Minimal leptin elimination into ultrafiltrate during continuous venovenoushaemofiltration in patients with sepsis

Intensive care patients with organ failure often suffer an acute catabolic state. Leptin is a 16-kDa hormone which is produced by mature adipocytes an d correlates with human energy expenditure. We investigated whether continu ous venovenous haemofiltration, which may eliminate molecules up to 20-30 k Da, is capable of removing human leptin. Leptin measurements were made in t he plasma of 15 patients with sepsis before continuous venovenous haemofilt ration (T-0) and during the procedure at 24 h (T-1), 48 h (T-2), and 72 h ( T-3), using samples taken before and after haemofiltration. In addition, me asurements were made in the ultrafiltrate at T-1-T-3. The plasma leptin lev el at T-0 was 17.6 ng mL(-1). The concentration at T-1 was 17.5 ng mL(-1) p re-filter and 26.5 ng mL(-1) post-filter (T-2: 14.2/23.2 ng mL(-1); T-3: 12 .4/16.3 ng mL(-1)). This concentration effect after haemofiltration was als o seen with albumin. The values measured at T-3 tended to be lower than tho se recorded at T-1. The mean leptin levels in the ultrafiltrate were 0.15-0 .18 ng mL(-1). The range of leptin levers in the ultrafiltrate was thus onl y 0.5-3% of that measured in plasma. We conclude that human leptin is only minimally elimininated into the ultrafiltrate by continuous venovenous haem ofiltration and that plasma leptin levels may decrease during sepsis.