It is now generally accepted that adipose tissue acts as an endocrine organ producing a number of substances with an important role in the regulation of food intake, energy expenditure and a series of metabolic processes. Adiponectin is a recently discovered protein produced exclusively by adipocytes. A number of studies have shown that obesity, insulin resistance and atherosclerosis are accompanied by decreased adiponectin levels and that adiponectin replacement under experimental settings is able to diminish both insulin resistance and atherosclerosis. The aim of this review is to summarize the current knowledge about the physiology and pathophysiology of adiponectin and to discuss its potential in the treatment of insulin resistance and atherosclerosis.
This study was designed primarily to identify relationships among indices of muscle tissue structure (m. vastus lateralis) and of somatic qualities (anthropometric parameters) in 44 untrained men and 105 well-trained athletes. The ratio of glycolytic to oxidative muscle fibres was significantly less (P<0.05) in endurance athletes as opposed to both the controls and the power athletes. Correlations between anthropometric factors and indices of muscle morphology were stronger in trained men, particularly in power athletes. Relationships between body fat and muscle fibre distribution were low in trained and untrained subjects. Documented muscle plasticity may enhance relationships between somatic and muscle tissue indices. Our results suggest that the response of the three major muscle fibre types to prolonged training may be relatively high. Finally, it was proposed that enhanced oxidative capacity of skeletal muscle might be characteristic of those resistant to heart disease.
Polyunsaturated fatty acids of n-3 series (n-3 PUFA) were shown to increase basal fat oxidation in humans. The aim of the study was to compare the effect of n-3 PUFA added to a very low calorie diet (VLCD), with VLCD only during three-week inpatient weight reduction. Twenty severely obese women were randomly assigned to VLCD with n-3 PUFA or with placebo. Fatty acids in serum lipid fractions were quantified by gas chromatography. Differences between the groups were determined using ANOVA. Higher weight (7.55±1.77 vs. 6.07±2.16 kg, NS), BMI (2.82± 0.62 vs. 2.22±0.74, p<0.05) and hip circumference losses (4.8±1.81 vs. 2.5±2.51cm, p<0.05) were found in the n-3
group as compared to the control group. Significantly higher increase in beta-hydroxybutyrate was found in the n-3 group showing higher ketogenesis and possible higher fatty acid oxidation. The increase in beta-hydroxybutyrate significantly correlated with the increase in serum phospholipid arachidonic acid (20:4n-6; r = 0.91, p<0.001). In the n-3 group significantly higher increase was found in n-3 PUFA (eicosapentaenoic acid, 20:5n-3, docosahexaenoic acid, 22:6n-3) in trigycerides and phospholipids. The significant decrease of palmitoleic acid (16:1n-7) and vaccenic acid (18:1n-7) in triglycerides probably reflected lower lipogenesis. A significant negative correlation between BMI change and phospholipid docosahexaenoic acid change was found (r = -0.595, p<0.008). The results suggest that long chain n-3 PUFA enhance weight loss in obese females treated by VLCD. Docosahexaenoate (22:6n-3) seems to be the active
component.