| Epidemiologic Reviews | Vol. 19, No. 2 |
| Copyright © 1997 by The Johns Hopkins University School of Hygiene and Public Health | Printed in U.S.A. |
| All rights reserved |
|
TABLE 1. Results from autopsy studies of myocardial magnesium concentrations |
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|
Authors and year (ref.) |
Location of study |
Mean myocardial magnesium content (µg/g)* |
p value |
|||
|
Controls† |
No. of patients |
Sudden deaths |
No. of patients |
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|
Chipperfield and Chipperfield, 1973 (59) |
England |
205 |
14 |
172 |
19 |
<0.001 |
|
Anderson et al., 1975 (60)‡ |
Canada |
|
|
|
|
|
|
Soft water |
|
918 |
54 |
697 |
27 |
<0.01 |
|
Hard water |
|
982 |
29 |
744 |
12 |
|
|
Chipperfield et al, 1976 (61) |
England |
219 |
12 |
174 |
12 |
<0.001 |
|
Chipperfield and Chipperfield, 1978 (62) |
England |
186 |
158 |
154 |
59 |
<0.001 |
|
Johnson et al., 1979 (63) |
United States |
221 |
7 |
194 |
14 |
<0.05 |
|
Chipperfield and Chipperfield, 1979 (64)§ |
England |
186 |
158 |
179 |
7 |
NS¶ |
|
Elwood et al., 1980 (65) |
England/Wales |
181 |
305 |
159 |
489 |
<0.05 |
|
* Wet weight of myocardial tissue. |
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|
TABLE 2. Correlation coefficients for water hardness and
cardiovascular |
||
| Author(s) and year (ref.) | r* | |
| Calcium | Magnesium | |
| Biersteker, 1967 (71) | -0.15 | |
| -0.46 | ||
| Björck et al., 1965 (72) | -0.03 | -0.03 |
| -0.40 | 0.15 | |
| Blachly, 1969 (73) | -0.40 | |
| Crawford and Crawford, 1967 (74) | -0.56 | |
| Dudley et al., 1969 (75) | -0.39 | |
| Elwood et al., 1974 (76) | -0.56 | -0.35 |
| Hart, 1970 (77) | -0.46 | |
| Lindemann and Assenzo, 1964 (78) | 0.18 | 0.16 |
| 0.05 | 0.03 | |
| Morris et al., 1961 (79) | -0.54 | -0.04 |
| -0.48 | 0.08 | |
| -0.54 | -0.09 | |
| -0.43 | 0.05 | |
| Nerbrand et al., 1992 (80) | --† | --‡ |
| Neri et al., 1974 (69) | -0.08 | -0.10 |
| Roberts and Lloyd, 1972 (81) | -0.46 | |
| -0.43 | ||
| Sauer et al., 1971 (82) | -0.32 | |
| Scassellati-Sforzolini and Pascasio, 1971 (83) | -0.11 | |
| Schroeder, 1966 (84) | -0.51 | |
| Schroeder and Kraemer, 1974 (85) | -0.32 | -0.30 |
| -0.35 | -0.28 | |
| Shaper et al., 1980 (86) | --§ | --‡ |
| Voors, 1971 (87) | -0.35 | -0.32 |
| Winton and McCabe, 1970 (88) | -0.32 | |
| -0.55 | ||
|
* Pearson's product-moment correlation coefficient. Coefficients
listed pertain to different study methods, age/sex groups, and ICD-9-CM codes. † Significant at the 0.05 level. ‡ Not significant. § Standardized regression effect: -3.9%/100 mg of calcium carbonate. |
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| Table 3. Rate-based studies of magnesium in the drinking water and diet and ischemic heart disease | |||||||||||
| Author(s) and year (ref.) | Location of study | Study population | Outcome | Magnesium | Calcium | Observa- tion period (years) | Parameters | RR* | p value of 95% CI* | Attrib- utable risk† | |
| Level (mg/liter) | Level (mg/liter of CaCO3*) | Rate (per 100,000) | |||||||||
| Ecologic studies | |||||||||||
| Luoma et al., 1973 (98) | Finland | 300 men aged 24-70 years | Prevalence of IHD* morbidity | 5.8 | N/A* | "Several" | 8,600 | 7.82 | —‡ | 0.87 | |
| 11.0 | 1,100 | ||||||||||
| Allwright et al., (1974 (99) | Los Angeles, California | n=244,524, all ages§ | IHD mortality | 5.0 | 82 | 2 | 99 | 1.03 | NS* | 0.03 | |
| 18.0 | 327 | 96 | |||||||||
| Leary et al., 1983 (100) | South Africa | White males, age N/A | IHD mortality | 1.0 | N/A | 1 | 500 | 5.00 | p<0.02 | 0.80 | |
| 45.0 | N/A | 100 | |||||||||
| Teitge, 1990 (102) | East Germany | n=105,000; males and females aged > 40 yrs | Incidence of MI* | 2.9 | N/A | 10 | 332 | 1.61 | p<0.05 | 0.38 | |
| 5.8 | N/A | 206 | |||||||||
| Rylander et al., 1991 (103) | Sweden | n=800,655; males and females, all ages | IHD mortality | 1.0 | N/A | 10 | N/A | 1.41¶ | p<0.02 | 0.29 | |
| 15.0 | N/A | N/A | |||||||||
| No. of cases | No. of controls | ||||||||||
| Case-control studies | |||||||||||
| Luoma et al., 1983 (104) | Finland | Men aged 30-64 years | First MI | <1.2 | N/A | 2 | 50 | 50 | 4.67¶ | 1.3-25.32 | 0.65 |
| >3.0 | N/A | 1.63¶ | 0.62-4.52 | ||||||||
| Rubenowitz et al., 1996 (12) | Sweden | Men aged 50-69 years (median age, 64 years) | Mortality from acute MI | <3.5 | 8 | 854 | 989 | 1.51¶ | p<0.05 | 0.34 | |
| >9.8 | 1.00¶ | ||||||||||
| No. of cases | Sample size | ||||||||||
| Cohort studies | |||||||||||
| Punsar and Karvonen, 1979 (106) | Finland | Men aged 40-59 years | |||||||||
| Eastern Finland | IHD mortality | 3.1 (0.3)# | Lower | 15 | 121 | 823 | 1.57 | p<0.001 | 0.36 | ||
| Western Finland | 13.1 (2.0) | Higher | 77 | 888 | |||||||
| Eastern Finland | Sudden cardiac death | 3.1 (0.3) | 45 | 823 | 1.50 | NS | 0.33 | ||||
| Western Finland | 13.1 (2.0) | 30 | 888 | ||||||||
| Intake (mg/day) | Intake (mg/day) | ||||||||||
| Dietary Intervention Studies | |||||||||||
| Singh, 1990 (56) | India | 400 men aged 25-63 yrs | |||||||||
| Intervention group | IHD complications | 1.142 (233) | 880 (212) | 10 | 59 | 206 | 2.11 | p<0.001 | 0.53 | ||
| Control group | 418 (105) | 512 (150) | 117 | 194 | |||||||
| Intervention group | Sudden cardiac death | 1.142 (233) | 880 (212) | 19 | 206 | 1.58 | p<0.02 | 0.37 | |||
| Control group | 418 (105) | 512 (150) | 30 | 194 | |||||||
|
* RR, relative risk; CI, confidence Interval; CaCO3,
calcium carbonate; IHD, ischemic heart disease; N/A, not available;
NS, not significant; MI, myocardial infarction. † Attributable risk=(incidence in exposed—Incidence in unexposed)/Incidence in exposed=(relative risk-1)/relative risk. ‡ The trend of ischemic heart disease prevalence with increasing levels of waterborne magnesium was not uniform. § Communities matched according to age, sex, race, income, socioeconomic status, and stability of mineral concentrations. ¶ Risk estimate provided in original published article. # Numbers in parentheses, standard deviation. |
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| TABLE 4. Range of absolute rates and relative risk gradients for the relation of magnesium intake with cardiovascular morbidity and mortality in various studies | |||||||||
| Author(s) and year (ref.) | Outcome |
Daily magnesium intake (mg)* |
Estimated rate per 100,000 population |
Absolute risk gradient† (mg x 100,000-1) |
Rate ratio |
RR‡ gradient§ (1/mg) |
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| Lowest | Highest | Range | Low intake | High intake | |||||
| Allwright et al., 1974 (99) | IHD‡ mortality | 10 | 36 | 26 | 99.0 | 96.0 | 0.1 | 1.03 | 0.001 |
| Leary et al., 1983 (100) | IHD mortality | 2 | 90 | 88 | 500.0 | 100.0 | 4.5 | 5.00 | 0.045 |
| Punsar and Karvonen, 1979 (106) | IHD mortality | 6.2 | 26.2 | 20 | 980.0 | 580.0 | 20.0 | 1.69 | 0.034 |
| Rylander et al., 1991 (103) | MI‡ incidence | 2 | 30 | 28 | (RR=1.1) | (RR=0.78) | N/A‡ | 1.41 | 0.015 |
| Singh, 1990 (56)¶ | IHD morbidity | 418 | 1142 | 724 | 1800.0 | 1070.0 | 1.0 | 2.11 | 0.002 |
| Teitge, 1990 (102) | MI incidence | 5.8 | 11.6 | 5.8 | 332.0 | 206.0 | 21.7 | 1.61 | 0.105 |
|
* Consumption of 2 liters of water per day was assumed in order to
obtain an estimate of the range of differences in magnesium intake
from drinking water or dietary intervention † Absolute slope = (rate for low magnesium intake - rate for high magnesium intake)/range (in mg), which has units of [mg x 100,000]-1. ‡ RR, relative risk; IHD, ischemic heart disease; MI, myocardial infarction; N/A, not available. § Relative risk slope = (rr - 1)/range (in mg), which has units of 1/mg. ¶ Dietary intervention study. |
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