title: Sex-dependent association between erythrocyte n-3 PUFA and type 2 diabetes in older overweight people.
abstract: The association between n-3 PUFA intake and type 2 diabetes (T2D) is unclear, and studies relating objective biomarkers of n-3 PUFA consumption to diabetic status remain limited. The aim of this study was to determine whether erythrocyte n-3 PUFA levels (n-3 index; n-3I) are associated with T2D in a cohort of older adults (n 608). To achieve this, the n-3I (erythrocyte %EPA+%DHA) was determined by GC and associated with fasting blood glucose; HbA1c; and plasma insulin. Insulin resistance (IR) was assessed using the homeostatic model assessment of insulin resistance (HOMA--IR). OR for T2D were calculated for each quartile of n-3I. In all, eighty-two type 2 diabetic (46·3 % female; 76·7 (sd 5·9) years) and 466 non-diabetic (57·9 % female; 77·8 (sd 7·1) years) individuals were included in the analysis. In overweight/obese (BMI≥27 kg/m2), the prevalence of T2D decreased across ascending n-3I quartiles: 1·0 (reference), 0·82 (95 % CI 0·31, 2·18), 0·56 (95 % CI 0·21, 1·52) and 0·22 (95 % CI 0·06, 0·82) (P trend=0·015). A similar but non-significant trend was seen in overweight men. After adjusting for BMI, no associations were found between n-3I and fasting blood glucose, HbA1c, insulin or HOMA-IR. In conclusion, higher erythrocyte n-3 PUFA status may be protective against the development of T2D in overweight women. Further research is warranted to determine whether dietary interventions that improve n-3 PUFA status can improve measures of IR, and to further elucidate sex-dependent differences.
authors.affiliation: 1School of Health Sciences,University of Newcastle,NSW 2308,Australia.
authors.forename: Kylie A
authors.initials: KA
authors.lastname: Abbott
authors.affiliation: 2School of Medicine & Public Health,University of Newcastle,NSW 2308,Australia.
authors.forename: Martin
authors.initials: M
authors.lastname: Veysey
authors.affiliation: 3School of Environmental & Life Sciences,University of Newcastle,NSW 2308,Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: Lucock
authors.affiliation: 2School of Medicine & Public Health,University of Newcastle,NSW 2308,Australia.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Niblett
authors.affiliation: 2School of Medicine & Public Health,University of Newcastle,NSW 2308,Australia.
authors.forename: Katrina
authors.initials: K
authors.lastname: King
authors.affiliation: 1School of Health Sciences,University of Newcastle,NSW 2308,Australia.
authors.forename: Tracy
authors.initials: T
authors.lastname: Burrows
authors.affiliation: 4Nutraceuticals Research Group,School of Biomedical Sciences & Pharmacy,University of Newcastle,NSW 2308,Australia.
authors.forename: Manohar L
authors.initials: ML
authors.lastname: Garg
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001315:Australia / Q000453:epidemiology; D001786:Blood Glucose / Q000032:analysis; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000453:epidemiology; D004032:Diet; D004912:Erythrocytes / Q000737:chemistry*; D015525:Fatty Acids, Omega-3 / Q000097:blood*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D009765:Obesity / Q000097:blood; D050177:Overweight / Q000097:blood*; D012737:Sex Factors
chemical_list: D001786:Blood Glucose; D015525:Fatty Acids, Omega-3; D006442:Glycated Hemoglobin; D007328:Insulin
keywords:    n-3 Index; HOMA-IR homeostatic model assessment of insulin resistance; IR insulin resistance; Insulin resistance; Obesity; PUFA; RHLS Retirement Health and Lifestyle Study; T2D type 2 diabetes; Type 2 diabetes; n-3I 
                    n-3 index