. 2023 Jul 7;10:1205481. doi: 10.3389/fcvm.2023.1205481

Table 2.

Summary hazard ratio (HR) estimates [95% confidence intervals (CIs)] for sub-group analysis of the association between the serum C-peptide levels with the all-cause and CVDs mortality.

Subgroups	Study numbers	Summary HR (95% CI)	Between studies		Between subgroups
Subgroups	Study numbers	Summary HR (95% CI)	I ²	P _{heterogeneity}	Q	P _{heterogeneity}
All-cause mortality
Region					8.54	0.036^a
United States	8	1.25 (1.11–1.42)	79.7	0.000
Europe	4	1.33 (1.04–1.71)	77.2	0.004
Oceania	1	1.02 (0.96–1.07)	0.0	0.0
Asia	1	1.14 (0.62–2.07)	0.0	0.0
Diabetes status					0.49	0.485^b
Diabetic	4	1.17 (1.01–1.35)	81.1	0.001
Non-diabetic	10	1.27 (1.11–1.46)	77.4	0.000
Cancer status					1.89	0.170^c
Cancer	5	1.16 (0.98–1.36)	58.2	0.048
Non-cancer	9	1.27 (1.12–1.43)	82.1	0.000
Type of exposure analysis					2.84	0.092
Per 1 unit	9	1.22 (1.10–1.34)	83.2	0.000
Highest vs. lowest category	5	1.22 (1.04–1.42)	30.7	0.217
CVDs mortality
Region					0.52	0.469^d
United States	4	1.53 (1.06–2.22)	85.5	0.000
Europe	5	1.22 (0.80–1.86)	82.3	0.000
Diabetes status					14.33	0.000^b
Diabetic	5	1.11 (0.82–1.50)	78.7	0.001
Non-diabetic	4	1.77 (1.26–2.50)	72.1	0.013
Type of exposure analysis					3.25	0.072
Per 1 unit	7	1.46 (1.07–1.98)	82.9	0.000
Highest vs. lowest category	2	1.17 (0.70–1.95)	81.6	0.020

All statistical tests were two-sided.

^{^a}

Test for heterogeneity between studies conducted on the different regions including the United States, Europe, Oceania, and Asia.

^{^b}

Test for heterogeneity between studies conducted on diabetes status (diabetic or non-diabetic).

^{^c}

Test for heterogeneity between studies conducted on cancer status (cancer or non-cancer).

^{^d}

Test for heterogeneity between studies conducted on the different regions including the United States and Europe.