Introduction
Methods
Searching strategy
Selection of eligible trials
Validity assessment and data abstraction
Study characteristics
Quantitative data synthesis
Results
Trial flow
Study characteristics
Study | Treatment (Rx) † | Isoflavones content in Rx (mg/d) ‡ | Control | Isoflavones content in control (mg/d) | No. of subjects | Lipid status § | Subject gender || | Length of treatment (weeks) |
---|---|---|---|---|---|---|---|---|
*Calvert 1981 [7] | soy biscuits | NA | soy biscuits | 0 | 10 | H | male | 4 |
Clifton-Bligh 2001(I) [8] | T | 57 | T | |||||
Clifton-Bligh 2001(II) [8] | T | 85.5 | 28.5 | 46 | B | female | 26 | |
Dewell 2002 [9] | T | 150 G = 40; D = 50; glycosides = 60 | placebo | 0 | 36 | H | female | 24 |
Hale 2002 [10] | T | 80 G = 40; D = 40 | placebo | 0 | 29 | NS | post | 2 |
Han 2002 [11] | soy protein capsule | 100 G = 70; D = 18; glycitein = 12 | soy protein capsule | 0 | 78 | N | peri | 16 |
Hodgson 1998 [12] | T | 55 G = 30; D = 1; B = 16; F = 8 | placebo | 0 | 59 | N | male & female | 8 |
Howes 2000 [13] | T | 40 G = 1; D = 0.5; B = 26; F = 16 | placebo | 0 | 75 | NS | post | 5 |
Mackey 2000 [14] | ISP | 65 | ISP | < 4 | 49 | H | post | 12 |
*Merz-Demlow 2000(I) [15] | ISP | 113–144 | ISP | |||||
*Merz-Demlow 2000(II) [15] | ISP | 55–74 | 9–11 | 13 | N | female | 3 | |
*Nestel 1997 [16] | T | 40–80 G= 22–43; D = 17–33; glycitein= 1–3 | placebo | 0 | 21 | B | female | 5 |
*Nestel 1999(I) [17] | T | 80 G = 8; D = 7; B = 49; F = 16 | placebo | |||||
*Nestel 1999(II) [17] | T | 40 G = 4; D = 3.5; B = 24.5; F = 8 | 0 | 13 | B | female | 5 | |
*Samman 1999 [18] | T | 86 G = 8.6; D = 7.4; B = 51.4; F = 18.6 | placebo | 0 | 14 | N | pre | 16 |
*Sanders 2002 [19] | soy burger | 56 G = 34.8; D = 21.2 | soy burger | 2 | 22 | N | male & female | 2 |
*Simons 2000 [20] | T | 80 | placebo | 0 | 20 | N | post | 8 |
Squadrito 2002 [21] | T | 54 G= 54 | placebo | 0 | 60 | N | female | 24 |
*Urban 2001 [22] | T | 70 G = 42; D = 27 | ISP | 3 | 28 | N | elderly men | 6 |
*Wangen 2001(I) [23] | ISP | 110–154 | ISP | |||||
*Wangen 2001(II) [23] | ISP | 54–76 | 6–8.2 | 18 | NS | post | 4 |
Quantitative data synthesis
Subgroup outcome | No. of comparisons | No. of subjects || | Treatment effect on TC (mmol/L) ¶ | Heterogeneity p-value § |
---|---|---|---|---|
Form of intervention †: | ||||
a.) isoflavones tablets | 482 | 0.01 (-0.17, 0.18) | 1.00 | |
b.) ISP(+) | 229 | -0.11 (-0.21, -0.01)* | 0.34 | |
c.) soy protein capsule | 1 [11] | 78 | -0.69 (-1.19, -0.19)* | NA |
d.) soy biscuit | 1 [7] | 20 | -0.05 (-0.47, 0.37) | NA |
e.) soy burger | 1 [19] | 44 | 0.09 (-0.38, 0.56) | NA |
f.) Overall | 853 | -0.09 (-0.18, -0.01)* | 0.77 | |
Isoflavones mixture ‡: | ||||
G&D&B&F | 214 | -0.06 (-0.34, 0.21) | 0.96 | |
G&D | 285 | -0.22 (-0.41, -0.03)* | 0.06 | |
G | 1 [21] | 60 | 0.10 (-0.35, 0.55) | NA |
Isoflavones intake (mg per day): | ||||
< 50 | 132 | -0.12 (-0.54, 0.29) | 0.99 | |
51–100 | 484 | -0.10 (-0.21,0.01) | 0.74 | |
101 – 150 | 176 | -0.10 (-0.24, 0.05) | 0.09 | |
Design : | ||||
parallel crossover | 447 | -0.08 (-0.27, 0.10) | 0.48 | |
a.) no washout | 1 [22] | 56 | -0.43 (-0.73, -0.13)* | NA |
b.) washout mentioned | 208 | -0.07 (-0.17, 0.03) | 0.91 | |
Gender: | ||||
male | 76 | -0.30 (-0.54, -0.05)* | 0.15 | |
female | 674 | -0.07 (-0.17, 0.02) | 0.89 | |
Treatment length: | ||||
2–10 weeks | 541 | -0.09 (-0.18, 0.00) | 0.84 | |
11–20 weeks | 155 | -0.22 (-0.52, 0.07) | 0.07 | |
21–30 weeks | 157 | 0.02 (-0.28, 0.31) | 0.96 | |
Menopausal status: | ||||
pre-menopausal | 80 | -0.06 (-0.17, 0.06) | 0.58 | |
peri-menopausal | 1 [11] | 78 | -0.69 (-1.19, -0.19)* | NA |
post-menopausal | 516 | -0.05 (-0.20, 0.10) | 1.00 | |
Subjects with: | ||||
normolipidemia | 377 | -0.11 (-0.21, -0.01)* | 0.08 | |
hyperlipidemia | 105 | -0.05 (-0.36, 0.26) | 1.00 |
Type of intervention* | No. of trials | No. of comparisons | No. of subjects | Treatment effect (mmol/L) † | Heterogeneity p-value |
---|---|---|---|---|---|
1.) Isoflavones tablets | |||||
LDL | 9 | 446 | 0.00 (-0.14, 0.15) | 0.94 | |
HDL | 10 | 482 | 0.01 (-0.05, 0.06) | 0.98 | |
TG | 9 | 482 | 0.03 (-0.06, 0.12) | 0.93 | |
2.) ISP (+) | |||||
LDL | 3 | 173 | -0.06 (-0.16, 0.03) | 0.84 | |
HDL | 3 | 173 | -0.01 (-0.07, 0.05) | 0.97 | |
TG | 3 | 173 | 0.02 (-0.05, 0.09) | 1.00 |