipoprotein-cholesterol, total cholesterol, triglycerides, alanine aminotransferase, HbsAg positive, cirrhosis, fatty liver, hypertension, diabetes, drinking status, smoking status and physical exercise.

Results: During the follow-up period of 1 113 816 person-years, 397 PLC events were diagnosed. After adjusting for most potential confounders, subjects in intermediate salt intake and high salt intake had a multivariable hazard ratio and 95% confidence interval of 1.49 (0.97-2.29) and 1.98 (1.22-3.22) (P for trend = 0.0042), respectively, compared to low salt intake.

Conclusions: A higher perceived salt intake was associated with a higher risk of PLC.

Keywords: incidence; perceived salt intake; primary liver cancer; prospective cohort; risk.