Contributions of elevated CRP, hyperglycaemia, and type 2 diabetes to cardiovascular risk in the general population: observational and Mendelian randomization studies.

OBJECTIVE: To investigate the contributions of low-grade inflammation measured by C-reactive protein (CRP), hyperglycaemia, and type 2 diabetes to risk of ischemic heart disease (IHD) and cardiovascular disease (CVD) death in the general population, and whether hyperglycaemia and high CRP are causally related. RESEARCH DESIGN AND METHODS: Observational and bidirectional, one-sample Mendelian randomization (MR) analyses in 112,815 individuals from the Copenhagen General Population Study and the Copenhagen City Heart Study, and bidirectional, two-sample MR with summary level data from two publicly available consortia, CHARGE and MAGIC. RESULTS: Observationally, higher plasma CRP was associated with stepwise higher risk of IHD and CVD death, with hazard ratios and 95% confidence intervals (95%CI) of 1.50 (1.38, 1.62) and 2.44 (1.93, 3.10) in individuals with the 20% highest CRP concentrations. The corresponding hazard ratios for elevated plasma glucose were 1.10 (1.02, 1.18) and 1.22 (1.01, 1.49), respectively. Cumulative incidences of IHD and CVD death were 365% and 592% higher, respectively, in individuals with both type 2 diabetes and plasma CRP ≥ 2 mg/L compared to individuals without either. Plasma CRP and glucose were observationally associated (ß-coefficient: 0.02 (0.02, 0.03), p = 3 × 10- 20); however, one- and two-sample MR did not support a causal effect of CRP on glucose (-0.04 (-0.12, 0.32) and - 0.03 (-0.13, 0.06)), nor of glucose on CRP (-0.01 (-0.08, 0.07) and - 0.00 (-0.14, 0.13)). CONCLUSIONS: Elevated concentrations of plasma CRP and glucose are predictors of IHD and CVD death in the general population. We found no genetic association between CRP and glucose, or vice versa, suggesting that lowering glucose pharmacologically does not have a direct effect on low-grade inflammation.

Hyperglycaemia, diabetes and risk of fragility fractures: observational and Mendelian randomisation studies.

AIMS/HYPOTHESIS: Fragility fractures may be a complication of diabetes, partly caused by chronic hyperglycaemia. We hypothesised that: (1) individuals with hyperglycaemia and diabetes have increased risk of fragility fracture; (2) hyperglycaemia is causally associated with increased risk of fragility fracture; and (3) diabetes and fragility fracture jointly associate with the highest risk of all-cause mortality. METHODS: In total, 117,054 individuals from the Copenhagen City Heart Study and the Copenhagen General Population Study (the Copenhagen studies) and 390,374 individuals from UK Biobank were included for observational and one-sample Mendelian randomisation (MR) analyses. Fragility fractures were defined as fractures at the hip, spine and arm (humerus/wrist), collected from national health registries. Summary data for fasting glucose and HbA1c concentrations from 196,743 individuals in the Meta-Analyses of Glucose and Insulin-related traits Consortium (MAGIC) were combined with data on fragility fractures from the Copenhagen studies in two-sample MR analyses. RESULTS: Higher fasting and non-fasting glucose and HbA1c concentrations were associated with higher risk of any fragility fracture (p<0.001). Individuals with vs without diabetes had HRs for fragility fracture of 1.50 (95% CI 1.19, 1.88) in type 1 diabetes and 1.22 (1.13, 1.32) in type 2 diabetes. One-sample MR supported a causal association between high non-fasting glucose concentrations and increased risk of arm fracture in the Copenhagen studies and UK Biobank combined (RR 1.41 [1.11, 1.79], p=0.004), with similar results for fasting glucose and HbA1c in two-sample MR analyses (ORs 1.50 [1.03, 2.18], p=0.03; and 2.79 [1.12, 6.93], p=0.03, respectively). The corresponding MR estimates for any fragility fracture were 1.18 (1.00, 1.41), p=0.06; 1.36 (0.89, 2.09), p=0.15; and 2.47 (0.95, 6.43), p=0.06, respectively. At age 80 years, cumulative death was 27% in individuals with fragility fracture only, 54% in those with diabetes only, 67% in individuals with both conditions and 17% in those with neither. CONCLUSIONS/INTERPRETATION: Hyperglycaemia and diabetes are risk factors for fragility fracture and one- and two-sample MR analyses supported a causal effect of hyperglycaemia on arm fractures. Diabetes and previous fragility fracture jointly conferred the highest risk of death in the general population.

Plasma adiponectin levels and risk of heart failure, atrial fibrillation, aortic valve stenosis, and myocardial infarction: large-scale observational and Mendelian randomization evidence.

AIMS: Adiponectin may play an important protective role in heart failure and associated cardiovascular diseases. We hypothesized that plasma adiponectin is associated observationally and causally, genetically with risk of heart failure, atrial fibrillation, aortic valve stenosis, and myocardial infarction. METHODS AND RESULTS: In the Copenhagen General Population Study, we examined 30 045 individuals with plasma adiponectin measurements observationally and 96 903 individuals genetically in one-sample Mendelian randomization analyses using five genetic variants explaining 3% of the variation in plasma adiponectin. In the HERMES, UK Biobank, The Nord-Trøndelag Health Study (HUNT), deCODE, the Michigan Genomics Initiative (MGI), DiscovEHR, and the AFGen consortia, we performed two-sample Mendelian randomization analyses in up to 1 030 836 individuals using 12 genetic variants explaining 14% of the variation in plasma adiponectin.In observational analyses modelled linearly, a 1 unit log-transformed higher plasma adiponectin was associated with a hazard ratio of 1.51 (95% confidence interval: 1.37-1.66) for heart failure, 1.63 (1.50-1.78) for atrial fibrillation, 1.21 (1.03-1.41) for aortic valve stenosis, and 1.03 (0.93-1.14) for myocardial infarction; levels above the median were also associated with an increased risk of myocardial infarction, and non-linear U-shaped associations were more apparent for heart failure, aortic valve stenosis, and myocardial infarction in less-adjusted models. Corresponding genetic, causal risk ratios were 0.92 (0.65-1.29), 0.87 (0.68-1.12), 1.55 (0.87-2.76), and 0.93 (0.67-1.30) in one-sample Mendelian randomization analyses, and no significant associations were seen for non-linear one-sample Mendelian randomization analyses; corresponding causal risk ratios were 0.99 (0.89-1.09), 1.00 (0.92-1.08), 1.01 (0.79-1.28), and 0.99 (0.86-1.13) in two-sample Mendelian randomization analyses, respectively. CONCLUSION: Observationally, elevated plasma adiponectin was associated with an increased risk of heart failure, atrial fibrillation, aortic valve stenosis, and myocardial infarction. However, genetic evidence did not support causality for these associations.

Women, lipids, and atherosclerotic cardiovascular disease: a call to action from the European Atherosclerosis Society.

Cardiovascular disease is the leading cause of death in women and men globally, with most due to atherosclerotic cardiovascular disease (ASCVD). Despite progress during the last 30 years, ASCVD mortality is now increasing, with the fastest relative increase in middle-aged women. Missed or delayed diagnosis and undertreatment do not fully explain this burden of disease. Sex-specific factors, such as hypertensive disorders of pregnancy, premature menopause (especially primary ovarian insufficiency), and polycystic ovary syndrome are also relevant, with good evidence that these are associated with greater cardiovascular risk. This position statement from the European Atherosclerosis Society focuses on these factors, as well as sex-specific effects on lipids, including lipoprotein(a), over the life course in women which impact ASCVD risk. Women are also disproportionately impacted (in relative terms) by diabetes, chronic kidney disease, and auto-immune inflammatory disease. All these effects are compounded by sociocultural components related to gender. This panel stresses the need to identify and treat modifiable cardiovascular risk factors earlier in women, especially for those at risk due to sex-specific conditions, to reduce the unacceptably high burden of ASCVD in women.

SGLT2-inhibition increases total, LDL, and HDL cholesterol and lowers triglycerides: Meta-analyses of 60 randomized trials, overall and by dose, ethnicity, and drug type.

BACKGROUND AND AIMS: Sodium glucose co-transporter 2 (SGLT2)-inhibitors were developed as glucose-lowering drugs. Surprisingly, SGLT2-inhibitors also reduced risk of cardiovascular disease. The impact of SGLT2-inhibitors on lipids and lipoproteins is unclear, but an effect might contribute to the observed lower cardiovascular risk. We conducted a meta-analysis to examine this, overall and by dose, ethnicity, and drug type. METHODS: PubMed, EMBASE and Web of Science were searched for randomized controlled trials examining all available SGLT2-inhibitors. Studies with available lipid measurements were included. Quantitative data synthesis was performed using random and fixed effects models. RESULTS: We identified 60 randomized trials, including 147,130 individuals. Overall, using random effects models, SGLT2-inhibitor treatment increased total cholesterol by 0.09 mmol/L (95% CI: 0.06, 0.13), low-density lipoprotein (LDL) cholesterol by 0.08 mmol/L (0.05, 0.10), and high-density lipoprotein (HDL) cholesterol by 0.06 mmol/L (0.05, 0.07), while it reduced triglycerides by 0.10 mmol/L (0.06, 0.14). Fixed effects estimates were similar but with smaller effect sizes for HDL cholesterol and triglycerides. For higher SGLT2-inhibitor doses, there was a nominally higher non-significant effect on lipids and lipoproteins. In Asian compared to non-Asian populations, a slightly larger increase in HDL cholesterol and a decrease in triglycerides were observed, but with similar results for total and LDL cholesterol. Treatment effects on lipids and lipoproteins were generally robust across different SGLT2-inhibitor drugs. CONCLUSION: In meta-analyses, SGLT2-inhibition increased total, LDL, and HDL cholesterol and decreased triglycerides. Effect sizes varied slightly by drug dose and ethnicity but were generally robust by drug type.

Genetic variation in solute carrier family 5 member 2 mimicking sodium-glucose co-transporter 2-inhibition and risk of cardiovascular disease and all-cause mortality: reduced risk not explained by lower plasma glucose.

AIMS: Treatment with sodium-glucose co-transporter 2 (SGLT2)-inhibitors reduces the risk of cardiovascular disease and mortality, but the mechanism is unclear. We hypothesized that a functional genetic variant in solute carrier family 5 member 2 (SLC5A2), known to be associated with familial renal glucosuria, would mimic pharmacological SGLT2-inhibition, and thus provide an opportunity to examine potential mediators of the effects on lower risk of cardiovascular disease and mortality. METHODS AND RESULTS: We examined 112 712 individuals from the Copenhagen City Heart Study and Copenhagen General Population Study (CCHS + CGPS), 488 687 from the UK Biobank, and 342 499 from FinnGen, genotyped for SLC5A2 rs61742739, c.1961A > G; p.(Asn654Ser). The 2.0% heterozygotes and 0.01% homozygotes were pooled as carriers and compared with the 98% non-carriers. First, we examined the risk of cardiovascular disease and mortality; second, whether carrying the variant was associated with potential mediators of the effect; and third, whether identified potential mediators could explain the observed reduced risk of cardiovascular disease and mortality. In the CCHS + CGPS, carriers vs. non-carries had a 31% lower risk of heart failure, 21% lower risk of myocardial infarction, 16% lower risk of ischaemic heart disease, and 22% lower risk of all-cause mortality. Corresponding values in meta-analyses of the three studies combined were lower risk by 10%, 6%, 6%, and 10%, respectively. The SLC5A2 rs61742739 variant was not associated with a risk of ischaemic stroke or cardiovascular mortality. Of the lower risks observed in CCHS + CGPS, lower plasma glucose mediated 2.0%(P = 0.004) on heart failure, 3.1%(P = 0.09) on myocardial infarction, 4.1%(P = 0.02) on ischaemic heart disease, and 6.0%(P = 0.39) on all-cause mortality; corresponding values in the UK Biobank were 2.9%(P = 0.70), 1.5%(P = 0.77), 4.1%(P = 0.23), and 3.1%(P = 0.21), respectively. CONCLUSION: A functional genetic variant in SLC5A2, mimicking SGLT2-inhibition, was associated with a lower risk of heart failure, myocardial infarction, ischaemic heart disease, and all-cause mortality. These effects were at most minimally mediated through lower plasma glucose.

Health behavioral responses to parental myocardial infarction and impact on own risk of disease in the general population.

Aims: A family history of coronary heart disease increases one's own risk of experiencing cardiovascular disease and death. An implication of the hereditary nature of the disease is that individuals are provided information about their own risk when a parent is affected, potentially leading them to engage in behaviors that reduce their own risk. In this study, we assessed how a 10-year risk of a cardiovascular event, measured by SCORE, changes for the offspring in response to a parent experiencing a myocardial infarction. Methods: We analyzed 19,995 individuals from the general population in the Copenhagen City Heart Study of whom 2,071 had a parent, who suffered from a myocardial infarction during four decades of observation using fixed-effects regressions. Results: Following a parental myocardial infarction, individuals reduced their 10-year risk by 0.16 percentage points constituting a 7.1% reduction of baseline risk. Male participants had the largest change in the risk SCORE following an event of the mother, with a 12.4% reduction from the baseline risk. The degree of response contingent on their own level of risk was found to be the largest for individuals with a 10-year risk between 5% and 10%, who also showed a reduction in systolic blood pressure following paternal myocardial infarction. Parental myocardial infarction was associated with an increased smoking rate in individuals with a baseline risk above 10%, while reductions in risk were seen for individuals with a lower baseline risk. Conclusion: Following a parental event, individuals reduced their 10-year risk with the largest reductions in their own risk, as observed in men and individuals experiencing a maternal event. The response was the largest for individuals with a 10-year risk for myocardial infarction between 5 and 10%.

Height Explains Sex Difference in Atrial Fibrillation Risk: Copenhagen General Population Study.

OBJECTIVE: To test the hypothesis that the increased risk of atrial fibrillation (AF) in men compared with women is explained by height. METHODS: From the Copenhagen General Population Study, we included 106,207 individuals (47,153 men and 59,054 women) from 20 to 100 years of age, without a prior diagnosis of AF, examined between November 25, 2003, and April 28, 2015. The main outcome was AF incidence from national hospital registers until April 2018. The association of risk factors with AF incidence was assessed by cause-specific Cox proportional hazards regression and Fine-Gray subdistribution hazards regression analysis. RESULTS: During a maximum of 14.4 years of follow-up (median, 8.9 years), incident AF was observed in 3449 men and 2772 women with 845 (95% CI, 815 to 875) and 514 (95% CI, 494 to 535) events per 100,000 person-years, respectively. The age-adjusted hazard of incident AF was 63% (95% CI, 55% to 72%) higher in men compared with women. Risk factors for AF were generally similar in men and women, except men were taller than women (179 cm vs 166 cm, respectively; P<.001). When controlling for height, the difference in hazard of incident AF between sexes disappeared. For population attributable risk of AF, height was the most important risk factor investigated and explained 21% and 19% of the risk of incident AF in men and women, respectively. CONCLUSION: A 63% higher risk of incident AF in men compared with women is explained by differences in height.

Red blood cell parameters in early childhood: a prospective cohort study.

OBJECTIVES: Red blood cell parameters are frequently used biomarkers when assessing clinical status in newborns and in early childhood. Cell counts, amounts, and concentrations of these parameters change through gestation and after birth. Robust age-specific reference intervals are needed to optimize clinical decision making. METHODS: The Copenhagen Baby Heart Study (CBHS) and the COMPARE study are prospective cohort studies including red blood cell parameters from 7,938 umbilical cord blood samples and 295 parallel venous blood samples from newborns with follow-up at two and at 14-16 months after birth. RESULTS: For venous blood at birth, reference intervals for hemoglobin, erythrocytes, and hematocrit were 145-224 g/L, 4.1-6.4 × 1012/L, and 0.44-0.64, respectively. Hemoglobin, erythrocytes, and hematocrit were lower at birth in children delivered by prelabor cesarean section compared to vaginal delivery. Conversion algorithms based on term newborns were: venous hemoglobin=(umbilical cord hemoglobin-86.4)/0.39; venous erythrocytes=(umbilical cord erythrocytes-2.20)/0.44; and venous hematocrit=(umbilical cord hematocrit-0.24)/0.45. CONCLUSIONS: This study presents new reference intervals for red blood cell parameters in early childhood, describes the impact of delivery mode, and provide exact functions for converting umbilical cord to venous blood measurements for term newborns. These findings may improve clinical decision making within neonatology and infancy and enhance our clinical understanding of red blood cell parameters for health and diseases in early life.

Obesity increases heart failure incidence and mortality: observational and Mendelian randomization studies totalling over 1 million individuals.

AIMS: Whether high body mass index (BMI) causally influences development and prognosis of heart failure has implications for clinical practice. We tested the hypotheses that high BMI causally influences heart failure incidence and mortality. METHODS AND RESULTS: Using observational and Mendelian randomization causal, genetic analyses, we studied 106 121 individuals from the Copenhagen General Population Study, 18 407 from the Copenhagen City Heart Study, and 977 323 from publicly available databases. In observational analyses in the Copenhagen studies with 10 years of median follow-up, multivariable adjusted hazard ratios per 1 kg/m2 increment of BMI were 1.06 (95% confidence interval: 1.05-1.07; P < 0.001; n = 124 528; events = 6589) for heart failure incidence, 1.04 (1.03-1.06; P < 0.001; n = 124 528; events = 1237) for heart failure mortality, and 1.01 (1.00-1.01; P < 0.001; n = 124 528; events = 24 144) for all-cause mortality. In genetic analyses in the Copenhagen studies, the age and sex adjusted causal risk ratios per 1 kg/m2 increment of BMI were 1.19 (1.05-1.36; P = 0.008; n = 118 200; events = 6541) for heart failure incidence, 1.27 (0.82-1.98; P = 0.28; n = 118 200; events = 889) for heart failure mortality, and 1.11 (1.02-1.22; P = 0.022; n = 118 200; events = 16 814) for all-cause mortality. Finally, combining genetic data from the Copenhagen studies, the Genetic Investigation of ANthropometric Traits, the Heart Failure Molecular Epidemiology for Therapeutic Targets, and the UK Biobank, the unadjusted causal risk ratios per 1 kg/m2 increment of BMI were 1.39 (1.27-1.52; P < 0.001; n = 1 095 523; events = 53 850) for heart failure incidence, 1.18 (1.00-1.38; P = 0.05; n = 576 853; events = 2373) for heart failure mortality, and 1.02 (1.00-1.04; P = 0.03; n = 576 853; events = 44 734) for all-cause mortality. CONCLUSION: High BMI causally increases the risk of both heart failure incidence and mortality.

Causal risk factors for asthma in Mendelian randomization studies: A systematic review and meta-analysis.

BACKGROUND: Several risk factors for asthma have been proposed; however, the causality of these associations is sometimes unclear. Mendelian randomization is a powerful epidemiological approach that can help elucidate the causality of risk factors. The aim of the present study was to identify causal risk factors for asthma through Mendelian Randomization studies. METHODS: A systematic search of PubMed and EMBASE was conducted, to identify studies investigating risk factors for asthma or respiratory allergies through Mendelian Randomization. When two or more studies investigated the same risk factor a meta-analysis was conducted. Of 239 studies initially identified, 41 were included. RESULTS: A causal association between adiposity and adult asthma risk was found in 10 out of 12 studies with a summary risk ratio of 1.05 per kg/m2 increase in BMI (95% CI: 1.03-1.07). Puberty timing (n = 3), alcohol (n = 2), and linoleic acid (n = 1) had causal effects on asthma risk, while vitamins/minerals (n = 6) showed no consistent effect on asthma. The effect of smoking on adult asthma conflicted between studies. Several of the significant associations of asthma with immune related proteins (n = 5) and depression (n = 2) investigated through multiple traits analyses could generally benefit from replications in independent datasets. CONCLUSION: This systematic review and meta-analysis found evidence for causal effects of adiposity, puberty timing, linoleic acid, alcohol, immune related proteins, and depression on risk of asthma.

The spoils of war and the long-term spoiling of health conditions of entire nations.

The healthcare system of Ukraine was already suffering from several shortfalls before February 2022, but the war of aggression started by the Russian leadership is poised to inflict a further severe blow that will have long-lasting consequences for the health of all Ukrainians. In pre-war Ukraine, noncommunicable diseases (NCDs) contributed to 91% of deaths, especially cardiovascular diseases (67%). Ukrainians have a high prevalence of risk factors for NCDs ranking among the highest levels reported by the World Health Organization (WHO) in the European (EU) Region. Cardiovascular disease is one of the key health risks for the conflict-affected Ukrainian population due to significant limitations in access to health care and interruptions in the supply of medicines and resources. The excess mortality observed during the COVID-19 pandemic, due to a combination of viral illness and chronic disease states, is bound to increase exponentially from poorly treated NCDs. In this report, we discuss the impact of the war on the public health of Ukraine and potential interventions to provide remote health assistance to the Ukrainian population.

Familial Hypercholesterolemia Prevalence Among Ethnicities-Systematic Review and Meta-Analysis.

Background: Heterozygous familial hypercholesterolemia (FH) is a common genetic disorder leading to premature cardiovascular disease and death as a result of lifelong high plasma low-density lipoprotein cholesterol levels, if not treated early in life. The prevalence of FH varies between countries because of founder effects, use of different diagnostic criteria, and screening strategies. However, little is known about differences in FH prevalence according to ethnicity. We aimed to investigate the ethnic distribution of FH in diverse populations and estimate the prevalence of FH according to ethnicity. Methods: We performed a systematic review and meta-analysis, searching PubMed and Web of Science for studies presenting data on the prevalence of heterozygous FH among different ethnicities in non-founder populations. Studies with more than 100 individuals, relevant data on prevalence, ethnicity, and using the Dutch Lipid Clinical Network Criteria, Simon Broome, Making Early Diagnosis Prevents Early Death, genetic screening, or comparable diagnostic criteria were considered eligible for inclusion. Results: Eleven general population studies and two patient studies were included in a systematic review and 11 general population studies in a random-effects meta-analysis. The overall pooled FH prevalence was 0.33% or 1:303 in 1,169,879 individuals (95% confidence interval: 0.26-0:40%; 1:385-1:250). Included studies presented data on six ethnicities: black, Latino, white, Asian, brown, and mixed/other. Pooled prevalence was estimated for each group. The highest prevalence observed was 0.52% or 1:192 among blacks (0.34-0.69%; 1:294-1:145) and 0.48% or 1:208 among browns (0.31-0.74%; 1:323-1:135) while the lowest pooled prevalence was 0.25% or 1:400 among Asians (0.15-0.35; 1:500-1:286). The prevalence was 0.37% or 1:270 among Latino (0.24-0.69%; 1:417-1:145), 0.31% or 1:323 among white (0.24-0.41%; 1:417-1:244), and 0.32% or 1:313 among mixed/other individuals (0.13-0.52%; 1:769-1:192). Conclusion: The estimated FH prevalence displays a variation across ethnicity, ranging from 0.25% (1:400) to 0.52% (1:192), with the highest prevalence seen among the black and brown and the lowest among the Asian individuals. The differences observed suggest that targeted screening among subpopulations may increase the identification of cases and thus the opportunity for prevention.

Plasma adiponectin and risk of asthma: observational analysis, genetic Mendelian randomisation and meta-analysis.

BACKGROUND: Adiponectin, an adipocyte-secreted protein-hormone with inflammatory properties, has a potentially important role in the development and progression of asthma. Unravelling whether adiponectin is a causal risk factor for asthma is an important issue to clarify as adiponectin could be a potential novel drug target for the treatment of asthma. OBJECTIVE: We tested the hypothesis that plasma adiponectin is associated observationally and causally (using genetic variants as instrumental variables) with risk of asthma. METHODS: In the Copenhagen General Population Study, we did an observational analysis in 28 845 individuals (2278 asthma cases) with plasma adiponectin measurements, and a genetic one-sample Mendelian randomisation analysis in 94 868 individuals (7128 asthma cases) with 4 genetic variants. Furthermore, in the UK Biobank, we did a genetic two-sample Mendelian randomisation analysis in 462 933 individuals (53 598 asthma cases) with 12 genetic variants. Lastly, we meta-analysed the genetic findings. RESULTS: While a 1 unit log-transformed higher plasma adiponectin in the Copenhagen General Population Study was associated with an observational OR of 1.65 (95% CI 1.29 to 2.08) for asthma, the corresponding genetic causal OR was 1.03 (95% CI 0.75 to 1.42). The genetic causal OR for asthma in the UK Biobank was 1.00 (95% CI 0.99 to 1.00). Lastly, genetic meta-analysis confirmed lack of association between genetically high plasma adiponectin and causal OR for asthma. CONCLUSION: Observationally, high plasma adiponectin is associated with increased risk of asthma; however, genetic evidence could not support a causal association between plasma adiponectin and asthma.

Low Plasma Adiponectin in Risk of Type 2 Diabetes: Observational Analysis and One- and Two-Sample Mendelian Randomization Analyses in 756,219 Individuals.

We tested the hypothesis that low plasma adiponectin is associated observationally and causally with increased risk of type 2 diabetes. Observational analyses are prone to confounding and reverse causation, while genetic Mendelian randomization (MR) analyses are much less influenced by these biases. We examined 30,045 individuals from the Copenhagen General Population Study observationally (plasma adiponectin [1,751 individuals with type 2 diabetes]), 96,903 Copenhagen individuals using one-sample MR (5 genetic variants [5,012 individuals with type 2 diabetes]), and 659,316 Europeans (ADIPOGen, GERA, DIAGRAM, UK Biobank) using two-sample MR (10 genetic variants [62,892 individuals type 2 diabetes]). Observationally, and in comparisons with individuals with median plasma adiponectin of 28.9 µg/mL (4th quartile), multivariable adjusted hazard ratios (HRs) for type 2 diabetes were 1.42 (95% CI 1.18-1.72) for 19.2 µg/mL (3rd quartile), 2.21 (1.84-2.66) for 13.9 µg/mL (2nd quartile), and 4.05 (3.38-4.86) for 9.2 µg/mL (1st quartile). Corresponding cumulative incidence for type 2 diabetes at age 70 years was 3%, 7%, 11%, and 20%, respectively. A 1 µg/mL lower plasma adiponectin conferred an HR for type 2 diabetes of 1.07 (1.06-1.09), while genetic, causal risk ratio per 1 unit log-transformed lower plasma adiponectin was 1.13 (95% CI 0.83-1.53) in one-sample MR and 1.26 (1.01-1.57) in two-sample MR. In conclusion, low plasma adiponectin is associated with increased risk of type 2 diabetes, an association that could represent a causal relationship.

Impact of high glucose levels and glucose lowering on risk of ischaemic stroke: a Mendelian randomisation study and meta-analysis.

AIMS/HYPOTHESIS: It is unclear whether glucose per se has a causal impact on risk of stroke and whether glucose-lowering drugs reduce this risk. This is important for the choice of treatment for individuals at risk. We tested the hypotheses that high plasma glucose has a causal impact on increased risk of ischaemic stroke, and that glucose-lowering drugs reduce this risk. METHODS: Using a Mendelian randomisation design, we examined 118,838 individuals from two Copenhagen cohorts, the Copenhagen General Population Study and the Copenhagen City Heart Study, and 440,328 individuals from the MEGASTROKE study. Effects of eight glucose-lowering drugs on risk of stroke were summarised by meta-analyses. RESULTS: In genetic, causal analyses, a 1 mmol/l higher plasma glucose had a risk ratio of 1.48 (95% CI 1.04, 2.11) for ischaemic stroke in the Copenhagen studies. The corresponding risk ratio from the MEGASTROKE study combined with the Copenhagen studies was 1.74 (1.31, 2.18). In meta-analyses of glucose-lowering drugs, the risk ratio for stroke was 0.85 (0.77, 0.94) for glucagon-like peptide-1 receptor agonists and 0.82 (0.69, 0.98) for thiazolidinediones, while sulfonylureas, dipeptidyl peptidase-4 inhibitors, sodium-glucose cotransporter 2 inhibitors, α-glucosidase inhibitors, meglitinides and metformin individually lacked statistical evidence of an effect on stroke risk. CONCLUSIONS/INTERPRETATION: Genetically high plasma glucose has a causal impact on increased risk of ischaemic stroke. Treatment with glucose-lowering glucagon-like peptide-1 receptor agonists and thiazolidinediones reduces this risk. These results may guide clinicians in the treatment of individuals at high risk of ischaemic stroke.

LDL-Cholesterol versus Glucose in Microvascular and Macrovascular Disease.

BACKGROUND: The causal relationships between increased concentrations of low density lipoprotein (LDL)-cholesterol and glucose and risk of ischemic heart disease are well established. The causal contributions of LDL-cholesterol and glucose to risk of peripheral micro- and macrovascular diseases are less studied, especially in prediabetic stages and in a general population setting. CONTENT: This review summarizes the current evidence for a causal contribution of LDL-cholesterol and glucose to risk of a spectrum of peripheral micro- and macrovascular diseases and reviews possible underlying disease mechanisms, including differences between vascular compartments, and finally discusses the clinical implications of these findings, including strategies for prevention and treatment. SUMMARY: Combined lines of evidence suggest that LDL-cholesterol has a causal effect on risk of peripheral arterial disease and chronic kidney disease, both of which represent manifestations of macrovascular disease due to atherosclerosis and accumulation of LDL particles in the arterial wall. In contrast, there is limited evidence for a causal effect on risk of microvascular disease. Glucose has a causal effect on risk of both micro- and macrovascular disease. However, most evidence is derived from studies of individuals with diabetes. Further studies in normoglycemic and prediabetic individuals are warranted. Overall, LDL-cholesterol-lowering reduces risk of macrovascular disease, while evidence for a reduction in risk of microvascular disease is inconsistent. Glucose-lowering has a beneficial effect on risk of microvascular diseases and on risk of chronic kidney disease and estimated glomerular filtration rate (eGFR) in some studies, while results on risk of peripheral arterial disease are conflicting.

Causal Relationship between Plasma Adiponectin and Body Mass Index: One- and Two-Sample Bidirectional Mendelian Randomization Analyses in 460 397 Individuals.

BACKGROUND: Adiponectin is a protein hormone produced by adipocytes that may play an important role in obesity. However, the causal interrelation between plasma adiponectin and body mass index (BMI) is still uncertain. We tested the hypotheses that (a) plasma adiponectin and BMI are inversely associated observationally, (b) genetically high BMI is associated with lower plasma adiponectin, and (c) genetically high plasma adiponectin is associated with lower BMI. METHODS: Information on 108 896 individuals from the Copenhagen General Population Study was used in observational and bidirectional one-sample Mendelian randomization analyses, using 5 genetic variants for BMI and 3 for adiponectin. For independent confirmation, information on 322 154 individuals from the GIANT consortium, and 29 347 individuals from the ADIPOGen consortium was used in bidirectional two-sample Mendelian randomization analysis, using 68 genetic variants for BMI and 14 for adiponectin. RESULTS: In observational analyses, a 1 kg/m2 increase in BMI was associated with -0.44 µg/mL (95% confidence interval: -0.46, -0.42) in plasma adiponectin, whereas a 1 µg/mL increase in plasma adiponectin was associated with -0.11 kg/m2 (-0.12, -0.11) in BMI. In causal genetic analyses, no associations were observed between BMI and plasma adiponectin and vice versa. In one-sample Mendelian randomization analyses, a 1 kg/m2 genetically determined increase in BMI was associated with -0.13 µg/mL (-0.53, 0.28) in plasma adiponectin, whereas a 1 µg/mL genetically determined increase in plasma adiponectin was associated with 0.01 kg/m2 (-0.05, 0.07) in BMI. Corresponding estimates in the two-sample Mendelian randomization analyses were 0.03 µg/mL (-0.02, 0.07) and 0.03 kg/m2(-0.02, 0.07), respectively. CONCLUSIONS: Observationally, plasma adiponectin and BMI are inversely associated. In contrast, genetically high plasma adiponectin is unlikely to influence BMI, and genetically high BMI is unlikely to influence plasma adiponectin.