Serum prealbumin: an independent marker of short-term energy intake

Background: Serum prealbumin was shown to have a prognostic value in several diseases, but its serum levels can be influenced by different factors. Previous studies investigated the effect of single variables on serum prealbumin levels, while a multivariable analysis to test the independent effect of each of them has never been performed. The aim of this cross-sectional study was to investigate the association between prealbumin and several factors potentially affecting its serum levels in the presence of multiple organ disease involvement. Methods: Multivariable general linear regression models of non-collinear variables were fitted to assess the association of demographic (gender, age), nutritional (short-term energy intake, unintentional weight loss, body mass index [BMI]) and clinical (cardiac and liver involvement, kidney function, C-reactive protein [CRP]) parameters with serum prealbumin levels in 187 newly diagnosed outpatients affected by immunoglobulin light-chain amyloidosis. Results: Serum prealbumin levels were associated with CRP and short-term energy intake (p<0.001 for both). A significant association was also detected with age (p=0.023), serum creatinine (p=0.017), liver involvement (p=0.002) and the presence of peripheral edema (p=0.032). In a pre-specified subgroup analysis (N=140) on patients with normal CRP (<0.5 mg/dL), all the other associations were confirmed. A significant relationship was also observed with gender (p=0.022) and BMI (p=0.041). Conclusions: Serum prealbumin is associated with short-term energy intake independently of the presence of multiple organ involvement and inflammation. Its serum levels should be always interpreted in light of its influencing factors, among which inflammation, liver and kidney function appear predominant.