TABLE 4.
Quartiles of dietary pattern factor scores from multiple statistical methods and subclinical carotid atherosclerosis among 1246 participants of the Study of Women's Health Across the Nation (USA), 1996–20131
| Quartile 1 | Quartile 2 | Quartile 3 | Quartile 4 | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| n | Mean difference | RR | n | Mean difference | RR | n | Mean difference | RR | n | Mean difference | RR | P-trend2 | |
| CCA-IMT, mm | |||||||||||||
| PCA-Western | 311 | 0 (Ref) | — | 312 | 0.014 (−0.0083, 0.037) | — | 312 | 0.035 (0.0086, 0.061)* | — | 311 | 0.042 (0.011, 0.073)* | — | 0.013 |
| PCA-Prudent | 311 | 0 (Ref) | — | 312 | 0.0042 (−0.017, 0.025) | — | 312 | −0.018 (−0.039, 0.0038) | — | 311 | −0.0060 (−0.028, 0.016) | — | 0.38 |
| RRR-Western | 253 | 0 (Ref) | — | 254 | 0.0035 (−0.019, 0.026) | — | 254 | 0.016 (−0.0074, 0.040) | — | 254 | 0.033 (0.0086, 0.057)* | — | 0.0058 |
| PLS-Western | 253 | 0 (Ref) | — | 254 | 0.019 (−0.0039, 0.041) | — | 254 | 0.019 (−0.0042, 0.042) | — | 254 | 0.049 (0.025, 0.074)* | — | < 0.001 |
| CCA-AD, mm | |||||||||||||
| PCA-Western | 311 | 0 (Ref) | — | 312 | 0.036 (−0.072, 0.14) | — | 312 | 0.091 (−0.034, 0.21) | — | 311 | 0.057 (−0.091, 0.20) | — | 0.65 |
| PCA-Prudent | 311 | 0 (Ref) | — | 312 | 0.040 (−0.059, 0.14) | — | 312 | −0.014 (−0.12, 0.088) | — | 311 | −0.017 (−0.12, 0.090) | — | 0.51 |
| RRR-Western | 253 | 0 (Ref) | — | 254 | 0.052 (−0.056, 0.16) | — | 254 | 0.027 (−0.086, 0.14) | — | 254 | 0.040 (−0.075, 0.15) | — | 0.56 |
| PLS-Western | 253 | 0 (Ref) | — | 254 | 0.034 (−0.074, 0.14) | — | 254 | 0.026 (−0.085, 0.14) | — | 254 | 0.11 (−0.0021, 0.23) | — | 0.071 |
| Carotid plaque | |||||||||||||
| PCA-Western | 311 | — | 1.00 (Ref) | 312 | — | 0.87 (0.65, 1.15) | 312 | — | 0.85 (0.61, 1.17) | 311 | — | 0.79 (0.53, 1.17) | 0.35 |
| PCA-Prudent | 311 | — | 1.00 (Ref) | 312 | — | 1.14 (0.88, 1.47) | 312 | — | 1.02 (0.77, 1.35) | 311 | — | 1.09 (0.82, 1.50) | 0.74 |
| RRR-Western | 253 | — | 1.00 (Ref) | 254 | — | 0.77 (0.56, 1.05) | 254 | — | 0.86 (0.63, 1.18) | 254 | — | 1.01 (0.75, 1.35) | 0.79 |
| PLS-Western | 253 | — | 1.00 (Ref) | 254 | — | 1.17 (0.86, 1.58) | 254 | — | 1.06 (0.78, 1.46) | 254 | — | 1.10 (0.80, 1.51) | 0.66 |
Values are mean differences (95% CIs) for CCA-IMT/CCA-AD, and risk ratios (95% CIs) for carotid plaque. The dietary patterns were derived using the energy-adjusted food groups averaged across available visits of baseline (1996–1997), Visit 5 (2001–2003), and Visit 9 (2005–2007). The outcomes were measured at Visit 12 (2009–2011) or Visit 13 (2011–2013). The sample size for reduced rank regression and partial least squares regression was 1015 due to missing data on the intermediate response variables. All models were adjusted for age at the carotid scan (continuous), race/ethnicity (non-Hispanic white or not), education level (
high school, some college, or college degree/postcollege), economic strain (somewhat/very hard paying for basics, or not hard paying for basics), self-rated overall health (excellent/very good, good, or fair/poor), Center for Epidemiologic Studies Depression scale (
16 or <16), smoking status (ever or never), nonoccupational physical activity level (continuous), total energy intake (continuous average across available visits of baseline, Visit 5, and Visit 9), menopausal status (premenopausal or early perimenopausal), use of hormone therapy from baseline to the visit of the carotid scan (ever or never), abdominal obesity, elevated blood pressure, elevated glucose, elevated triglycerides, reduced HDL cholesterol, and the number of missing visits for dietary measurements (0, 1, or 2). The baseline covariates were used except age, total energy intake, hormone therapy use, and the number of missing visits for dietary measurements.
Computed by assigning the median factor score of each quartile to participants in the corresponding quartile as a continuous variable.
Different from Quartile 1, P <0.01.
AD, adventitial diameter; CCA, common carotid artery; IMT, intima-media thickness; PCA, principal component analysis; PLS, partial least squares regression; Ref, reference group; RR, risk ratio; RRR, reduced rank regression.