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A study was conducted to investigate whether increased levels of nonfasting triglycerides are associated with a risk of ischemic stroke amongst the general population.

A study to examine whether the mutated gene ABCA1 was responsible for the increased risk of ischemic heart disease (IHD) and enhanced levels of high-density lipoprotein (HDL) cholesterol levels is conducted. Results reveal that the mutated gene did not have any effect of increased risk of IHD and HDL.

A study conducted provides evidence for hypothesis that very high levels of nonfasting triglycerides levels were associated with increased risk of myocardial infarction (MI), ischemic disease (IHD) and death in men and women.

Importance: Mendelian randomization (MR) studies use genetic variation associated with modifiable exposures to assess their possible causal relationship with outcomes and aim to reduce potential bias from confounding and reverse causation.Objective: To develop the STROBE-MR Statement as a stand-alone extension to the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guideline for the reporting of MR studies.Design, Setting, and Participants: The development of the STROBE-MR Statement followed the Enhancing the Quality and Transparency of Health Research (EQUATOR) framework guidance and used the STROBE Statement as a starting point to draft a checklist tailored to MR studies. The project was initiated in 2018 by reviewing the literature on the reporting of instrumental variable and MR studies. A group of 17 experts, including MR methodologists, MR study design users, developers of previous reporting guidelines, and journal editors, participated in a workshop in May 2019 to define the scope of the Statement and draft the checklist. The draft checklist was published as a preprint in July 2019 and discussed on the preprint platform, in social media, and at the 4th Mendelian Randomization Conference. The checklist was then revised based on comments, further refined through 2020, and finalized in July 2021.Findings: The STROBE-MR checklist is organized into 6 sections (Title and Abstract, Introduction, Methods, Results, Discussion, and Other Information) and includes 20 main items and 30 subitems. It covers both 1-sample and 2-sample MR studies that assess 1 or multiple exposures and outcomes, and addresses MR studies that follow a genome-wide association study and are reported in the same article. The checklist asks authors to justify why MR is a helpful method to address the study question and state prespecified causal hypotheses. The measurement, quality, and selection of genetic variants must be described and attempts to assess validity of MR-specific assumptions should be well reported. An item on data sharing includes reporting when the data and statistical code required to replicate the analyses can be accessed.Conclusions and Relevance: STROBE-MR provides guidelines for reporting MR studies. Improved reporting of these studies could facilitate their evaluation by editors, peer reviewers, researchers, clinicians, and other readers, and enhance the interpretation of their results. [ABSTRACT FROM AUTHOR]

Importance: Research has shown a U-shaped pattern in the association of body mass index (BMI) with mortality. Although average BMI has increased over time in most countries, the prevalence of cardiovascular risk factors may also be decreasing among obese individuals over time. Thus, the BMI associated with lowest all-cause mortality may have changed.Objective: To determine whether the BMI value that is associated with the lowest all-cause mortality has increased in the general population over a period of 3 decades.Design, Setting, and Participants: Three cohorts from the same general population enrolled at different times: the Copenhagen City Heart Study in 1976-1978 (n = 13,704) and 1991-1994 (n = 9482) and the Copenhagen General Population Study in 2003-2013 (n = 97,362). All participants were followed up from inclusion in the studies to November 2014, emigration, or death, whichever came first.Exposures: For observational studies, BMI was modeled using splines and in categories defined by the World Health Organization. Body mass index was calculated as weight in kilograms divided by height in meters squared.Main Outcomes and Measures: Main outcome was all-cause mortality and secondary outcomes were cause-specific mortality.Results: The number of deaths during follow-up was 10,624 in the 1976-1978 cohort (78% cumulative mortality; mortality rate [MR], 30/1000 person-years [95%CI, 20-46]), 5025 in the 1991-1994 cohort (53%; MR, 16/1000 person-years [95%CI, 9-30]), and 5580 in the 2003-2013 cohort (6%;MR, 4/1000 person-years [95%CI, 1-10]). Except for cancer mortality, the association of BMI with all-cause, cardiovascular, and other mortality was curvilinear (U-shaped). The BMI associated with the lowest all-cause mortality increased by 3.3 from the 1976-1978 cohort compared with the 2003-2013 cohort. [table: see text] The multivariable-adjusted hazard ratios for all-cause mortality for BMI of 30 or more vs BMI of 18.5 to 24.9 were 1.31 (95%CI, 1.23-1.39;MR, 46/1000 person-years [95%CI, 32-66] vs 28/1000 person-years [95%CI, 18-45]) in the 1976-1978 cohort, 1.13 (95%CI, 1.04-1.22; MR, 28/1000 person-years [95%CI, 17-47] vs 15/1000 person-years [95%CI, 7-31]) in the 1991-1994 cohort, and 0.99 (95%CI, 0.92-1.07;MR, 5/1000 person-years [95%CI, 2-12] vs 4/1000 person-years [95%CI, 1-11]) in the 2003-2013 cohort. CONCLUSIONS AND RELEVANCE Among 3 Danish cohorts, the BMI associated with the lowest all-cause mortality increased by 3.3 from cohorts enrolled from 1976-1978 through 2003-2013. Further investigation is needed to understand the reason for this change and its implications. [ABSTRACT FROM AUTHOR]

Background Factor V Leiden homozygosity predisposes patients to deep venous thrombosis and major pulmonary thromboembolism. Consequently, factor V Leiden homozygosity could, via unrecognized repeated minor pulmonary thromboemboli, cause chronic pulmonary disease. We tested the hypothesis that factor V Leiden homozygosity is associated with pulmonary symptoms and signs. Methods We studied a general population sample of 9253 individuals from the Copenhagen City Heart Study who were examined in 1991-1994. Of these, 6475 participants were also examined in 1976-1978 and/or 1981-1983. End points were dyspnea and lung function. Results Among 20 factor V Leiden homozygotes, a mean ± SD of 32% ± 11% had severe dyspnea compared with 6% ± 0.3% of 8534 noncarriers (χ2 test; P<.001). The corresponding adjusted odds ratio for severe dyspnea was 5.4 (95% confidence interval, 1.9-15.7). During follow-up, forced expiratory volume in 1 second and forced vital capacity were 5% to 10% lower in homozygotes vs noncarriers (analysis of variance; P = .003 and P = .03). The annual mean ± SD loss of forced expiratory volume in 1 second and forced vital capacity was 39 ± 8 mL/y and 35 ± 8 mL/y in homozygotes vs 21 ± 10 mL/y and 15 ± 10 mL/y in noncarriers (t test; P = .03 and P = .04), respectively. Factor V Leiden heterozygosity (n = 699) did not influence pulmonary symptoms and signs. Conclusion We demonstrate a previously unrecognized clinical presentation of factor V Leiden homozygosity with severe dyspnea and decreased pulmonary function. [ABSTRACT FROM AUTHOR]

Jacob Freiberg, Anne Tybjaerg-Hansen and Borge G. Nordestgaard respond to a letter to the editor about their article "Nonfasting Triglycerides and Risk of Ischemic Stroke in the General Population" in a previous issue.

Anne Tybjaerg-Hansen, Borge G. Nordestgaard and Ruth Frikke-Schmidt respond to a letter to the editor about their article "Association of Loss of Function Mutations in the ABC1 Gene With High Density Lipoprotein Cholesterol Levels and Risk of Ischemic Heart Disease" in a previous issue.

A reply is presented by Drs. Børge G. Nordestgaard and Anne Tybjærg-Hansen to letters to the editor about their article "Nonfasting triglycerides and risk of myocardial infarction, ischemic heart disease, and death in men and women."

Importance: Human genetic studies have indicated that plasma lipoprotein(a) (Lp[a]) is causally associated with the risk of coronary heart disease (CHD), but randomized trials of several therapies that reduce Lp(a) levels by 25% to 35% have not provided any evidence that lowering Lp(a) level reduces CHD risk., Objective: To estimate the magnitude of the change in plasma Lp(a) levels needed to have the same evidence of an association with CHD risk as a 38.67-mg/dL (ie, 1-mmol/L) change in low-density lipoprotein cholesterol (LDL-C) level, a change that has been shown to produce a clinically meaningful reduction in the risk of CHD., Design, Setting, and Participants: A mendelian randomization analysis was conducted using individual participant data from 5 studies and with external validation using summarized data from 48 studies. Population-based prospective cohort and case-control studies featured 20 793 individuals with CHD and 27 540 controls with individual participant data, whereas summarized data included 62 240 patients with CHD and 127 299 controls. Data were analyzed from November 2016 to March 2018., Exposures: Genetic LPA score and plasma Lp(a) mass concentration., Main Outcomes and Measures: Coronary heart disease., Results: Of the included study participants, 53% were men, all were of white European ancestry, and the mean age was 57.5 years. The association of genetically predicted Lp(a) with CHD risk was linearly proportional to the absolute change in Lp(a) concentration. A 10-mg/dL lower genetically predicted Lp(a) concentration was associated with a 5.8% lower CHD risk (odds ratio [OR], 0.942; 95% CI, 0.933-0.951; P = 3 × 10-37), whereas a 10-mg/dL lower genetically predicted LDL-C level estimated using an LDL-C genetic score was associated with a 14.5% lower CHD risk (OR, 0.855; 95% CI, 0.818-0.893; P = 2 × 10-12). Thus, a 101.5-mg/dL change (95% CI, 71.0-137.0) in Lp(a) concentration had the same association with CHD risk as a 38.67-mg/dL change in LDL-C level. The association of genetically predicted Lp(a) concentration with CHD risk appeared to be independent of changes in LDL-C level owing to genetic variants that mimic the relationship of statins, PCSK9 inhibitors, and ezetimibe with CHD risk., Conclusions and Relevance: The clinical benefit of lowering Lp(a) is likely to be proportional to the absolute reduction in Lp(a) concentration. Large absolute reductions in Lp(a) of approximately 100 mg/dL may be required to produce a clinically meaningful reduction in the risk of CHD similar in magnitude to what can be achieved by lowering LDL-C level by 38.67 mg/dL (ie, 1 mmol/L).

Context: High levels of lipoprotein(a) are associated with increased risk of myocardial infarction (MI)., Objective: To assess whether genetic data are consistent with this association being causal., Design, Setting, and Participants: Three studies of white individuals from Copenhagen, Denmark, were used: the Copenhagen City Heart Study (CCHS), a prospective general population study with 16 years of follow-up (1991-2007, n = 8637, 599 MI events); the Copenhagen General Population Study (CGPS), a cross-sectional general population study (2003-2006, n = 29 388, 994 MI events); and the Copenhagen Ischemic Heart Disease Study (CIHDS), a case-control study (1991-2004, n = 2461, 1231 MI events)., Main Outcome Measures: Plasma lipoprotein(a) levels, lipoprotein(a) kringle IV type 2 (KIV-2) size polymorphism genotype, and MIs recorded from 1976 through July 2007 for all participants., Results: In the CCHS, multivariable-adjusted hazard ratios (HRs) for MI for elevated lipoprotein(a) levels were 1.2 (95% confidence interval [CI], 0.9-1.6; events/10,000 person-years, 59) for levels between the 22nd and 66th percentile, 1.6 (95% CI, 1.1-2.2; events/10,000 person-years, 75) for the 67th to 89th percentile, 1.9 (95% CI, 1.2-3.0; events/10,000 person-years, 84) for the 90th to 95th percentile, and 2.6 (95% CI, 1.6-4.1; events/10,000 person-years, 108) for levels greater than the 95th percentile, respectively, vs levels less than the 22nd percentile (events/10,000 person-years, 55) (trend P < .001). Numbers of KIV-2 repeats (sum of repeats on both alleles) ranged from 6 to 99 and on analysis of variance explained 21% and 27% of all variation in plasma lipoprotein(a) levels in the CCHS and CGPS, respectively. Mean lipoprotein(a) levels were 56, 31, 20, and 15 mg/dL for the first, second, third, and fourth quartiles of KIV-2 repeats in the CCHS, respectively (trend P < .001); corresponding values in the CGPS were 60, 34, 22, and 19 mg/dL (trend P < .001). In the CCHS, multivariable-adjusted HRs for MI were 1.5 (95% CI, 1.2-1.9; events/10,000 person-years, 75), 1.3 (95% CI, 1.0-1.6; events/10,000 person-years, 66), and 1.1 (95% CI, 0.9-1.4; events/10,000 person-years, 57) for individuals in the first, second, and third quartiles, respectively, as compared with individuals in the fourth quartile of KIV-2 repeats (events/10,000 person-years, 51) (trend P < .001). Corresponding odds ratios were 1.3 (95% CI, 1.1-1.5), 1.1 (95% CI, 0.9-1.3), and 0.9 (95% CI, 0.8-1.1) in the CGPS (trend P = .005), and 1.4 (95% CI, 1.1-1.7), 1.2 (95% CI, 1.0-1.6), and 1.3 (95% CI, 1.0-1.6) in the CIHDS (trend P = .01). Genetically elevated lipoprotein(a) was associated with an HR of 1.22 (95% CI, 1.09-1.37) per doubling of lipoprotein(a) level on instrumental variable analysis, while the corresponding value for plasma lipoprotein(a) levels on Cox regression was 1.08 (95% CI, 1.03-1.12)., Conclusion: These data are consistent with a causal association between elevated lipoprotein(a) levels and increased risk of MI.