Table 3.
Interaction between a GRS and dietary patterns on metabolic syndrome over four visits in ARIC
| Risk ratio (95% confidence interval) P value | ||||||||
|---|---|---|---|---|---|---|---|---|
| Dietary patterns | Lowest GRS Tertile | P value | Second GRS Tertile | P value | Highest GRS Tertile | P value | Overall effect of diet × GRS interaction | P value |
| Whites | ||||||||
| No. per group | 3072 | 2487 | 2892 | 8451 | ||||
| Western | 1.17 (1.01–1.35) | 0.031 | 1.28 (1.11–1.47) | 0.001* | 1.23 (1.09–1.38) | 0.001* | 1.10 (0.47–2.57) | 0.831 |
| Healthy | 1.07 (0.92–1.23) | 0.383 | 0.98 (0.85–1.13) | 0.827 | 1.02 (0.91–1.15) | 0.679 | 1.04 (0.45–2.41) | 0.920 |
| High-fat dairy | 0.62 (0.52–0.74) | < 0.001* | 0.74 (0.63–0.87) | < 0.001* | 0.81 (0.71–0.91) | 0.001* | 0.26 (0.10–0.70) | 0.008* |
| African Americans | ||||||||
| No. per group | 710 | 795 | 725 | 2230 | ||||
| Western | 1.46 (1.04–2.04) | 0.028 | 1.18 (0.93–1.50) | 0.174 | 0.89 (0.70–1.13) | 0.329 | 7.43 (1.57–35.08) | 0.011* |
| Healthy | 1.15 (0.73–1.81) | 0.549 | 1.09 (0.80–1.48) | 0.597 | 1.39 (1.07–1.82) | .015* | 1.25 (0.15–10.08) | 0.837 |
| High-fat dairy | 0.67 (0.49–0.91) | 0.011* | 0.71 (0.533–0.96) | 0.024 | 1.03 (0.81–1.29) | 0.828 | 0.17 (0.03–0.88) | 0.035 |
Bold indicates p values that were significant at p < 0.05
*Bonferroni adjustment for multiple testing for dietary patterns (p = 0.05/3 = 0.017)
Dietary patterns were calculated using factor analysis with the principal components factor option and the varimax rotation with correlation ≥ 0.3
MetS was regressed against the GRS adjusting for covariate summary score composed of age, gender, sports physical activity (Baecke questionnaire), cigarette smoking status, drinker status, education level at visit 1, time in study, and 20 principle components for admixture
Dietary patterns are from Additional file 1: Table S2
Dietary pattern contents for Whites:
Western: fried foods, red meat, chips and fries, chicken with skin, processed meat, eggs, and condiments
Healthy: rice, pasta, vegetables, mashed potato, chicken without skin, lentils and beans
High-fat dairy: butter, whole milk, eggs
Dietary pattern contents for African Americans:
Western: Eggs, processed meat, biscuit and cornbread, whole wheat bread, fried foods, white bread, and margarine-butter
Healthy: Chicken without skin, vegetables, lentils and beans, fruit, cooked breakfast cereal, fish, mashed potato, shellfish, and cold breakfast cereal
High-fat dairy: Butter, margarine-butter, whole milk, cottage cheese