| Study |
Participants |
Design |
Outcomes |
| T2DM |
|
| Choi et al. [40] |
681 men and 1092 women recruited for health survey in rural Korea |
All Participants subjected to glucose tolerance testing and venous blood samples takenà identified 104 subjects with newly diagnosed T2DM and 104 age, sex and BMI matched controls for study population |
Irisin has a significant inverse correlation with new onset T2DM |
| Liu et al. [41] |
96 T2DM individuals and 60 non-matched, non-diabetic healthy controls recruited from hospital in Singapore |
Venous blood samples collected for irisin levels from participants. |
Serum irisin levels were lower in those with T2DM, significant after adjusting for age and gender differences |
| Liu et al. [42] |
365 T2DM subjects recruited from Singapore hospital |
Venous blood samples for lipids, irisin and eGFR and morning spot urine for albumin levels, as well as measurement body composition from each participant. |
Irisin was lowest in those with Stage 5 CKD.
No correlation was found between irisin and non-fat lean body mass. |
| Morreno-Navarrete et al. [46] |
Study 1: 35 non-obese, 56 obese, 6 non-obese T2DM and 28 obese T2DM recruited from hospital in Spain.
Study 2: 76 Caucasian men from northern Spain |
Study 1: Adipose tissue and Myocytes from participants were cultured and examined for mRNA and protein levels including FNDC5 and PGC1α.
Serum irisin samples obtained from 29 obese participants.
Study 2: participants underwent OGTT and anthropometric measurements |
Study 1: white adipose tissue FNDC5 expression decreased with obesity.
In obese T2DM, white adipose FNDC5 was decreased significantly.
Study 2: Circulating irisin was decreased significantly in those with T2DM. |
| Kuridova et al. [33] |
Study 1: 29 lean healthy controls, 29 healthy overweight/obese individuals, 25 individuals with impaired glucose tolerance, 16 with new onset T2DM
Study 2: described in Table 1. |
Subcutaneous adipose tissue collected from abdominal fat biopsy and cultured.
Myocytes collected form vastus lateralis biopsy, and cultured with 100μ palmitate and 5.5-20mM glucose.
Circulating irisin from venous blood samples. |
Circulating irisin decreased by 40% in T2DM, unaltered in other states.
In T2DM, Adipose tissue, but not muscle displayed a ~40% decrease in FNDC5 expression.
T2DM myocyte FNDC5 expression in vitro was decreased by palmitate and glucose. |
| Metabolic Syndrome |
|
| Yan et al. [47] |
1115 community recruited Chinese individuals with central obesity |
Venous blood samples, clinical measurements and lifestyle information obtained |
Serum irisin levels significantly reduced in those with metabolic syndrome and raised fasting plasma glucose. |
| Hee Park et al. [48] |
151 Caucasian and African American subjects |
Fasting venous blood samples, clinical measurements and lifestyle information obtained |
Irisin levels were significantly higher in those with the metabolic syndrome |
| NAFLD |
|
| Polyzos et al. [49] |
24 lean controls, 28 obese controls, 15 NAFL, 16 NASH |
Fasting venous blood samples, liver biopsy from NAFLD/NASH individuals, clinical information and measurments including BMI were obtained |
Serum irisin levels were significantly lower in the NASH, NAFL and obese group compared to lean.
Lower irisin was associated with higher intrahepatic triglyceride content, and higher irisin with portal inflammation |
| Zhang et al. [50] |
296 obese Chinese adults |
Venous blood samples, clinical information were obtained. OGTT and intrahepatic triglyceride content were determined. |
Serum irisin levels decreased with increasing intrahepatic triglyceride content. |
| Chronic Kidney Disease |
|
| Wen et al. [44] |
38 patients with Stage 5 CKD (excluding those with other health conditions including diabetes), 19 age and sex matched healthy controls |
Morning fasting venous blood samples were collected. |
Irisin levels are lower in subjects with Stage 5 CKD |
| Ebert et al. [51] |
532 patients with Stage 1-5CKD |
Venous blood samples were collected, and clinical information and characteristics obtained. |
Irisin levels decrease with increasing severity of CKD. |
