Determinants of plasma levels of proglucagon and the metabolic impact of glucagon receptor signalling: a UK Biobank study.

AIMS/HYPOTHESES: Glucagon and glucagon-like peptide-1 (GLP-1) are derived from the same precursor; proglucagon, and dual agonists of their receptors are currently being explored for the treatment of obesity and metabolic dysfunction-associated steatotic liver disease (MASLD). Elevated levels of endogenous glucagon (hyperglucagonaemia) have been linked with hyperglycaemia in individuals with type 2 diabetes but are also observed in individuals with obesity and MASLD. GLP-1 levels have been reported to be largely unaffected or even reduced in similar conditions. We investigated potential determinants of plasma proglucagon and associations of glucagon receptor signalling with metabolic diseases based on data from the UK Biobank. METHODS: We used exome sequencing data from the UK Biobank for ~410,000 white participants to identify glucagon receptor variants and grouped them based on their known or predicted signalling. Data on plasma levels of proglucagon estimated using Olink technology were available for a subset of the cohort (~40,000). We determined associations of glucagon receptor variants and proglucagon with BMI, type 2 diabetes and liver fat (quantified by liver MRI) and performed survival analyses to investigate if elevated proglucagon predicts type 2 diabetes development. RESULTS: Obesity, MASLD and type 2 diabetes were associated with elevated plasma levels of proglucagon independently of each other. Baseline proglucagon levels were associated with the risk of type 2 diabetes development over a 14 year follow-up period (HR 1.13; 95% CI 1.09, 1.17; n=1562; p=1.3×10-12). This association was of the same magnitude across strata of BMI. Carriers of glucagon receptor variants with reduced cAMP signalling had elevated levels of proglucagon (ß 0.847; 95% CI 0.04, 1.66; n=17; p=0.04), and carriers of variants with a predicted frameshift mutation had higher levels of liver fat compared with the wild-type reference group (ß 0.504; 95% CI 0.03, 0.98; n=11; p=0.04). CONCLUSIONS/INTERPRETATION: Our findings support the suggestion that glucagon receptor signalling is involved in MASLD, that plasma levels of proglucagon are linked to the risk of type 2 diabetes development, and that proglucagon levels are influenced by genetic variation in the glucagon receptor, obesity, type 2 diabetes and MASLD. Determining the molecular signalling pathways downstream of glucagon receptor activation may guide the development of biased GLP-1/glucagon co-agonist with improved metabolic benefits. DATA AVAILABILITY: All coding is available through https://github.com/nicwin98/UK-Biobank-GCG.

Circulating sphingolipids and subclinical brain pathology: the cardiovascular health study.

Background: Sphingolipids are implicated in neurodegeneration and neuroinflammation. We assessed the potential role of circulating ceramides and sphingomyelins in subclinical brain pathology by investigating their association with brain magnetic resonance imaging (MRI) measures and circulating biomarkers of brain injury, neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) in the Cardiovascular Health Study (CHS), a large and intensively phenotyped cohort of older adults. Methods: Brain MRI was offered twice to CHS participants with a mean of 5 years between scans, and results were available from both time points in 2,116 participants (mean age 76 years; 40% male; and 25% APOE ε4 allele carriers). We measured 8 ceramide and sphingomyelin species in plasma samples and examined the associations with several MRI, including worsening grades of white matter hyperintensities and ventricular size, number of brain infarcts, and measures of brain atrophy in a subset with quantitative measures. We also investigated the sphingolipid associations with serum NfL and GFAP. Results: In the fully adjusted model, higher plasma levels of ceramides and sphingomyelins with a long (16-carbon) saturated fatty acid were associated with higher blood levels of NfL [ß = 0.05, false-discovery rate corrected P (PFDR) = 0.004 and ß = 0.06, PFDR = < 0.001, respectively]. In contrast, sphingomyelins with very long (20- and 22-carbon) saturated fatty acids tended to have an inverse association with levels of circulating NfL. In secondary analyses, we found an interaction between ceramide d18:1/20:0 and sex (P for interaction = <0.001), such that ceramide d18:1/20:0 associated with higher odds for infarcts in women [OR = 1.26 (95%CI: 1.07, 1.49), PFDR = 0.03]. We did not observe any associations with GFAP blood levels, white matter grade, ventricular grade, mean bilateral hippocampal volume, or total brain volume. Conclusion: Overall, our comprehensive investigation supports the evidence that ceramides and sphingomyelins are associated with increased aging brain pathology and that the direction of association depends on the fatty acid attached to the sphingosine backbone.

Association of Tumor Necrosis Factor-α Inhibitors with Incident Dementia: Analysis Based on Population-Based Cohort Studies.

BACKGROUND AND OBJECTIVE: Preliminary evidence suggests a possible preventive effect of tumor necrosis factor-α inhibitors (TNFi) on incident dementia. The objective of the analysis was to investigate the association between TNFi and the risk of incident dementia in a population undergoing treatment for rheumatological disorders. METHODS: We followed patients aged ≥ 65 years with dementia and rheumatological conditions in two cohort studies, DANBIO (N = 21,538), a Danish clinical database, and AOK PLUS (N = 7112), a German health insurance database. We defined incident dementia using diagnostic codes and/or medication use and used Cox regression to compare the associations of TNFi with other rheumatological therapies on the risk of dementia. To ensure that the patients were receiving long-term medication, we included patients with rheumatic diseases and systemic therapies. RESULTS: We observed similar trends towards a lower risk of dementia associated with TNFi versus other anti-inflammatory agents in both cohorts (hazard ratios were 0.92 [95% confidence interval 0.76, 1.10] in DANBIO and 0.89 [95% confidence interval 0.63, 1.24] in AOK PLUS, respectively). CONCLUSIONS: Tumor necrosis factor-α inhibitors may decrease the risk of incident dementia although the association did not reach statistical significance in this analysis. Further research, ideally with randomization, is needed to gauge the potential of repurposing TNFi for dementia prevention and/or treatment.

Levels of procoagulant factors and peak thrombin generation in relation to dementia risk in older adults: The Cardiovascular Health Study.

INTRODUCTION: Markers of hemostasis such as procoagulant factors and peak thrombin generation are associated with cardiovascular outcomes, but their associations with dementia risk are unclear. We aimed to evaluate prospective associations of selected procoagulant factors and peak thrombin generation with dementia risk. METHODS: We measured levels of 7 hemostatic factors (fibrinogen, factor VII coagulant activity [FVIIc], activated factor VII [FVIIa], factor VIIa-antithrombin [FVIIa-AT], factor XI antigen [FXI], peak thrombin generation, and platelet count) among participants in the Cardiovascular Health Study, a cohort of older adults free of dementia in 1992/1993 (n = 3185). Dementia was adjudicated and classified by DSM-IV criteria through 1998/1999. Cox proportional hazards models estimated hazard ratios (HRs) for any dementia associated with 1-standard deviation (SD) differences, adjusting for sociodemographic and clinical factors and APOE genotype. Secondary analyses separately evaluated the risk of vascular dementia, Alzheimer's disease, and mixed dementia. RESULTS: At baseline, participants had a median age of 73 years. Over 5.4 years of follow-up, we identified 448 dementia cases. There was no evidence of linear associations between levels of these hemostatic factors with any dementia risk (HRs per 1-SD difference ranged from 1.0 to 1.1; 95 % confidence intervals included 1.0). Results of secondary analyses by dementia subtype were similar. CONCLUSIONS: In this prospective study, there was no strong evidence of linear associations between levels of fibrinogen, FVIIc, FVIIa, FVIIa-AT, FXI, peak thrombin generation, or platelet count with dementia risk. Despite their associations with cardiovascular disease, higher levels of these biomarkers measured among older adults may not reflect dementia risk.

Societal costs and survival of patients with biopsy-verified non-alcoholic steatohepatitis: Danish nationwide register-based study.

INTRODUCTION AND OBJECTIVES: Studies on the societal burden of patients with biopsy-confirmed non-alcoholic fatty liver disease (NAFLD) are sparse. This study examined this question, comparing NAFLD with matched reference groups. MATERIALS AND METHODS: Nationwide Danish healthcare registers were used to include all patients (≥18 years) diagnosed with biopsy-verified NAFLD (1997-2021). Patients were classified as having simple steatosis or non-alcoholic steatohepatitis (NASH) with or without cirrhosis, and all matched with liver-disease free reference groups. Healthcare costs and labour market outcomes were compared from 5 years before to 11 years after diagnosis. Patients were followed for 25 years to analyse risk of disability insurance and death. RESULTS: 3,712 patients with biopsy-verified NASH (n = 1,030), simple steatosis (n = 1,540) or cirrhosis (n = 1,142) were identified. The average total costs in the year leading up to diagnosis was 4.1-fold higher for NASH patients than the reference group (EUR 6,318), 6.2-fold higher for cirrhosis patients and 3.1-fold higher for simple steatosis patients. In NASH, outpatient hospital contacts were responsible for 49 % of the excess costs (EUR 3,121). NASH patients had statistically significantly lower income than their reference group as early as five years before diagnosis until nine years after diagnosis, and markedly higher risk of becoming disability insurance recipients (HR: 4.37; 95 % CI: 3.17-6.02) and of death (HR: 2.42; 95 % CI: 1.80-3.25). CONCLUSIONS: NASH, simple steatosis and cirrhosis are all associated with substantial costs for the individual and the society with excess healthcare costs and poorer labour market outcomes.

The Gompertz Law emerges naturally from the inter-dependencies between sub-components in complex organisms.

Understanding and facilitating healthy aging has become a major goal in medical research and it is becoming increasingly acknowledged that there is a need for understanding the aging phenotype as a whole rather than focusing on individual factors. Here, we provide a universal explanation for the emergence of Gompertzian mortality patterns using a systems approach to describe aging in complex organisms that consist of many inter-dependent subsystems. Our model relates to the Sufficient-Component Cause Model, widely used within the field of epidemiology, and we show that including inter-dependencies between subsystems and modeling the temporal evolution of subsystem failure results in Gompertizan mortality on the population level. Our model also provides temporal trajectories of mortality-risk for the individual. These results may give insight into understanding how biological age evolves stochastically within the individual, and how this in turn leads to a natural heterogeneity of biological age in a population.

Serum NfL and GFAP are associated with incident dementia and dementia mortality in older adults: The cardiovascular health study.

INTRODUCTION: Circulating neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) have been independently associated with dementia risk. Their additive association, and their associations with dementia-specific mortality, have not been investigated. METHODS: We associated serum NfL, GFAP, total tau ,and ubiquitin carboxyl-terminal hydrolase-L1, measured in 1712 dementia-free adults, with 19-year incident dementia and dementia-specific mortality risk, and with 3-year cognitive decline. RESULTS: In adjusted models, being in the highest versus lowest tertile of NfL or GFAP associated with a hazard ratio (HR) of 1.49 (1.20-1.84) and 1.38 (1.15-1.66) for incident dementia, and 2.87 (1.79-4.61) and 2.76 (1.73-4.40) for dementia-specific mortality. Joint third versus first tertile exposure further increased risk; HR = 2.06 (1.60-2.67) and 9.22 (4.48-18.9). NfL was independently associated with accelerated cognitive decline. DISCUSSION: Circulating NfL and GFAP may, independently and jointly, provide useful clinical insight regarding dementia risk and prognosis.

Apo CIII Proteoforms, Plasma Lipids, and Cardiovascular Risk in MESA.

BACKGROUND: Apo CIII (apolipoprotein CIII) is an important regulator of triglyceride metabolism and was associated with cardiovascular risk in several cohorts. It is present in 4 major proteoforms, a native peptide (CIII0a), and glycosylated proteoforms with zero (CIII0b), 1 (CIII1, most abundant), or 2 (CIII2) sialic acids, which may differentially modify lipoprotein metabolism. We studied the relationships of these proteoforms with plasma lipids and cardiovascular risk. METHODS: Apo CIII proteoforms were measured by mass spectrometry immunoassay in baseline plasma samples of 5791 participants of Multi-Ethnic Study of Atherosclerosis, an observational community-based cohort. Standard plasma lipids were collected for up to 16 years and cardiovascular events (myocardial infarction, resuscitated cardiac arrest, or stroke) were adjudicated for up to 17 years. RESULTS: Apo CIII proteoform composition differed by age, sex, race and ethnicity, body mass index, and fasting glucose. Notably, CIII1 was lower in older participants, men and Black and Chinese (versus White) participants, and higher in obesity and diabetes. In contrast, CIII2 was higher in older participants, men, Black, and Chinese persons, and lower in Hispanic individuals and obesity. Higher CIII2 to CIII1 ratio (CIII2/III1) was associated with lower triglycerides and higher HDL (high-density lipoprotein) in cross-sectional and longitudinal models, independently of clinical and demographic risk factors and total apo CIII. The associations of CIII0a/III1 and CIII0b/III1 with plasma lipids were weaker and varied through cross-sectional and longitudinal analyses. Total apo CIII and CIII2/III1 were positively associated with cardiovascular disease risk (n=669 events, hazard ratios, 1.14 [95% CI, 1.04-1.25] and 1.21 [1.11-1.31], respectively); however, the associations were attenuated after adjustment for clinical and demographic characteristics (1.07 [0.98-1.16]; 1.07 [0.97-1.17]). In contrast, CIII0b/III1 was inversely associated with cardiovascular disease risk even after full adjustment including plasma lipids (0.86 [0.79-0.93]). CONCLUSIONS: Our data indicate differences in clinical and demographic relationships of apo CIII proteoforms, and highlight the importance of apo CIII proteoform composition in predicting future lipid patterns and cardiovascular disease risk.

Plasma Proteomic Risk Markers of Incident Type 2 Diabetes Reflect Physiologically Distinct Components of Glucose-Insulin Homeostasis.

High-throughput proteomics allows researchers to simultaneously explore the roles of thousands of biomarkers in the pathophysiology of diabetes. We conducted proteomic association studies of incident type 2 diabetes and physiologic responses to an intravenous glucose tolerance test (IVGTT) to identify novel protein contributors to glucose homeostasis and diabetes risk. We tested 4,776 SomaScan proteins measured in relation to 18-year incident diabetes risk in participants from the Cardiovascular Health Study (N = 2,631) and IVGTT-derived measures in participants from the HERITAGE Family Study (N = 752). We characterize 51 proteins that were associated with longitudinal diabetes risk, using their respective 39, 9, and 8 concurrent associations with insulin sensitivity index (SI), acute insulin response to glucose (AIRG), and glucose effectiveness (SG). Twelve of the 51 diabetes associations appear to be novel, including ß-glucuronidase, which was associated with increased diabetes risk and lower SG, suggesting an alternative pathway to insulin for glucose disposal; and plexin-B2, which also was associated with increased diabetes risk, but with lower AIRG, and not with SI, indicating a mechanism related instead to pancreatic dysfunction. Other novel protein associations included alcohol dehydrogenase-1C, fructose-bisphosphate aldolase-B, sorbitol dehydrogenase with elevated type 2 diabetes risk, and a leucine-rich repeat containing protein-15 and myocilin with decreased risk. ARTICLE HIGHLIGHTS: Plasma proteins are associated with the risk of incident diabetes in older adults independent of various demographic, lifestyle, and biochemical risk factors. These same proteins are associated with subtle differences in measures of glucose homeostasis earlier in life. Proteins that are associated with lower insulin sensitivity in individuals without diabetes tend to be associated with appropriate compensatory mechanisms, such as a stronger acute insulin response or higher glucose effectiveness. Proteins that are associated with future diabetes risk, but not with insulin insensitivity, tend to be associated with lower glucose effectiveness and/or impaired acute insulin response.

Associations between Alcohol Consumption and HDL Subspecies Defined by ApoC3, ApoE and ApoJ: the Cardiovascular Health Study.

Alcohol consumption increases circulating high-density lipoprotein cholesterol (HDL-C), but HDL protein cargo may better reflect HDL function. This study examined the associations between alcohol intake and HDL subspecies containing or lacking apoC3, apoE, and apoJ in a well-phenotyped cohort. We performed a cross-sectional analysis of 2092 Cardiovascular Health Study participants aged 70 or older with HDL subspecies measured in stored specimens from 1998 to 1999. Associations between alcohol intake and apoA1 defined HDL subspecies lacking or containing apoC3, apoE, and apoJ, and circulating levels of total apoA1, apoC3, apoE, and apoJ were examined. HDL subspecies lacking and containing apoC3, apoE, and apoJ were all positively associated with alcohol intake, with ∼1% per additional drink per week or ∼7% per additional drink per day (subspecies without the apolipoproteins, P ≤ 2 × 10-9, subspecies with the apolipoproteins, P ≤ 3 × 10-5). Total apoA1 was also directly associated with alcohol consumption, with a 1% increase per additional drink per week (P = 1 × 10-14). Total apoC3 blood levels were 0.5% higher per additional drink per week (P = 0.01), but the association was driven by a few heavily drinking men. Alcohol intake was positively associated with HDL subspecies lacking and containing apoC3, apoE, or apoJ, and with total plasma apoA1. ApoC3 was directly, albeit not as robustly associated with alcohol intake. HDL protein cargo is crucial for its anti-atherosclerotic functions, but it remains to be determined whether HDL subspecies play a role in the putative association between limited alcohol intake and lower risk of coronary heart disease.

High-Density Lipoprotein and Long-Term Incidence and Progression of Aortic Valve Calcification: The Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: Aortic valve calcification (AVC) shares pathological features with atherosclerosis. Lipoprotein components have been detected in aortic valve tissue, including HDL (high-density lipoprotein). HDL measures have inverse associations with cardiovascular disease, but relationships with long-term AVC progression are unclear. We investigated associations of HDL cholesterol, HDL-particle number and size, apoC3-defined HDL subtypes, and, secondarily, CETP (cholesteryl ester transfer protein) mass and activity, with long-term incidence and progression of AVC. METHODS: We used linear mixed-effects models to evaluate the associations of baseline HDL indices with AVC. AVC was quantified by Agatston scoring of up to 3 serial computed tomography scans over a median of 8.9 (maximum 11.2) years of follow-up in the Multi-Ethnic Study of Atherosclerosis (n=6784). RESULTS: After adjustment, higher concentrations of HDL-C (high-density lipoprotein cholesterol), HDL-P (HDL particles), large HDL-P, and apoC3-lacking HDL-C were significantly associated with lower incidence/progression of AVC. Neither small or medium HDL-P nor apoC3-containing HDL-C was significantly associated with AVC incidence/progression. When included together, a significant association was observed only for HDL-C, but not for HDL-P. Secondary analyses showed an inverse relationship between CETP mass, but not activity, and AVC incidence/progression. In exploratory assessments, inverse associations for HDL-C, HDL-P, large HDL-P, and apoC3-lacking HDL with AVC incidence/progression were more pronounced for older, male, and White participants. ApoC3-containing HDL-C only showed a positive association with AVC in these subgroups. CONCLUSIONS: In a multiethnic population, HDL-C, HDL-P, large HDL-P, and apoC3-lacking HDL-C were inversely associated with long-term incidence and progression of AVC. Further investigation of HDL composition and mechanisms could be useful in understanding pathways that slow AVC.

Dynamical indicators in time series of healthcare expenditures predict mortality risk of older adults following spousal bereavement.

BACKGROUND: The process of aging renders older people susceptible for adverse outcomes upon stress. Various indicators derived from complex systems theory have been proposed for quantifying resilience in living organisms, including humans. We investigated the ability of system-based indicators in capturing the dynamics of resilience in humans who suffer the adversity of spousal bereavement and tested their predictive power in mortality as a finite health transition. METHODS: Using longitudinal register data on weekly healthcare consumption of all Danish citizens over the age of 65 from January 1st, 2011, throughout December 31st, 2016, we performed statistical comparisons of the indicators 'average', 'slope', 'mean squared error', and 'lag-1 autocorrelation' one year before and after spousal bereavement, stratified for age and sex. The relation between levels of these indicators before bereavement and mortality hazards thereafter was determined by time to event analysis. We assessed the added value for mortality prediction via the time dependent area (AUC) under the receiver operating characteristic curve. RESULTS: The study included 934,003 citizens of whom 51,890 experienced spousal bereavement and 2862 died in the first year thereafter. Healthcare consumption is increased, more volatile and accelerating with aging and in men compared to women (all p-values < 0.001). All dynamic indicators before bereavement were positively related with mortality hazards thereafter (all p-values < 0.001). The average discriminative performance for the 1-year mortality risk of the model with only age as a predictor (AUC: 68.9% and 70.2%) was significantly increased with the addition of dynamical indicators (78.5% and 82.4%) for males and females, respectively. CONCLUSIONS: Dynamic indicators in time series of health care expenditures are strong predictors of mortality risk and could be part of predictive models for prognosis after life stressors, such as bereavement.

HDL (High-Density Lipoprotein) Subspecies, Prevalent Covert Brain Infarcts, and Incident Overt Ischemic Stroke: Cardiovascular Health Study.

BACKGROUND: Whether HDL (high-density lipoprotein) is associated with risk of vascular brain injury is unclear. HDL is comprised of many apo (apolipoprotein) species, creating distinct subtypes of HDL. METHODS: We utilized sandwich ELISA to determine HDL subspecies from plasma collected in 1998/1999 from 2001 CHS (Cardiovascular Health Study) participants (mean age, 80 years). RESULTS: In cross-sectional analyses, participants with higher apoA1 in plasma and lower apoE in HDL were less likely to have prevalent covert magnetic resonance imaging-defined infarcts: odds ratio for apoA1 Q4 versus Q1, 0.68 (95% CI, 0.50-0.93), and odds ratio for apoE Q4 versus Q1, 1.36 (95% CI, 1.01-1.84). Similarly, apoA1 in the subspecies of HDL that lacked apoC3, apoJ, or apoE was inversely related to covert infarcts, and apoE in the subspecies of HDL that lacked apoC3 or apoJ was directly related to covert infarcts in prospective analyses. In contrast, the concentrations of apoA1 and apoE in the complementary subspecies of HDL that contained these apos were unrelated to covert infarcts. Patterns of associations between incident overt ischemic stroke and apoA1, apoE, and apoA1 and apoE in subspecies of HDL were similar to those observed for covert infarcts but less pronounced. CONCLUSIONS: This study highlights HDL subspecies defined by apo content as relevant biomarkers of covert and overt vascular brain injury.

Sphingomyelins and ceramides: possible biomarkers for dementia?

PURPOSE OF REVIEW: Dementia is a public health challenge with no existing cure or early biomarkers. We review the evidence for blood-based measures of sphingomyelins and ceramides as potential novel biomarkers of dementia. RECENT FINDINGS: In recent years, lipids have been under investigation for their role in neurodegenerative diseases especially dementia and Alzheimer's disease. Increasing evidence from postmortem human brains suggests that alterations in the metabolism of sphingolipids could play a crucial part in dementia. Findings from epidemiological investigations of blood-based sphingomyelins and ceramides have been inconsistent. SUMMARY: This review focuses on blood-based measures of 10 specific ceramides and sphingomyelins (Cer C16:0, Cer C20:0, Cer C22:0, Cer C24:0, Cer C24:1 and SM C16:0, SM C20:0, SM C22:0, SM C24:0, SM C24:1) in relation to cognition and dementia. On the bais of 15 studies, there was no robust association between ceramide and sphingomyelin levels and prevalent or incident dementia. Cross-sectionally, Cer C16:0 and Cer C24:1 tends to be higher in dementia cases vs. controls.

Plasma antioxidants and risk of dementia in older adults.

INTRODUCTION: Plant-based diets rich in fruits and vegetables have been associated with lower risk of dementia, but the specific role of antioxidants, a key class of bioactive phytochemicals, has not been well ascertained. METHODS: We measured antioxidants in a case-cohort study nested within the Ginkgo Evaluation of Memory Study. We included 996 randomly selected participants and 521 participants who developed dementia, of which 351 were diagnosed with Alzheimer's disease (AD) during a median of 5.9 years of follow-up. We measured baseline plasma levels of retinol, α-, and γ-tocopherol; zeaxanthin and lutein (combined); beta-cryptoxanthin; cis-lycopene; trans-lycopene; α-carotene; and trans-ß-carotene by organic phase extraction followed by chromatographic analysis and related these to neurologist-adjudicated risks of all-cause dementia and AD. RESULTS: Plasma retinol, α-, and γ-tocopherol, and carotenoids were not significantly related to risk of dementia or AD. Associations were not significant upon Bonferroni correction for multiple testing and were consistent within strata of sex, age, apolipoprotein E ε4 genotype, mild cognitive impairment at baseline, and intake of multivitamin, vitamin A or ß-carotene, or vitamin E supplements. Higher trans-ß-carotene tended to be related to a higher risk of dementia (adjusted hazard ratio [HR] per 1 standard deviation [SD] higher trans-ß-carotene: 1.10; 95% confidence interval [CI]: 1.00, 1.20) and α-carotene tended to be associated with higher risk of AD only (adjusted HR per 1 SD higher α-carotene: 1.15; 95% CI: 1.02, 1.29). DISCUSSION: Plasma antioxidants were not significantly associated with risk of dementia or AD among older adults. Similar studies in younger populations are required to better understand the association between plasma antioxidants and dementia risk.

Case-cohort study of plasma phospholipid fatty acid profiles, cognitive function, and risk of dementia: a secondary analysis in the Ginkgo Evaluation of Memory Study.

BACKGROUND: Phospholipids are biomarkers of dietary fat intake and metabolism, linked to several cardiometabolic disorders. Few prospective studies have assessed plasma phospholipids in relation to dementia risk and cognitive function. OBJECTIVES: We aimed to evaluate the association between a decrease in linoleic acid accompanied with an increase in other fatty acids and cognitive function and dementia risk. METHODS: We conducted a case-cohort study nested within the Ginkgo Evaluation of Memory Study. We included 1252 participants, 498 of whom who developed dementia during a mean of 5 y of follow-up. We measured 45 individual plasma phospholipids (as a percentage of total plasma phospholipid fatty acids) by GC and related these to Modified Mini-Mental State Examination (3MSE) scores at baseline and neurologist-adjudicated incidence of all-cause dementia and Alzheimer disease (AD), adjusting for sociodemographic and clinical characteristics. RESULTS: Substitution of 1% of SFAs for 1% of linoleic acid, the predominant polyunsaturated n-6 (É·-6) fatty acid, was associated with higher risk of dementia (HR per 1% of SFAs instead of linoleic acid = 1.03; 95% CI: 1.00, 1.07) and a 0.08 point lower 3MSE score at baseline (95% CI: -0.12, -0.03), signifying worse cognitive function. When compared with linoleic acid, we found no associations of total monounsaturated, n-3 polyunsaturated, or trans fatty acids with risk of dementia or AD. However, the substitution of 1% of the marine n-3 PUFA DHA for linoleic acid was associated with lower risk of dementia (HR = 0.86 per 1% of DHA instead of linoleic acid; 95% CI: 0.76, 0.96). These associations were not modified by apolipoprotein E genotype, mild cognitive impairment at baseline, age, or sex. CONCLUSIONS: Specific elements of diet may be associated with late-life dementia, a hypothesis that requires formal testing in randomized controlled trials and that represents a possible preventive intervention.

HDL Containing Apolipoprotein C-III is Associated with Insulin Sensitivity: A Multicenter Cohort Study.

CONTEXT: High density lipoprotein (HDL) in humans is composed of a heterogeneous group of particles varying in protein composition as well as biological effects. OBJECTIVE: We investigated the prospective associations between HDL subspecies containing and lacking apolipoprotein (apo) C-III at baseline and insulin sensitivity at year 3. DESIGN, SETTING, AND PARTICIPANTS: A prospective cohort study of 864 healthy volunteers drawn from the relationship between insulin sensitivity and cardiovascular disease (RISC) study, a multicenter European clinical investigation, whose recruitment initiated in 2002, with a follow-up of 3 years. MAIN MEASURES: Insulin sensitivity was estimated from an oral glucose tolerance test at baseline and year 3, and by euglycemic-hyperinsulinemic clamp at baseline only. The apolipoprotein concentrations were measured at baseline by a sandwich enzyme-linked immunosorbent assay (ELISA)-based method. RESULTS: The 2 HDL subspecies demonstrated significantly opposite associations with insulin sensitivity at year 3 (P-heterogeneity = 0.004). The highest quintile of HDL containing apoC-III was associated with a 1.2% reduction in insulin sensitivity (P-trend = 0.02), while the highest quintile of HDL lacking apoC-III was associated with a 1.3% increase (P-trend = 0.01), compared to the lowest quintile. No significant association was observed for total HDL, and very low density lipoprotein (VLDL) and low density lipoprotein (LDL) containing apoC-III. ApoC-III contained in HDL was associated with a decrease in insulin sensitivity even more strongly than plasma total apoC-III. CONCLUSION: Both HDL containing apoC-III and apoC-III in HDL adversely affect the beneficial properties of HDL on insulin response to glucose. Our results support the potential of HDL-associated apoC-III as a promising target for diabetes prevention and treatment.

Hemostatic factor levels and cognitive decline in older adults: The Cardiovascular Health Study.

BACKGROUND: Hemostasis is a key factor in cerebrovascular disease, but the association of hemostatic factors with cognitive decline is unclear. OBJECTIVE: To prospectively evaluate associations of 20 hemostatic factor levels with changes in cognition during ≥8 years of follow-up in the Cardiovascular Health Study (CHS) of older adults. METHODS: We included participants of an existing CHS cross-sectional substudy (n = 400) with hemostatic factors measured in 1989-1990. Between 1989-1990 and 1998-1999, cognitive function was measured using the Modified Mini-Mental State Examination (3MSE) and Digit Symbol Substitution Tests. Mixed-effects linear regression models estimated change in cognitive function over time, adjusting for sociodemographic and clinical factors and APOE genotype, using Bonferroni adjustment. We also derived principal components to account for the interrelationship among factors. RESULTS: Of 20 factors evaluated individually, only higher levels of plasmin-α2 -antiplasmin complex (PAP), tissue factor pathway inhibitor (TFPI), and lower factor X (FXc) levels were associated with faster cognitive decline, estimated by annual change in 3MSE points (1 standard deviation PAP ß = -0.65, 95% confidence interval [CI]: -1.08 to -0.21; TFPI ß = -0.55, 95% CI: -0.90 to -0.19; FXc ß = 0.52, 95% CI: 0.21-0.84). One of four principal components, loading positively on D-dimer, prothrombin fragment 1.2 (F1.2), and PAP was significantly associated with change in 3MSE. CONCLUSIONS: Levels of PAP, TPFI, and FXc and a combination of factors driven by PAP, D-dimer, and F1.2 were associated with cognitive decline. Whether these findings can be used to improve dementia prevention or prediction requires further study.