Triglyceride, Free Fatty Acid and Carbohydrate Metabolism in Hyperlipaemic (Type IV) and Normolipaemic Subjects on Carbohydrate- or Fat-Rich Diets

Abstract

1. Five patients with hyperlipoproteinaemia type IV and five normolipaemic controls were maintained on diets containing either a fat or a carbohydrate content of approximately 60%. Leg exchanges of triglycerides, free fatty acid (NEFA), glucose and other metabolites were measured in the basal state. The metabolic response to an intravenous glucose load and the turnover of intravenously infused (14C)oleic acid were determined. Individual fatty acids were analysed in plasma NEFA and very-low-density lipoprotein triglyceride. 2. No differences were detected between patients and controls with regard to leg uptake of triglyceride or NEFA on either diet. On shifting from a fat-rich to a carbohydrate-rich diet, the control subjects showed reduced values for arterial NEFA and for NEFA turnover, accompanied by a lowered release of NEFA and glycerol from the leg. In patients, on the other hand, the arterial concentration and turnover of NEFA remained unchanged and the release of glycerol from the leg increased. Glucose administration gave a less-pronounced fall of arterial NEFA on either diet in the patients and the incorporation of (14C)oleic acid into triglycerides after glucose administration was more marked than in the controls. 3. No difference in net uptake of triglyceride by the leg was demonstrable between patients and controls. 4. it is concluded that hyperlipaemic patients show an altered metabolic response to a carbohydrate-rich diet, possibly contributing to the development of a hyperlipaemic state, and that acute glucose loading results in a greater incorporation of circulating NEFA into very-low-density lipoproteins in these patients.

A comparison of average daily gain, apparent digestibilities, energy balance, rumen fermentation parameters, and serum metabolites between yaks (Bos grunniens) and Qaidam cattle (Bos taurus) consuming diets differing in energy level

“…Serum NEFA concentration reflects the mobilization of fat, whereas BHBA reflects the completeness of oxidization of fatty acids in the liver ( De Koster and Opsomer, 2013 ). Triglycerides, a vital energy source for cells synthesized by NEFA, and glycerol ( Hagenfeldt et al., 1975 ) increased with increasing dietary energy level in the present study, which was in agreement with findings in dairy cattle ( Canfield and Butler, 1990 ). Mobilization of NEFA from adipose tissue increases the NEFA concentrations in blood when energy intake is below maintenance requirements in ruminants ( Bell, 1995 ).…”

Skeletal muscle substrate metabolism during exercise: methodological considerations

“…Blood-borne TG is not regarded as a major supplier of FA for muscle energy turnover during exercise. Values for lipid oxidation of from 5 to 10 % are usually observed when based on measurements of a-v difference and blood flow (Havel et al 1967;Hagenfeldt et al 1975;Olssen et al 1975;Kiens et al 1993; for review see Van der Vusse & Reneman, 1996). This value does not take into account whether the FA released from the blood-borne TG is oxidized.…”