Table 3.
Associations between sex-specific tertiles of physical activity and mortality stratified by the intake of calcium, magnesium or calcium to magnesium ratio
| Deaths/person-year | All-cause HR (95% CI) | p-trend | Deaths/person-year | CVD HR (95% CI) | p-trend | Deaths/person-year | Cancer HR (95% CI) | p-trend | |
|---|---|---|---|---|---|---|---|---|---|
| Ca:Mg < 2.6 | |||||||||
| Inactive2 | 727/26,990 | REF | 193/26,990 | REF | 165/26,990 | REF | |||
| Insufficient | 160/10,176 | 0.77 (0.58, 1.02) | 40/10,176 | 0.78 (0.45, 1.34) | 32/10,176 | 0.48 (0.26, 0.87) | |||
| Moderate | 146/11,039 | 0.71 (0.56, 0.91) | 41/11,039 | 0.77 (0.50, 1.20) | 39/11,038 | 0.80 (0.50, 1.27) | |||
| High | 82/10,787 | 0.55 (0.39, 0.77) | <0.001 | 15/10,787 | 0.27 (0.12, 0.65) | 0.001 | 27/10,787 | 0.48 (0.26, 0.87) | 0.01 |
| Ca:Mg ratio ≥ 2.6 | |||||||||
| Inactive | 1,011/37,961 | REF | 273/37,961 | REF | 199/37,961 | REF | |||
| Insufficient | 198/17,221 | 0.68 (0.55, 0.84) | 42/17,221 | 0.50 (0.32, 0.78) | 54/17,221 | 0.86 (0.57, 1.30) | |||
| Moderate | 196/17,957 | 0.73 (0.57,0.93) | 55/17,958 | 0.80 (0.49, 1.30) | 47/17,957 | 0.77 (0.47, 1.27) | |||
| High | 130/17,869 | 0.54 (0.42, 0.69) | <0.001 | 21/17,869 | 0.43 (0.25, 0.73) | 0.005 | 39/17,869 | 0.68 (0.44, 1.05) | 0.06 |
| p-interaction1 | |||||||||
| Magnesium: male < 420 or female < 320 mg/day | |||||||||
| Inactive | 1,423/48,713 | REF | 387/48,713 | REF | 288/48,713 | REF | |||
| Insufficient | 270/19,122 | 0.68 (0.56, 0.82) | 60/19,122 | 0.48 (0.32, 0.72) | 66/19,122 | 0.79 (0.54, 1.17) | |||
| Moderate | 259/18,899 | 0.80 (0.66, 0.97) | 73/18,899 | 0.84 (0.60, 1.16) | 69/18,899 | 1.00 (0.69, 1.45) | |||
| High | 150/17,922 | 0.53 (0.43, 0.65) | <0.001 | 26/17,922 | 0.37 (0.22, 0.64) | 0.002 | 49/17,922 | 0.66 (0.45, 0.96) | 0.08 |
| Magnesium: male ≥ 420 or female ≥ 320 mg/day | |||||||||
| Inactive | 325/16,296 | REF | 84/16,296 | REF | 77/16,296 | REF | |||
| Insufficient | 90/8,305 | 0.81 (0.59, 1.11) | 22/8,305 | 1.01 (0.52, 1.97) | 20/8,305 | 0.52 (0.27, 1.01) | |||
| Moderate | 83/10,127 | 0.56 (0.44, 0.72) | 23/10,127 | 0.65 (0.35, 1.21) | 17/10,127 | 0.42 (0.22, 0.81) | |||
| High | 63/10,747 | 0.57 (0.39, 0.82) | <0.001 | 10/10,747 | 0.40 (0.16, 0.98) | 0.02 | 17/10,747 | 0.47 (0.23, 0.98) | 0.01 |
| p-interaction1 | 0.09 | 0.10 | 0.02 | ||||||
| Calcium < 1,000 mg/day | |||||||||
| Inactive | 1,243/41,780 | REF | 327/41,780 | REF | 255/41,780 | REF | |||
| Insufficient | 218/15,067 | 0.67 (0.53, 0.83) | 52/15,067 | 0.55 (0.37, 0.84) | 47/15,067 | 0.56 (0.35, 0.88) | |||
| Moderate | 211/15,073 | 0.79 (0.65, 0.96) | 63/15,073 | 0.87 (0.62, 1.23) | 53/15,073 | 0.87 (0.59, 1.28) | |||
| High | 120/14,427 | 0.65 (0.49, 0.85) | <0.001 | 25/14,427 | 0.56 (0.30, 1.06) | 0.04 | 39/14,427 | 0.69 (0.43, 1.11) | 0.07 |
| Calcium ≥ 1,000 mg/day | |||||||||
| Inactive | 545/23,508 | REF | 255/23,508 | REF | 114/23,508 | REF | |||
| Insufficient | 148/12,492 | 0.78 (0.61, 0.99) | 47/12,492 | 0.65 (0.41, 1.03) | 39/12,492 | 0.90 (0.52, 1.59) | |||
| Moderate | 139/14,078 | 0.66 (0.50, 0.86) | 53/14,078 | 0.65 (0.36, 1.17) | 35/14,078 | 0.75 (0.44, 1.26) | |||
| High | 95/14,361 | 0.45 (0.33, 0.61) | <0.001 | 39/14,361 | 0.22 (0.09, 0.55) | 0.003 | 28/14,361 | 0.53 (0.30, 0.94) | 0.02 |
| p-interaction1 | 0.10 | 0.09 | 0.34 | ||||||
Cox proportional hazards models were performed with the SAS SURVEYPHREG procedure to estimate odds ratios and 95% confidence intervals, adjusting for age, sex, ethnicity, education, poverty income ratio, smoking, alcohol use, BMI, total intake of energy, calcium and magnesium.
The p values are the interactions between the intakes of magnesium, or calcium, or calcium/magnesium ratio (continuous) with physical activity (categorical).
Sex-specific tertiles: inactive, low (performing < 562 (men) or <371 (women) MET-min/week), moderate (performing 562–1,757 [men] or 371–1,200 [women] MET-min activity/week) and high (performing greater than 1,757 [men] or 1,200 [women] MET-min activity/week).