TABLE 3.
Risk of total stroke according to plasma fatty acid biomarkers of dairy fat consumption in the NHS (n = 472 cases) and HPFS (n = 122 cases)1
| Cohort-specific fatty acid quartiles |
|||||
| Fatty acid | 1 | 2 | 3 | 4 | P-trend |
| 14:0 | |||||
| NHS | |||||
| Median percentage of total fatty acids | 0.26 | 0.50 | 0.72 | 1.05 | — |
| No. of cases | 115 | 107 | 107 | 143 | — |
| Multivariable HRs (95% CIs) | Reference | 0.88 (0.58, 1.35) | 0.79 (0.48, 1.31) | 1.02 (0.59, 1.79) | 0.77 |
| HPFS | |||||
| Median percentage of total fatty acids | 0.36 | 0.69 | 0.90 | 1.37 | — |
| No. of cases | 17 | 41 | 33 | 31 | — |
| Multivariable HRs (95% CIs) | Reference | 2.92 (1.01, 8.42) | 1.08 (0.30, 3.95) | 1.40 (0.27, 7.22) | 0.83 |
| Pooled | Reference | 1.04 (0.70, 1.54) | 0.82 (0.52, 1.31) | 1.05 (0.62, 1.78) | 0.73 |
| 15:0 | |||||
| NHS | |||||
| Median percentage of total fatty acids | 0.12 | 0.15 | 0.18 | 0.23 | — |
| No. of cases | 126 | 105 | 122 | 119 | — |
| Multivariable HRs (95% CIs) | Reference | 0.74 (0.48, 1.12) | 0.86 (0.56, 1.34) | 0.86 (0.53, 1.39) | 0.79 |
| HPFS | |||||
| Median percentage of total fatty acids | 0.13 | 0.17 | 0.20 | 0.24 | — |
| No. of cases | 27 | 27 | 42 | 26 | — |
| Multivariable HRs (95% CIs) | Reference | 0.80 (0.28, 2.25) | 1.84 (0.65, 5.21) | 0.77 (0.21, 2.87) | 0.72 |
| Pooled | Reference | 0.75 (0.51, 1.11) | 0.96 (0.64, 1.44) | 0.85 (0.54, 1.33) | 0.73 |
| 17:0 | |||||
| NHS | |||||
| Median percentage of total fatty acids | 0.27 | 0.31 | 0.34 | 0.41 | — |
| No. of cases | 142 | 96 | 116 | 118 | — |
| Multivariable HRs (95% CIs) | Reference | 0.68 (0.45, 1.01) | 0.88 (0.59, 1.32) | 1.04 (0.67, 1.60) | 0.62 |
| HPFS | |||||
| Median percentage of total fatty acids | 0.28 | 0.32 | 0.34 | 0.40 | — |
| No. of cases | 42 | 27 | 23 | 30 | — |
| Multivariable HRs (95% CIs) | Reference | 1.08 (0.45, 2.60) | 0.69 (0.27, 1.80) | 0.80 (0.29, 2.16) | 0.59 |
| Pooled | Reference | 0.74 (0.51, 1.07) | 0.85 (0.59, 1.23) | 0.99 (0.67, 1.49) | 0.87 |
| trans 16:1n−7 | |||||
| NHS | |||||
| Median percentage of total fatty acids | 0.14 | 0.19 | 0.23 | 0.31 | — |
| No. of cases | 114 | 95 | 151 | 112 | — |
| Multivariable HRs (95% CIs) | Reference | 0.90 (0.58, 1.41) | 1.41 (0.90, 2.20) | 0.94 (0.55, 1.63) | 0.97 |
| HPFS | |||||
| Median percentage of total fatty acids | 0.14 | 0.20 | 0.24 | 0.29 | — |
| No. of cases | 33 | 33 | 31 | 25 | — |
| Multivariable HRs (95% CIs) | Reference | 1.15 (0.46, 2.85) | 0.87 (0.32, 2.38) | 0.70 (0.23, 2.17) | 0.52 |
| Pooled | Reference | 0.94 (0.63, 1.41) | 1.30 (0.87, 1.96) | 0.89 (0.55, 1.45) | 0.94 |
Multivariable HRs from a conditional logistic model were adjusted for age (y); race (white or nonwhite); month of blood collection; smoking status (never, former, current, or missing); physical activity (metabolic equivalent tasks per week); alcohol (servings/d); family history of diabetes (yes, no, or missing); parental history of myocardial infarction (yes, no, or missing); menopausal status in the NHS (before and after); postmenopausal hormone use in the NHS (no, yes, or missing); consumption of fish (servings/d), processed meats (servings/d), unprocessed meats (servings/d), fruit (servings/d), vegetables (servings/d), whole grains (g/d), coffee (servings/d), sugar-sweetened beverages (servings/d), glycemic load (continuous), dietary calcium (mg/d), polyunsaturated fat (g/d), and total energy (kcal/d); plasma total trans 18:1 (percentage of total fatty acids); plasma total trans 18:2 (percentage of total fatty acids); plasma 16:0 (percentage of total fatty acids); and plasma 18:0 (percentage of total fatty acids). P-trend values within each cohort were computed by assigning the median concentration in each quartile to participants and evaluating this concentration as a continuous variable. Pooled P-trend values were computed by using a generalized least-squares trend analysis (45). HPFS, Health Professionals Follow-Up Study; NHS, Nurses’ Health Study.