Soluble urokinase plasminogen activator receptor is a marker of dysmetabolism in HIV-infected patients receiving highly active antiretroviral therapy

Circulating soluble urokinase plasminogen activator receptor (suPAR) reflects the immune and pro-inflammatory status of the HIV-infected patient. Highly active antiretroviral therapy (HAART) suppresses suPAR. Independent of the immune response to HAART, suPAR remains elevated in some HIV-infected patients, reflecting possibly a low-grade pro-inflammatory state. Low-grade inflammation has been implicated in insulin resistance and other features of dysmetabolism. Accordingly it is hypothesized that circulating suPAR is associated with the metabolic status of HIV-infected patients on HAART. Fasting plasma suPAR was determined in 36 normoglycaemic HIV-infected patients on HAART (n = 18 lipodystrophic, and n = 18 non-lipodystrophic) who had estimated insulin sensitivity (Rd) and non-oxidative glucose disposal (NOGM) by euglycaemic hyperinsulinaemic clamps, indirect calorimetry, and glucose tracer infusion. Five patients had circadian suPAR concentrations measured (24 hr, 20 min-intervals). suPAR and non-HDL-cholesterol were higher and Rd, NOGM, and limb fat were lower in lipodystrophic patients than in non-lipodystrophic patients (P < 0.05). suPAR correlated positively with non-HDL-cholesterol and inversely with Rd, NOGM and limb fat (P < 0.005, n = 36). suPAR also correlated positively with leukocyte count and TNF-alpha (P < 0.01, n = 36) but not with IL-6. In multiple regression analyses suPAR was a stronger predictor of dysmetabolism than TNF-alpha and IL-6. Circadian suPAR did not systematically fluctuate. In conclusion, suPAR may reflect the metabolic status of the HIV-infected patient on HAART, thus linking low-grade inflammation, immune constitution, lipid and glucose metabolism, and fat redistribution. Circadian suPAR concentration appeared stable, suggesting that sampling schedule does not affect measurement. Further studies addressing whether suPAR predicts lipodystrophy and dysmetabolism in HIV-infected patients are warranted.