110
VOLUME 8 NUMBER 3 • SEPTEMBER 2011
ACHIEVING BEST PRACTICE
SA JOURNAL OF DIABETES & VASCULAR DISEASE
Table 1.
Demographic, haematological and biochemical results of groups
Normal OGl
GIGT
GDM
Age (year)
29.6
±
4.8 30.9
±
6.2 31.2
±
5.1
Gravidity (
n
)
2.2
±
1.4
2.2
±
1.2
2.3
±
1.5
Parity (
n
)
0.9
±
1.2
1.0
±
1.0
1.0
±
0.8
Gestational age (week)
25.7
±
1.3 25.9
±
1.1 25.6
±
1.4
OGl (mg/dl) (mmol/l)
118.1
±
23.5
(6.6
±
1.3)
149.3
±
18.9
(8.3
±
1.1)
172.1
±
27.9
(9.6
±
1.6)
RBC (million)
4.18
±
0.50 4.22
±
0.40 4.25
±
0.50
Haemoglobin (g/dl) (mmol/l)
11.9
±
1.2
(7.4
±
0.8)
12.4
±
1.00
(7.4
±
0.8)
12.0
±
1.4
(7.5
±
0.9)
Haematocrit (%)
35.3
±
3.4 35.1
±
2.8 34.3
±
2.3
RDW (%)
13.8
±
2.1 13.3
±
1.4 13.4
±
1.0
Platelet (
n
)
253.2
±
68.0 241.1
±
45.0 236.4
±
59.3
MPV (fl)
8.19
±
0.85 8.22
±
0.97 8.67
±
1.43*
PDW (%)
16.1
±
1.5 16.2
±
1.5 15.9
±
2.0
*
p
<
0.05: statistically significant difference between normal OGl and GDM
group.
GDM = gestational diabetes mellitus; GIGT = gestational impaired glucose
tolerance; MPV = mean platelet volume; OGl = oral glucose load; PDW =
platelet distribution width; RBC = red blood cell; RDW = red cell distribution
width.
Fig. 1.
Correlation between platelet count and mean platelet volume.
12.00
10.00
8.00
6.00
Mean platelet volume (fl)
100.00 200.00 300.00 400.00 500.00 600.00
Platelet count (
x
1000)
R Square Linear: 0.105
In all cases, haematological parameters (haemoglobin,
haemotocrit, RBC and platelet count, MPV, RDW and PDW)
were studied. Platelet count and MPV were performed as part
of each full blood count. Samples were taken by antecubital
venipuncture into tubes containing tripotassium EDTA. All samples
were analysed on a Beckman/Coulter MAXM Hematology Analyzer
(Beckman Coulter, CA, UsA) 2–6 h after collection, to minimise
changes in platelet size. MPV reference range is determined as
7.8–11.0 fl. Strict quality-control procedures were adopted; Tri-
level controls and external quality assurance programmes were
used on a regular basis to ensure the accuracy and precision of
the instrument.
Data were analysed with the SPSS software version 13.0 for
Windows (SPSS Inc., Chicago, Illinois, USA). Mean (± SD) were
calculated for age andMPV for all three groups separately. Difference
between the means of age, MPV and sex between the groups and
within the groups were calculated by analysis of variance (ANOVA)
using Tukey’s HSD test;
p
-values and 95% confidence intervals (CI)
were also calculated. A
p
-value of ≤ 0.05 was taken as significant.
The relationships between two continuous variables, platelet count
and MPV were assessed by linear regression analysis. All tests were
two-sided with a 0.05 significance level.
Results
A total of 318 patients fulfilling the selection criteria were selected
and allocated to three groups. These included 239 (75.2%) normal
OGl, 34 (10.6%) GIGT and 45 (14.2%) GDM groups. Mean age,
gravity, parity and gestational age in three groups were similar
(Table 1).
The mean OGl results were 118.1 (6.6 mmol/l), 149.3 (8.3
mmol/l), 172.1 mg/dl (9.6 mmol/l) in the non-diabetic, GIGT and
GDM groups, respectively. There were significant differences
between the three groups in terms of OGl results (
p
< 0.001 for
GDM versus GIGT, GDM versus normal OGl, GDM versus GIGT and
GIGT versus normal OGl).
When groups were compared for haematological parameters,
RBC count, haemoglobin, haematocrit, RDW and PDW values were
similar (Table 1). The mean platelet counts in non-diabetes, GIGT
and GDM groups were 236 400, 241 100 and 253 200 thousand,
respectively. Mean platelet counts were higher in normal OGl
than in the GIGT group and in GIGT than in the GDM group. The
statistical analysis showed, however, that there was no significant
difference between the platelet counts of the three groups.
The mean MPV values in the three groups were 8.19, 8.22
and 8.67 fl, in non-diabetic, GIGT and GDM groups, respectively.
Although MPV values were higher in GDM than GIGT and GIGT
than normal OGl groups, no significant differences were found
between them with
p
-values of 0.099 and 0.987 respectively. The
only significance was observed in MPV values of the GDM versus
normal OGl group with a
p
-value of 0.007 (Table 1). In linear
regression analysis an inverse relationship between platelet count
and MPV levels was observed (
p
< 0.001,
r
= 0.105). Patients with
high MPV values had a lower platelet count (Fig. 1).
Discussion
GDM is a significant but frequently neglected problem for the
future health of the mother. Women with a history of GDM have
an 18–50% risk of developing type 2 diabetes mellitus within five
years following pregnancy.
19,20
Although this risk for future type 2
diabetes mellitus is well established for women with GDM, there
have been few studies of this issue in women with lesser degrees
of glucose intolerance in pregnancy.
21-25
Research by Carr
et al
.
26
on
this subject showed that women with a history of GIGT have an
increased risk of developing diabetes. In a recent study Vambergue
et al
.
27
reported that GIGT was independently associated with
glucose intolerance at 6.75 years postpartum, and cases with GIGT
had an 4.57-fold increased risk compared with normal pregnant
women.
