| 61. |
- Imamura, Fumiaki, et al.
(författare)
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Fatty acid biomarkers of dairy fat consumption and incidence of type 2 diabetes : A pooled analysis of prospective cohort studies
- 2018
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Ingår i: PLoS Medicine. - : Public Library of Science (PLoS). - 1549-1277 .- 1549-1676. ; 15:10
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Tidskriftsartikel (refereegranskat)abstract
- Background We aimed to investigate prospective associations of circulating or adipose tissue odd-chain fatty acids 15: 0 and 17: 0 and trans-palmitoleic acid, t16:1n-7, as potential biomarkers of dairy fat intake, with incident type 2 diabetes (T2D). Methods and findings Sixteen prospective cohorts from 12 countries (7 from the United States, 7 from Europe, 1 from Australia, 1 from Taiwan) performed new harmonised individual-level analysis for the prospective associations according to a standardised plan. In total, 63,682 participants with a broad range of baseline ages and BMIs and 15,180 incident cases of T2D over the average of 9 years of follow-up were evaluated. Study-specific results were pooled using inverse-variance-weighted meta-analysis. Prespecified interactions by age, sex, BMI, and race/ethnicity were explored in each cohort and were meta-analysed. Potential heterogeneity by cohort-specific characteristics (regions, lipid compartments used for fatty acid assays) was assessed with metaregression. After adjustment for potential confounders, including measures of adiposity (BMI, waist circumference) and lipogenesis (levels of palmitate, tri-glycerides), higher levels of 15:0, 17:0, and t16:1n-7 were associated with lower incidence of T2D. In the most adjusted model, the hazard ratio (95% CI) for incident T2D per cohort-specific 10th to 90th percentile range of 15:0 was 0.80 (0.73-0.87); of 17:0, 0.65 (0.59-0.72); of t16:1n7, 0.82 (0.70-0.96); and of their sum, 0.71 (0.63-0.79). In exploratory analyses, similar associations for 15:0, 17:0, and the sum of all three fatty acids were present in both genders but stronger in women than in men ((pinteraction) < 0.001). Whereas studying associations with biomarkers has several advantages, as limitations, the biomarkers do not distinguish between different food sources of dairy fat (e.g., cheese, yogurt, milk), and residual confounding by unmeasured or imprecisely measured confounders may exist. Conclusions In a large meta-analysis that pooled the findings from 16 prospective cohort studies, higher levels of 15:0, 17:0, and t16:1n-7 were associated with a lower risk of T2D.
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| 62. |
- Imamura, Fumiaki, et al.
(författare)
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Fatty acids in the de novo lipogenesis pathway and incidence of type 2 diabetes : A pooled analysis of prospective cohort studies
- 2020
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Ingår i: PLoS Medicine. - : Public Library of Science (PLoS). - 1549-1277 .- 1549-1676. ; 17:6
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundDe novo lipogenesis (DNL) is the primary metabolic pathway synthesizing fatty acids from carbohydrates, protein, or alcohol. Our aim was to examine associations of in vivo levels of selected fatty acids (16:0, 16:1n7, 18:0, 18:1n9) in DNL with incidence of type 2 diabetes (T2D).Methods and findingsSeventeen cohorts from 12 countries (7 from Europe, 7 from the United States, 1 from Australia, 1 from Taiwan; baseline years = 1970–1973 to 2006–2010) conducted harmonized individual-level analyses of associations of DNL-related fatty acids with incident T2D. In total, we evaluated 65,225 participants (mean ages = 52.3–75.5 years; % women = 20.4%–62.3% in 12 cohorts recruiting both sexes) and 15,383 incident cases of T2D over the 9-year follow-up on average. Cohort-specific association of each of 16:0, 16:1n7, 18:0, and 18:1n9 with incident T2D was estimated, adjusted for demographic factors, socioeconomic characteristics, alcohol, smoking, physical activity, dyslipidemia, hypertension, menopausal status, and adiposity. Cohort-specific associations were meta-analyzed with an inverse-variance-weighted approach. Each of the 4 fatty acids positively related to incident T2D. Relative risks (RRs) per cohort-specific range between midpoints of the top and bottom quintiles of fatty acid concentrations were 1.53 (1.41–1.66; p < 0.001) for 16:0, 1.40 (1.33–1.48; p < 0.001) for 16:1n-7, 1.14 (1.05–1.22; p = 0.001) for 18:0, and 1.16 (1.07–1.25; p < 0.001) for 18:1n9. Heterogeneity was seen across cohorts (I2 = 51.1%–73.1% for each fatty acid) but not explained by lipid fractions and global geographical regions. Further adjusted for triglycerides (and 16:0 when appropriate) to evaluate associations independent of overall DNL, the associations remained significant for 16:0, 16:1n7, and 18:0 but were attenuated for 18:1n9 (RR = 1.03, 95% confidence interval (CI) = 0.94–1.13). These findings had limitations in potential reverse causation and residual confounding by imprecisely measured or unmeasured factors.ConclusionsConcentrations of fatty acids in the DNL were positively associated with T2D incidence. Our findings support further work to investigate a possible role of DNL and individual fatty acids in the development of T2D.
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| 63. |
- Lai, Heidi T. M., et al.
(författare)
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Trans Fatty Acid Biomarkers and Incident Type 2 Diabetes : Pooled Analysis of 12 Prospective Cohort Studies in the Fatty Acids and Outcomes Research Consortium (FORCE)
- 2022
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Ingår i: Diabetes Care. - : American Diabetes Association. - 0149-5992 .- 1935-5548. ; 45:4, s. 854-863
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Trans fatty acids (TFAs) have harmful biologic effects that could increase the risk of type 2 diabetes (T2D), but evidence remains uncertain. We aimed to investigate the prospective associations of TFA biomarkers and T2D by conducting an individual participant-level pooled analysis.RESEARCH DESIGN AND METHODS: We included data from an international consortium of 12 prospective cohorts and nested case-control studies from six nations. TFA biomarkers were measured in blood collected between 1990 and 2008 from 25,126 participants aged >= 18 years without prevalent diabetes. Each cohort conducted de novo harmonized analyses using a prespecified protocol, and findings were pooled using inverse-variance weighted meta-analysis. Heterogeneity was explored by prespecified between-study and within-study characteristics.RESULTS: During a mean follow-up of 13.5 years, 2,843 cases of incident T2D were identified. In multivariable-adjusted pooled analyses, no significant associations with T2D were identified for trans/trans-18:2, relative risk (RR) 1.09 (95% CI 0.94-1.25); cis/trans-18:2, 0.89 (0.73-1.07); and trans/cis-18:2, 0.87 (0.73-1.03). Trans-16:1n-9, total trans-18:1, and total trans-18:2 were inversely associated with T2D (RR 0.81 [95% CI 0.67-0.99], 0.86 [0.75-0.99], and 0.84 [0.74-0.96], respectively). Findings were not significantly different according to prespecified sources of potential heterogeneity (each P >= 0.1).CONCLUSIONS: Circulating individual trans-18:2 TFA biomarkers were not associated with risk of T2D, while trans-16:1n-9, total trans-18:1, and total trans-18:2 were inversely associated. Findings may reflect the influence of mixed TFA sources (industrial vs. natural ruminant), a general decline in TFA exposure due to policy changes during this period, or the relatively limited range of TFA levels.
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| 64. |
- Sun, Qi, et al.
(författare)
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Healthy Lifestyle and Leukocyte Telomere Length in US Women
- 2012
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:5
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Tidskriftsartikel (refereegranskat)abstract
- Context: Whether a healthy lifestyle may be associated with longer telomere length is largely unknown. Objectives: To examine healthy lifestyle practices, which are primary prevention measures against major age-related chronic diseases, in relation to leukocyte telomere length. Design and Setting: Cross-sectional analysis in the Nurses' Health Study (NHS). Participants: The population consisted of 5,862 women who participated in multiple prospective case-control studies within the NHS cohort. Z scores of leukocyte telomere length were derived within each case-control study. Based on prior work, we defined low-risk or healthy categories for five major modifiable factors assessed in 1988 or 1990: non-current smoking, maintaining a healthy body weight (body mass index in 18.5-24.9 kg/m(2)), engaging in regular moderate or vigorous physical activities (>= 150 minutes/week), drinking alcohol in moderation (1 drink/week to,2 drinks/day), and eating a healthy diet (Alternate Healthy Eating Index score in top 50%). We calculated difference (%) of the z scores contrasting low-risk groups with reference groups to evaluate the association of interest. Results: Although none of the individual low-risk factors was significantly associated with larger leukocyte telomere length z scores, we observed a significant, positive relationship between the number of low-risk factors and the z scores. In comparison with women who had zero low-risk factors (1.9% of the total population) and were, therefore, considered the least healthy group, the leukocyte telomere length z scores were 16.4%, 22.1%, 28.7%, 22.6%, and 31.2% (P for trend = 0.015) higher for women who had 1 to 5 low-risk factors, respectively. Conclusions: Adherence to a healthy lifestyle, defined by major modifiable risk factors, was associated with longer telomere length in leukocytes.
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| 65. |
- Todd, Jennifer N., et al.
(författare)
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Variation in Glucose Homeostasis Traits Associated With P2RX7 Polymorphisms in Mice and Humans
- 2015
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 100:5, s. 688-696
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Tidskriftsartikel (refereegranskat)abstract
- Context: Extracellular nucleotide receptors are expressed in pancreatic B-cells. Purinergic signaling via these receptors may regulate pancreatic B-cell function. Objective: We hypothesized that purinergic signaling might influence glucose regulation and sought evidence in human studies of glycemic variation and a mouse model of purinergic signaling dysfunction. Design: In humans, we mined genome-wide meta-analysis data sets to examine purinergic signaling genes for association with glycemic traits and type 2 diabetes. We performed additional testing in two genomic regions (P2RX4/P2RX7 and P2RY1) in a cohort from the Prevalence, Prediction, and Prevention of Diabetes in Botnia (n = 3504), which includes more refined measures of glucose homeostasis. In mice, we generated a congenic model of purinergic signaling dysfunction by crossing the naturally hypomorphic C57BL6 P2rx7 allele onto the 129SvJ background. Results: Variants in five genes were associated with glycemic traits and in three genes with diabetes risk. In the Prevalence, Prediction, and Prevention of Diabetes in Botnia study, the minor allele in the missense functional variant rs1718119 (A348T) in P2RX7 was associated with increased insulin sensitivity and secretion, consistent with its known effect on increased pore function. Both male and female P2x7-C57 mice demonstrated impaired glucose tolerance compared with matched P2x7-129 mice. Insulin tolerance testing showed that P2x7-C57 mice were also less responsive to insulin than P2x7-129 mice. Conclusions: We show association of the purinergic signaling pathway in general and hypofunctioning P2X7 variants in particular with impaired glucose homeostasis in both mice and humans.
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| 66. |
- Wang, Conan, et al.
(författare)
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Combined X-ray and NMR analysis of the stability of the cyclotide cystine knot fold that underpins its insecticidal activity and potential use as a drug scaffold
- 2009
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 284:16, s. 10672-10683
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Tidskriftsartikel (refereegranskat)abstract
- Cyclotides are a family of plant defense proteins that are highly resistant to adverse chemical, thermal, and enzymatic treatment. Here, we present the first crystal structure of a cyclotide, varv F, from the European field pansy, Viola arvensis, determined at a resolution of 1.8 angstrom. The solution state NMR structure was also determined and, combined with measurements of biophysical parameters for several cyclotides, provided an insight into the structural features that account for the remarkable stability of the cyclotide family. The x-ray data confirm the cystine knot topology and the circular backbone, and delineate a conserved network of hydrogen bonds that contribute to the stability of the cyclotide fold. The structural role of a highly conserved Glu residue that has been shown to regulate cyclotide function was also determined, verifying its involvement in a stabilizing hydrogen bond network. We also demonstrate that varv F binds to dodecylphosphocholine micelles, defining the binding orientation and showing that its structure remains unchanged upon binding, further demonstrating that the cyclotide fold is rigid. This study provides a biological insight into the mechanism by which cyclotides maintain their native activity in the unfavorable environment of predator insect guts. It also provides a structural basis for explaining how a cluster of residues important for bioactivity may be involved in self-association interactions in membranes. As well as being important for their bioactivity, the structural rigidity of cyclotides makes them very suitable as a stable template for peptide-based drug design.
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