Table 2 Effects of gender, smoking and alcohol on the apolipoprotein apo A-IV Levels
On-medication subjects Normal subjects
All subjects Levels mgdl
P value
a
n Levels mgdl
P value n
n Levels mgdl
P value 14.7 9 4.1
316 15.3 9 5.3
Total 407
723 15.0 9 4.6
Gender 14.9 9 4.1
123 16.6 9 6.1
249 Males
372 15.5 9 4.9
158 Females
14.5 9 4.0 ns
b
193 14.4 9 4.5
B 0.001
351 14.4 9 4.3
B 0.01
Smoking 14.8 9 4.0
21 Yes
15.6 9 4.8 52
73 14.9 9 4.0
No 349
14.6 9 3.6 ns
293 15.2 9 5.3
ns 650
15.0 9 4.7 ns
Alcohol intake 15.1 9 4.05
231 15.1 9 4.90
318 Yes
549 14.8 9 4.45
89 No
14.7 9 4.09 ns
85 15.7 9 6.15
ns 174
15.4 9 5.18 ns
a
t-Test P value.
b
Not statistically significant. Table 3
The effects of diseasemedication status on apolipoprotein apo A-IV levels
a
Diabetesb
b
CLMc
b
TMd
b
HRTe
b
P values Normala
18.2 9 7.7 16.7 9 6.0
Males 17.1 9 5.8
14.8 9 4.7 n = 51
ba
n = 77 n = 24
– B
0.001 n = 249
ab
17.0 9 4.3 14.3 9 3.2
14.8 9 4.3 14.5 9 4.0
13.9 9 4.5 Females
n = 20
ba ,bc
,be
n = 42
cb
n = 82 n = 127
ea ,eb
n = 158
ab
B 0.01
17.8 9 7.4 15.9 9 5.3
15.4 9 4.7 14.7 9 4.1
All subjects n = 71
ba ,bc
,bd
n = 119
bc
n = 106
bd
– n = 407
ab
B 0.001
a a,b,c,d,e
The different superscript letters represent that a statistically significant difference exists between the two means.
b
Subject groups, Diabetes = on diabetic medication, CLM = on cholesterol lowering medication, TM = on thyroid medication, and HRT = on hormone replacement therapy.
PB0.05; PB0.01; data analyzed by general linear models GLM procedure.
isolated from whole blood using the QIA amp Blood Kit Qiagen. The 360 bp polymorphism within the apo
A-IV gene was assessed as previously described by Tenkanen et al. [34].
SAS 6.12 and Systat 7.0 SPSS statistical programs were used to carry out hypothesis testing, correlation
and regression analysis. A statistical P value less than 0.05 was considered as a significant boundary.
3. Results
The lipid and apolipoprotein concentrations as well as glucose levels of the study subjects are summarized
in Table 1. With the exception of LDL-C, all of these variables differed significantly between males and fe-
males. The apo A-IV plasma levels of different subject groups and the influence of gender, smoking, and alco-
hol consumption on plasma apo A-IV concentration are shown in Table 2. No significant gender differences
in apo A-IV levels were observed in normal subjects. However, for all subjects, the mean apo A-IV concen-
tration of males 15.5 9 4.9 mgdl was significantly higher than that of females 14.4 9 4.6 mgdl P B
0.01. The gender difference in apo A-IV levels was also observed in the subjects on different types of medica-
tions 16.6 9 6.1 mgdl for males versus 14.4 9 4.5 mg dl for females, P B 0.001. No significant effect of apo
A-IV-12 polymorphism on apo A-IV levels was noted in either males or females. There was no significant
effect of smoking and alcohol consumption on plasma apo A-IV concentrations.
The impact of healthmedication status on plasma apo A-IV levels is shown in Table 3. Using analysis
with general linear models GLM adjusted for age, it was observed that diabetic subjects on diabetic medica-
tion had significantly higher apo A-IV levels than did normal subjects in the male, female, and total groups.
The mean apo A-IV level of diabetic subjects was also significantly higher than the mean values of subjects on
cholesterol-lowering medication and subjects on thyroid medication, in all subjects. Female subjects on hormone
replacement therapy had significantly lower apo A-IV levels than controls. Female diabetics had significantly
higher apo A-IV levels than subjects either on hormone replacement therapy or cholesterol-lowering medica-
tion. Use of cholesterol-lowering medication or thyroid medication was not associated with any significant ef-
fect on plasma apo A-IV. To assess the relationships between apo A-IV plasma
concentrations and other variables, multivariate regres- sion models were employed. After continuity tests for
non-category variables, univariate correlationregres- sion screening was conducted. Then, the linear relation-
ships between apo A-IV and selected variables were determined by multiple linear regression models. The
results of these analyses are summarized in Table 4. After adjustment for age, gender, BMI, percent body
fat, smoking, alcohol consumption, and healthmedica- tion status, the main variables which correlated signifi-
cantly with apo A-IV concentrations were age and apo A-I levels. A correlation was also observed between apo
A-IV and apo E in all subjects, in male subjects, and in subjects on medication both before and after adjust-
ment. A weakly significant correlation between TG levels and apo A-IV levels was observed in male sub-
jects only. A significant inverse correlation between plasma apo A-IV levels and BMI was noted in women,
but it was not observed in men. After adjustment for other variables the correlation between apo A-IV levels
and HDL-C in women was no longer significant. The correlation between apo A-IV and glucose also disap-
peared after multiple adjustment.
4. Discussion
