Impact of anabolic steroid consumption on biochemical and hematological parameters in bodybuilders: A systematic review and evidence gap mapping

The consumption of anabolic androgenic steroids (AAS) by competitive and non-competitive bodybuilders is relatively common, yet there is diverse and often conflicting evidence on the short- and long-term side-effects of AAS abuse. We aimed at assessing the impact of AAS use (supraphysiological doses/schedule) on adult bodybuilders by means of a broad systematic review and evidence gap mapping (CRD42023401245). Electronic searches in PubMed, Scopus, and Web of Science were performed (Apr-2024). The methodological quality of the included studies was evaluated using the Effective Public Health Practice Project tool. An evidence gap map considering the most reported parameters (e.g., liver, kidney, hematopoietic system) was built. Twenty-two studies (1,023 bodybuilders, of which 662 AAS-users) published between 1987 and 2022, mostly by North America (n = 5 studies; 22.7 %) and West Asia (n = 5; 22.7 %) and mainly designed as cross-sectional case-controls (n = 17; 77.3 %) were synthesized. Testosterone, nandrolone, and stanozolol were the most consumed substances. Altogether, studies reported at least 30 different parameters. Although some parameters, such as urea levels, did not significantly differ between AAS users vs. nonusers (p > 0.05), an increase in both serum alanine and aspartate aminotransferases and a decrease in follicle stimulating and luteinizing hormones (p < 0.05) were reported in AAS users. Evidence is conflicting on the effect of steroids on cholesterol, triglyceride, high density lipoprotein, and low-density lipoprotein levels. Very few studies reported data on hematological parameters. The overall methodological quality of the studies was judged as weak-to-moderate. Further larger and well-designed studies to properly inform about the benefits and risks of AAS on other outcomes are still needed.