Background: We tested the hypothesis that serum apolipoprotein H (apo H) concentration increases after an oral fat load. Such a study would give valuable insight into whether apo H was influenced by the postprandial state.
Methods: Ten male subjects aged 24-48 years were fed 62.5 g of total fat (saturates 12 g, monounsaturates 35.3 g, polyunsaturates 12.5 g). Venous blood was sampled hourly for 5 h post-oral fat load.
Results: No significant change in serum apo H concentration occurred following the oral fat load. However, serum apo H in the baseline samples correlated significantly with subject body mass index (r = 0.683, P < 0.05), body fat mass (r = 0.778, P < 0.01), lean body mass (r = 0.693, P < 0.05), serum triglyceride (r = 0.732, P < 0.02), serum insulin (r = 0.808, P < 0.01) and insulin resistance index (r = 0.794, P < 0.01). In stepwise multiple linear regression model, with serum apo A1, apo B, lipoprotein(a), total cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol, plasma glucose and insulin and apo H as the dependent variable, insulin remained in the model (r = 0.81, P < 0.01). Conversely, with body mass index, body fat mass, lean body mass and waist/hip ratio in the model and apo H as dependent variable, only body fat mass remained in the model (r = 0.78, P < 0.01).
Conclusions: Serum apo H may be involved in insulin resistance and relates to various indices of adipose tissue, including body fat mass. However, serum apo H concentrations do not significantly change postprandially.
