Deleterious associations of sitting time and television viewing time with cardiometabolic risk biomarkers: Australian Diabetes, Obesity and Lifestyle (AusDiab) study 2004-2005

Abstract

Objective: We examined the associations of sitting time and television (TV) viewing time with continuously measured biomarkers of cardio-metabolic risk in Australian adults.

Research design and methods: Waist circumference, BMI, resting blood pressure, triglycerides, HDL cholesterol, fasting and 2-h postload plasma glucose, and fasting insulin were measured in 2,761 women and 2,103 men aged > or =30 years (mean age 54 years) without clinically diagnosed diabetes from the 2004-2005 Australian Diabetes, Obesity and Lifestyle (AusDiab) study. Multivariate linear regression analyses examined associations of self-reported sitting time and TV viewing time (hours per day) with these biomarkers, adjusting for potential confounding variables.

Results: For both women and men, sitting time was detrimentally associated with waist circumference, BMI, systolic blood pressure, fasting triglycerides, HDL cholesterol, 2-h postload plasma glucose, and fasting insulin (all P < 0.05), but not with fasting plasma glucose and diastolic blood pressure (men only). With the exception of HDL cholesterol and systolic blood pressure in women, the associations remained significant after further adjustment for waist circumference. TV viewing time was detrimentally associated with all metabolic measures in women and all except HDL cholesterol and blood pressure in men. Only fasting insulin and glucose (men only) remained deleteriously associated with TV viewing time after adjustment for waist circumference.

Conclusions: In women and men, sitting time and TV viewing time were deleteriously associated with cardio-metabolic risk biomarkers, with sitting time having more consistent associations in both sexes and being independent of central adiposity. Preventive initiatives aimed at reducing sitting time should focus on both nonleisure and leisure-time domains.

Figure 1

Associations of individual metabolic risk variables with quartiles of sitting time for women (□) and men (●). Data are presented as marginal means (95% CI) adjusted for waist circumference (except for waist circumference and BMI outcomes), age, education, parental history of diabetes, employment status, cigarette smoking, total alcohol and total energy intake, diet quality, and leisure physical activity time. For insulin, triglycerides, HDL cholesterol, and fasting and 2-h postload plasma glucose, P values for trend and between individual quartiles of sitting time from reference category (Q1) are derived from the natural logarithm of these values. To allow for clinical interpretation, marginal means (95% CI) are presented as back-transformed log values. *P ≤ 0.05; †P ≤ 0.01; ‡P ≤ 0.001. Sex interaction P values are presented in the box. DBP, diastolic blood pressure; SBP, systolic blood pressure.

Figure 1

Associations of individual metabolic risk variables with quartiles of sitting time for women (□) and men (●). Data are presented as marginal means (95% CI) adjusted for waist circumference (except for waist circumference and BMI outcomes), age, education, parental history of diabetes, employment status, cigarette smoking, total alcohol and total energy intake, diet quality, and leisure physical activity time. For insulin, triglycerides, HDL cholesterol, and fasting and 2-h postload plasma glucose, P values for trend and between individual quartiles of sitting time from reference category (Q1) are derived from the natural logarithm of these values. To allow for clinical interpretation, marginal means (95% CI) are presented as back-transformed log values. *P ≤ 0.05; †P ≤ 0.01; ‡P ≤ 0.001. Sex interaction P values are presented in the box. DBP, diastolic blood pressure; SBP, systolic blood pressure.

Figure 2

Associations of individual metabolic risk variables with quartiles of TV viewing time for women (□) and men (●). Data are presented as marginal means (95% CI) adjusted for waist circumference (except for waist circumference and BMI outcomes), age, education, parental history of diabetes, employment status, cigarette smoking, total alcohol and total energy intake, diet quality, and leisure physical activity time. For insulin, triglycerides, HDL cholesterol, and fasting and 2-h postload plasma glucose, P values for trend and between individual quartiles of TV viewing time from reference category (Q1) are derived from the natural logarithm of these values. To allow for clinical interpretation, marginal means (95% CI) are presented as back-transformed log values. *P ≤ 0.05; †P ≤ 0.01; ‡P ≤ 0.001. Sex interaction P values are presented in the box.

Figure 2

Associations of individual metabolic risk variables with quartiles of TV viewing time for women (□) and men (●). Data are presented as marginal means (95% CI) adjusted for waist circumference (except for waist circumference and BMI outcomes), age, education, parental history of diabetes, employment status, cigarette smoking, total alcohol and total energy intake, diet quality, and leisure physical activity time. For insulin, triglycerides, HDL cholesterol, and fasting and 2-h postload plasma glucose, P values for trend and between individual quartiles of TV viewing time from reference category (Q1) are derived from the natural logarithm of these values. To allow for clinical interpretation, marginal means (95% CI) are presented as back-transformed log values. *P ≤ 0.05; †P ≤ 0.01; ‡P ≤ 0.001. Sex interaction P values are presented in the box.