Association between Metformin and a Lower Risk of Age-Related Macular Degeneration in Patients with Type 2 Diabetes

Table 3

Characteristics of the PS-matched sample.

Variable	Metformin group (n = 22681)	Nonmetformin group (n = 22681)	-value
Age, years	57.8 ± 12.6	57.8 ± 12.7	0.87
Age group, years			0.76
<50	6639 (29.3)	6642 (29.3)
50–60	6088 (26.8)	6071 (26.8)
60–70	4868 (21.5)	4799 (21.1)
≥70	5086 (22.4)	5169 (22.8)
Sex			0.91
Male	11136 (49.1)	11121 (49.0)
Female	11545 (50.9)	11560 (51.0)
Hypertension			0.82
Yes	14493 (63.9)	14517 (64.0)
No	8188 (36.1)	8164 (36.0)
Hyperlipidemia			0.70
Yes	31527 (59.6)	13486 (59.5)
No	9154 (40.4)	9195 (40.5)
Coronary artery disease			0.84
Yes	6378 (28.1)	6357 (28.0)
No	16303 (71.9)	16324 (72.0)
Obesity
Yes	922 (4.1)	927 (4.1)	0.92
No	21759 (95.9)	21754 (95.9)
Diabetic retinopathy			0.16
Yes	392 (1.7)	433 (1.9)
No	22289 (98.3)	22248 (98.1)
Chronic kidney disease			0.97
Yes	5403 (23.8)	5399 (23.8)
No	17278 (76.2)	17282 (76.2)
Medications
Insulin	1409 (6.2)	1429 (6.3)	0.71
Sulfonylurea	14135 (62.3)	14176 (62.5)	0.70
DDP-4 inhibitor	3718 (16.4)	3674 (16.2)	0.59
Thiazolidinedione	2719 (12.0)	2746 (12.1)	0.71
Meglitinide	2109 (9.3)	2135 (9.4)	0.69
α-glucosidase inhibitor	1842 (8.1)	1858 (8.2)	0.80
Antihypertensives	12654 (55.8)	12631 (55.7)	0.84
Lipid-lowering agents	12831 (56.6)	12840 (56.6)	0.94
PS	0.60 ± 0.12	0.60 ± 0.13	0.80

PS: propensity score; DPP-4: dipeptidyl peptidase-4. Data are presented as mean ± standard deviation or n (%).