Serum FGF21 levels are elevated in association with lipodystrophy, insulin resistance and biomarkers of liver injury in HIV-1-infected patients

HIV-1-infected patients with lipodystrophy show insulin resistance, dyslipidemia and other signs of metabolic syndrome. Fibroblast growth factor-21 (FGF21) is a novel metabolic regulator that has been suggested to exert beneficial effects on metabolic homeostasis and insulin sensitivity. Our goal was to determine the relationship between FGF21 levels and metabolic alterations in these patients. Serum FGF21 levels were analyzed in 179 individuals belonging to four groups: HIV-1-infected, antiretroviral-treated patients that have developed lipodystrophy (n = 59); HIV-1-infected, antiretroviral-treated patients without lipodystrophy (n = 45); untreated (naive) HIV-1-infected patients (n = 41); and healthy control individuals (n = 34). Serum FGF21 levels were correlated with parameters indicative of altered fat distribution, metabolic and cardiovascular risk, and in relation to HIV-1 infection and antiretroviral treatment regimens. Serum FGF21 levels were increased in all HIV-1-infected patients, but the increases were most marked in those with lipodystrophy. FGF21 levels showed a strong positive correlation with indicators of lipodystrophy (trunk/apendicular fat ratio, waist-to-hip ratio), insulin resistance (fasting glucose, HOMA-R), dyslipidemia (low-density lipoprotein cholesterol), and liver injury (γ-glutamyltransferase). FGF21 levels are increased in HIV-1-infected patients, especially in those with lipodystrophy, and this increase is closely associated with insulin resistance, metabolic syndrome and makers of liver damage. Further research will be required to determine whether the increase in FGF21 levels is caused by a compensatory response or resistance to FGF21, and to establish the potential of FGF21 as a biomarker of altered metabolism in HIV-1-infected, antiretroviral-treated patients.