TABLE 2.
Linear regression models testing the relation of serum magnesium with handgrip strength and knee extension torque, independent of confounders1
| Handgrip strength |
Knee extension torque |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Model 1: R2 = 0.71 |
Model 2: R2 = 0.71 |
Model 3: R2 =0.73 |
Model 1: R2 = 0.57 |
Model 2: R2 = 0.59 |
Model 3: R2 = 0.62 |
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| β ±SE | P | β ±SE | P | β ±SE | P | β ±SE | P | β ±SE | P | β ±SE | P | |
| Age (y) | −0.5 ± 0.0 | <0.0001 | −0.5 ± 0.0 | <0.0001 | −0.4 ± 0.0 | <0.0001 | −5.7 ± 0.3 | <0.0001 | −5.9 ± 0.3 | <0.0001 | −5.0 ± 0.3 | <0.0001 |
| Sex | 16.9 ± 0.5 | <0.0001 | 15.4 ± 0.7 | <0.0001 | 13.2 ± 0.8 | <0.0001 | 207.0 ± 8.0 | <0.0001 | 169.1 ± 10.6 | <0.0001 | 137.3 ± 12.2 | <0.0001 |
| BMI (kg/m2) | −1.0 ± 0.1 | <0.0001 | −1.0 ± 0.1 | <0.0001 | −1.2 ± 0.1 | <0.0001 | −10.7 ± 1.0 | <0.0001 | −11.5 ± 1.0 | <0.0001 | −15.0 ± 1.3 | <0.0001 |
| Magnesium (mg/dL) | 2.0 ± 0.5 | 0.0001 | 2.3 ± 0.6 | <0.0001 | 2.0 ± 0.5 | 0.0002 | 33.0 ± 7.8 | <0.0001 | 33.7 ± 8.3 | <0.0001 | 31.2 ± 7.9 | <0.0001 |
| Calcium (mg/dL) | — | — | −0.7 ± 0.8 | 0.42 | −0.9 ± 0.8 | 0.27 | — | — | −1.1 ± 12.0 | 0.93 | −2.0 ± 12.0 | 0.87 |
| Albumin (g/dL) | — | — | −0.3 ± 1.1 | 0.79 | −0.7 ± 1.1 | 0.53 | — | — | −28.7 ± 16.5 | 0.08 | −35.0 ± 16.3 | 0.03 |
| Hemoglobin (g/dL) | — | — | 0.6 ± 0.3 | 0.02 | 0.7 ± 0.3 | 0.01 | — | — | 11.8 ± 3.9 | 0.002 | 11.7 ± 3.9 | 0.003 |
| Plasma glucose (mg/dL) | — | — | −0.0 ± 0.0 | 0.24 | −0.0 ± 0.0 | 0.36 | — | — | −0.0 ± 0.2 | 0.88 | 0.1 ± 0.2 | 0.59 |
| Creatinine (mg/dL) | — | — | 3.4 ± 1.9 | 0.07 | 3.6 ± 1.9 | 0.06 | — | — | 164.1 ± 28.0 | <0.0001 | 163.5 ± 28.6 | <0.0001 |
| 25-Hydroxyvitamin D (ng/mL) | — | — | 0.0 ± 0.0 | 0.03 | 0.0 ± 0.0 | 0.19 | — | — | 0.1 ± 0.1 | 0.24 | −0.0 ± 0.1 | 0.99 |
| Angina pectoris | — | — | — | — | 0.4 ± 0.8 | 0.61 | — | — | — | — | 10.4 ± 11.7 | 0.37 |
| COPD | — | — | — | — | −0.2 ± 0.7 | 0.78 | — | — | — | — | 3.1 ± 10.3 | 0.77 |
| Cancer | — | — | — | — | 0.7 ± 1.2 | 0.58 | — | — | — | — | 8.8 ± 18.0 | 0.62 |
| CHF | — | — | — | — | 0.5 ± 0.4 | 0.18 | — | — | — | — | −6.2 ± 5.8 | 0.28 |
| DM2 | — | — | — | — | 0.2 ± 1.0 | 0.87 | — | — | — | — | −9.9 ± 14.4 | 0.49 |
| HTN 1 | — | — | — | — | −0.6 ± 0.6 | 0.33 | — | — | — | — | −14.9 ± 8.7 | 0.09 |
| HTN 2 | — | — | — | — | −0.2 ± 0.4 | 0.62 | — | — | — | — | −3.0 ± 6.2 | 0.62 |
| MI | — | — | — | — | −2.9 ± 1.2 | 0.01 | — | — | — | — | −38.8 ± 18.0 | 0.03 |
| Stroke | — | — | — | — | −0.4 ± 0.7 | 0.56 | — | — | — | — | −28.9 ± 10.5 | 0.005 |
| Muscle area (mm2) | — | — | — | — | 0.0 ± 0.0 | <0.0001 | — | — | — | — | 0.0 ± 0.0 | <0.0001 |
| Muscle density (mg/cm3) | — | — | — | — | 0.0 ± 0.1 | 0.96 | — | — | — | — | −1.7 ± 1.3 | 0.17 |
| Physical activity level | — | — | — | — | 4.2 ± 1.3 | <0.001 | — | — | — | — | 35.6 ± 19.2 | 0.06 |
Linear regression models. n = 1138; 615 women; 523 men. Men equals 1 and women equals 0. Model 1 was adjusted for age, sex, and BMI. Model 2 was adjusted for age, sex, BMI, calcium, albumin, hemoglobin, plasma glucose, creatinine, and 25-hydroxyvitamin D. Model 3 was adjusted for age; sex; BMI; calcium; albumin; hemoglobin; plasma glucose; creatinine; 25-hydroxyvitamin D; the presence of angina pectoris, chronic abstructive pulmonary disease (COPD), cancer, congestive heart failure (CHF), type 2 diabetes (DM2), hypertension detected via blood pressure reading (HTN 1), hypertension detected via self-report or drug use (HTN 2), myocardial infarction (MI), and stroke; muscle area; muscle density; and physical activity level.