Table 1 Characteristics at baseline between patients diagnosed with and without breast cancer in this cohort of women with T2DM

Basic characteristics

Age continuous (years)

66.66 (12.30)

67.36 (10.35)

0.129

Year at baseline

    < 2008

9806 (33.83)

271 (52.62)

< 0.001

    ≥ 2008

19,177 (66.17)

244 (47.38)

BMI categorical (kg/m²)

    <30

11,763 (40.59)

214 (41.55)

0.553

    ≥ 30

10,733 (37.03)

208 (40.39)

    missing

6487 (22.38)

93 (18.06)

BMI continuous (kg/m²)

30.52 (6.26)

30.64 (6.04)

0.668

Smoking status

    no

23,405 (80.75)

409 (79.42)

0.666

    yes

5305 (18.30)

98 (19.03)

    missing

273 (0.94)

8 (1.55)

A history of cardiovascular diseases

    no

23,596 (81.41)

418 (81.17)

0.931

    yes

5387 (18.59)

97 (18.83)

A history of hypertension

    no

16,696 (57.61)

315 (61.17)

0.115

    yes

12,287 (42.39)

200 (38.83)

Duration of diabetes categorical (years)

    < 2

12,614 (43.52)

224 (43.50)

0.003

    ≥ 2, <5

6798 (23.46)

150 (29.13)

    ≥ 5

9571 (33.02)

141 (27.38)

Duration of diabetes continuous (years)

4.29 (5.15)

3.81 (4.37)

0.015

HbA1c categorical (%)^‡

    < 7.0

18,969 (65.45)

364 (70.68)

0.061

    ≥ 7.0, < 8.0

6873 (23.71)

101 (19.61)

    ≥ 8.0

1463 (5.05)

27 (5.24)

    missing

1678 (5.79)

23 (4.47)

HbA1c continuous (%)^‡

6.77 (1.44)

6.64 (0.92)

0.003

LDL-C categorical (mmol/L)^‡

    < 2.6

12,760 (44.03)

224 (43.50)

0.861

    ≥ 2.6, < 3.6

9343 (32.24)

155 (30.10)

    ≥ 3.6

5527 (19.07)

96 (18.64)

    missing

1353 (4.67)

40 (7.77)

LDL-C continuous (mmol/L)^‡

2.76 (1.60)

2.77 (0.98)

0.876

eGFR (mL/min/1.73m²)^‡

    < 60

6675 (23.03)

128 (24.85)

0.347

    ≥ 60, < 90

14,292 (49.31)

262 (50.87)

    ≥ 90

7466 (25.76)

115 (22.33)

    missing

550 (1.90)

10 (1.94)

Metformin^‡

    no

12,767 (44.05)

262 (50.87)

0.002

    yes

16,216 (55.95)

253 (49.13)

Sulfonylurea^‡

    no

20,428 (70.48)

359 (69.71)

0.739

    yes

8555 (29.52)

156 (30.29)

Insulin^‡

    no

26,053 (89.89)

474 (92.04)

0.126

    yes

2930 (10.11)

41 (7.96)

Statins^‡

    no

13,552 (46.76)

249 (48.35)

0.501

    yes

15,431 (53.24)

266 (51.65)

Tumor Characteristics

TNM stage

    0

50 (9.71)

    1

188 (36.50)

    2

182 (35.34)

    3

62 (12.04)

    4

25 (4.85)

    unclear

8 (1.55)

ER

    negative

60 (11.65)

    positive

382 (74.17)

    unclear

73 (14.17)

PR

    negative

102 (19.81)

    positive

289 (56.12)

    unclear

124 (24.08)

HER2

    negative

373 (72.43)

    positive

48 (9.32)

    unclear

94 (18.25)