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- Hindy, George, et al.
(författare)
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Role of Blood Lipids in the Development of Ischemic Stroke and its Subtypes : A Mendelian Randomization Study
- 2018
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Ingår i: Stroke. - 0039-2499 .- 1524-4628. ; 49:4, s. 820-827
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Statin therapy is associated with a lower risk of ischemic stroke supporting a causal role of low-density lipoprotein (LDL) cholesterol. However, more evidence is needed to answer the question whether LDL cholesterol plays a causal role in ischemic stroke subtypes. In addition, it is unknown whether high-density lipoprotein cholesterol and triglycerides have a causal relationship to ischemic stroke and its subtypes. Our aim was to investigate the causal role of LDL cholesterol, high-density lipoprotein cholesterol, and triglycerides in ischemic stroke and its subtypes through Mendelian randomization (MR).METHODS: Summary data on 185 genome-wide lipids-associated single nucleotide polymorphisms were obtained from the Global Lipids Genetics Consortium and the Stroke Genetics Network for their association with ischemic stroke (n=16 851 cases and 32 473 controls) and its subtypes, including large artery atherosclerosis (n=2410), small artery occlusion (n=3186), and cardioembolic (n=3427) stroke. Inverse-variance-weighted MR was used to obtain the causal estimates. Inverse-variance-weighted multivariable MR, MR-Egger, and sensitivity exclusion of pleiotropic single nucleotide polymorphisms after Steiger filtering and MR-Pleiotropy Residual Sum and Outlier test were used to adjust for pleiotropic bias.RESULTS: A 1-SD genetically elevated LDL cholesterol was associated with an increased risk of ischemic stroke (odds ratio: 1.12; 95% confidence interval: 1.04-1.20) and large artery atherosclerosis stroke (odds ratio: 1.28; 95% confidence interval: 1.10-1.49) but not with small artery occlusion or cardioembolic stroke in multivariable MR. A 1-SD genetically elevated high-density lipoprotein cholesterol was associated with a decreased risk of small artery occlusion stroke (odds ratio: 0.79; 95% confidence interval: 0.67-0.90) in multivariable MR. MR-Egger indicated no pleiotropic bias, and results did not markedly change after sensitivity exclusion of pleiotropic single nucleotide polymorphisms. Genetically elevated triglycerides did not associate with ischemic stroke or its subtypes.CONCLUSIONS: LDL cholesterol lowering is likely to prevent large artery atherosclerosis but may not prevent small artery occlusion nor cardioembolic strokes. High-density lipoprotein cholesterol elevation may lead to benefits in small artery disease prevention. Finally, triglyceride lowering may not yield benefits in ischemic stroke and its subtypes.
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| 2. |
- Larsson, Susanna C., et al.
(författare)
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Circulating Vitamin K₁ Levels in Relation to Ischemic Stroke and Its Subtypes : A Mendelian Randomization Study.
- 2018
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Ingår i: Nutrients. - : MDPI AG. - 2072-6643. ; 10:11
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Tidskriftsartikel (refereegranskat)abstract
- Vitamin K plays a crucial role in blood coagulation, and hypercoagulability has been linked to atherosclerosis-related vascular disease. We used the Mendelian randomization study design to examine whether circulating vitamin K₁ (phylloquinone) levels are associated with ischemic stroke. Four single-nucleotide polymorphisms associated with vitamin K₁ levels were used as instrumental variables. Summary-level data for large artery atherosclerotic stroke (n = 4373 cases), small vessel stroke (n = 5386 cases), cardioembolic stroke (n = 7193 cases), and any ischemic stroke (n = 34,217 cases and 404,630 non-cases) were available from the MEGASTROKE consortium. Genetically-predicted circulating vitamin K₁ levels were associated with large artery atherosclerotic stroke but not with any other subtypes or ischemic stroke as a whole. The odds ratios per genetically predicted one nmol/L increase in natural log-transformed vitamin K₁ levels were 1.31 (95% confidence interval (CI) 1.12⁻1.53; p = 7.0 × 10-4) for large artery atherosclerotic stroke, 0.98 (95% CI 0.85⁻1.12; p = 0.73) for small vessel stroke, 1.01 (95% CI 0.90⁻1.14; p = 0.84) for cardioembolic stroke, and 1.05 (95% CI 0.99⁻1.11; p = 0.11) for any ischemic stroke. These findings indicate that genetic predisposition to higher circulating vitamin K₁ levels is associated with an increased risk of large artery atherosclerotic stroke.
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| 3. |
- Larsson, Susanna C., et al.
(författare)
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Genetically-Predicted Adult Height and Alzheimer's Disease
- 2017
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 60:2, s. 691-698
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Observational studies have linked increased adult height with better cognitive performance and reduced risk of Alzheimer's disease (AD). It is unclear whether the associations are due to shared biological processes that influence height and AD or due to confounding by early life exposures or environmental factors.OBJECTIVE: To use a genetic approach to investigate the association between adult height and AD.METHODS: We selected 682 single nucleotide polymorphisms (SNPs) associated with height at genome-wide significance (p < 5×10-8) in the Genetic Investigation of ANthropometric Traits (GIANT) consortium. Summary statistics for each of these SNPs on AD were obtained from the International Genomics of Alzheimer's Project (IGAP) of 17,008 individuals with AD and 37,154 controls. The estimate of the association between genetically predicted height and AD was calculated using the inverse-variance weighted method.RESULTS: The odds ratio of AD was 0.91 (95% confidence interval, 0.86-0.95; p = 9.8×10-5) per one standard deviation increase (about 6.5 cm) in genetically predicted height based on 682 SNPs, which were clustered in 419 loci. In an analysis restricted to one SNP from each height-associated locus (n = 419 SNPs), the corresponding OR was 0.92 (95% confidence interval, 0.86-0.97; p = 4.8×10-3).CONCLUSIONS: This finding suggests that biological processes that influence adult height may have a role in the etiology of AD.
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| 4. |
- Larsson, Susanna C., et al.
(författare)
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Homocysteine and small vessel stroke : A mendelian randomization analysis
- 2019
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Ingår i: Annals of Neurology. - : Wiley. - 0364-5134 .- 1531-8249. ; 85:4, s. 495-501
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Tidskriftsartikel (refereegranskat)abstract
- Objective Trials of B vitamin therapy to lower blood total homocysteine (tHcy) levels for prevention of stroke are inconclusive. Secondary analyses of trial data and epidemiological studies suggest that tHcy levels may be particularly associated with small vessel stroke (SVS). We assessed whether circulating tHcy and B vitamin levels are selectively associated with SVS, but not other stroke subtypes, using Mendelian randomization.MethodsWe used summary statistics data for single-nucleotide polymorphisms (SNPs) associated with tHcy (n = 18), folate (n = 3), vitamin B-6 (n = 1), and vitamin B-12 (n = 14) levels, and the corresponding data for stroke from the MEGASTROKE consortium (n = 16,952 subtyped ischemic stroke cases and 404,630 noncases).ResultsGenetically predicted tHcy was associated with SVS, with an odds ratio of 1.34 (95% confidence interval [CI], 1.13-1.58; p = 6.7 x 10(-4)) per 1 standard deviation (SD) increase in genetically predicted tHcy levels, but was not associated with large artery or cardioembolic stroke. The association was mainly driven by SNPs at or near the MTHFR and MUT genes. The odds ratios of SVS per 1 SD increase in genetically predicted folate and vitamin B-6 levels were 0.49 (95% CI, 0.34-0.71; p = 1.3 x 10(-4)) and 0.70 (95% CI, 0.52-0.94; p = 0.02), respectively. Genetically higher vitamin B-12 levels were not associated with any stroke subtype.Interpretation These findings suggest that any effect of homocysteine-lowering treatment in preventing stroke will be confined to the SVS subtype. Whether genetic variants at or near the MTHFR and MUT genes influence SVS risk through pathways other than homocysteine levels and downstream effects require further investigation. Ann Neurol 2019;85:495-501
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| 5. |
- Larsson, Susanna C, et al.
(författare)
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Serum 25-Hydroxyvitamin D Concentrations and Ischemic Stroke and Its Subtypes.
- 2018
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Ingår i: Stroke. - 0039-2499 .- 1524-4628. ; 49:10, s. 2508-2511
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose- Observational studies have reported increased risk of ischemic stroke among individuals with low serum 25-hydroxyvitamin D (S-25OHD) concentrations but uncertainty remains about the causality of this association. We sought to determine whether S-25OHD concentrations are causally associated with ischemic stroke and its subtypes using Mendelian randomization. Methods- We used summary-level data for ischemic stroke (34 217 cases and 404 630 noncases) from the MEGASTROKE consortium. As instruments, we used 6 single nucleotide polymorphisms, explaining 7.5% of the variance in S-25OHD, previously identified to be associated with S-25OHD concentrations in the Study of Underlying Genetic Determinants of Vitamin D and Highly Related Traits consortium (n=79 366). The analyses were conducted using the inverse-variance-weighted method and complemented with the weighted median, heterogeneity-penalized, and Mendelian randomization-Egger approaches. Results- Genetically higher S-25OHD concentration was not associated with ischemic stroke. The odds ratios (95% CI) per genetically predicted 1-SD (≈18 nmol/L) increase in S-25OHD concentrations, based on all 6 single nucleotide polymorphisms, were 1.01 (0.94-1.08; P=0.84) for all ischemic stroke, 0.94 (0.80-1.11; P=0.49) for large artery stroke, 0.95 (0.82-1.11; P=0.55) for small vessel stroke, and 1.02 (0.90-1.16; P=0.74) for cardioembolic stroke. The results were similar in sensitivity analyses. Conclusions- These findings provide no support that higher S-25OHD concentrations are causally associated with any ischemic stroke subtype. Thus, vitamin D supplementation will unlikely reduce the risk of ischemic stroke in the general population.
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| 6. |
- Larsson, Susanna C, et al.
(författare)
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Serum Parathyroid Hormone, 25-Hydroxyvitamin D, and Risk of Alzheimer's Disease : A Mendelian Randomization Study
- 2018
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Ingår i: Nutrients. - : MDPI AG. - 2072-6643. ; 10:9
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Tidskriftsartikel (refereegranskat)abstract
- We conducted Mendelian randomization analyses to investigate the associations of serum parathyroid hormone (S-PTH) and serum 25-hydroxyvitamin D (S-25OHD) concentrations with Alzheimer's disease (AD). Five and seven single nucleotide polymorphisms associated with S-PTH and S-25OHD concentrations, respectively, were used as instrumental variables. Data for AD were acquired from the International Genomics of Alzheimer's Project (17,008 AD cases and 37,154 controls). Genetically higher S-PTH concentrations were not associated with AD (odds ratio per standard deviation increase in S-PTH = 1.11; 95% CI 0.97-1.26; p = 0.12). In contrast, all seven 25OHD-increasing alleles were inversely associated with AD and two of the associations were statistically significant (p < 0.05). The odds ratio of AD per genetically-predicted one standard deviation increase in S-25OHD was 0.86 (95% CI 0.78-0.94; p = 0.002). This study provides evidence that vitamin D may play a role in AD but found no significant association between S-PTH and AD.
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