Introduction
Methods
Study population
Ascertainment of incident fractures
Measurement of risk factors
Statistical analysis
Results
Baseline characteristics and correlates of serum magnesium levels
Overall (N = 2245) Mean (SD), median (IQR), or n (%) | Partial correlation, r (95% CIs)†
| |
---|---|---|
Magnesium (mg/dl) | 1.98 (0.15) | – |
Questionnaire/prevalent conditions
| ||
Age at survey (years) | 53.1 (5.0) | 0.05 (0.01–0.09)* |
Alcohol consumption (g/week) | 75.9 (137.6) | −0.08 (−0.13 to −0.04)*** |
Total energy intake (kJ/day) | 9855 (2609) | −0.03 (−0.07 to 0.01) |
Socioeconomic status | 8.51 (4.24) | −0.06 (−0.10 to −0.02)* |
Dietary magnesium intake (mg/day) | 417.2 (69.3) | −0.03 (−0.07 to 0.01) |
History of diabetes | ||
No | 2156 (96.0) | – |
Yes | 89 (4.0) | – |
Smoking status | ||
Other | 1529 (68.1) | – |
Current | 716 (31.9) | – |
History of hypertension | ||
No | 1564 (69.7) | – |
Yes | 681 (30.3) | – |
Physical measurements
| ||
BMI (kg/m2) | 26.9 (3.6) | −0.02 (−0.06 to 0.02) |
Height (cm) | 172.8 (6.2) | −0.00 (−0.04, 0.04) |
SBP (mmHg) | 134 (17) | −0.03 (−0.07 to 0.01) |
DBP (mmHg) | 89 (10) | −0.01 (−0.05 to 0.03) |
Physical activity (kj/day) | 1546 (1489) | 0.00 (−0.04 to 0.04) |
Lipid markers
| ||
Total cholesterol (mmol/l) | 5.90 (1.08) | 0.07 (0.03–0.11)*** |
HDL-C (mmol/l) | 1.29 (0.30) | −0.03 (−0.07 to 0.02) |
Triglycerides (mmol/l) | 1.10 (0.80–1.56) | 0.01 (−0.03 to 0.05) |
Metabolic and renal markers
| ||
Fasting plasma glucose (mmol/l) | 5.36 (1.27) | −0.17 (−0.21 to −0.13)*** |
Serum creatinine (µmol/1) | 89.7 (21.3) | 0.13 (0.09–0.17)*** |
Estimated GFR (ml/min/1.73 m2) | 87.0 (17.0) | −0.14 (−0.18 to −0.10)*** |
Trace elements
| ||
Serum zinc (mg/l) | 0.94 (0.12) | 0.11 (0.07–0.16)*** |
Serum ionized calcium (mmol/l) | 1.18 (0.05) | 0.06 (0.02–0.10)** |
Serum potassium (mmol/l) | 3.92 (0.30) | −0.02 (−0.06 to 0.02) |
Magnesium and risk of fractures
Serum magnesium (mg/dl) | Events/total | Model 1 | Model 2 | Model 3 | |||
---|---|---|---|---|---|---|---|
HR (95% CI) |
P value | HR (95% CI) |
P value | HR (95% CI) |
P value | ||
Total fractures
| |||||||
Q4 (2.08–2.55) | 26/557 | ref | ref | ref | |||
Q3 (1.98–2.08) | 24/564 | 0.93 (0.53–1.61) | 0.787 | 0.92 (0.53–1.60) | 0.768 | 0.86 (0.50–1.51) | 0.608 |
Q2 (1.88–1.98) | 27/558 | 1.12 (0.65–1.92) | 0.677 | 1.10 (0.64–1.90) | 0.720 | 1.01 (0.59–1.74) | 0.968 |
Q1 (0.92–1.88) | 46/566 | 2.10 (1.30–3.41) | 0.003 | 1.99 (1.23–3.24) | 0.005 | 1.80 (1.10–2.94) | 0.019 |
Femoral fractures
| |||||||
Q4 (2.08–2.55) | 15/556 | ref | ref | ref | |||
Q3 (1.98–2.08) | 16/556 | 1.08 (0.53–2.19) | 0.828 | 1.08 (0.53–2.18) | 0.840 | 1.01 (0.50–2.04) | 0.987 |
Q2 (1.88–1.98) | 16/553 | 1.20 (0.59–2.43) | 0.615 | 1.19 (0.59–2.42) | 0.626 | 1.08 (0.53–2.20) | 0.833 |
Q1 (0.92–1.88) | 31/559 | 2.56 (1.38–4.76) | 0.003 | 2.43 (1.30–4.53) | 0.005 | 2.13 (1.13–3.99) | 0.019 |
Serum magnesium(mg/dl) | Events/total | Model 1 | Model 2 | Model 3 | |||
---|---|---|---|---|---|---|---|
HR (95% CI) |
P value | HR (95% CI) |
P value | HR (95% CI) |
P value | ||
Total fractures
| |||||||
>2.0 | 34/722 | ref | ref | ref | |||
1.8–2.0 | 74/1387 | 1.25 (0.83–1.88) | 0.284 | 1.24 (0.82–1.86) | 0.308 | 1.18 (0.78–1.78) | 0.431 |
<1.8 | 15/136 | 3.30 (1.79–6.08) | < 0.001 | 2.95 (1.59–5.49) | 0.001 | 2.51 (1.34–4.70) | 0.004 |
Femoral fractures
| |||||||
>2.0 | 20/719 | ref | ref | ref | |||
1.8–2.0 | 48/1370 | 1.42 (0.84–2.39) | 0.192 | 1.41 (0.83–2.37) | 0.202 | 1.32 (0.78–2.23) | 0.304 |
<1.8 | 10/135 | 3.80 (1.77–8.16) | 0.001 | 3.32 (1.53–7.22) | 0.002 | 2.64 (1.20–5.78) | 0.016 |
Dietary magnesium(mg/day) | Events/total | Model 1 | Model 2 | Model 3 | |||
---|---|---|---|---|---|---|---|
HR (95% CI) |
P value | HR (95% CI) |
P value | HR (95% CI) |
P value | ||
Total fractures
| |||||||
Q4 (≥ 457.70) | 35/561 | ref | ref | ref | |||
Q3 (413.40–457.60) | 29/561 | 0.80 (0.49–1.31) | 0.382 | 0.85 (0.52–1.39) | 0.512 | 0.92 (0.56–1.52) | 0.743 |
Q2 (372.59–413.32) | 29/561 | 0.77 (0.47–1.26) | 0.305 | 0.82 (0.50–1.34) | 0.422 | 0.88 (0.53–1.46) | 0.626 |
Q1 (30.13–372.53) | 30/562 | 0.82 (0.50–1.34) | 0.429 | 0.82 (0.50–1.34) | 0.424 | 0.89 (0.54–1.47) | 0.654 |
Femoral fractures
| |||||||
Q4 (≥ 457.70) | 18/553 | ref | ref | ref | |||
Q3 (413.40–457.60) | 17/554 | 0.93 (0.48–1.80) | 0.821 | 0.98 (0.51–1.91) | 0.959 | 1.08 (0.55–2.12) | 0.813 |
Q2 (372.59–413.32) | 23/558 | 1.17 (0.63–2.18) | 0.609 | 1.25 (0.67–2.32) | 0.488 | 1.34 (0.71–2.52) | 0.362 |
Q1 (30.13–372.53) | 20/559 | 1.07 (0.57–2.02) | 0.838 | 1.04 (0.55–2.00) | 0.896 | 1.20 (0.62–2.32) | 0.581 |