Hearing impairment risk and interaction of folate metabolism related gene polymorphisms in an aging study

BMC Medical Genetics

Table 1 General characteristics and genotype frequencies at baseline according to hearing impairment status.

Variable	Total N (%)	Hearing impairment		No hearing impairment
		N	%	N	%	p
	1426	275	19.3	1151	80.7
MTR A2756G
AA (wild-type homozygotes)	939 (65.8)	174	18.5	765	81.5	0.2459
AG (heterozygotes)	436 (30.6)	94	21.6	342	78.4
GG (mutant homozygotes)	51 (3.6)	7	13.7	44	86.3
A allele	81.1%	442	19.1	1872	80.9	-
G allele	18.9%	108	20.1	430	79.9
MTHFR C677T
CC (wild-type homozygotes)	529 (37.1)	115	21.7	414	78.3	0.1954
CT (heterozygotes)	681 (47.8)	122	17.9	559	82.1
TT (mutant homozygotes)	216 (15.1)	38	17.6	178	82.4
C allele	61.0%	352	20.2	1387	79.8	-
T allele	39.0%	198	17.8	915	82.2
Gender
Male		173	24.0	549	76.0	<.0001
Female		102	14.5	602	85.5
Age
<60		19	2.8	660	97.2	<.0001
≥60		256	34.3	491	65.7
Occupational noise exposure
Yes		111	37.4	186	62.6	<.0001
No		164	14.5	965	85.5
History of hypertension
Yes		98	26.8	268	73.2	<.0001
No		177	16.7	883	83.3
History of heart disease
Yes		42	27.3	112	72.7	0.0078
No		233	18.3	1039	81.7
History of diabetes
Yes		41	35.3	75	64.7	<.0001
No		234	17.9	1076	82.1
Smoking
Current and ex-smoker		144	23.0	481	77.0	0.0015
Nonsmoker (Never smoked)		131	16.4	670	83.6
Obesity
BMI ≥ 25		55	17.4	261	82.6	0.3371
BMI < 25		220	19.8	890	80.2

ISSN: 1471-2350