Small Dense Low-Density Lipoprotein Cholesterol and Ischemic Stroke.

OBJECTIVE: For decades, it has been suggested that small dense low-density lipoprotein (sdLDL) may be particularly atherogenic. High levels of sdLDL are associated with an increased risk of ischemic heart disease; however, the association of sdLDL with ischemic stroke has not been explored in a large prospective study on the general population. We tested the hypothesis that high sdLDL cholesterol levels are associated with an increased risk of ischemic stroke. METHODS: This prospective study included 38,319 individuals from the Copenhagen General Population Study with fresh sample measurements of sdLDL cholesterol. Median follow-up time was 3.1 years. We observed 302 and 74 ischemic and hemorrhagic strokes from baseline in 2013 to 2017 to the end of follow-up in 2018. For comparison, we included estimates for large buoyant LDL cholesterol and total LDL cholesterol. RESULTS: Higher levels of sdLDL cholesterol were log-linearly associated with increased risk of ischemic stroke. Compared with individuals with sdLDL cholesterol in the lowest tertile (≤0.60 mmol/l; ≤23 mg/dl) the multivariable adjusted hazard ratio for ischemic stroke was 1.79 (95% confidence interval = 1.31-2.43) for the highest tertile (≥0.86 mmol/l; ≥33 mg/dl). Multivariable adjusted hazard ratios for ischemic stroke per 1 mmol/l (38.7 mg/dl) higher levels were 1.69 (1.28-2.22) for sdLDL cholesterol, 0.95 (0.78-1.16) for large buoyant LDL cholesterol, and 1.08 (0.93-1.25) for total LDL cholesterol. Hazard ratios were similar when further adjusting for body mass index (BMI) and diabetes mellitus in the biological pathway in combination with related lipids and lipoproteins. INTERPRETATION: Higher sdLDL cholesterol levels were robustly associated with increased risk of ischemic stroke. ANN NEUROL 2023;93:952-964.

Hypertriglyceridemia-Associated Pancreatitis: New Concepts and Potential Mechanisms.

BACKGROUND: Triglycerides are a major source of energy, while high plasma triglycerides are a risk factor for various diseases and premature death. Severely elevated plasma triglycerides are a well-established cause of acute pancreatitis with high mortality, likely due to the presence of elevated levels of chylomicrons and large very low-density lipoproteins in plasma. As markedly elevated levels of these very large lipoproteins are not generally found in mild to moderate hypertriglyceridemia, this was previously not regarded as a cause or marker of increased risk of acute pancreatitis. However, mild to moderate hypertriglyceridemia may identify individuals who at a later timepoint develop severe hypertriglyceridemia and acute pancreatitis. CONTENT: We describe measurement of plasma triglycerides and studies on plasma triglycerides and risk of acute pancreatitis. Further, we summarize current European and American guidelines for the prevention of acute pancreatitis and, finally, the potential for future prevention of acute pancreatitis through lowering of plasma triglycerides. SUMMARY: Recent observational and genetic studies indicate that mild to moderate hypertriglyceridemia is causally related to increased risk of acute pancreatitis, most likely as a marker of future severe hypertriglyceridemia. Current guidelines do not mention individuals with mild to moderate hypertriglyceridemia, even though newer evidence suggests an unmet medical need. Treatment could include plasma triglyceride-lowering therapy targeting the pathway for lipoprotein lipase as the main triglyceride degrading enzyme in plasma. Angiopoietin-like 3 and apolipoproteinC-III are inhibitors of lipoprotein lipase, and blocking of these 2 inhibitors is showing promising results in relation to marked triglyceride-lowering and could perhaps be used to prevent acute pancreatitis in the future.

Association between body mass index, weight loss and the chance of pregnancy in women with polycystic ovary syndrome and overweight or obesity: a retrospective cohort study in the UK.

STUDY QUESTION: What are the associations between baseline BMI (Study 1) and change in body weight (Study 2) with the likelihood of pregnancy in women with polycystic ovary syndrome (PCOS). SUMMARY ANSWER: In women with PCOS, higher baseline BMI was associated with a lower chance of pregnancy; however, weight loss was associated with an increased chance of pregnancy versus maintaining a stable weight or gaining weight. WHAT IS KNOWN ALREADY: Two studies in large cohorts of Danish women with the intention to become pregnant showed a decline in fecundability ratios with higher BMI. Furthermore, a meta-analysis found that overweight/obesity significantly worsened metabolic and reproductive outcomes in women with PCOS. STUDY DESIGN, SIZE, DURATION: Data were extracted from the UK Clinical Practice Research Datalink GOLD database. Patients included women aged 18-45 years with BMI ≥18.5 (Study 1) or ≥25 kg/m2 (Study 2) at time of PCOS diagnosis (index date). The primary outcome was the time to first pregnancy recorded during 36-months' follow-up, analysed with Cox proportional hazard models and presented as hazard ratios (HRs). PARTICIPANTS/MATERIALS, SETTING, METHODS: Study 1 included 9955 women with PCOS. Study 2 included 7593 women with PCOS and median BMI of 34.0 kg/m2. MAIN RESULTS AND THE ROLE OF CHANCE: Higher BMI was associated with a lower chance of pregnancy in the 3 years following diagnosis. It was estimated that 41% of women with normal weight (18.5-24.9 kg/m2) would become pregnant compared to 17% of women with obesity class III (BMI ≥40.0 kg/m2) during follow-up. Furthermore, the chance of pregnancy for women with obesity class III was estimated to be 63% lower than for women with normal weight, with the same age and glycaemic status (HR 0.37, 95% CI 0.31-0.44; P < 0.0001). A significant inverse association was found between BMI change and chance of pregnancy: 10% weight loss was estimated to increase the chance of pregnancy by 68% for women with baseline BMI of 40 kg/m2 (HR 1.68, 95% CI 1.49-1.90). LIMITATIONS, REASONS FOR CAUTION: Multiple factors influence the chance of pregnancy (the ability and willingness to become pregnant), which was addressed by exclusion criteria employed. The real-world nature of the study means that use of non-prescription contraceptives was not available. Bias may have been introduced by the fact that only around 40% of women with PCOS in the CPRD GOLD database had their BMI recorded during the year prior to PCOS diagnosis. BMI categories used in the analyses may not be applicable to women of all ethnicities. The study population was only representative of women in the UK and results may not be generalizable to other regions. PCOS diagnoses were based on codes entered into the system by primary care providers, and no information was available regarding the criteria used for diagnosis, although symptoms used to diagnose PCOS have not changed over time. WIDER IMPLICATIONS OF THE FINDINGS: Our observations provide further evidence of the benefits of weight loss in women with overweight/obesity and PCOS who are seeking to become pregnant. STUDY FUNDING/COMPETING INTEREST(S): Novo Nordisk A/S. A.H.B. declares fees for consultancy from Novo Nordisk. P.N.L. and C.L.H. are employees of Novo Nordisk. V.S. and A.V. are employees of, and hold shares in, Novo Nordisk. TRIAL REGISTRATION NUMBER: N/A.

Novel Insights From Human Studies on the Role of High-Density Lipoprotein in Mortality and Noncardiovascular Disease.

The vast majority of research about HDL (high-density lipoprotein) has for decades revolved around the possible role of HDL in atherosclerosis and its therapeutic potential within cardiovascular disease prevention; however, failures with therapies aimed at increasing HDL cholesterol has left questions as to what the role and function of HDL in human health and disease is. Recent observational studies have further shown that extreme high HDL cholesterol is associated with high mortality leading to speculations that HDL could in some instances be harmful. In addition, evidence from observational, and to a lesser extent genetic studies has emerged indicating that HDL might be associated with the development of other major noncardiovascular diseases, such as infectious disease, autoimmune disease, cancer, type 2 diabetes, kidney disease, and lung disease. In this review, we discuss (1) the association between extreme high HDL cholesterol and mortality and (2) the emerging human evidence linking HDL to several major diseases outside the realm of cardiovascular disease.

Directly measured vs. calculated remnant cholesterol identifies additional overlooked individuals in the general population at higher risk of myocardial infarction.

AIMS: We tested the hypothesis that high directly measured remnant cholesterol is associated with increased risk of ischaemic heart disease (IHD) and myocardial infarction (MI) in the general population. We also explored whether directly measured vs. calculated remnant cholesterol is superior in identifying individuals at increased risk. METHODS AND RESULTS: Overall, 16 207 individuals from the Copenhagen General Population Study with both directly measured and calculated remnant cholesterol, both representing cholesterol content in triglyceride-rich lipoproteins, were followed up for 14 years to analyse the risk for IHD and MI. For directly measured and calculated remnant cholesterol, hazard ratios for individuals with concentrations ≥95th percentile vs. <40th percentile were 1.75 (95% confidence interval 1.42-2.15) and 1.76 (1.42-2.17) for IHD and 2.05 (1.50-2.80) and 1.93 (1.40-2.66) for MI. Compared to individuals with both directly measured and calculated remnant cholesterol <80th percentile (75% of the whole population), those with only directly measured remnant cholesterol ≥80th percentile (5%) had hazard ratios of 1.42 (1.15-1.75) for IHD and 1.83 (1.35-2.47) for MI. Corresponding hazard ratios for individuals with only calculated remnant cholesterol ≥80th percentile (5%) were 1.14 (0.91-1.44) and 1.14 (0.80-1.62), respectively, and corresponding hazard ratios for individuals with both directly measured and calculated remnant cholesterol ≥80th percentiles (15%) were 1.48 (1.30-1.68) and 1.67 (1.38-2.01), respectively. In individuals with high directly measured or high calculated remnant cholesterol, the median directly measured remnant cholesterol was 1.9 and 1.5 mmol/L, the median plasma triglycerides were 2.0 and 2.7 mmol/L, and the median plasma apolipoprotein B was 132 and 142 mg/dL, respectively. CONCLUSIONS: Directly measured vs. calculated remnant cholesterol identifies 5% overlooked individuals in the general population with cholesterol-rich, triglyceride-poor remnants and 1.8-fold increased risk of MI.

Genetic Variants Associated With Increased Plasma Levels of Triglycerides, via Effects on the Lipoprotein Lipase Pathway, Increase Risk of Acute Pancreatitis.

BACKGROUND & AIMS: Almost one third of adults in the West have increased plasma levels of triglycerides. Even mild to moderate hypertriglyceridemia (2-10 mmol/L or 177-886 mg/dL) is associated with an increased risk of acute pancreatitis. However, it is not clear whether hypertriglyceridemia is a cause or result of acute pancreatitis. Lipoprotein lipase degrades plasma triglycerides. Variants in LPL, APOA5, APOC3, ANGPTL3, and ANGPTL4, which regulate the lipoprotein lipase pathway, result in increased or reduced plasma triglyceride levels. We investigated associations between these variants and acute pancreatitis in a study of the general population. METHODS: In a prospective cohort study, men and women randomly selected from the area of Copenhagen were invited to complete a questionnaire, undergo a physical examination, and provide blood samples for biochemical and genetic analyses, from 2003 through 2015. We obtained triglyceride measurements from 117,427 participants. We examined for 15 genetic variants that are associated with lipoprotein lipase function in DNA samples from 102,888 participants and analyzed data from 117,427 participants in observational analyses. Diagnoses of acute pancreatitis (970 diagnoses among participants in the genetic analysis and 527 among participants in the observational study) were obtained from Danish registries. We performed a 1-sample Mendelian randomization analysis in which specific variants were used as markers of the plasma level of triglycerides to determine the association between the plasma level of triglyceride and acute pancreatitis. We calculated unweighted, internally weighted, and externally weighted allele scores for each participant by adding numbers of triglyceride-increasing alleles. RESULTS: The highest genetic allele score correlated with a higher plasma level of triglycerides of 0.54 mmol/L (48 mg/dL). Among participants with the highest vs the lowest genetic allele score, the odds ratio for acute pancreatitis was 1.55 (95% CI, 1.08-2.23). Using instrumental variable analysis, integrating the effect of genotype on both triglycerides levels and risk of acute pancreatitis, we associated higher unweighted allele scores with an increased risk of acute pancreatitis (odds ratio [OR], 1.76; 95% CI, 1.16-2.65), as well as internally weighted higher allele scores (OR, 1.41; 95% CI, 1.01-1.97) and externally weighted higher allele scores (OR, 1.44; 95% CI, 1.01-2.04). Every 1 mmol/L (89 mg/dL) increase in triglycerides was observationally associated with an increase in OR of 1.09 (95% CI, 1.05-1.14) after multivariable adjustment. CONCLUSIONS: Based on an analysis of individuals with genetic variants associated with an increased level of triglycerides, via their effects on the lipoprotein lipase pathway, we associated an increased plasma levels of triglycerides with an increased risk of acute pancreatitis. Strategies to reduce plasma levels of triglycerides, by increasing lipoprotein lipase function, might be developed for prevention of acute pancreatitis.

Lipoprotein(a)-Lowering by 50 mg/dL (105 nmol/L) May Be Needed to Reduce Cardiovascular Disease 20% in Secondary Prevention: A Population-Based Study.

OBJECTIVE: High Lp(a) (lipoprotein[a]) cause cardiovascular disease (CVD) in a primary prevention setting; however, it is debated whether high Lp(a) lead to recurrent CVD events. We tested the latter hypothesis and estimated the Lp(a)-lowering needed for 5 years to reduce CVD events in a secondary prevention setting. Approach and Results: From the CGPS (Copenhagen General Population Study; 2003-2015) of 58 527 individuals with measurements of Lp(a), 2527 aged 20 to 79 with a history of CVD were studied. The primary end point was major adverse cardiovascular event (MACE). We also studied 1115 individuals with CVD from the CCHS (Copenhagen City Heart Study; 1991-1994) and the CIHDS (Copenhagen Ischemic Heart Disease Study; 1991-1993). During a median follow-up of 5 years (range, 0-13), 493 individuals (20%) experienced a MACE in the CGPS. MACE incidence rates per 1000 person-years were 29 (95% CI, 25-34) for individuals with Lp(a)<10 mg/dL, 35 (30-41) for 10 to 49 mg/dL, 42 (34-51) for 50 to 99 mg/dL, and 54 (42-70) for ≥100 mg/dL. Compared with individuals with Lp(a)<10 mg/dL (18 nmol/L), the multifactorially adjusted MACE incidence rate ratios were 1.28 (95% CI, 1.03-1.58) for 10 to 49 mg/dL (18-104 nmol/L), 1.44 (1.12-1.85) for 50 to 99 mg/dL (105-213 nmol/L), and 2.14 (1.57-2.92) for ≥100 mg/dL (214 nmol/L). Independent confirmation was obtained in individuals from the CCHS and CIHDS. To achieve 20% and 40% MACE risk reduction in secondary prevention, we estimated that plasma Lp(a) should be lowered by 50 mg/dL (95% CI, 27-138; 105 nmol/L [55-297]) and 99 mg/dL (95% CI, 54-273; 212 nmol/L [114-592]) for 5 years. CONCLUSIONS: High concentrations of Lp(a) are associated with high risk of recurrent CVD in individuals from the general population. This study suggests that Lp(a)-lowering by 50 mg/dL (105 nmol/L) short-term (ie, 5 years) may reduce CVD by 20% in a secondary prevention setting.

Low and high pancreatic amylase is associated with pancreatic cancer and chronic pancreatitis.

Incidences of pancreatic cancer and acute and chronic pancreatitis are rising globally, and often no curative treatment is available at the time of diagnosis. We tested the hypothesis that low and high plasma concentrations of pancreatic amylase are associated with increased risk of pancreatic cancer, acute pancreatitis, and chronic pancreatitis in the general population. We included 101,765 individuals (55% women) aged 20-100 years from the Copenhagen General Population Study with baseline measurements of plasma pancreatic amylase. After recruitment in 2004-2015 during a median 9 years of follow-up (range 0-15), we collected information about diagnoses of pancreatic cancer, acute pancreatitis, and chronic pancreatitis from the national Danish Patient Registry, the national Danish Cancer Registry, and the national Danish Causes of Death Registry. The median age was 58 years (interquartile range: 48-67) and the median plasma pancreatic amylase 32 U/L (26-40). During follow-up, 442 individuals were diagnosed with pancreatic cancer, 282 with chronic pancreatitis, and 401 with acute pancreatitis. Compared to individuals with pancreatic amylase levels in the 41st-60th percentiles, those with extreme low (1st-2.5th percentiles) and extreme high (97.5th-100th percentiles) pancreatic amylase had hazard ratios of 2.4 (95% confidence interval; 1.6-3.6) and 2.2 (1.4-3.7) for pancreatic cancer, of 1.8 (1.1-3.3) and 3.2 (1.8-5.6) for chronic pancreatitis, and of 1.1 (0.6-1.8) and 1.5 (0.8-2.7) for acute pancreatitis, respectively. In apparently healthy individuals from the general population, extreme low and extreme high plasma pancreatic amylase were associated with 2-threefold higher risk of both pancreatic cancer and chronic pancreatitis.

Whole-Genome Sequencing Coupled to Imputation Discovers Genetic Signals for Anthropometric Traits.

Deep sequence-based imputation can enhance the discovery power of genome-wide association studies by assessing previously unexplored variation across the common- and low-frequency spectra. We applied a hybrid whole-genome sequencing (WGS) and deep imputation approach to examine the broader allelic architecture of 12 anthropometric traits associated with height, body mass, and fat distribution in up to 267,616 individuals. We report 106 genome-wide significant signals that have not been previously identified, including 9 low-frequency variants pointing to functional candidates. Of the 106 signals, 6 are in genomic regions that have not been implicated with related traits before, 28 are independent signals at previously reported regions, and 72 represent previously reported signals for a different anthropometric trait. 71% of signals reside within genes and fine mapping resolves 23 signals to one or two likely causal variants. We confirm genetic overlap between human monogenic and polygenic anthropometric traits and find signal enrichment in cis expression QTLs in relevant tissues. Our results highlight the potential of WGS strategies to enhance biologically relevant discoveries across the frequency spectrum.

Remnant cholesterol and risk of ischemic stroke in 112,512 individuals from the general population.

OBJECTIVE: High remnant cholesterol concentrations are associated with high risk of ischemic heart disease, but whether this is also the case for ischemic stroke is unknown. We tested the hypothesis that high remnant cholesterol concentrations are associated with increased risk of ischemic stroke in the general population. METHODS: A total of 102,964 individuals from the Copenhagen General Population Study with information on remnant cholesterol at baseline in 2003-2015 were included in a prospective, observational association study. Individuals were followed for up to 14 years, during which time 2,488 were diagnosed with an ischemic stroke. Hazard ratios were estimated using Cox proportional hazard regression models. Results were independently confirmed in 9,548 individuals enrolled in the Copenhagen City Heart Study in 1991-1994; 983 ischemic strokes developed during up to 26 years of follow-up. RESULTS: Step-wise higher remnant cholesterol concentrations were associated with step-wise higher ischemic stroke risk in the Copenhagen General Population Study, with multivariable adjusted hazard ratios up to 1.99 (95%confidence interval: 1.49-2.67) for individuals with remnant cholesterol concentrations ≥1.5 mmol/l (58 mg/dl), compared to individuals with remnant cholesterol <0.5 mmol/l (19 mg/dl). Results were similar in the Copenhagen City Heart Study. Cumulative incidence of ischemic stroke at age 80 in the Copenhagen General Population Study ranged from 7.3% for individuals with remnant cholesterol <0.5 mmol/l (19 mg/dl) to 11.5% for individuals with remnant cholesterol ≥1.5 mmol/l (58 mg/dl). INTERPRETATION: Individuals with high remnant cholesterol concentrations had higher risk of ischemic stroke. These results indicate that randomized clinical trials with remnant cholesterol lowering in individuals with high concentrations, with the aim of preventing ischemic strokes, are needed. Ann Neurol 2019;85:550-559.

Relationship of Familial Hypercholesterolemia and High Low-Density Lipoprotein Cholesterol to Ischemic Stroke: Copenhagen General Population Study.

BACKGROUND: Familial hypercholesterolemia (FH) is a condition with very high concentrations of low-density lipoprotein (LDL) cholesterol and high risk of ischemic heart disease including myocardial infarction. However, there is limited and contradictory information on whether FH and high LDL cholesterol per se confer high risk of ischemic stroke. We tested the hypotheses that individuals in the general population with FH and/or high LDL cholesterol have higher risk of ischemic stroke. METHODS: The associations of FH and high LDL cholesterol with ischemic stroke risk were tested in both causal, genetic, and observational analyses using 106 412 individuals from the CGPS (Copenhagen General Population Study; 2823 ischemic strokes and 3792 myocardial infarctions) and/or 10 372 individuals from the CCHS (Copenhagen City Heart Study; 945 ischemic strokes and 1142 myocardial infarctions). FH causative mutations were LDLR W23X(rs267607213), W66G(rs121908025) and W556S, and APOB R3500Q(rs5742904). A Mendelian randomization design tested whether high LDL cholesterol per se has a causal effect on ischemic stroke risk, using a combination of the FH causative mutations and common genetic variants associated with high LDL cholesterol. RESULTS: The cumulative incidences in individuals in the CGPS with and without FH causative mutations were similar for ischemic stroke ( P=0.50) but not for myocardial infarction ( P<0.001): at age 80 years, 4% and 7% of these individuals developed ischemic stroke and 20% and 8% myocardial infarction, with similar results in the CCHS. There was no association between clinical FH and ischemic stroke, except if personal premature ischemic heart disease was included in the clinical FH criteria. Ischemic heart disease at baseline was associated with higher ischemic stroke risk, explaining the higher ischemic stroke risk in those with high LDL cholesterol. For a 1 mmol/L higher LDL cholesterol, the genetic causal risk ratio was 1.11 (0.62-2.02) for ischemic stroke and 1.45 (1.08-1.93) for myocardial infarction. CONCLUSIONS: FH and high LDL cholesterol did not confer an increased risk of ischemic stroke. A positive association with ischemic stroke observed for some clinical FH criteria and high LDL cholesterol appears to be due to previous ischemic heart disease, rather than to high LDL cholesterol per se.

Low-Grade Inflammation in the Association between Mild-to-Moderate Hypertriglyceridemia and Risk of Acute Pancreatitis: A Study of More Than 115000 Individuals from the General Population.

BACKGROUND: How mild-to-moderate hypertriglyceridemia (2-10 mmol/L; 177-886 mg/dL) potentially causes acute pancreatitis is unknown; however, cellular studies indicate that inflammation might be a driver of disease progression. We tested the hypotheses that (a) mild-to-moderate hypertriglyceridemia is associated with low-grade inflammation and that (b) the association between mild-to-moderate hypertriglyceridemia and risk of acute pancreatitis depends on low-grade inflammation. METHODS: From the Copenhagen General Population Study and the Copenhagen City Heart Study, 117865 men and women 20-100+ years of age with measurements of nonfasting plasma triglycerides at baseline were followed prospectively for development of acute pancreatitis. RESULTS: After multivariable adjustment, a 1 mmol/L (89 mg/dL) higher nonfasting triglyceride concentration was associated with 17% (95% CI, 16%-18%, P = 3 × 10-17) higher plasma C-reactive protein (CRP) and a 4.2% (4.0%-4.4%, P = 6 × 10-17) higher blood leukocyte count. Higher concentrations of nonfasting triglycerides were associated almost linearly with higher risk of acute pancreatitis (P for trend = 5 × 10-6), with hazard ratios of 1.5 (95% CI, 0.9-2.5), 2.0 (95% CI, 1.1-3.6), 2.2 (95% CI, 1.0-4.7), 4.2 (95% CI, 1.6-11.5), and 7.7 (95% CI, 3.0-19.8) in individuals with nonfasting triglycerides of 1.00-1.99 mmol/L (89-176 mg/dL; 46% of the population), 2.00-2.99 mmol/L (177-265 mg/dL; 17%), 3.00-3.99 mmol/L (266-353 mg/dL; 6%), 4.00-4.99 mmol/L (354-442 mg/dL; 2%), and ≥5mmol/L(443 mg/dL; 2%), respectively, vs individuals with <1 mmol/L (89 mg/dL; 27%). The association with risk of acute pancreatitis appeared more pronounced in individuals with CRP of ≥1.39 mg/L (P for trend = 0.001) and leukocytes of ≥7 × 109/L (P = 2 × 10-4) than in those with CRP <1.39 mg/L (P = 0.03) and leukocytes <7 × 109/L (P = 0.04); however, there was no formal evidence of statistical interaction (P = 0.38 for CRP and P = 0.41 for leukocytes). CONCLUSIONS: Mild-to-moderate hypertriglyceridemia is associated with low-grade inflammation and higher risk of acute pancreatitis. The association between mild-to-moderate hypertriglyceridemia and risk of acute pancreatitis is possibly partly mediated by low-grade inflammation.

Low HDL Cholesterol and High Risk of Autoimmune Disease: Two Population-Based Cohort Studies Including 117341 Individuals.

BACKGROUND: HDL is quantitatively the most important lipoprotein in most species and mechanistic evidence points toward a role for HDL in normal immune function. We tested the hypothesis that concentrations of HDL cholesterol are associated with risk of autoimmune disease. METHODS: From 2 studies of the general population-the Copenhagen General Population Study and the Copenhagen City Heart study-we included 107954 and 9387 individuals with baseline measurements of HDL cholesterol. These were followed with the national Danish Patient Registry from baseline in 2003-2015 or 1991-1994 through 2017, during which time 4078 and 1101 individuals developed autoimmune disease in the 2 studies. RESULTS: In the Copenhagen General Population Study, compared to individuals with HDL cholesterol ≥2.0 mmol/L (77 mg/dL), the multifactorially adjusted hazard ratios for any autoimmune disease were 1.06 (95% CI, 0.94-1.19) for individuals with HDL cholesterol of 1.5-1.99 mmol/L (58-77 mg/dL), 1.18 (95% CI, 1.04-1.35) for individuals with HDL cholesterol of 1.0-1.49 mmol/L (39-58 mg/dL), and 1.84 (95% CI, 1.52-2.22) for individuals with HDL cholesterol <1.0 mmol/L (39 mg/dL) (P for trend <0.001). These results were similar when excluding events within 5 years of baseline, in women and men separately, for events at baseline, irrespective of low-grade inflammation or triglyceride concentrations, for the apolipoprotein A1 part of HDL, and for more restrictive end point definitions. Finally, the Copenhagen City Heart Study provided independent confirmation. CONCLUSIONS: Low HDL cholesterol level is associated with high risk of autoimmune disease in individuals from the general population. Our observational findings cannot determine causality.

Nonfasting Triglycerides, Low-Density Lipoprotein Cholesterol, and Heart Failure Risk: Two Cohort Studies of 113 554 Individuals.

OBJECTIVE: The prevalence of heart failure is increasing in the aging population, and heart failure is a disease with large morbidity and mortality. There is, therefore, a need for identifying modifiable risk factors for prevention. We tested the hypothesis that high concentrations of nonfasting triglycerides and low-density lipoprotein cholesterol are associated with higher risk of heart failure in the general population. APPROACH AND RESULTS: We included 103 860 individuals from the Copenhagen General Population Study and 9694 from the Copenhagen City Heart Study in 2 prospective observational association studies. Nonfasting triglycerides and low-density lipoprotein cholesterol were measured at baseline. Individuals were followed for ≤23 years, during which time 3593 were diagnosed with heart failure. Hazard ratios were estimated using Cox proportional hazard regression models. In the Copenhagen General Population Study, stepwise higher concentrations of nonfasting triglycerides were associated with stepwise higher risk of heart failure (P for trend <0.001), with a multivariable adjusted hazard ratio of 2.59 (95% confidence interval, 1.48-4.54) for individuals with nonfasting triglycerides ≥5 mmol/L (440 mg/dL) compared with individuals with concentrations <1 mmol/L (88 mg/dL). Concentrations of low-density lipoprotein cholesterol were not associated with risk of heart failure. Results were independently confirmed in the Copenhagen City Heart Study. CONCLUSIONS: Stepwise higher concentrations of nonfasting triglycerides were associated with stepwise higher risk of heart failure; however, concentrations of low-density lipoprotein cholesterol were not associated with risk of heart failure in the general population.

Unmet need for primary prevention in individuals with hypertriglyceridaemia not eligible for statin therapy according to European Society of Cardiology/European Atherosclerosis Society guidelines: a contemporary population-based study.

Aims: To identify individuals at high risk of atherosclerotic cardiovascular disease (ASCVD), who are not definite statin eligible according to the 2016 European Society of Cardiology/European Atherosclerosis Society (ESC/EAS) guidelines, based on high concentrations of plasma triglycerides. Methods and results: From the Copenhagen General Population Study (2003-2015) 58 547 individuals aged 40-65 and free of ASCVD, diabetes, and statin use at baseline were included. Of these, 14% were definite statin eligible, 7% were not eligible and had triglycerides ≥3.0 mmol/L (264 mg/dL), and 79% were not statin eligible and had triglycerides <3.0 mmol/L (264 mg/dL). During 456 057 person-years of follow-up, 1770 individuals experienced a major adverse cardiovascular event (MACE) and 734 experienced a myocardial infarction (MI). The cumulative incidences of MACE at age 70 were 8.1% (95% confidence interval 7.3-8.9%) and 14.6% (12.6-16.8%) in statin non-eligible individuals with triglycerides <3.0 mmol/L (264 mg/dL) and ≥3.0 mmol/L (264 mg/dL), and 16.5% (14.0-19.3%) in statin eligible individuals. Corresponding cumulative incidences of MI were 3.0% (2.7-3.3%), 7.8% (6.4-9.5%), and 7.1% (5.9-8.4%), respectively. The estimated 10-year risks of MACE were 2.8% (2.6-3.0%) and 5.7% (4.9-6.6%) in statin non-eligible individuals with triglycerides <3.0 mmol/L (264 mg/dL) and ≥3.0 mmol/L (264 mg/dL), and 7.6% (6.9-8.3%) in statin eligible individuals; the median age in these three groups were 51, 51, and 60 years, respectively. Corresponding risks of MI were 1.0% (0.9-1.1%), 3.0% (2.4-3.7%), and 3.3% (2.8-3.7%), respectively. Conclusion: Statin non-eligible individuals with triglycerides ≥3.0 mmol/L (264 mg/dL) had risk of ASCVD similar to statin eligible individuals, defined according to the 2016 ESC/EAS guidelines. This illustrates an unmet need for primary prevention, calling for expansion of guidelines on statin eligibility, and the potential for placebo-controlled randomized clinical trials in individuals with hypertriglyceridaemia.

U-shaped relationship of HDL and risk of infectious disease: two prospective population-based cohort studies.

Aims: Preclinical evidence has indicated that HDL may play an important role in the immune system; however, very little is known about the role of HDL in the immune system in humans. We tested the hypothesis that low and high concentrations of HDL cholesterol are associated with risk of infectious disease in the general population. Methods and results: We included 97 166 individuals from the Copenhagen General Population Study and 9387 from the Copenhagen City Heart Study with measurements of HDL cholesterol at baseline. The primary endpoint was any infectious disease requiring hospital admission, ascertained in the Danish health registries from baseline in 2003-13 or 1991-94 through 2014; 9% and 31% of individuals in the two studies experienced one or more infectious disease events. Using restricted cubic splines, there was a U-shaped association between concentrations of HDL cholesterol and risk of any infection. Following multifactorial adjustment, individuals with HDL cholesterol below 0.8 mmol/L (31 mg/dL) and above 2.6 mmol/L (100 mg/dL) had hazard ratios for any infection of 1.75 (95% confidence interval 1.31-2.34) and 1.43 (1.16-1.76), compared to those with HDL cholesterol of 2.2-2.3 mmol/L (85-95 mg/dL). In the Copenhagen City Heart Study, corresponding hazard ratios for any infection were 2.00 (1.16-3.43) and 1.13 (0.80-1.60). Conclusion: Low and high HDL cholesterol concentrations found in 21% and 8% of individuals were associated with higher risk of infectious disease in the general population. These findings do not necessarily indicate causality.

Remnant Cholesterol and Myocardial Infarction in Normal Weight, Overweight, and Obese Individuals from the Copenhagen General Population Study.

BACKGROUND: We tested whether high remnant cholesterol is associated with high myocardial infarction risk, independent of whether an individual is normal weight, overweight, or obese. METHODS: A total of 106216 individuals from the Copenhagen General Population Study were followed for up to 11 years, during which 1565 experienced a myocardial infarction. Individuals were grouped by clinically meaningful remnant cholesterol concentrations of <0.5 mmol/L (19 mg/dL), 0.5 to 0.99 mmol/L (19-38 mg/dL), 1.0 to 1.49 mmol/L (39-58 mg/dL), and ≥1.5 mmol/L (58 mg/dL), and by body mass index (BMI) of <18.5 kg/m2 (underweight), 18.5 to 24.9 kg/m2 (normal weight), 25 to 29.9 kg/m2 (overweight), and ≥30 kg/m2 (obese). RESULTS: Median calculated remnant cholesterol was 0.40 mmol/L [interquartile range (IQR), 0.30-0.55 mmol/L] [15 mg/dL (12-21 mg/dL)] for underweight, 0.50 mmol/L (IQR, 0.37-0.71 mmol/L) [19 mg/dL (14-27 mg/dL)] for normal weight, 0.70 mmol/L (IQR, 0.49-1.00 mmol/L) [27 mg/dL (19-39 mg/dL)] for overweight, and 0.85 mmol/L (IQR, 0.61-1.20 mmol/L) [(33 mg/dL (24-46 mg/dL)] for obese individuals. On continuous scales, remnant cholesterol was positively correlated with BMI until reaching a plateau of approximately 1 mmol/L (39 mg/dL) at BMI >35 kg/m2. R2 from an unadjusted linear regression for the correlation between calculated remnant cholesterol and BMI was 12%. Stepwise higher remnant cholesterol was associated with stepwise higher myocardial infarction risk in a similar pattern for normal weight, overweight, and obese individuals. When compared with individuals with remnant cholesterol <0.5 mmol/L (19 mg/dL), individuals with remnant cholesterol ≥1.5 mmol/L (58 mg/dL) had hazard ratios for myocardial infarction of 2.0 (95% CI, 1.3-3.2) for normal weight, 1.9 (95% CI, 1.4-2.6) for overweight, and 2.3 (95% CI, 1.4-3.5) for obese individuals. Directly measured remnant cholesterol increased 0.91 mmol/L (95% CI, 0.89-0.94 mmol/L) [35 mg/dL (34-36 mg/dL)] per 1 mmol/L (39 mg/dL) increase in calculated remnant cholesterol. CONCLUSIONS: Remnant cholesterol and BMI were positively correlated; however, high remnant cholesterol was associated with higher myocardial infarction risk across the examined BMI subcategories, indicating that remnant cholesterol is a risk factor for myocardial infarction independent of overweight and obesity.

Lactase persistence, milk intake, and mortality in the Danish general population: a Mendelian randomization study.

Meta-analyses have suggested no association between milk intake and mortality. Since only few studies have been conducted, we investigated the association between the lactase persistent genetic variant LCT-13910 C/T (rs4988235), a proxy for long-term low and high intake of milk, and mortality. We used two Danish population-based studies with self-reported intake of milk and genotyping for LCT-13910 C/T. We obtained information on all-cause and cause-specific mortality (cardiovascular and cancer) from the national Danish registries. We used multivariable adjusted Cox regression to assess the association between milk intake and mortality in 74,241 individuals, and both logistic and Cox-regression to assess the association between genetic lactase persistence and mortality in 82,964 individuals using a Mendelian randomization design. We applied per T-allele, co-dominant and dominant models. During a mean follow-up of 7 years, 9759 individuals died, 2166 from cardiovascular disease, and 2822 from cancer. Observationally, there was no association between intake of skimmed milk and all-cause or cardiovascular mortality, and we did not find any associations between intake of semi-skimmed or whole milk with all-cause or cause-specific mortality. Intake of skimmed milk was associated with lower cancer mortality with a hazard ratio of 0.97 (95% CI 0.96-1.00) per doubling in milk intake. Per T-allele, milk intake increased with 0.58 (0.50-0.68) glasses/week. Genetically, we found no associations between the lactase persistent LCT-13910 C/T genotype and all-cause or cause-specific mortality; per T-allele OR (95% CI) for all-cause mortality was 1.02 (0.97-1.06). Our study did not provide strong evidence of observational or genetic associations between milk intake and all-cause or cause-specific mortality.

Extreme high high-density lipoprotein cholesterol is paradoxically associated with high mortality in men and women: two prospective cohort studies.

AIMS: High-density lipoprotein (HDL) cholesterol concentrations are inversely associated with cardiovascular disease and mortality across a range of concentrations, but genetic evidence suggest that extreme high concentrations may paradoxically lead to more cardiovascular disease. We tested the hypothesis that extreme high concentrations of HDL cholesterol are associated with high all-cause mortality in men and women. METHODS AND RESULTS: A total of 52 268 men and 64 240 women were included from the two prospective population-based studies, the Copenhagen City Heart Study and the Copenhagen General Population Study. During 745 452 person-years of follow-up, number of deaths from any cause were 5619 (mortality rate, 17.1/1000 person-years (95% confidence interval (CI): 16.7-17.6)) in men and 5059 (mortality rate, 12.1/1000 person-years (11.8-12.4)) in women. The association between HDL cholesterol concentrations and all-cause mortality was U-shaped for both men and women, with both extreme high and low concentrations being associated with high all-cause mortality risk. The concentration of HDL cholesterol associated with the lowest all-cause mortality was 1.9 mmol/L (95% CI: 1.4-2.0) (73 mg/dL (54-77)) in men and 2.4 mmol/L (1.8-2.5) (93 mg/dL (69-97)) in women. When compared with the groups with the lowest risk, the multifactorially adjusted hazard ratios for all-cause mortality were 1.36 (95% CI: 1.09-1.70) for men with HDL cholesterol of 2.5-2.99 mmol/L (97-115 mg/dL) and 2.06 (1.44-2.95) for men with HDL cholesterol ≥3.0 mmol/L (116 mg/dL). For women, corresponding hazard ratios were 1.10 (0.83-1.46) for HDL cholesterol of 3.0-3.49 mmol/L (116-134 mg/dL) and 1.68 (1.09-2.58) for HDL cholesterol ≥3.5 mmol/L (135 mg/dL). CONCLUSION: Men and women in the general population with extreme high HDL cholesterol paradoxically have high all-cause mortality. These findings need confirmation in other studies.

Remnant lipoproteins.

PURPOSE OF REVIEW: To review recent advances in the field of remnant lipoproteins and remnant cholesterol with a focus on cardiovascular disease risk. RECENT FINDINGS: In line with previous years' research, current observational, genetic, and mechanistic studies find remnant lipoproteins (defined in different ways) to be involved in atherosclerosis development and cardiovascular disease risk. High concentrations of remnant cholesterol could explain some of the residual risk of cardiovascular disease seen after LDL cholesterol lowering. This will be increasingly important as populations worldwide become more obese and more have diabetes, both of which elevate remnant cholesterol concentrations. Many smaller scale studies and post hoc analyses show that remnant cholesterol can be lowered by different types of drugs; however, results from large scale studies with the primary aim of reducing cardiovascular disease risk through lowering of remnant cholesterol in individuals with elevated concentrations are still missing, although some are under way. SUMMARY: Remnant cholesterol is a risk factor for cardiovascular disease, and can be lowered by different types of drugs; however, large scale studies of cardiovascular disease risk reduction through remnant lipoprotein lowering are under way.