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Background The onset of menopause increases the risk of metabolic syndrome (MetS). Adiponectin is an adipokine associated with insulin sensitivity that is lower in people with MetS. Supplementing diets with linoleic acid (LA)-rich oil increased adiponectin concentrations and improved glucose control in women with type 2 diabetes. The effect of LA on adipokines, especially total and the bioactive form of adiponectin, high-molecular-weight (HMW) adiponectin, in women with MetS is unknown. Objectives The aim of this study was to explore the effect of supplementation of the diet with an oil rich in LA on adipokines in women with MetS. The effect of the LA-rich oil (LA-oil) on oxylipins, key metabolites that may influence inflammation and metabolism, was also explored. Methods In this open-label single-arm pilot study, 18 postmenopausal nondiabetic women with MetS enrolled in a 2-phase study were instructed to consume LA-rich vegetable oil (10 mL/d) as part of their habitual diets. Women consumed an oleic acid–rich oil (OA-oil) for 4 wk followed by an LA-oil for 16 wk. Fasting concentrations of adipokines, fatty acids, oxylipins, and markers of glycemia and inflammation were measured. Results After 4 wk of OA-oil consumption, fasting glucose and total adiponectin concentrations decreased whereas fasting C-reactive protein increased. After 16 wk of LA-oil supplementation total and HMW adiponectin and plasma oxylipins increased. Markers of inflammation and glycemia were unchanged after LA-oil consumption. Conclusions Supplementation with LA-oil increased total and HMW adiponectin concentrations and altered plasma oxylipin profiles. Larger studies are needed to elucidate the links between these changes and MetS. This trial was registered at clinicaltrials.gov as NCT02063165., The essential fatty acid, linoleate, affects glucose homeostasis. This article evaluates the addition of a small amount of linoleate-rich oil to increase the insulin-sensitizing adipokine, adiponectin.

OBJECTIVE The objective of this study was to evaluate the relationship between blood levels of adiponectin and leptin with lean body and trunk adipose mass in women with and without type 2 diabetes mellitus (T2DM). METHODS This cross-sectional study analyzed baseline data from five previous clinical studies involving postmenopausal women (n = 95). Body composition was assessed by dual-energy x-ray absorptiometry, and appendicular lean mass was calculated based on body mass index (ALMBMI). Adipokines and cytokines were measured by enzyme-linked immunosorbent assay. Linear mixed-effect models with a random study effect were used to investigate the relationship between predictors (eg, adiponectin, leptin), outcomes (eg, ALMBMI, trunk adipose mass), and co-variables (T2DM status, age, interleukin-6, and C-reactive protein). RESULTS Postmenopausal women with T2DM had lower ALMBMI than those without T2DM. There was a positive association between blood adiponectin and ALMBMI in postmenopausal women without T2DM, but no association in those with T2DM. Blood leptin was negatively associated with ALMBMI for women regardless of T2DM diagnosis. Blood adiponectin was negatively associated, whereas blood leptin was positively associated with trunk adipose mass for the entire cohort. CONCLUSIONS T2DM status moderated the relationship between blood adiponectin and ALMBMI, where blood adiponectin was positively associated with ALMBMI in postmenopausal women without T2DM, but not those with T2DM. Dysregulated metabolism in T2DM may contribute to lower muscle mass in women with T2DM, but future research is required to elucidate this mechanistic link. The negative association between blood leptin and ALMBMI was a novel finding. Future studies will need to more clearly define the relationship between these variables.

OBJECTIVES: Investigate the impact of LA-rich oil (LO) on measures of energy metabolism in a mouse model of metabolic syndrome. METHODS: Ob/ob mice were fed diets containing 6% wt LO, oleic acid-rich (OO) or palmitic acid-rich (PO) for 6 weeks. Body composition was measured at weeks 0 and 6. Plasma was collected at necropsy to measure adiponectin, insulin, and glucose. Grip strength and muscle fiber cross-sectional area (CSA) of total and succinate dehydrogenase-positive (SDH) fibers were quantified in quadriceps. In white adipose tissue, mRNA was measured for markers of beiging and lipid storage. RESULTS: Mice fed OO and LO diets (vs. PO diet) had reduced % adipose. There was no difference of oils on plasma adiponectin or HOMA-IR. Decreases in grip strength were observed in PO-fed mice, while OO and LO-fed mice maintained strength throughout the study. LO-fed mice exhibited smaller skeletal muscle fibers compared to the PO-fed mice. OO-fed mice had fewer intermediate-sized SDH fibers. In white adipose tissue, LO-fed mice exhibited increased PGC1a, and decreased PPARy and LPL mRNA compared to PO-fed mice. CONCLUSIONS: These findings suggest that dietary LA may alter lipid mobilization and metabolism in obese mice. These preliminary results showcase the importance of future investigation of lipid storage and mitochondrial phospholipid biology in skeletal muscle. FUNDING SOURCES: Funding was provided by NIH R21CA185140, Ohio Agriculture Research and Development Center and the Carol S. Kennedy Professorship. DBS received support from the AOCS Thomas H. Smouse Memorial Fellowship.

OBJECTIVES: Higher blood levels of the essential fatty acid, linoleic acid (LA), are associated with a decreased risk of type 2 diabetes. However, many dietary oils once high in LA are now low in LA and high in oleic acid (OA). We have previously shown in healthy adults that supplementation with a high LA oil can increase plasma LA levels and decrease plasma OA levels. The current study examines the relationship of habitual levels of plasma LA and OA with markers of body composition, inflammation and glycemia in healthy adults. METHODS: Data from baseline visit were analyzed from 127 health adults participating in a 2-week study of the effect of dietary oils on blood fatty acid profiles. Plasma fatty acid composition was measured by gas chromatography. Insulin, glucose, total and high molecular weight (HMW) adiponectin, tumor necrosis factor receptor 2 (TNF-r2) and lipopolysaccharide binding protein (LBP) were measured in fasting plasma samples. Body mass index (BMI) and sagittal diameter (SAD) were measured as markers of body composition. Grip strength was measured as a marker of muscle strength and gait speed was measured as a marker of muscle function. Linear regression was used to assess the association of study measurements to plasma LA or OA. Results were adjusted for sex, age, physical activity and BMI. RESULTS: Plasma LA was negatively associated with both BMI and SAD while plasma OA was positively associated with both insulin and grip strength. In males, but not females, higher plasma LA was associated with higher HMW adiponectin while higher plasma OA was positively associated with fasting glucose. Neither plasma LA or OA were associated with total adiponectin, TNF-r2, LBP or gait speed. CONCLUSIONS: Higher levels of plasma LA predicted for lower measures of adiposity in both males and females and higher HMW adiponectin levels in males. Higher levels of plasm OA predicted for increased grip strength and higher glycemia, particularly in men. To our knowledge no randomized controlled trial has compared LA or OA supplementation on body composition, glycemia, and adiponectin in healthy men and women. FUNDING SOURCES: Funding was provided by the Carol S. Kennedy Professorship and the Ohio Agriculture Research and Development Center.

Dietary fat quality, especially the intake of specific types of fatty acids, impacts the risk of many chronic diseases, including cardiovascular diseases, certain cancers and type 2 diabetes (T2DM). A recent pooled analysis involving 20 studies from around the world revealed that higher linoleic acid (18:2n-6 LA) biomarker is associated with dose-dependent decreases in the incidence of T2DM. This latest study corroborates earlier cross-sectional studies and intervention trials showing that biomarkers of LA intake are associated with reduced risk of T2DM and better glycemic control and/or insulin sensitivity. This review highlights key clinical trials that have evaluated the role of LA in glycemia and the related condition, insulin sensitivity.