The determination of FAME by GC is among the most commonplace analyses in lipid research. Quantification of FAME by GC with FID has been effectively performed for some time, whereas detection with MS has been used chiefly for qualitative analysis of FAME. Nonetheless, the sensitivity and selectivity of MS methods advocate a quantitative role for GC-MS in FAME analysis-an approach that would be particularly advantageous for FAME determination in complex biological samples, where spectrometric confirmation of analytes is advisable. To assess the utility of GC-MS methods for FAME quantification, a comparative study of GC-FID and GC-MS methods has been conducted. FAME in prepared solutions as well as a biological standard reference material were analyzed by GC-FID and GC-MS methods using both ion trap and quadrupole MS systems. Quantification by MS, based on total ion counts and processing of selected ions, was investigated for FAME ionized by electron impact. Instrument precision, detection limits, calibration behavior, and response factors were investigated for each approach, and quantitative results obtained by each technique were compared. Although there were a number of characteristic differences between the MS methods and FID with respect to FAME analysis, the quantitative performance of GC-MS compared satisfactorily with that of GC-FID. The capacity to combine spectrometric examination and quantitative determination advances GC-MS as a powerful alternative to GC-FID for FAME analysis.

Objectives. To test the hypothesis that the unusually low prevalences of insulin resistance (IR), metabolic syndrome (MS) and diabetes (DM) in Alaskan Eskimos, compared to American Indians, is related to the traditional Eskimo diet, high in C20-C22 ω-3 fatty acids (FAs). To determine if the relatively low blood pressures, low serum triglycerides and high HDL cholesterol levels in Eskimos result from high ω-3 FA consumption. Study design. Cross-sectional study. Methods. We measured plasma FA concentrations in 447 Norton Sound Eskimos (35-74 years of age) and screened for DM, CHD and associated risk factors. A dietary assessment (24-hr recall) was obtained for comparison the day before the blood sampling.Results. Plasma ω-3 FA concentrations were highly correlated with dietary ω-3 FAs and HDL levels and inversely correlated with plasma levels of insulin, 2-h insulin (OGTT), HOMI-IR, 2-h glucose (OGTT), triglyceride levels and diastolic blood pressure. Conclusions. High consumption of ω-3 FAs positively affects components of the MS, insulin sensitivity and glucose tolerance. This finding suggests that high consumption of C20-C22 ω-3 FAs protects against the development of the MS and glucose intolerance. (Int J Circumpolar Health 2005; 64(4):396-408.)

Dramatic improvements of risk factors for DM and CVD were achieved in the intervention by primarily stressing the need for changes in the consumption of specific fats. The results suggest that fat consumption is an important risk factor for DM.

No abstract

No abstract

BackgroundAlthough saturated fatty acids (FAs) have been linked to cardiovascular mortality, it is not clear whether this outcome is attributable solely to their effects on low-density lipoprotein cholesterol (LDL-C) or whether other risk factors are also associated with FAs. The Western Alaskan Native population, with its rapidly changing lifestyles, shift in diet from unsaturated to saturated fatty acids and dramatic increase in cardiovascular disease (CVD), presents an opportunity to elucidate any associations between specific FAs and known CVD risk factors.ObjectiveWe tested the hypothesis that the specific FAs previously identified as related to CVD mortality are also associated with individual CVD risk factors.MethodsIn this community-based, cross-sectional study, relative proportions of FAs in plasma and red blood cell membranes were compared with CVD risk factors in a sample of 758 men and women aged ≥35 years. Linear regression analyses were used to analyze relations between specific FAs and CVD risk factors (LDL-C, high-density lipoprotein cholesterol, triglycerides, C-reactive protein, systolic blood pressure, diastolic blood pressure, heart rate, body mass index, fasting glucose and fasting insulin, 2-hour glucose and 2-hour insulin).ResultsThe specific saturated FAs previously identified as related to CVD mortality, the palmitic and myristic acids, were adversely associated with most CVD risk factors, whereas unsaturated linoleic acid (18:2n-6) and the marine n-3 FAs were not associated or were beneficially associated with CVD risk factors.ConclusionsThe results suggest that CVD risk factors are more extensively affected by individual FAs than hitherto recognized, and that risk for CVD, MI and stroke can be reduced by reducing the intake of palmitate, myristic acid and simple carbohydrates and improved by greater intake of linoleic acid and marine n-3 FAs.

A number of techniques are available for the extraction of lipids from a variety of tissues; however, conventional methods are characteristically labor intensive, typically involve large volumes of toxic solvents, and usually require at least 1 g of tissue. With the availability of accelerated solvent extraction (ASE) technology, the opportunity exists to modify classical lipid extraction techniques such that automated highpressure, high-temperature extractions may be performed with the use of far smaller volumes of costly and harmful solvents. Moreover, the high extraction efficiency attainable by ASE suggests that significantly less tissue would be required than is routinely used. This paper describes the adaptation of previously developed lipid extraction solvent systems for use with ASE toward the purpose of extracting total lipids from 100 mg of fish tissue. The efficacy of three solvent systems for lipid extraction from representative fish tissues, including a standard reference material, was explored using gravimetry and FA analysis by GC. A TG was used as a surrogate to monitor overall method performance. The findings herein demonstrate that microscale ASE represents an effective and efficient alternative to traditional lipid extraction techniques based on quantity and composition of extracted lipid, surrogate recovery, and precision.

Blubber fatty acid (FA) profiles of young Steller sea lions Eumetopias jubatus (< 24 mo old; n = 477) were investigated to determine whether regional, seasonal, age-class and sex differences occur in the diets of these demographic groups. Blubber FA profiles of spring (March to May) pups differed significantly by region, probably reflecting regional differences in the diet of adult females, who provide their pups with milk. While there were statistically significant seasonal and age-class differences in both Prince William Sound (PWS) and SE Alaska (SEA), differences in FA profiles between sexes were only evident in the blubber of yearlings from PWS. Within SEA, blubber FA profiles of summer pups differed significantly from all other seasonal/age-class groups in that region. This is consistent with movements of female-pup pairs from rookeries to haul-outs and hence differences in female foraging. In SEA, seasonal differences in blubber FA composition were evident and similar between yearlings and pups. In contrast, there was a gradual change in the FA profile of pup blubber from summer to spring in PWS, which did not follow the same seasonal pattern of yearling profiles. These differences in FA profiles suggest either differences in the timing of weaning between the 2 areas or shifts in the diets of lactating females, or both. KEY WORDS: Fatty acids · Dietary intake · Eumetopias jubatus · Independent foragingResale or republication not permitted without written consent of the publisher