Table 2.
Bivariate correlation analysis of Fndc5/irisin with clinical metabolic phenotypes (Study 1)
| Irisin | Fndc5 mRNA Sc. | Fndc5 mRNA | |
|---|---|---|---|
| circulation | adipose tissue | skeletal muscle | |
| Age (years) | r = −0.399 | — | — |
| P < 0.0001 | |||
| n = 96 | |||
| Fasting plasma glucose (mmol l–1) | r = −0.221 | — | — |
| P = 0.0308 | |||
| n = 96 | |||
| 2 h glucose (mmol l–1) | — | r = −0.494 | — |
| P = 0.0016 | |||
| n = 46 | |||
| Area under the curve glucose oGTT | r = −0.293 | r = −0.468 | r = 0.253 |
| P = 0.0056 | P = 0.0030 | P = 0.0267 | |
| n = 88 | n = 46 | n = 78 | |
| Fasting plasma insulin (μU ml–1) | — | r = −0.295 | r = 0.242 |
| P = 0.0718 | P = 0.0260 | ||
| n = 46 | n = 85 | ||
| M-value/insulin (mg kg–1 min–1 μU–1 ml–1) | — | r = 0.362 | r = −0.223 |
| P = 0.0133 | P = 0.0454 | ||
| n = 46 | n = 84 | ||
| BMI (kg m–2) | — | r = −0.296 | r = 0.358 |
| P = 0.0702 | P = 0.0007 | ||
| n = 46 | n = 86 | ||
| Waist circumference (cm) | — | r = −0.347 | r = 0.350 |
| P = 0.0197 | P = 0.0011 | ||
| n = 46 | n = 84 | ||
| Body fat content (%) | — | r = −0.271 | r = 0.251 |
| P = 0.0073 | P = 0.0211 | ||
| n = 46 | n = 84 | ||
| Lean body mass (kg) | — | r = −0.299 | r = 0.300 |
| P = 0.0464 | P = 0.0055 | ||
| n = 46 | n = 84 | ||
| Fat cell size – diameter (μm) | — | r = −0.361 | r = 0.296 |
| P = 0.0162 | P = 0.0070 | ||
| n = 46 | n = 82 | ||
| Sc. AT cross-sectional area (cm2) | — | r = −0.371 | r = 0.269 |
| P = 0.00155 | P = 0.0160 | ||
| n = 46 | n = 80 | ||
| Visceral AT cross-sectional area (cm2) | r = −0.237 | r = −0.268 | — |
| P = 0.0264 | P = 0.0856 | ||
| n = 88 | n = 46 | ||
| IMCL (relative to creatine) | — | — | r = 0.280 |
| P = 0.0100 | |||
| n = 81 | |||
| EMCL (relative to creatine) | r = −0.320 | r = −0.264 | — |
| P = 0.0020 | P = 0.099 | ||
| n = 86 | n = 46 | ||
| ΔRQ | — | r = −0.320 | |
| P = 0.0265 | |||
| n = 48 | |||
| Triglycerides (mmol l–1) | — | r = −0.280 | r = 0.235 |
| P = 0.0443 | P = 0.0307 | ||
| n = 46 | n = 85 | ||
| HDL cholesterol (mmol l–1) | — | — | r = −0.252 |
| P = 0.0206, | |||
| n = 84 | |||
| Atherogenic index (T.chol. – HDL chol.)/HDL chol.) | — | — | r = 0.309 |
| P = 0.0042 | |||
| n = 84 | |||
| FFAs during the steady state of clamp (mmol l–1) | — | — | r = 0.246 |
| P = 0.0241 | |||
| n = 84 | |||
| hsCRP (mg l–1) | — | — | r = 0.233 |
| P = 0.0318 | |||
| n = 85 | |||
| Moderate and high intensity ambulatory activity (%) | r = 0.262 | r = 0.260 | — |
| P = 0.0118 | P = 0.1002 | ||
| n = 92 | n = 46 |
AT, adipose tissue; EMCL, extramyocellular lipid content; hsCRP, high-sensitivity C-reactive protein; IMCL, intramyocellular lipid content; oGTT, oral glucose tolerance test; Sc. subcutaneous; T. chol, total cholesterol.