Omega-3 fatty acids and lipoprotein associated phospholipase A(2) in healthy older adult males and females.

PURPOSE: Lipoprotein associated phospholipase A(2) (Lp-PLA(2)) is a novel inflammatory factor that has been independently associated with stroke and cardiovascular disease (CVD). Omega-3 fats have been implicated in reducing inflammation associated with CVD. The aim of this study was to determine if an 8-week isocaloric diet supplemented with eicosapentaenoic acid (EPA) and docosahexaenoic (DHA) in the form of fish oil or α-linolenic acid (ALA) in the form of flaxseed oil would alter Lp-PLA(2) among healthy adults ages 50 years and older. METHODS: Fifty-nine healthy adults (~75% female, average age 61 years) were randomized to one of three groups with equal amounts of total fat intake. All capsules contained ~1 g of fat. The control group (n = 19) consumed olive oil capsules (~11 g/day); the ALA group (n = 20) consumed flaxseed oil capsules (~11 g/day) and the EPA/DHA group (n = 20) consumed fish oil capsules (~2 g/day + 9 g/day of olive oil). Fasting blood samples were obtained before and after the 8-week intervention for determination of Lp-PLA(2) mass and activity as well as lipid values. RESULTS: We did not find any significant changes in Lp-PLA(2) mass or activity after the intervention in any of the groups; however, change in oxidized LDL was associated with change in Lp-PLA(2) mass (r = 0.37, p < 0.01). CONCLUSION: Supplementing the diet with omega-3 fatty acids for 8-weeks did not influence Lp-PLA(2) activity or mass among older adults; altering oxidized LDL may be necessary to see changes in Lp-PLA(2) levels.

A new paradigm for type 2 diabetes mellitus: could it be a disease of the foregut?

SUMMARY BACKGROUND DATA: We previously reported, in a study of 608 patients, that the gastric bypass operation (GB) controls type 2 diabetes mellitus in the morbidly obese patient more effectively than any medical therapy. Further, we showed for the first time that it was possible to reduce the mortality from diabetes; GB reduced the chance of dying from 4.5% per year to 1% per year. This control of diabetes has been ascribed to the weight loss induced by the operation. These studies, in weight-stable women, were designed to determine whether weight loss was really the important factor. METHODS: Fasting plasma insulin, fasting plasma glucose, minimal model-derived insulin sensitivity and leptin levels were measured in carefully matched cohorts: six women who had undergone GB and had been stable at their lowered weight 24 to 30 months after surgery versus a control group of six women who did not undergo surgery and were similarly weight-stable. The two groups were matched in age, percentage of fat, body mass index, waist circumference, and aerobic capacity. RESULTS: Even though the two groups of patients were closely matched in weight, age, percentage of fat, and even aerobic capacity, and with both groups maintaining stable weights, the surgical group demonstrated significantly lower levels of serum leptin, fasting plasma insulin, and fasting plasma glucose compared to the control group. Similarly, minimal model-derived insulin sensitivity was significantly higher in the surgical group. Finally, self-reported food intake was significantly lower in the surgical group. CONCLUSIONS: Weight loss is not the reason why GB controls diabetes mellitus. Instead, bypassing the foregut and reducing food intake produce the profound long-term alterations in glucose metabolism and insulin action. These findings suggest that our current paradigms of type 2 diabetes mellitus deserve review. The critical lesion may lie in abnormal signals from the gut.

Effect of fat emulsion infusion and fat feeding on muscle glycogen utilization during cycle exercise.

Elevated plasma fatty acids have been shown to spare muscle glycogen during exercise. However, on the basis of recent findings, the saturation of fatty acids may influence this response. The purpose of this study was to determine whether saturated or unsaturated fatty acids affected muscle glycogenolysis to varying degrees during cycle exercise. Five healthy men completed three 60-min cycle ergometer trials (EX) at approximately 70% maximal O2 uptake (VO2max). Triglyceride levels were elevated by a fat feeding (FF) composed of 90% saturated fatty acids (heavy whipping cream, 90 g) or by the infusion of Intralipid (IL; Clintec Nutrition; 45 ml/h of 20% IL, 9.0 g), which was 85% unsaturated. A control trial (CON) consisted of a light breakfast (43 g carbohydrate and 1 g fat). Heparin (2,000 U) was administered 15 min before EX in FF and IL trials, resulting in one- and threefold increases in free fatty acid (FFA) levels in IL and FF, respectively. Pre-EX muscle glycogen did not differ. The utilization of muscle glycogen during 60 min of EX was less (P < 0.05) during the FF (60.0 +/- 5.2 mmol/kg wet wt) and IL (58.6 +/- 6.2 mmol/kg wet wt) compared with CON (81.8 +/- 7.5 mmol/kg wet wt). There was no difference between FF and IL in the amount of glycogen utilized. Serum triglyceride levels were greater (P < 0.05) at preheparin in FF (1.58 +/- 0.37 mmol/l) and IL (0.98 +/- 0.13 mmol/l) compared with CON (0.47 +/- 0.14 mmol/l).(ABSTRACT TRUNCATED AT 250 WORDS)