. 2026 Jun 15;17:120. doi: 10.1186/s13293-026-00940-7

Table 3.

Results of the multivariable regression analysis

Marker	Model 1 (unadjusted)	Model 2	Model 3	Model 4	Model 5	Model 6
L-arginine [µmol/L]	1.31 (−4.44 to 7.06), p = 0.654	1.85 (−4.05 to 7.74), p = 0.537	1.62 (−4.35 to 7.60), p = 0.593	1.85 (−4.66 to 8.36), p = 0.576	1.36 (−5.60 to 8.32), p = 0.700	0.8 (−6.25 to 7.85), p = 0.823
L-homoarginine [µmol/L]	−0.24 (−0.46 to −0.01), p = 0.043	−0.28 (−0.51 to −0.05), p = 0.017	−0.30 (−0.53 to −0.07), p = 0.012	−0.23 (−0.48 to 0.02), p = 0.077	−0.18 (−0.45 to 0.09), p = 0.192	−0.20 (−0.47 to 0.07), p = 0.150
ADMA [µmol/L]	−0.03 (−0.06 to 0.003), p = 0.076	−0.02 (−0.05 to 0.01), p = 0.261	−0.01 (−0.04 to 0.02), p = 0.528	−0.01 (−0.04 to 0.02), p = 0.494	−0.01 (−0.05 to 0.02), p = 0.470	−0.02 (−0.05 to 0.02), p = 0.350
SDMA [µmol/L]	−0.11 (−0.20 to −0.03), p = 0.010	−0.09 (−0.18 to 0), p = 0.043	−0.06 (−0.14 to 0.02), p = 0.152	−0.09 (−0.18 to 0), p = 0.045	−0.10 (−0.17 to −0.04), p = 0.002	−0.11 (−0.17 to −0.04), p = 0.002
L-citrulline [µmol/L]	−0.82 (−5.42 to 3.77), p = 0.724	0.52 (−4.10 to 5.14), p = 0.824	1.45 (−3.13 to 6.04), p = 0.533	−0.51 (−5.43 to 4.41), p = 0.838	−1.27 (−6.04 to 3.49), p = 0.598	−1.25 (−5.99 to 3.50), p = 0.605
L-lysine [µmol/L]	−7.26 (−16.90 to 2.38), p = 0.139	−6.53 (−16.41 to 3.36), p = 0.194	−7.35 (−17.34 to 2.64), p = 0.148	−4.52 (−15.26 to 6.22), p = 0.407	−1.23 (−12.59 to 10.12), p = 0.831	−1.45 (−12.76 to 9.86), p = 0.800
L-ornithine [µmol/L]	−1.97 (−9.20 to 5.24), p = 0.589	0.07 (−7.20 to 7.34), p = 0.984	0.17 (−7.2 to 7.54), p = 0.964	−0.56 (−8.63 to 7.51), p = 0.892	−0.03 (−8.65 to 8.59), p = 0.994	0.77 (−7.92 to 9.47), p = 0.861
L-arginine/ADMA ratio	7.33 (−2.61 to 17.26), p = 0.147	6.18 (−3.99 to 16.36), p = 0.232	4.46 (−5.70 to 14.61), p = 0.388	4.83 (−6.24 to 15.90), p = 0.390	4.15 (−7.42 to 15.72), p = 0.479	3.95 (−7.81 to 15.70), p = 0.508
L-arginine/L-ornithine ratio	0.06 (−0.04 to 0.16), p = 0.225	0.05 (−0.06 to 0.15), p = 0.389	0.04 (−0.06 to 0.15), p = 0.447	0.05 (−0.06 to 0.17), p = 0.356	0.04 (−0.08 to 0.16), p = 0.478	0.03 (−0.09 to 0.15), p = 0.645
GABR	0.04 (−0.02 to 0.09), p = 0.235	0.02 (−0.04 to 0.08), p = 0.469	0.02 (−0.04 to 0.07), p = 0.608	0.03 (−0.04 to 0.09), p = 0.398	0.03 (−0.04 to 0.09), p = 0.405	0.02 (−0.05 to 0.09), p = 0.523

Marker

Model 1
(unadjusted)

Model 2

Model 3

Model 4

Model 5

Model 6

L-arginine [µmol/L]

1.31

(−4.44 to 7.06),

p = 0.654

1.85

(−4.05 to 7.74),

p = 0.537

1.62

(−4.35 to 7.60),

p = 0.593

1.85

(−4.66 to 8.36),

p = 0.576

1.36

(−5.60 to 8.32),

p = 0.700

0.8

(−6.25 to 7.85),

p = 0.823

L-homoarginine

[µmol/L]

−0.24

(−0.46 to −0.01),

p = 0.043

−0.28

(−0.51 to −0.05),

p = 0.017

−0.30

(−0.53 to −0.07),

p = 0.012

−0.23

(−0.48 to 0.02),

p = 0.077

−0.18

(−0.45 to 0.09), p = 0.192

−0.20

(−0.47 to 0.07), p = 0.150

ADMA [µmol/L]

−0.03

(−0.06 to 0.003),

p = 0.076

−0.02

(−0.05 to 0.01),

p = 0.261

−0.01

(−0.04 to 0.02), p = 0.528

−0.01

(−0.04 to 0.02), p = 0.494

−0.01

(−0.05 to 0.02),

p = 0.470

−0.02

(−0.05 to 0.02), p = 0.350

SDMA [µmol/L]

−0.11

(−0.20 to −0.03),

p = 0.010

−0.09

(−0.18 to 0),

p = 0.043

−0.06

(−0.14 to 0.02),

p = 0.152

−0.09

(−0.18 to 0),

p = 0.045

−0.10

(−0.17 to −0.04),

p = 0.002

−0.11

(−0.17 to −0.04),

p = 0.002

L-citrulline [µmol/L]

−0.82

(−5.42 to 3.77),

p = 0.724

0.52

(−4.10 to 5.14),

p = 0.824

1.45

(−3.13 to 6.04),

p = 0.533

−0.51

(−5.43 to 4.41),

p = 0.838

−1.27

(−6.04 to 3.49),

p = 0.598

−1.25

(−5.99 to 3.50),

p = 0.605

L-lysine [µmol/L]

−7.26

(−16.90 to 2.38),

p = 0.139

−6.53

(−16.41 to 3.36), p = 0.194

−7.35

(−17.34 to 2.64), p = 0.148

−4.52

(−15.26 to 6.22), p = 0.407

−1.23

(−12.59 to 10.12), p = 0.831

−1.45

(−12.76 to 9.86), p = 0.800

L-ornithine [µmol/L]

−1.97

(−9.20 to 5.24),

p = 0.589

0.07

(−7.20 to 7.34),

p = 0.984

0.17

(−7.2 to 7.54),

p = 0.964

−0.56

(−8.63 to 7.51),

p = 0.892

−0.03

(−8.65 to 8.59),

p = 0.994

0.77

(−7.92 to 9.47),

p = 0.861

L-arginine/ADMA ratio

7.33

(−2.61 to 17.26),

p = 0.147

6.18

(−3.99 to 16.36),

p = 0.232

4.46

(−5.70 to 14.61),

p = 0.388

4.83

(−6.24 to 15.90),

p = 0.390

4.15

(−7.42 to 15.72),

p = 0.479

3.95

(−7.81 to 15.70),

p = 0.508

L-arginine/L-ornithine ratio

0.06

(−0.04 to 0.16),

p = 0.225

0.05

(−0.06 to 0.15),

p = 0.389

0.04

(−0.06 to 0.15), p = 0.447

0.05

(−0.06 to 0.17), p = 0.356

0.04

(−0.08 to 0.16),

p = 0.478

0.03

(−0.09 to 0.15),

p = 0.645

GABR

0.04

(−0.02 to 0.09),

p = 0.235

0.02

(−0.04 to 0.08),

p = 0.469

0.02

(−0.04 to 0.07),

p = 0.608

0.03

(−0.04 to 0.09),

p = 0.398

0.03

(−0.04 to 0.09),

p = 0.405

0.02

(−0.05 to 0.09),

p = 0.523

Results show the regression coefficient β for sex and the corresponding 95% confidence interval

-ß coefficient: lower values in women

+ß coefficient: higher values in women

Model 1: unadjusted

Model 2: Model 1 + age

Model 3: Model 2 + %-predicted VO2peak

Model 4: Model 3 + BMI, HDL cholesterol

Model 5: Model 4 + comorbidities (diabetes, hypertension, coronary artery disease, atrial fibrillation, eGFR)

Model 6: Model 5 + ACE inhibitors, angiotensin receptor blocker, diuretics, and statins