Physical activity and global genomic DNA methylation in a cancer-free population

Figures & data

Figure 1 Association between physical activity and global genomic DNA methylation (LINE-1) in the North Texas Healthy Heart Study 2006−2008. Regression coefficients (βs) and 95% confidence intervals (CIs) were generated from a simple linear regression model where LINE-1 methylation was modeled as a continuous outcome and daily physical activity was categorized into seven groups (0–5, 6–10, 11–15, 16–20, 21–25, 26–30, >30 min/day). 0–5 min/day was the reference group. Regression coefficients (βs), shown as the red dots in the figure, represent the difference in LINE-1 methylation (%) comparing each physical activity category with the reference. The vertical line represents the 95% CI with upper bar indicating the upper confidence limit and lower bar indicating the lower confidence limit.

Table 1 Duration of moderate and vigorous activity (minutes/day) by characteristics of the study population in the North Texas Healthy Heart study, 2006–2008

		Women				Men
		N	Moderate	Vigorous	Combined	N	Moderate	Vigorous	Combined
Age (yrs)
	40–49	38	14.8	0.9	15.7a	20	34.3	0.8	35.1
	50–59	22	8.3	0.1	8.4a	19	24.0	1.6	25.7
	60+	22	7.7	0.0	7.7a	10	23.0	0.2	23.3
Race/ethnicity
	Non-Hispanic white	10	19.1	1.9	21.0a	14	32.5	1.0	33.6
	Non-Hispanic black	37	10.6	0.4	11.0a	20	21.5	1.7	23.2
	Hispanic	35	9.5	0.0	9.5a	14	31.1	0.0	31.1
Education
	High school or less	34	9.3	0.0	9.3	14	30.1	0.0	30.2
	Some college/college graduate	48	12.4	0.7	13.2	15	27.2	1.4	28.6
Body mass index (kg/m^2)
	<25	11	20.3a	1.5	21.8a	4	18.5	0.6	19.0
	25–29	25	14.3a	0.1	14.4a	29	31.9	0.4	32.3
	≥30	46	7.4a	0.3	7.6a	16	23.5	2.2	25.6
Smoking status
	Non-Smoker	57	11.2	0.4	11.6	27	27.4	0.7	28.1
	Former Smoker	16	11.9	0.8	12.6	17	26.5	1.8	28.3
	Current Smoker	8	10.0	0.0	10.0	5	36.5	0.0	36.5
Alcohol drinking
	Non-drinker	33	11.2	0.5	11.7	20	26.0	1.7	27.7
	Monthly or Less	28	8.1	0.1	8.2	9	32.2	0.2	32.4
	≥2–4 times/month	21	15.2	0.7	15.9	20	28.2	0.6	28.8
Dietary folate intake (µg/1,000 kcal)
	<median	36	12.3	0.4	12.6	20	28.9	2.0	30.9
	≥median	36	11.1	0.6	11.8	25	28.2	0.4	28.6
LINE-1 methylation (%)
	<median	50	10.3	0.3	10.6	16	35.0	0	35.0
	≥median	32	12.5	0.6	13.1	33	24.7	1.5	26.1

a p < 0.05.

Table 2 Differences in global genomic DNA methylation (%) according to duration of physical activity in the North Texas Healthy Heart study, 2006–2008

Physical activity (min/day)	N (%)	Simple linear regression model	Multivariate linear regression model 1	Multivariate linear regression model 2
		β (95% CI)	β (95% CI)a	β (95% CI)b
0–10	61 (47.3)
11–15	20 (15.5)	0.86 (−0.52, 2.24)	0.69 (−0.61, 1.99)	0.61 (−0.91, 2.13)
16–25	15 (11.6)	0.33 (−1.21, 1.88)	−0.30 (−1.76, 1.16)	−0.28 (−2.07, 1.51)
26–30	10 (7.8)	2.52 (0.70, 4.35)	1.03 (−0.85, 2.90)	1.24 (−0.93, 3.40)
>30	25 (17.8)	1.20 (−0.11, 2.51)	−0.01 (−1.40, 1.40)	0.26 (−1.34, 1.86)
Non-Hispanics
0–25	54 (66.7)
≥26	27 (33.3)	1.96 (0.77, 3.15)	1.48 (0.12, 2.84)	1.50 (−0.08, 3.08)
Hispanics
0–25	42 (89.4)
≥26	5 (10.6)	0.30 (−2.49, 3.09)	−0.84 (−3.48, 1.80)	−0.79 (−4.68, 3.11)

a Adjusted for age (continuous), gender, race/ethnicity (non-Hispanic white, non-Hispanic black, Hispanic).

b Additionally adjusted for central obesity (yes/no), the ratio of fat mass to fat-free mass, the ratio of subcutaneous fat to visceral fat, cigarette smoking (nonsmokers, former and current smokers), alcohol drinking (never, monthly or less, and ≥2–4 times/month), dietary folate equivalent (quartiles) and education (high school or less and some college/college graduate).