Lipoprotein particle distribution and size, insulin resistance, and metabolic syndrome in Alaska Eskimos: the GOCADAN study.

BACKGROUND: Metabolic syndrome (MS) is associated with dyslipidemia, and insulin resistance (IR) may be a main determinant of this dyslipidemia. OBJECTIVE: To determine how lipoprotein particle concentration and size are related to MS and IR in a population-based sample of Alaska Eskimos. DESIGN: Participants underwent a physical exam, personal interview, collection of biological specimens, and diagnostic tests. SETTING: This study was conducted in the Norton Sound region of Alaska. PARTICIPANTS: One thousand one hundred fifty-eight Inupiat Eskimo adults (women=653, men=505). MAIN OUTCOME MEASURES: Lipoprotein particle profile was evaluated by nuclear magnetic resonance (NMR) and related to presence of MS and level of IR. RESULTS: Participants with MS had (a) significantly higher concentrations of all VLDLs and a larger VLDL size (women, p=0.007; men, p=0.0001); (b) higher concentrations of small LDL (women, p<0.0001; men, p=0.09) and lower concentrations of large LDL (women, p<0.0001), leading to a smaller overall LDL size (women, p<0.0001; men, p<0.05); (c) significantly lower concentrations of large HDL (both genders, p<0.0001) and an increase in intermediate (women, p<0.05) and small HDL (women, p<0.0001; men, p<0.004). Lipoprotein profile with increasing HOMA-IR resembled that of individuals with MS. CONCLUSIONS: In this population MS is characterized by lipoprotein distribution and size abnormalities independent of obesity, age, and other cardiovascular risk factors, including lipid concentration. IR seems the major determinant.