Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Meta-Analysis
. 2016 Jan;59(1):44-55.
doi: 10.1007/s00125-015-3751-0. Epub 2015 Sep 24.

Role of insulin in the regulation of human skeletal muscle protein synthesis and breakdown: a systematic review and meta-analysis

Haitham Abdulla  1 , Kenneth Smith  1 , Philip J Atherton  1 , Iskandar Idris  2
Affiliations
Meta-Analysis

Role of insulin in the regulation of human skeletal muscle protein synthesis and breakdown: a systematic review and meta-analysis

Haitham Abdulla et al. Diabetologia. 2016 Jan.

Abstract

Aims/hypothesis: We aimed to investigate the role of insulin in regulating human skeletal muscle metabolism in health and diabetes.

Methods: We conducted a systematic review and meta-analysis of published data that examined changes in skeletal muscle protein synthesis (MPS) and/or muscle protein breakdown (MPB) in response to insulin infusion. Random-effects models were used to calculate weighted mean differences (WMDs), 95% CIs and corresponding p values. Both MPS and MPB are reported in units of nmol (100 ml leg vol.)(-1) min(-1).

Results: A total of 104 articles were examined in detail. Of these, 44 and 25 studies (including a total of 173 individuals) were included in the systematic review and meta-analysis, respectively. In the overall estimate, insulin did not affect MPS (WMD 3.90 [95% CI -0.74, 8.55], p = 0.71), but significantly reduced MPB (WMD -15.46 [95% CI -19.74, -11.18], p < 0.001). Overall, insulin significantly increased net balance protein acquisition (WMD 20.09 [95% CI 15.93, 24.26], p < 0.001). Subgroup analysis of the effect of insulin on MPS according to amino acid (AA) delivery was performed using meta-regression analysis. The estimate size (WMD) was significantly different between subgroups based on AA availability (p = 0.001). An increase in MPS was observed when AA availability increased (WMD 13.44 [95% CI 4.07, 22.81], p < 0.01), but not when AA availability was reduced or unchanged. In individuals with diabetes and in the presence of maintained delivery of AA, there was a significant reduction in MPS in response to insulin (WMD -6.67 [95% CI -12.29, -0.66], p < 0.05).

Conclusions/interpretation: This study demonstrates the complex role of insulin in regulating skeletal muscle metabolism. Insulin appears to have a permissive role in MPS in the presence of elevated AAs, and plays a clear role in reducing MPB independent of AA availability.

Keywords: Amino acids; Insulin; Meta-analysis; Muscle protein breakdown; Muscle protein synthesis; Systematic review.

PubMed Disclaimer

References

    1. Am J Physiol. 1983 Dec;245(6):E604-10 - PubMed
    1. Diabetes. 1989 May;38(5):618-24 - PubMed
    1. Diabetes. 1995 Nov;44(11):1249-58 - PubMed
    1. Diabetes. 2007 Jun;56(6):1615-22 - PubMed
    1. Diabetes Care. 2013 Aug;36(8):2372-9 - PubMed

Publication types

LinkOut - more resources