3.4. Sensitivity and Publication Bias
According to the ”leave-one-out” strategy, 19 outcomes estimated values
from -0.479 to -0.411 were got, indicated that there were no
particularly prominent sensitivity issues in the included literature
(Supplementary
Material Fig 1).
The shape of the funnel plots appeared symmetrical in the comparison
model showed that most effect sizes seem to locate symmetrically upwards
the graph, and scatter around both sides of the line. Egger’s regression
test did not show
a
publication bias
(P =0.939).
Besides, there was no obvious change in the results after the trim and
-fill estimate.
(Supplementary
Material Fig.2)
3.5. Typeof
phytoestrogens
A
total of 10 studies with 19 independent reports with 1,248 participants
were included in investigating the effects of different phytoestrogens
on depressive symptoms in postmenopausal women. Among them, six studies
employed isoflavones including red clover
isoflavones18,37, daidzein
isoflavone32, soy isoflavones20,
isoflavones aglycone33 and phytoestrogen
genistein16; two studies employed lignans including
Schisandra chinensis34 and
Kava-Kava38; two studies employed fenugreek
extract35 and resveratrol36 which
could not give a clear classification. The effectiveness of
postmenopausal women based on two different categories of phytoestrogens
indicated that isoflavone (SMD=-0.52; 95% [CI]= -0.75 to 0.30;I 2=65.8%, P <0.05) was better
than treatment with lignans (SMD= -0.23; 95%[CI]= -0.05 to 0.01;I2 =0%; P >0.05)
(Supplementary Material Fig.3).
3.6.Dose
of phytoestrogens
To compare the effects of various doses of phytoestrogens more
intuitively, phytoestrogens intake dose were
classified33. After sorting by the daily dosage of
phytoestrogens intake. Doses more than 0 and less than 25mg were
classified as the ultra-low dose
group (Ultra-low dose:
0<dose<25mg/day), doses more or equal to 25mg and
less or equal to 100mg were in the low dose
group (Low Dose:
25mg/day≤dose≤100mg/day),
while doses more than 100mg were in the high dose group (High Dose:
dose>100mg). According to the various dosages in
Supplementary Material Figure 4,
the results indicated that compared with the low dose
(25mg/day≤dose≤100mg/day) (SMD=-0.45; 95%[CI]=-0.68 to-0.23;I 2=66.7%; P >0.05) and
ultra-low-dose group (0<dose<25mg) (SMD=-0.31;
95%CI=-0.47 to 0.04; I 2=0%,P >0.05), the intake of phytoestrogens in the high
dose group (dose>100mg/day) was the most effective in
improving the symptoms of menopausal depression (SMD =-0.48;
95%[CI] = -0.76 to -0.20; I 2=52.8%,P <0.05).
3.7.Measurements
of depression
Ten RCTs with 19 independent reports and 1,248 participants were
included in investigating the effects of different measurements on
depressive symptoms in postmenopausal women. All the included studies in
this meta-analysis used the evaluation scales to evaluate depression in
postmenopausal women. The result based on different assessment scales
were detected in Supplementary Material Figure 5, indicated that using
the HDS as an assessment scale was associated with the most varied data
(SMD=-0.65; 95% [CI]=-1.38 to 0.08;I2=80.3% ; P <0.05). Meanwhile,
the data in GCS (SMD=-0.37; 95%[CI]=-0.62 to -0.21;I2=54.1% ; P <0.05) and
SDS (SMD=-0.59; 95% [CI]=-0.92 to 0.25,I2 =58.4%; P >0.05)
To explore whether different evaluation scales could reduce the moderate
and high heterogeneity, assessment scales of specific postmenopausal
evaluation (GCS42 and KMI43) with
depression items were excluded for supplementary analysis. Results
showed that heterogeneity of the isoflavone group slightly decreased
from 65.8% to 60.6% (P= 0.01) (Supplementary Material Fig.6), as
well as the heterogeneity of the low dose group obviously decreased from
66.7% to 10.5% (P= 0.34) (Supplementary Material Fig.7).