Table 3 Univariable Mendelian randomization estimates of sarcopenia-related traits on iron status.

From: Iron status and sarcopenia-related traits: a bi-directional Mendelian randomization study

Exposure

Outcome

IVs

R2 (%)

F-statistics

Method

Beta

95% CI

P-value

Appendicular lean mass

Ferritin

534

11.326

107.565

IVW

− 0.01

− 0.026, 0.006

0.215

MR Egger

− 0.017

− 0.054, 0.02

0.372

WM

− 0.003

− 0.029, 0.023

0.796

Serum iron

571

12.468

112.178

IVW

− 0.013

− 0.031, 0.004

0.135

MR Egger

− 0.026

− 0.067, 0.015

0.222

WM

− 0.028

− 0.056, − 0.001

0.046

TIBC

555

11.597

106.294

IVW

− 0.031

− 0.052, − 0.01

0.004

MR Egger

− 0.049

− 0.099, 3.6 × 10–4

0.049

WM

− 0.036

− 0.069, − 0.002

0.037

TSAT

566

12.453

113.006

IVW

0.002

− 0.018, 0.022

0.827

MR Egger

0.029

− 0.016, 0.074

0.210

WM

0.01

− 0.022, 0.042

0.539

Hand grip strength (left)

Ferritin

141

1.396

46.261

IVW

− 0.014

− 0.075, 0.047

0.648

MR Egger

0.015

− 0.215, 0.244

0.899

WM

0.02

− 0.068, 0.109

0.653

Serum iron

129

1.289

46.672

IVW

− 0.087

− 0.156, − 0.018

0.013

MR Egger

− 0.079

− 0.337, 0.179

0.549

WM

− 0.056

− 0.156, 0.045

0.279

TIBC

143

1.444

47.234

IVW

− 0.038

− 0.12, 0.044

0.362

MR Egger

0.001

− 0.316, 0.318

0.997

WM

0.012

− 0.101, 0.125

0.838

TSAT

148

1.492

47.172

IVW

− 0.009

− 0.086, 0.068

0.824

MR Egger

− 0.088

− 0.377, 0.2

0.549

WM

− 0.012

− 0.122, 0.099

0.838

Hand grip strength (right)

Ferritin

151

1.502

46.551

IVW

− 0.001

− 0.059, 0.058

0.981

MR Egger

− 0.091

− 0.313, 0.132

0.425

WM

0.002

− 0.079, 0.084

0.953

Serum iron

164

1.659

47.425

IVW

− 0.051

− 0.115, 0.013

0.119

MR Egger

− 0.031

− 0.264, 0.202

0.796

WM

− 0.009

− 0.099, 0.081

0.844

TIBC

158

1.591

47.162

IVW

− 0.05

− 0.128, 0.028

0.211

MR Egger

− 0.016

− 0.303, 0.27

0.910

WM

− 0.091

− 0.197, 0.016

0.097

TSAT

163

1.652

47.504

IVW

0.007

− 0.065, 0.08

0.840

MR Egger

0.134

− 0.127, 0.395

0.315

WM

0.056

− 0.046, 0.159

0.283

Low hand grip strength

Ferritin

14

0.208

38.164

IVW

− 0.007

− 0.055, 0.041

0.774

MR Egger

0.135

1.5 × 10–4, 0.271

0.074

WM

− 0.007

− 0.064, 0.05

0.810

Serum iron

12

0.188

40.322

IVW

0.026

− 0.025, 0.078

0.315

MR Egger

0.079

− 0.087, 0.246

0.371

WM

0.053

− 0.011, 0.116

0.104

TIBC

11

0.164

38.303

IVW

0.006

− 0.069, 0.081

0.870

MR Egger

− 0.239

− 0.426, − 0.052

0.034

WM

− 0.001

− 0.092, 0.091

0.987

TSAT

15

0.235

40.359

IVW

− 0.029

− 0.088, 0.029

0.325

MR Egger

0.067

− 0.118, 0.252

0.491

WM

− 0.028

− 0.1, 0.045

0.457

Walking pace

Ferritin

47

0.391

38.442

IVW

0.076

− 0.058, 0.209

0.267

MR Egger

− 0.056

− 0.56, 0.449

0.830

WM

0.154

− 0.028, 0.335

0.097

Serum iron

50

0.435

40.209

IVW

0.029

− 0.117, 0.175

0.695

MR Egger

0.215

− 0.37, 0.801

0.475

WM

0.014

− 0.191, 0.219

0.894

TIBC

53

0.462

40.315

IVW

− 0.147

− 0.322, 0.028

0.099

MR Egger

− 0.294

− 1.007, 0.42

0.424

WM

− 0.231

− 0.465, 0.004

0.054

TSAT

53

0.457

39.806

IVW

0.017

− 0.155, 0.189

0.849

MR Egger

0.475

− 0.208, 1.158

0.179

WM

0.049

− 0.183, 0.281

0.680

  1. WM weighted median, IVW inverse variance weighted, TIBC total iron binding capacity, TSAT transferrin saturation, IVs numbers of instrumental variable, CI confidence interval.