Association between SHBG (TAAAA)n and AR (CAG)n polymorphisms and PCOS risk: A meta-analysis

Table 1 Characteristics of studies on (TAAAA)n sex hormone-binding globulin polymorphism and polycystic ovarian syndrome

Ref.	Year	Country	Race	PCOS	Controls	PCOS alleles (2 n)		Controls alleles (2 n)		PCOS women genotype			Controls genotype			PCOS diagnostic
				women		S (< 8 repeats)	L (≥8 repeats)	S (< 8 repeats)	L (≥8 repeats)	SS	SL	LL	SS	SL	LL	criteria
Xita et al[10]	2003	Greece	Caucasian	185	324	230	140	446	202	NR	NR	NR	NR	NR	NR	A
Zhao et al[24]	2005	China	Asian	157	156	180	134	175	137	48	84	25	48	79	29	B
Ferk et al[26]	2007	Slovenia	Caucasian	123	110	155	91	151	69	54	48	21	52	47	11	C
Liu et al[27]	2008	China	Asian	187	176	216	158	210	142	59	96	32	66	78	32	C
Díaz et al[25]	2010	Spain	Caucasian	70	107	102	38	139	75	NR	NR	NR	NR	NR	NR	D

A: The 1990 National Institutes of Health–National Institute of Child Health and Human Development conference on PCOS; B: (1) Amenorrhoea or oligomenorrhoea; (2) LH/FSH ≥ 2.5 or T ≥ 1.56; (3) More than 10 follicles measuring 2-8 mm in diameter at least in one ovary; and (4) Exclusion of congenital adrenal hyperplasia, Cushing’s syndrome, androgen-secreting tumor, hyperprolactinaemia and thyroid dysfunction; C: The criteria of Rotterdam Revised 2003 (two of three) diagnosis; D: (1) Hirsutism; (2) Amenorrhoea or oligomenorrhoea; (3) Increased serum T and/or androstenedione and 17OH-P hyperresponse to GnRH agonist; and (4) Hyperinsulinaemia during an oral glucose tolerance test. PCOS: Polycystic ovarian syndrome; S: Short alleles; L: Long alleles; SS: Short-short genotype; SL: Short-long genotype; LL: Long-long genotype; NR: Non-reported.

Table 2 Characteristics of studies on (CAG)n androgen receptor polymorphism and polycystic ovarian syndrome

Ref.	Year	Country	Race	PCOS			Controls			PCOS diagnostic
				Size	Mean	Std dev	Size	Mean	Std dev	criteria
Mifsud et al[23]	2000	Singapore	Asian	91	22.97	0.24	112	23.09	0.23	A
Hickey et al[37]	2002	Australia	Caucasian	122	23	2.025	83	22.34	2.094	B
Jääskeläinen et al[43]	2005	Finland	Caucasian	106	21.5	2.2	112	21.5	2.1	C
Kim et al[39]	2008	South Korea	Asian	114	23.3	1.8	205	23.1	2	D
Ferk et al[38]	2008	Slovene	Caucasian	102	22.4	3.5	110	21.9	3.5	E
Liu et al[27]	2008	China	Asian	148	22.88	1.76	104	22.85	1.6	D
Shah et al[36]	2008 (1)	America	Caucasian	270	21.8	3.1	165	22.3	3.11	B
Shah et al[36]	2008 (2)	America	Black	37	20.1	3.44	84	20.2	3.08	B
Van Nieuwerburgh et al[40]	2008	Belgium	Caucasian	97	21.93	2.122	31	21.823	3.112	NC
Dasgupta et al[41]	2010	India	Asian	250	18.74	0.13	299	18.73	0.12	D
Laisk et al[34]	2010	Estonia	Caucasian	32	21.5	1.6	79	21.6	1.8	D
Robeva et al[44]	2010	Bulgaria	Caucasian	52	21.6	2.62	41	21.3	3.71	D
Skrgatic et al[42]	2011	Croatia	Caucasian	214	22.1	3.4	209	21.9	3.2	D
Schüring et al[35]	2011	Germany	Caucasian	72	21.43	1.87	179	21.99	2.07	D
Rajender et al[47]	2013	India	Asian	169	17.39	2.29	175	17.43	2.43	D

A: (1) Proven fertility; (2) No history of subfertility treatment; and (3) Normal menstrual cycles (25-32 d); B: National Institutes of Health criteria; C: (1) Non-hirsute; (2) Proven fertility; (3) Regular menstrual cycles; and (4) Normal ovaries; D: The criteria of Rotterdam Revised 2003 (two of three); E: (1) Oligo-/amenorrhea; (2) Polycystic ovaries; and (3) Hyper-androgenism. PCOS: Polycystic ovarian syndrome; NC: Unclear.

Table 3 Meta-analysis of (TAAAA)n sex hormone-binding globulin polymorphism and polycystic ovarian syndrome

	No. of studies	OR (95%CI)	Heterogeneity			Publication bias
			χ2	I2(%)	P	Begg’s P	Egger’s P
S (< 8 repeats)	5	Fixed, 0.91 (0.78-1.05)	7.59	47.8	0.108	0.221	0.221
L (≥ 8 repeats)	5	Fixed, 1.10 (0.95-1.27)	7.30	45.2	0.121	0.221	0.225
SS	3	Fixed, 0.87 (0.66-1.14)	0.60	0.0	0.749	1.000	0.564
SL	3	Fixed, 1.12 (0.86-1.46)	1.64	0.0	0.441	0.296	0.072
LL	3	Fixed, 1.03 (0.72-1.47)	2.84	29.6	0.242	1.000	0.256

OR: Odd ratio; S: Short alleles; L: Long alleles; SS: Short-short genotype; SL: Short-long genotype; LL: Long-long genotype.

Table 4 Meta-analysis of (CAG)n androgen receptor polymorphism and polycystic ovarian syndrome

		Number of studies	WMD (95%CI)	Heterogeneity			Publication bias
				χ2	I2(%)	P	Begg’s P	Egger’s P
All		15	Random, -0.03 (-0.13, 0.08)	28.55	51.0	0.012	0.621	0.866
Race	Asian	5	Random, -0.03 (-0.14, 0.07)	14.74	72.9	0.005	0.806	0.875
	Caucasian	9	Fixed, -0.02 (-0.24, 0.21)	13.77	41.9	0.088	0.175	0.596
The criteria of Rotterdam		8	Fixed, 0.01 (-0.01, 0.03)	5.91	0.0	0.550	1.000	0.784

WMD: Weighted mean difference.