Television viewing and fatty liver in early midlife. The Cardiovascular Risk in Young Finns Study

Abstract

Introduction. Both sedentary behaviour and fatty liver are associated with increased risk of obesity and non-communicable diseases, but their relationship remains unknown. We investigated the relationship of television (TV) viewing time with serum gamma-glutamyltransferase (GGT) and Fatty Liver Index (FLI), and ultrasonographically assessed liver fat.

Methods. A total of 1,367 adults of the population-based Cardiovascular Risk in Young Finns study (748 women, 619 men, aged 34–49 years) had fasting serum GGT, triglycerides, weight, height, and waist circumference, and self-reported TV time data from 2001, 2007, and 2011. Changes in GGT and FLI, and liver ultrasound images in 2011 were studied in groups with constantly low (≤ 1 h/d), moderate (1–3 h/d), or high (≥ 3 h/d) daily TV time, and in groups with ≥ 1 hour increase/decrease in daily TV time between 2001 and 2011.

Results. Constantly high TV time was associated with higher GGT and FLI (P < 0.02 in both), and 2.3-fold (95% CI 1.2–4.5) increased risk of fatty liver regardless of age, sex, leisure-time and occupational physical activity, energy intake, diet composition, alcohol use, sleep duration, socioeconomic status, and smoking. Adjustment for BMI partly attenuated the associations.

Conclusions. High TV viewing increases fatty liver risk. It may be one mechanism linking sedentary behaviour with increased cardiometabolic disease risks.

Key words::

• Echography
• elevated liver enzymes
• fatty liver
• Fatty Liver Index
• liver
• NAFLD
• non-alcoholic fatty liver disease
• sedentary lifestyle
• television
• ultrasound

Acknowledgements

Statistical support during the preparation of this manuscript was given by Irina Lisinen and Ville Aalto.

Funding: The Cardiovascular Risk in Young Finns Study has been financially supported by the Academy of Finland (grants 126925, 121584, 124282, 129378, 117797, and 41071), the Social Insurance Institution of Finland, Kuopio, Tampere and Turku University Hospital Medical Funds, the Juho Vainio Foundation, the Paavo Nurmi Foundation, the Yrjö Jahnsson Foundation (T.L.), the Finnish Foundation of Cardiovascular Research and the Finnish Cultural Foundation, the Sigrid Juselius Foundation, the Tampere Tuberculosis Foundation and the Emil Aaltonen Foundation.

Declaration of interest: The authors have no competing interests.