. 2012 Aug 29;21(22):5010–5018. doi: 10.1093/hmg/dds339

Table 3.

Pooled estimates for effects of TCF7L2 polymorphisms on phenotype traits of insulin homeostasis in healthy non-diabetic controls

Traits	rs7903146: T/T versus C/C					rs7903146: C/T versus C/C
Traits	n (studies)	n (TT/CC)	Pooled mean difference (95% CI)	P-value^a	Q-test for heterogeneity^b	n (studies)	n (CT/CC)	Pooled mean difference (95% CI)	P-value^a	Q-test for heterogeneity^b
Fasting measures^c
Fasting insulin, pmol/l	25	3421/22 473	−6.12 (−8.76, −3.48)	6.0 × 10⁻⁶	<0.001	26	17 236/26 117	−2.94 (−4.39, −1.49)	8.2 × 10⁻⁵	0.009
Fasting glucose, mmol/l	31	4039/31 013	0.084 (0.052, 0.12)	2.5 × 10⁻⁷	<0.001	30	18 209/27 446	0.02 (0.001, 0.04)	0.04	<0.001
HOMA-IR	17	2179/16 717	−0.06 (−0.14, 0.02)	0.17	0.33	18	11 415/17 603	−0.05 (−0.12, 0.01)	0.12	0.03
HOMA-%B	9	463/2479	−20.11 (−29.4, −10.9)	2.0 × 10⁻⁵	0.01	10	1975/3365	−21.0 (−39.7, −2.35)	0.03	<0.001
OGTT measures^c
2 h post-load glucose, mmol/l	17	1095/10 075	0.28 (0.15, 0.42)	6.0 × 10⁻⁵	<0.001	18	9189/15 063	0.10 (0.05, 0.16)	0.0003	0.02
2 h post-load insulin, pmol/l	8	587/7398	−19.3 (−51.1, 12.5)	0.10	0.24	9	3906/7693	−15.6 (−29.2, −2.02)	0.02	0.10
IVGTT measures^d
AIR	4	160/1045	−0.12 (−0.29, 0.05)	0.15	0.39	5	825/1268	−0.09 (−0.18, 0.01)	0.05	0.42
SI	4	160/1045	−0.38 (−0.68, −0.09)	0.01	0.03	4	787/1045	0.024 (−0.07, 0.12)	0.61	0.35
DI (SI*AIR)	4	160/1045	−0.28 (−0.45, −0.11)	0.001	0.22	4	787/1045	−0.05 (−0.14, 0.04)	0.29	0.30

OGTT, 75 g oral glucose tolerance test; HOMA-IR and HOMA-%B, homeostasis model assessment of insulin resistance and insulin secretion; IVGTT, intravenous glucose tolerance test; AIR, a measure of the first-phase insulin secretion; SI, insulin resistance index; DI, disposition index.

^aP-values for pooled mean differences.

^bP-values for heterogeneity between studies.

^cData are the weighted mean differences for those parameters labeled with units.

^dData are the standardized effect sizes used.