Table 1.
Baseline characteristics of the participants by quintiles of total magnesium intake *
| Characteristics | Total | Quintiles of total magnesium intake (mg/1000 kcal/day) | P-value† | ||||
|---|---|---|---|---|---|---|---|
| Q1(lowest) | Q2 | Q3 | Q4 | Q5(highest) | |||
| No. of participants | 4, 716 | 943 | 943 | 944 | 943 | 943 | -- |
| Total magnesium intake (mg/1000 kcal/day) | 132.3 (108.8–164.0) | 93.2 (85.1–99.1) | 113.5 (108.8–118.2) | 132.3 (127.6–137.5) | 155.7 (149.3–164.0) | 198.5 (182.9–225.2) | -- |
| Magnesium supplement (%) | 16.2 | 2.7 | 5.1 | 11.3 | 19.0 | 43.1 | <0.0001 |
| Whole grain, serving/week | 6.5 (2.0–14.0) | 2.0 (0.2–6.1) | 4.7 (1.2–10.0) | 7.0 (2.2–14.5) | 8.5 (4.0–15.2) | 11.2 (5.5–18.3) | <0.0001 |
| Coffee, serving/day | 0.1 (0.0–1.4) | 0.0 (0.0–0.3) | 0.0 (0.0–0.7) | 0.1 (0.0–1.3) | 0.4 (0.0–1.7) | 1.3 (0.0–3.0) | <0.0001 |
| Cook-Medley scale | 19.5±8.5 | 22.5±8.5 | 20.7±8.3 | 19.4±8.1 | 18.4±8.3 | 16.6±8.2 | <0.0001 |
| Age (years) | 24.9±3.6 | 23.8±3.8 | 24.2±3.7 | 25.0±3.6 | 25.4±3.5 | 26.2±3.1 | <0.0001 |
| Female gender (%) | 54.8 | 57.3 | 51.3 | 50.5 | 52.1 | 62.9 | <0.0001 |
| Black (%) | 50.6 | 79.1 | 68.6 | 51.7 | 33.7 | 20.0 | <0.0001 |
| Education (years) | 13.8±2.3 | 12.9±1.9 | 13.3±2.0 | 13.8±2.2 | 14.4±2.3 | 14.8±2.3 | <0.0001 |
| LCn3PUFA intake (g/day) | 0.11±0.17 | 0.09±0.11 | 0.11±0.13 | 0.11±0.13 | 0.13±0.24 | 0.13±0.19 | <0.0001 |
| A Priori diet quality score | 62.6±13.6 | 51.1±8.3 | 57.1±9.3 | 62.2±9.9 | 67.9±10.9 | 74.9±11.5 | <0.0001 |
| Smoking Status (%) | |||||||
| Never | 56.8 | 58.4 | 57.6 | 58.2 | 57.5 | 52.5 | <0.0001 |
| Former | 13.5 | 7.5 | 9.6 | 13.2 | 15.8 | 21.4 | |
| Current | 29.6 | 34.0 | 32.8 | 28.6 | 26.7 | 26.1 | |
| Alcohol Intake (ml/day) | 4.8 (0–14.5) | 2.4 (0–10.0) | 4.77 (0–15.13) | 4.8 (0–15.5) | 5.1 (0–17.0) | 4.9 (0–15.8) | <0.0001 |
| Physical Activity (EU) | 357.0 (195.0±573.0) | 269.5 (140.0±471.0) | 334.0 (169.0±544.0) | 369.0 (197.5±606.0) | 390.0 (220.0±580.0) | 427.0 (258.0±648.0) | <0.0001 |
| BMI (kg/m2) | 24.5±5.0 | 25.0±6.0 | 24.9±5.3 | 24.6±4.9 | 24.3±4.6 | 23.7±4.1 | <0.0001 |
| SBP (mmHg) | 110.2±10.8 | 110.6±10.6 | 110.9±10.8 | 111.0±10.8 | 109.9±10.6 | 108.7±11.1 | <0.0001 |
| Cholesterol (mg/dL) | 176.7±33.4 | 173.3±33.7 | 177.7±34.0 | 178.6±33.9 | 178.3±32.8 | 175.8±32.4 | <0.01 |
| LDL-C (mg/dL) | 109.2±31.1 | 107.6±31.8 | 110.4±31.8 | 111.1±31.7 | 111.0±30.5 | 106.9±29.6 | <0.05 |
| HDL-C (mg/dL) | 53.0±13.2 | 51.6±12.3 | 53.0±13.0 | 52.7±13.2 | 52.8±13.6 | 55.2±13.4 | <0.0001 |
| LDL-C/HDL-C ratio | 2.2±0.9 | 2.2±0.9 | 2.2±0.9 | 2.3±0.9 | 2.2±0.9 | 2.1±0.9 | <0.0001 |
| Glucose (mg/dL) | 82.5±16.0 | 81.8±14.7 | 82.6±20.1 | 82.2±14.0 | 83.5±18.4 | 82.3±11.0 | 0.25 |
| Insulin (μU/mL) | 10.8±8.0 | 12.5±9.1 | 11.7±8.3 | 10.8±8.6 | 10.1±6.9 | 9.0±6.1 | <0.000 |
Abbreviations: BMI, body mass index; CARDIA, Coronary Artery Risk Development in Young Adults; EU, exercise unit; HDL-C: high-density lipoprotein cholesterol; IQR, inter-quartile range; LCn3PUFA, long-chain omega-3 polyunsaturated fatty acids; LDL-C: low-density lipoprotein cholesterol; No., number; Q, quintile;
SBP, systolic blood pressure; SD, standard deviation.
The study population included 4,716 individuals from the CARDIA study. The summary statistics were reported as means ± SDs, medians (IQRs), or percentages.
P values were obtained for any difference across the quintiles of total magnesium intake by using analysis of variance, Kruskal-Wallis test, or chi-squared test as appropriate.