Table 2.

 Subgroup analyses

Subgroups	Fasting glucose 100-125 mg/dL				Fasting glucose 110-125 mg/dL				IGT or combination of IFG/IGT
	No of studies	RR (95% CI)	P value*		No of studies	RR (95% CI)	P value*		No of studies	RR (95% CI)	P value*
Population:			0.63				0.59				0.01
Without CVD history at entry	5	1.05 (0.91 to 1.21)			3	1.15 (0.99 to 1.33)			6	1.18 (1.06 to 1.31)
With CVD history at entry	3	1.17 (0.77 to 1.76)			2	1.36 (0.75 to 2.47)			2	1.77 (1.30 to 2.40)
Ethnicity:			0.92				0.60				0.98
Asians	4	1.07 (0.93 to 1.24)			2	1.08 (0.77 to 1.52)			4	1.24 (0.99 to 1.55)
Non-Asians	4	1.09 (0.77 to 1.55)			3	1.21 (0.94 to 1.55)			4	1.23 (1.06 to 1.44)
Sex:			0.21				0.44				0.09
Male	3	0.91 (0.67 to 1.24)			1	0.94 (0.57 to 1.55)			2	0.95 (0.72 to 1.27)
Female	3	1.09 (0.79 to 1.49)			1	1.22 (0.78 to 1.90)			2	1.16 (0.86 to 1.56)
Both	4	1.25 (1.04 to 1.51)			2	1.45 (0.94 to 2.24)			6	1.37 (1.16 to 1.62)
Mean age at entry:			0.02				—				0.007
<65 years	7	1.12 (0.98 to 1.28)			5	1.21 (1.02 to 1.44)			5	1.15 (1.03 to 1.29)
≥65 years	1	0.82 (0.65 to 1.03)			0	—			3	1.65 (1.30 to 2.08)
Possibility of enrolling patients with diabetes:			0.47				0.58				0.05
None enrolled	1	0.91 (0.50 to 1.63)			2	1.11 (0.77 to 1.61)			7	1.20 (1.07 to 1.35)
Might be enrolled	7	1.13 (0.99 to 1.29)			3	1.27 (0.95 to 1.72)			1	1.80 (1.23 to 2.63)
Adjustment for confounders:			0.25				—				0.001
Adequate	6	1.04 (0.87 to 1.25)			5	1.21 (1.02 to 1.44)			4	1.11 (0.99 to 1.25)
Inadequate	2	1.19 (1.05 to 1.36)			0	—			4	1.60 (1.32 to 1.93)

CVD=cardiovascular disease; IFG=impaired fasting glucose; IGT=impaired glucose tolerance; RR=relative risk.

*For heterogeneity among subgroups.