A 12-year study links longer TV viewing to faster kidney function decline

Could the hours spent watching television influence long-term kidney health? Researchers tracked more than 6,000 Australians over 12 years to examine how viewing habits, diabetes status, and physical activity relate to changes in kidney function.

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Exploratory analyses suggested the relationship might be stronger among women and physically inactive individuals, but subgroup findings were less consistent across sensitivity analyses. The findings suggest that strategies promoting physical activity and reducing prolonged sedentary time may be relevant to kidney health. These approaches warrant further investigation, particularly for people with T2D and women, because the study did not test whether changing these behaviors could slow the decline in kidney function.

The research was conducted by scientists from Swinburne University of Technology, the Baker Heart and Diabetes Institute, Monash University, Deakin University, and other Australian institutions, in collaboration with researchers from the University of Tsukuba in Japan, South-Eastern Finland University of Applied Sciences, and the Universities of Leicester and Cambridge in the United Kingdom.

Studies suggest that sedentary habits that increase time spent sitting or reclining, such as watching TV, are associated with kidney dysfunction. Sedentary behavior is distinct from physical inactivity, which means not meeting recommended activity levels.

Chronic kidney disease (CKD) may increase the risk of cardiovascular diseases (CVDs) and premature mortality. Whether T2D status can modify the long-term association between sedentary behavior and kidney function decline remains unclear.

A better understanding of these relationships could inform policymaking aimed at reducing the burden of kidney disease and associated healthcare costs worldwide.

About the study

In the present study, the researchers examined links between TV viewing and kidney function decline in community-dwelling Australian adults aged ≥25 years living with or without T2D. Kidney function decline was assessed over 12 years using estimated glomerular filtration rate (eGFR) values calculated from serum creatinine with the 2009 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.

The team obtained data from 6,220 Australian Diabetes, Obesity and Lifestyle Study (AusDiab) participants at baseline (1999/2000), 5,626 participants at five years (2004/2005), and 4,054 at 12 years (2011/2012). Participants needed at least one follow-up assessment to be included. Pregnant women and individuals with type 1 diabetes (T1D) were excluded. Participants reported how long they watched TV, videos, or DVDs on weekdays and weekends during the previous week. The Active Australia Survey (AAS) captured the extent of physical activity during leisure hours and walking for transport.

Individuals who engaged in physical activity for less than 150 minutes per week were classified as inactive, based on World Health Organization (WHO) guidelines. The team further classified them as having normal glucose metabolism, prediabetes, or T2D based on their glucose metabolism status (GMS). The classification used fasting blood glucose and two-hour oral glucose tolerance tests, along with previously diagnosed diabetes status.

At all three time points, the researchers assessed eGFR, physical activity, time spent watching TV, and GMS. The researchers used standardized blood creatinine measurements to calculate eGFR. Multilevel models estimated the rate of kidney function decline and tested whether its relationship with viewing time differed according to T2D status, gender, or physical inactivity.

The team also accounted for age, education, income, smoking habits, alcohol intake, waist circumference, total energy intake, systolic blood pressure, total cholesterol, prior CVD history, and antihypertensive medications. In the sensitivity analysis, individuals living with CKD (eGFR below 60 mL per minute per 1.73 m²) at baseline were excluded.

Results

More than 54% of participants were women, with a mean age of 50.7 years and a mean WC of 90.3 cm. At baseline, 6.4% had T2D, increasing to 10% at five years and nearly 11% at 12 years. By comparison, the proportion of physically inactive individuals decreased from approximately 46% (baseline) to 43% (five years), and 36% at 12 years.

Over 12 years, the team observed a decrease in average eGFR from 96.5 to 89.9 mL/min/1.73 m², while average television viewing rose from 1.77 to 1.91 hours per day. Longer viewing time was associated with a faster decline in kidney function. Individuals with T2D demonstrated lower eGFR and longer TV-viewing time across time points than those without T2D. At age 50 years, the modeled mean eGFR was 98 mL per minute per 1.73 m². Declines in eGFR of approximately 0.80 mL per minute per 1.73 m² per year were observed.

Increasing daily TV-watching duration was associated with faster eGFR decline, particularly among people with T2D. Exploratory analyses also suggested a stronger association in women, but this finding was less consistent across sensitivity analyses. Physical inactivity appeared to strengthen the relationship, but this interaction was not statistically significant in the main analysis and was inconsistent in analyses restricted to participants with complete follow-up data. The overall association remained consistent when the researchers excluded participants with baseline CKD or restricted the analysis to those assessed at all three time points. The stronger association among people with T2D was less conclusive in the latter analysis.

Conclusion

The findings suggest that spending more time watching TV is associated with faster declines in kidney function, particularly among those with T2D and women, with less consistent evidence for physically inactive individuals. Each additional hour of daily TV viewing was associated with a 2% to 3% faster annual decline in kidney function, equivalent to approximately two extra months of age-related decline over five years. The observational design, reliance on self-reported activity, and loss to follow-up limit causal interpretation. Reverse causation and unmeasured factors, including diabetes duration, diet, and medication use, may also have influenced the results.

The relationship also appeared more pronounced at longer viewing durations, including four hours or more per day, but the study did not establish a specific risk threshold. The findings support existing recommendations to reduce prolonged sitting and maintain regular physical activity.

In future studies, researchers could explore how exercise, T2D duration, and diet-related variables influence age-related physiological declines in kidney function, using objective measures of physical activity and sedentary behavior, including computer use and video gaming.

Source:

Journal reference:

• Dzakpasu, F.Q.S., Kosaki, K., Owen, N. et al. (2026). Leisure-time sedentary behaviour and kidney function decline over 12 years in Australian adults with and without type 2 diabetes. Scientific Reports. DOI: 10.1038/s41598-026-79103-y, https://www.nature.com/articles/s41598-026-79103-y