Affiliations 

  • 1 School of Medicine, Shandong University, No. 44 Wenhua West Road, Jinan, Shandong, 250012, China; Department of Endocrinology, Jinan Central Hospital Affiliated to Shandong University, No. 105 Jiefang Road, Jinan, Shandong, 250013, China; Department of Endocrinology, Jinan Central Hospital Affiliated to Shandong First Medical University, No. 105 Jiefang Road, Jinan, Shandong, 250013, China. Electronic address: [email protected]
  • 2 School of Medicine, Shandong University, No. 44 Wenhua West Road, Jinan, Shandong, 250012, China; Department of Endocrinology, Jinan Central Hospital Affiliated to Shandong University, No. 105 Jiefang Road, Jinan, Shandong, 250013, China; Department of Endocrinology, Jinan Central Hospital Affiliated to Shandong First Medical University, No. 105 Jiefang Road, Jinan, Shandong, 250013, China
  • 3 Department of Endocrinology, Jinan Central Hospital Affiliated to Shandong University, No. 105 Jiefang Road, Jinan, Shandong, 250013, China
  • 4 Central Laboratory, Jinan Central Hospital Affiliated to Shandong University, No. 105 Jiefang Road, Jinan, Shandong, 250013, China
  • 5 UKM Medical Molecular Biology Institute, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
  • 6 Department of Clinical Nutrition and Dietetics, Student Research Committee, Faculty of Nutrition and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
  • 7 Department of Endocrinology, Jinan Central Hospital Affiliated to Shandong University, No. 105 Jiefang Road, Jinan, Shandong, 250013, China; Department of Endocrinology, Jinan Central Hospital Affiliated to Shandong First Medical University, No. 105 Jiefang Road, Jinan, Shandong, 250013, China. Electronic address: [email protected]
Complement Ther Med, 2020 May;50:102360.
PMID: 32444042 DOI: 10.1016/j.ctim.2020.102360

Abstract

BACKGROUND: Data about the effects of resistance exercise on level of IGF-1 in the serum are conflicting. To resolve this inconsistency, we performed a systematic review and meta-analysis to precisely examine the effects of resistance exercise on the levels of serum IGF-1.

METHODS: PubMed, Scopus, Web of Science, and Embase databases were systematically searched from their inceptions until 10 December 2019 for randomized controlled trials (RCTs) comparing individuals who underwent resistance training and control participants. We applied a random-effects model to calculate the weighted mean difference (WMD).

RESULTS: 33 trials reported IGF-1 level as an outcome measure. The pooled estimate demonstrated a significant increase in IGF-1 (WMD: 10.34 ng/ml, 95 % CI: 4.93, 15.74, p = 0.000, I2 = 90.3 %) after resistance training compared with the control group. Subgroup analysis demonstrated that the increase in IGF-1 levels following resistance training was only statistically significant in treatment duration ≤16 weeks (WMD: 8.04 ng/ml), participants aged more than 60 years old (WMD: 9.84 ng/ml); and in women (WMD: 17.27 ng/ml). Subsequent analysis of the relationship between participants' age with plasma IGF-1 alterations revealed a U shape correlation in non-liner dose response, in which resistance training resulted in a declined IGF-1 level up to 40 years of age. Beyond 40 years old, the IGF-1 level was increased following resistance training.

CONCLUSION: We have successfully demonstrated that resistance training was associated with an increased IGF-1 level among those who received the training for ≤16 weeks, among participants older than 60 years old, and among women. Further studies are warranted to clarify the mechanisms underlying the influence of resistance training on IGF-1.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.