Overall findings
One SNP, Arg16Gly, significant association and low heterogeneity were
found between Arg16Gly polymorphism and salbutamol response in two
models: heterozygous model (OR=1.470, 95% CI: 1.046-2.066,P =0.026, I2=38.6%,P H=0.122; Table 2 & Figure 2.5); and additive
model (OR=0.668, 95% CI: 0.502-0.889, P =0.006,
I2=0.0%, P H=0.470; Table 2 &
Figure 2.6). This indicated that the patients with the AG genotype may
be associated with a better response to salbutamol in comparison to
those with the AA or GG+AA genotypes. However, statistically evident
heterogeneity and non-significant association were detected in the
dominant, recessive, allele and homozygous models (all P -value
for OR>0.05). Thus, it is needed to perform further
subgroup analysis and identify the sources of heterogeneity.
Concerning the ADRB2 Gln27Glu polymorphism, non-significant
association with salbutamol response was found in any models (allP -value for OR>0.05) (Table 3 & Figure 3). In
addition, no evidence of heterogeneity was detected between studies
under five models (dominant model: I2=35.2%,P H=0.186; recessive model:
I2=34.9%, P H=0.189, homozygous
model: I2=47.7%, P H=0.105;
heterozygous model: I2=0.0%,P H=0.452; and additive:
I2=0.0%, P H=0.776), but not
the allelic model (I2>50%,P H<0.1). (Table 3)