Maximal post-prandial triglyceride increase reflects post-prandial hypertriglyceridaemia and is associated with the insulin resistance syndrome.

AIMS: To assess the value of maximal post-prandial triglyceride increase after a high fat, low carbohydrate (CHO) test meal, as index of post-prandial hypertriglyceridaemia and its relation with insulin resistance. METHODS: Fifty non-diabetic subjects, 22 male and 28 female, aged 52.1+/-4.5 and 56.9+/-3.8 years, were studied. Glucose, insulin and triglycerides were measured fasting and 1, 2, 3 and 4 h after a meal consisting of 40 g fat, 19 g protein and 10 g CHO. Insulin resistance was calculated according to the HOMA model. RESULTS: The maximal triglyceride increment occurred during the 4th hour. Its absolute value (delta-TG) and the per cent increase over the fasting value (PTI), were considered appropriate for the evaluation of the post-prandial triglyceride response. Both delta-TG and PTI were strongly correlated with triglycerides incremental area in males and females, r = 0.797 and r = 0.700, P<0.01 and r = 0.805 and r = 0.774, P<0.001, respectively, and thus they can be used as indices of the post-prandial triglyceride response. No correlation was found between fasting triglyceride and triglyceride incremental area or delta-TG. Thus, post-prandial hypertriglyceridaemia can occur irrespectively of the fasting triglyceride concentrations. A weak correlation was found between PTI and insulin resistance in females, r = 0.384, P<0.05, but not in males, r = 0.224, P>0.05. However further analysis by quartiles of PTI showed similar insulin resistance levels in the first three quartiles and a significant increase in the 4th, both for males and females, 4th vs. 3rd quartile 7.4+/-3.6 vs. 2.2+/-0.7 and 6.4+/-2.4 vs. 2.2+/-0.6, respectively. The 4th quartile corresponds to a PTI > or =80%. CONCLUSIONS: PTI after the high fat, low CHO test meal used, consistently reflects post-prandial hypertriglyceridaemia, is easily measured and it is not predicted by fasting triglycerides. A PTI > or = 80% is associated with a significant increase of insulin resistance, and might therefore be considered the cut-off point for an abnormal post-prandial hypertriglyceridaemic response, at least in relation with insulin resistance. Such response could be added to the abnormalities of the insulin resistance syndrome, as an independent parameter.