Effect of Glycemic Load on Peptide-YY Levels in a Biracial Sample of Obese and Normal Weight Women

Black women suffer a disproportionately higher rate of obesity than their white counterparts. Reasons for this racial disparity may reflect underlying differences in the appetite suppressing peptide-YY (PYY). The PYY response to food is differentially influenced by macronutrient content but the effect of glycemic load on PYY response is unknown. This study examined whether glycemic load influences fasting and postprandial PYY levels and whether fasting and postprandial PYY levels are lower in obese black women compared to normal weight black women and to white women. Data were collected from 40 women (20 black, 20 white; 10 each normal weight vs. obese) at the University of North Carolina Clinical and Translational Research Center (CTRC). Participants completed in counterbalanced order two 4½-day weight-maintenance, mixed macronutrient high vs. low glycemic load diets followed by a test meal of identical composition. Total PYY levels were assessed before and after each test meal. Results show no differences in fasting PYY levels but significantly less postprandial PYY area under the curve (PYYAUC) in the group of obese black women compared to each other group (race × obesity interaction, P 0.27). These findings indicate that postprandial PYY secretion is not affected by glycemic load but is blunted in obese black women compared with normal weight black women and with white women; additionally, they begin to address whether blunted PYY secretion contributes uniquely to the pathogenesis of obesity in black women

Low-Glycemic Load Decreases Postprandial Insulin and Glucose and Increases Postprandial Ghrelin in White but Not Black Women

Alterations in appetite hormones favoring increased postprandial satiety have been implicated in both the glycemic control and potential weight-loss benefits of a low-glycemic diet. Racial differences exist in dietary glycemic load and appetite hormone concentrations. This study examined the impact of glycemic load on appetite hormones in 20 black women [10 normal weight, BMI = 22.8 ± 1.42 (mean ± SD); 10 obese, BMI = 35.1 ± 2.77] and 20 white women (10 normal weight, BMI = 22.9 ± 1.45; 10 obese, BMI = 34.3 ± 2.77). Each woman completed two 4.5-d weight-maintenance, mixed-macronutrient, high-glycemic vs. low-glycemic load diets that concluded with a test meal of identical composition. Blood samples collected before and serially for 3 h after each test meal were assayed for plasma ghrelin and serum insulin and glucose concentrations. Compared with the high-glycemic load meal, the low-glycemic load meal was associated with lower insulinAUC (P = 0.02), glucoseAUC (P = 0.01), and urge to eat ratings (P = 0.05) but with higher ghrelinAUC (P = 0.008). These results suggest the satiating effect of a low-glycemic load meal is not directly linked to enhanced postprandial suppression of ghrelin. Notably, these effects were significant among white but not black women, suggesting that black women may be less sensitive than white women to the glucoregulatory effects of a low-glycemic load. These findings add to a growing literature demonstrating racial differences in postprandial appetite hormone responses. If reproducible, these findings have implications for individualized diet prescription for the purposes of glucose or weight control in women

Radiological risk assessment to marine biota from exposure to NORM from a decommissioned offshore oil and gas pipeline

Scale residues can accumulate on the interior surfaces of subsea petroleum pipes and may incorporate naturally occurring radioactive materials (NORM). The persistent nature of ‘NORM scale’ may result in a radiological dose to the organisms living on or near intact pipelines. Following a scenario of in-situ decommissioning of a subsea pipeline, marine organisms occupying the exteriors or interiors of petroleum structures may have close contact with the scale or other NORM-associated contaminated substances and suffer subsequent radiological effects. This case study used radiological dose modelling software, including the ERICA Tool (v2.0), MicroShield® Pro and mathematical equations, to estimate the likely radiological doses and risks of effects from NORM-contaminated scale to marine biota from a decommissioned offshore oil and gas pipeline. Using activity concentrations of NORM (226Ra, 210Po, 210Pb, 228Ra, 228Th) from a subsea pipeline from Australia, environmental realistic exposure scenarios including radiological exposures from both an intact pipe (external only; accounting for radiation shielding by a cylindrical carbon steel pipe) and a decommissioned pipeline with corrosive breakthrough (resulting in both internal and external radiological exposure) were simulated to estimate doses to model marine organisms. Predicted dose rates for both the external only exposure (ranging from 26 μGy/h to 33 μGy/h) and a corroded pipeline (ranging from 300 μGy/h to 16,000 μGy/h) exceeded screening levels for radiological doses to environmental receptors. The study highlighted the importance of using scale-specific solubility data (i.e., Kd) values for individual NORM radionuclides for ERICA assessments. This study provides an approach for conducting marine organism dose assessments for NORM-contaminated subsea pipelines and highlights scientific gaps required to undertake risk assessments necessary to inform infrastructure decommissioning planning

Low-n-6 and low-n-6 plus high-n-3 diets for use in clinical research

Few trials have evaluated the metabolic effects and health outcomes of lowering dietary n-6 PUFA. The objectives of the present paper were (1) to report the methods employed to lower dietary n-6 PUFA, while either increasing or maintaining n-3 PUFA intake and (2) to validate our methods with 24 h recalls and erythrocyte fatty acid analyses. A total of sixty-seven subjects were randomised to either (1) an average-n-3 PUFA, low-n-6 PUFA (L6) intervention designed to lower linoleic acid (LA; ≤2·5 % of energy (en%)) and arachidonic acid (≤60 mg/d), while maintaining an average US intake of n-3 PUFA or (2) a high-n-3 PUFA, low-n-6 PUFA (H3-L6) intervention designed to lower n-6 LA, while increasing the n-3 PUFA α-linolenic acid (ALA; ≥1·5 en%) and EPA + DHA (≥1000 mg/d). Pre- and intra-intervention nutrient intakes were estimated with six 24 h dietary recalls per subject. Both groups achieved the targeted reductions in dietary LA to ≤2·5 en% (median LA 2·45 (2·1, 3·1); P<0·001). Intakes of n-3 PUFA did not change for the L6 group. Target increases in n-3 ALA (median 1·6 en%, (1·3, 2·0), P<0·001) and EPA + DHA (1482 mg, (374, 2558), P<0·001) were achieved in the H3-L6 group. Dietary changes were validated by corresponding changes in erythrocyte n-6 and n-3 fatty acid composition. Dietary LA can be lowered to ≤2·5 en%, with or without concurrent increases in dietary n-3 PUFA, in an outpatient clinical trial setting using this integrated diet method

Ad Libitum Choline Intake in Healthy Individuals Meets or Exceeds the Proposed Adequate Intake Level

Choline is an essential nutrient for humans that is used to synthesize membrane phospholipids and the neurotransmitter acetylcholine. Betaine, a metabolite of choline, functions as a methylgroup donor in the conversion of homocysteine to methionine, and is important for renal function. Accurate analysis of choline intake was previously not possible because the choline content of most foods was not known. Using new and recently published data on the concentrations of choline in common foods, we measured the choline content of diets consumed ad libitum by healthy adult volunteers housed in a clinical research center and compared these with estimates of choline intake derived from 3-d food records kept by subjects immediately before study enrollment. Mean choline intake in this subject population met or slightly exceeded the current Adequate Intake (AI) of 7 mg/(kg · d) set by the Institute of Medicine. Men and women consumed similar amounts of choline per day (8.4 and. 6.7 mg/kg, respectively; P = 0.11). Choline intakes estimated from the 3-d food records were significantly lower than this (when expressed as mg/kg, or as total mg, but not when normalized to energy intake), suggesting underreporting of food intake. Intake of betaine, which may spare choline utilization as a methylgroup donor, was 5.3 mg/(kg · d) in men and 4.7 mg/(kg · d) in women. Intake of folate, vitamin B-12, and methionine + cysteine, were similar and sufficient in all subjects. The current recommended AI for choline seems to be a good approximation of the actual intake of this nutrient

Dietary omega-6 fatty acid lowering increases bioavailability of omega-3 polyunsaturated fatty acids in human plasma lipid pools

Dietary linoleic acid (LA, 18:2n-6) lowering in rats reduces n-6 polyunsaturated fatty acid (PUFA) plasma concentrations and increases n-3 PUFA (eicosapentaenoic (EPA) and docosahexaenoic acid (DHA)) concentrations

Associations between Plasma Lipid Mediators and Chronic Daily Headache Outcomes in Patients Randomized to a Low Linoleic Acid Diet with or without Added Omega-3 Fatty Acids

A previous report showed that 12-week lowering of dietary omega-6 linoleic acid (LA) coupled with increased omega-3 polyunsaturated fatty acid (PUFA) intake (H3-L6 diet) reduced headache frequency and improved quality of life in patients with chronic daily headaches (CDHs) compared to dietary LA reduction alone (L6 diet). The trial also showed that targeted dietary manipulation alters PUFA-derived lipid mediators and endocannabinoids. However, several additional classes of lipid mediators associated with pain in preclinical models were not measured. The current secondary analysis investigated whether the clinical benefits of the H3-L6 diet were related to changes in plasma unesterified PUFA-derived lipid mediators known to be involved in nociception, including prostanoids. Lipid mediators were measured by ultra-high-pressure liquid chromatography coupled with tandem mass-spectrometry. Compared to baseline, dietary LA lowering with or without added omega-3 fatty acids did not alter unesterified n-6 PUFA-derived lipid mediators, although several species derived from LA, di-homo-gamma-linolenic acid, and arachidonic acid were positively associated with headache frequency and intensity, as well as mental health burden. Alpha-linolenic acid (ALA)-derived metabolites were also associated with increased headache frequency and intensity, although they did not change from the baseline in either dietary group. Compared to baseline, docosahexaenoic acid (DHA)-derived epoxides were more elevated in the H3-L6 group compared to the L6 group. Diet-induced elevations in plasma DHA-epoxides were associated with reduced headache frequency, better physical and mental health, and improved quality of life (p < 0.05). Prostanoids were not detected, except for PGF2-alpha, which was not associated with any outcomes. This study demonstrates that diet-induced changes in DHA-epoxides were associated with pain reduction in patients with chronic headaches, whereas n-6 PUFA and ALA metabolites were associated with nociception. Lipid mediator associations with mental health and quality of life paralleled pain management outcomes in this population. The findings point to a network of multiple diet-modifiable lipid mediator targets for pain management in individuals with CDHs

ERIS: revitalising an adaptive optics instrument for the VLT

ERIS is an instrument that will both extend and enhance the fundamental diffraction limited imaging and spectroscopy capability for the VLT. It will replace two instruments that are now being maintained beyond their operational lifetimes, combine their functionality on a single focus, provide a new wavefront sensing module that makes use of the facility Adaptive Optics System, and considerably improve their performance. The instrument will be competitive with respect to JWST in several regimes, and has outstanding potential for studies of the Galactic Center, exoplanets, and high redshift galaxies. ERIS had its final design review in 2017, and is expected to be on sky in 2020. This contribution describes the instrument concept, outlines its expected performance, and highlights where it will most excel.Comment: 12 pages, Proc SPIE 10702 "Ground-Based and Airborne Instrumentation for Astronomy VII

Dietary fatty acids improve perceived sleep quality, stress, and health in migraine: a secondary analysis of a randomized controlled trial

BackgroundMigraine is a prevalent disabling condition often associated with comorbid physical and psychological symptoms that contribute to impaired quality of life and disability. Studies suggest that increasing dietary omega-3 fatty acid is associated with headache reduction, but less is known about the effects on quality of life in migraine.MethodsAfter a 4-week run-in, 182 adults with 5–20 migraine days per month were randomized to one of the 3 arms for sixteen weeks. Dietary arms included: H3L6 (a high omega-3, low omega-6 diet), H3 (a high omega-3, an average omega-6 diet), or a control diet (average intakes of omega-3 and omega-6 fatty acids). Prespecified secondary endpoints included daily diary measures (stress perception, sleep quality, and perceived health), Patient-Reported Outcome Measurement Information System Version 1.0 ([PROMIS©) measures and the Migraine Disability Assessment (MIDAS). Analyses used linear mixed effects models to control for repeated measures.ResultsThe H3L6 diet was associated with significant improvements in stress perception [adjusted mean difference (aMD): −1.5 (95% confidence interval: −1.7 to −1.2)], sleep quality [aMD: 0.2 (95% CI:0.1–0.2)], and perceived health [aMD: 0.2 (0.2–0.3)] compared to the control. Similarly, the H3 diet was associated with significant improvements in stress perception [aMD: −0.8 (−1.1 to −0.5)], sleep quality [aMD: 0.2 (0.1, 0.3)], and perceived health [aMD: 0.3 (0.2, 0.3)] compared to the control. MIDAS scores improved substantially in the intervention groups compared with the control (H3L6 aMD: −11.8 [−25.1, 1.5] and H3 aMD: −10.7 [−24.0, 2.7]). Among the PROMIS-29 assessments, the biggest impact was on pain interference [H3L6 MD: −1.8 (−4.4, 0.7) and H3 aMD: −3.2 (−5.9, −0.5)] and pain intensity [H3L6 MD: −0.6 (−1.3, 0.1) and H3 aMD: −0.6 (−1.4, 0.1)].DiscussionThe diary measures, with their increased power, supported our hypothesis that symptoms associated with migraine attacks could be responsive to specific dietary fatty acid manipulations. Changes in the PROMIS© measures reflected improvements in non-headache pain as well as physical and psychological function, largely in the expected directions. These findings suggest that increasing omega-3 with or without decreasing omega-6 in the diet may represent a reasonable adjunctive approach to reducing symptoms associated with migraine attacks. Trial Registration: ClinicalTrials.gov NCT02012790

Targeted alterations in dietary n-3 and n-6 fatty acids improve life functioning and reduce psychological distress among patients with chronic headache: a secondary analysis of a randomized trial

Omega-3 and omega-6 fatty acids are precursors of bioactive lipid mediators posited to modulate both physical pain and psychological distress. In a randomized trial of 67 subjects with severe headaches, we recently demonstrated that targeted dietary manipulation-increasing omega-3 fatty acids with concurrent reduction in omega-6 linoleic acid (the H3-L6 intervention)-produced major reductions in headache compared with an omega-6 lowering (L6) intervention. Because chronic pain is often accompanied by psychological distress and impaired health-related quality of life (HRQOL), we used data from this trial to examine whether the H3-L6 intervention favorably impacted these domains. Additionally, we examined the effect of the interventions on the number of cases with substantial physical or mental impairments as defined by cutoff values in the Brief Symptom Inventory (BSI-18), Medical Outcomes Study Short Forms 12 (SF-12), Headache Impact Test (HIT-6), and the number of headache days per month. In the intention-to-treat analysis, participants in the H3-L6 group experienced statistically significant reductions in psychological distress (BSI-18 mean difference: -6.56; 95% confidence interval [CI]: -11.43 to -1.69) and improvements in SF-12 mental (mean difference: 6.01; 95% CI: 0.57 to 11.45) and physical (mean difference: 6.65; 95% CI: 2.14 to 11.16) health summary scores. At 12 weeks, the proportion of subjects experiencing substantial impairment according to cutoff values in the BSI-18, SF-12 physical, HIT-6, and headache days per month was significantly lower in the H3-L6 group. Dietary manipulation of n-3 and n-6 fatty acids, previously shown to produce major improvements in headache, was found to also reduce psychological distress and improve HRQOL and function