Table 1.

Characteristics of the studies included in this meta-analysis.

First author/year	Ethnicity	Age	Sex	Smoking habit	Case number	Control number	Score
Zheng/2002	Caucasian	63	Reported	Reported	384	386	8
Hung/2004	Caucasian	65	Mixed	Reported	201	214	7
Kellen/2007	Caucasian	70	Mixed	Mixed	200	385	7
Covolo/2008	Caucasian	50	Mixed	Mixed	197	211	9
Lumbreras/2008	Caucasian	NA	Mixed	Mixed	124	1089	9
Wang/2008	Asian	63	Mixed	Reported	300	300	8
Cui/2013	Asian	60	Mixed	Reported	282	257	7

HWE – Hardy-Weinberg equilibrium.