Impact of serum total bilirubin and ALT on lipid profiles and fatty liver in aviators

LI Xiaolong; WANG Xiaoling; LIANG Hui; ZHONG Zhengqin; YAN Xuhong; QIN Chi

doi:10.3969/j.issn.2097-1753.2025.04.010

Abstract：Objective To investigate the effects of serum total bilirubin(STB)and alanine aminotransferase(ALT)on blood lipids and the incidence of fatty liver among aviators.Methods A total of 1,318 flight personnel who underwent medical evaluation at Guilin Rehabilitation and Recuperation Center between January 2021 and January 2024 were selected and divided into three groups based on types of aircraft:the fighter jet group(581 cases),transport aircraft group(376 cases),and helicopter group(361 cases).The detection rates of related diseases and abnormal indicators were analyzed under different levels of STB and ALT across the three groups.Results Significant differences were observed in the detection rates of fatty liver between the three groups(χ2=7.820,P=0.021),with a notable difference between the fighter jet group and the helicopter group(χ2=7.424,P=0.006).The detection rates of elevated HDL-C also differed significantly(χ2=9.208,P=0.010),particularly between the fighter jet group and the other two groups(χ2=6.050,6.029,P=0.014,0.014).Total cholesterol(TC)levels were significantly different between the three groups(F=6.307,P=0.002),with a marked difference between the fighter jet group and the helicopter group(P=0.002).There were significant differences in HDL-C levels between these groups(F=3.987,P=0.019),especially between the fighter jet group and the transport aircraft group(P=0.025).A comparison of incidences of lipid metabolism disorders between elevated STB levels and normal ones suggested that the detection rates of high levels of TG were significantly different between the transporter aircraft group and the helicopter group(χ2=4.704,11.446,P=0.030,0.001),and that the detection rates of fatty liver(χ2=4.762,P=0.031)and abnormalities of low-density lipoprotein cholesterol(LDL-C)(χ2=14.23,P=0.001)were significantly different in the fighter jet group.The comparison of incidences of lipid metabolism disorders between elevated and normal ALT levels showed that the levels of TG differed significantly between the three groups(Z=3.638,2.509,5.515,P=0.001,0.012,0.001).The differences in TC levels of the fighter jet and helicopter groups,HDL-C levels of the transport aircraft group,LDL-C levels of the helicopter group were of statistical significance(t=2.850,3.297,2.107,2.617,P=0.005,0.001,0.036,0.009).Conclusion Fighter crews have better lipid profiles than transport and helicopter crews.Moderate SSTB levels may reduce hypertriglyceridemia and fatty liver risks while elevated ALT levels are associated with increased risks.