TABLE 3.
Pooled RRs (95% CIs) of total, ischemic, and hemorrhagic strokes by quintiles of total and dietary potassium intake in 86,149 women in the NHS I and 94,715 women in the NHS II1
| Quintile 1 | Quintile 2 | Quintile 3 | Quintile 4 | Quintile 5 | P-linear trend | |
| Total potassium intake | ||||||
| Total stroke | 647 | 723 | 732 | 795 | 883 | — |
| Age-adjusted model | 1.0 (reference) | 0.92 (0.83, 1.02) | 0.84 (0.75, 0.93) | 0.82 (0.74, 0.92) | 0.83 (0.75, 0.93) | 0.0003 |
| Multivariate model 1 | 1.0 (reference) | 0.97 (0.87, 1.08) | 0.89 (0.80, 0.99) | 0.89 (0.80, 0.99) | 0.89 (0.80, 0.99) | 0.01 |
| Multivariate model 2 | 1.0 (reference) | 1.00 (0.89, 1.12) | 0.92 (0.81, 1.05) | 0.91 (0.79, 1.05) | 0.91 (0.78, 1.06) | 0.16 |
| Ischemic stroke | 298 | 349 | 381 | 384 | 438 | — |
| Age-adjusted model | 1.0 (reference) | 0.95 (0.81, 1.11) | 0.93 (0.80, 1.08) | 0.85 (0.73, 0.99) | 0.87 (0.75, 1.01) | 0.03 |
| Multivariate model 1 | 1.0 (reference) | 0.96 (0.82, 1.12) | 0.93 (0.80, 1.09) | 0.86 (0.73, 1.00) | 0.87 (0.75, 1.02) | 0.04 |
| Multivariate model 2 | 1.0 (reference) | 0.98 (0.82, 1.16) | 0.95 (0.79, 1.15) | 0.87 (0.71, 1.07) | 0.89 (0.72, 1.11) | 0.23 |
| Hemorrhagic stroke | 128 | 135 | 114 | 117 | 142 | — |
| Age-adjusted model | 1.0 (reference) | 0.94 (0.73, 1.19) | 0.74 (0.57, 0.95) | 0.71 (0.55, 0.91) | 0.80 (0.63, 1.02) | 0.02 |
| Multivariate model 1 | 1.0 (reference) | 0.97 (0.76, 1.24) | 0.79 (0.61, 1.02) | 0.76 (0.59, 0.98) | 0.85 (0.67, 1.10) | 0.08 |
| Multivariate model 2 | 1.0 (reference) | 0.99 (0.76, 1.30) | 0.79 (0.58, 1.07) | 0.74 (0.53, 1.03) | 0.81 (0.56, 1.16) | 0.16 |
| Dietary potassium intake | ||||||
| Total stroke | 666 | 736 | 746 | 782 | 850 | — |
| Age-adjusted model | 1.0 (reference) | 0.91 (0.82, 1.02) | 0.84 (0.76, 0.94) | 0.80 (0.72, 0.89) | 0.81 (0.73, 0.90) | <0.001 |
| Multivariate model 1 | 1.0 (reference) | 0.96 (0.87, 1.07) | 0.90 (0.81, 1.00) | 0.87 (0.78, 0.96) | 0.88 (0.79, 0.98) | 0.006 |
| Multivariate model 2 | 1.0 (reference) | 1.05 (0.93, 1.18) | 1.01 (0.88, 1.16) | 0.96 (0.82, 1.12) | 1.00 (0.84, 1.18) | 0.76 |
| Ischemic stroke | 311 | 354 | 384 | 383 | 418 | — |
| Age-adjusted model | 1.0 (reference) | 0.93 (0.80, 1.08) | 0.91 (0.78, 1.06) | 0.82 (0.71, 1.96) | 0.83 (0.71, 0.96) | 0.004 |
| Multivariate model 1 | 1.0 (reference) | 0.94 (0.81, 1.10) | 0.92 (0.79, 1.07) | 0.84 (0.72, 0.98) | 0.86 (0.74, 1.00) | 0.02 |
| Multivariate model 2 | 1.0 (reference) | 1.00 (0.84, 1.19) | 1.00 (0.82, 1.21) | 0.88 (0.71, 1.10) | 0.92 (0.72, 1.18) | 0.38 |
| Hemorrhagic stroke | 130 | 132 | 122 | 114 | 138 | — |
| Age-adjusted model | 1.0 (reference) | 0.90 (0.70, 1.14) | 0.78 (0.61, 1.00) | 0.68 (0.53, 0.88) | 0.78 (0.61, 1.00) | 0.01 |
| Multivariate model 1 | 1.0 (reference) | 0.93 (0.73, 1.19) | 0.84 (0.65, 1.08) | 0.73 (0.56, 0.94) | 0.84 (0.66, 1.08) | 0.06 |
| Multivariate model 2 | 1.0 (reference) | 0.98 (0.74, 1.30) | 0.86 (0.62, 1.19) | 0.73 (0.51, 1.05) | 0.82 (0.55, 1.22) | 0.22 |
Values are the n of cases. Cox proportional hazards models were used to estimate RRs and 95% CIs. Model 1 was adjusted for age, calendar year, total calories (quintiles of kcal), BMI (in kg/m2; <25, 25 to <30, or ≥30), parental history of heart disease (aged ≤60 y), alcohol intake (0, 0 to <5, 5 to <10, 10 to <15, or ≥15 g/d), physical activity (<3, 3 to <9, 9 to<18, 18 to <27, or ≥27 metabolic equivalent tasks/wk), smoking, postmenopausal hormone therapy, oral contraceptive use (never, past, or current), menopausal status (premenopausal or postmenopausal), aspirin (0 to <2 or ≥2 pills/wk), multivitamin, history of hypertension, hypercholesterolemia, diabetes at baseline, and thiazide use (yes or no). Model 2 was adjusted as for model 1 and for intakes of magnesium and calcium (quintiles of g/d). NHS, Nurses’ Health Study.