Circulating fibroblast growth factor 23 (FGF23) levels are associated with metabolic disturbances and fat distribution but not cardiovascular risk in HIV-infected patients.

Objectives: Dyslipidaemia, insulin resistance, metabolic syndrome and HIV/HAART-associated lipodystrophy syndrome (HALS) are common comorbidities in HIV-1-infected patients, which may increase cardiovascular risk. Fibroblast growth factor 23 (FGF23) is a bone-derived hormone with effects on metabolism and phosphate homeostasis. The aim of this study was to determine the relationship between FGF23 levels, metabolic alterations, fat distribution and cardiovascular risk.

Methods: This was a cross-sectional study. Serum FGF23 levels were analysed in 152 patients and 34 healthy control individuals. Patients belonged to three groups: HIV-1-infected, antiretroviral-treated patients who have developed HALS (n = 60); HIV-1-infected, antiretroviral-treated patients without HALS (n = 43); and untreated (naive) HIV-1-infected patients (n = 49). Serum FGF23 levels were compared with lipid and glucose homeostasis parameters, fat distribution and cardiovascular risk.

Results: Serum FGF23 levels were increased in HIV-1-infected patients, but the increase was most marked in those with HALS. FGF23 levels showed a strong positive correlation with age, indicators of dyslipidaemia (LDL cholesterol, polyunsaturated fatty acids and monounsaturated fatty acids), HALS parameters (trunk/appendicular fat ratio), insulin resistance (fasting insulin and homeostasis model assessment of insulin resistance) and C-reactive protein. FGF23 levels correlated with cardiovascular risk but correlation was lost after age adjustment.

Conclusions: FGF23 levels are increased in HIV-1-infected patients, especially in those with HALS, and this increase is associated with dyslipidaemia, insulin resistance, metabolic syndrome, fat distribution and parameters of inflammation. FGF23 is not associated with cardiovascular risk when age is taken into account.