Sedentary behaviour and biomarkers for cardiovascular disease and diabetes in mid-life: the role of television-viewing and sitting at work

Abstract

Background: Knowledge of sedentary behaviour associations with health has relied mainly on television-viewing as a proxy and studies with other measures are less common. To clarify whether sedentary behaviour is associated with disease-risk, we examined associations for television-viewing and sitting at work.

Methods: Using the 1958 British birth cohort (n = 7660), we analysed cross-sectional associations between television-viewing and work sitting (four categories, 0-1 to ≥ 3 h/d) with total, high-density lipoprotein (HDL) and low-density lipoprotein (LDL)-cholesterol, triglycerides, blood pressure, glycated haemoglobin, fibrinogen, C-reactive protein, hypertension and metabolic syndrome at 45 y. We adjusted for lifestyle and socio-demographic factors and assessed mediation of associations by body mass index (BMI) and diet. We also assessed whether the sedentary indicators are related similarly to factors linked to disease-risk.

Results: There was a general trend of adverse socio-demographic and lifestyle characteristics with higher h/d television-viewing, but trends in the opposite direction for work sitting. Television-viewing was associated with most biomarkers and associations were mediated by BMI: e.g. for each category increase in television-viewing, HDL-cholesterol in men was lower by 2.3% (95% CI: 1.5%, 3.2%) and, in BMI and diet adjusted analyses, by 1.6% (0.8%, 2.4%); for women, by 2.0% (1.2%, 2.9%) and 0.9% (0.1%, 1.6%) respectively. Few, weaker associations for work sitting were found, in men only: e.g. corresponding values for HDL-cholesterol were 1.2% (0.5%, 1.9%) and 0.9% (0.3%, 1.5%). Odds for metabolic syndrome were elevated by 82% and 33% respectively for men watching television or work sitting for ≥ 3 vs. 0-1 h/d.

Conclusions: Associations with cardiovascular disease and diabetes biomarkers in mid-adulthood differed for television-viewing and work sitting. The role of sedentary behaviour may vary by leisure and work domains or the two indicators reflect differing associations with other disease-related influences.

Figure 1. Mean % change (95% CI) in biomarker level, for women, per category increase in television-viewing (a) and sitting at work (b).

Footnote: SBP = systolic blood pressure; DBP = diastolic blood pressure; HDL = high-density lipoprotein; LDL = low-density lipoprotein; HbA1c = glycated haemoglobin; CRP = C-reactive protein. *Quarter % change in CRP level per category increase in sedentary behaviour. Corresponding values for a % change in CRP per category increase in (a) television-viewing: 21.72% (95% CI: 17.42%, 26.02%), 15.56% (11.21%, 19.90%) and 8.39% (4.49%, 12.28%) and (b) sitting at work: −2.33% (−5.54%, 0.88%), −1.33% (−4.58%, 1.92%) and 0.13 (−2.74%, 3.00%) for “unadjusted”, “adjusted” and “adjusted+BMI+Diet” respectively. N varies from 3,752 to 3,037 due to variation in missing data. Model “Adjusted” includes: moderate-vigorous leisure activity frequency, smoking, social class at birth and in adulthood, education level, birth-weight, longstanding illness limiting daily activity, menopausal status, HRT and OC use; for total, HDL and LDL-cholesterol, triglycerides, HbA1c, fibrinogen and CRP additional adjustment for hypertension; for SBP, DBP, HbA1c,fibrinogen and CRP additional adjustment for total and HDL-cholesterol. Model “Adjusted+Diet+BMI” includes: all factors mentioned above plus consumption of chips, sweets/chocolates, alcohol, and BMI.

Figure 2. Mean % change (95% CI) in biomarker level, for men, per category increase in television-viewing (a) and sitting at work (b).

Footnote: SBP = systolic blood pressure; DBP = diastolic blood pressure; HDL = high-density lipoprotein; LDL = low-density lipoprotein; HbA1c = glycated haemoglobin; CRP = C-reactive protein. *Quarter % change in CRP level per category increase in sedentary behaviour. Corresponding values for a % change in CRP per category increase in (a) television-viewing: 10.88% (95% CI: 7.2%, 14.57%), 5.73% (1.99%, 9.47%) and 1.83% (−1.72%, 5.37%) and (b) sitting at work: −1.01% (−3.80%, 1.78%), 1.47% (−1.57%, 4.51%) and −0.07% (−2.93%, 2.79%) for unadjusted”, “adjusted” and “adjusted+BMI+Diet” respectively. N varies from 3,861 to 3,024 due to variation in missing data. Model “Adjusted” includes: moderate-vigorous leisure activity frequency, smoking, social class at birth and in adulthood, education level, birth-weight and longstanding illness limiting daily activity; for total, HDL and LDL-cholesterol, triglycerides, HbA1c,fibrinogen and CRP additional adjustment for hypertension; for SBP, DBP, HbA1c, fibrinogen and CRP additional adjustment for total and HDL-cholesterol. Model “Adjusted+Diet+BMI” includes: all factors mentioned above plus consumption of chips, sweets/chocolates, alcohol, and BMI.