Genome-wide meta-analysis uncovers novel loci influencing circulating leptin levels

Leptin is an adipocyte-secreted hormone, the circulating levels of which correlate closely with overall adiposity. Although rare mutations in the leptin (LEP) gene are well known to cause leptin deficiency and severe obesity, no common loci regulating circulating leptin levels have been uncovered. Therefore, we performed a genome-wide association study (GWAS) of circulating leptin levels from 32,161 individuals and followed up loci reaching P<10−6 in 19,979 additional individuals. We identify five loci robustly associated (P<5 × 10−8) with leptin levels in/near LEP, SLC32A1, GCKR, CCNL1 and FTO. Although the association of the FTO obesity locus with leptin levels is abolished by adjustment for BMI, associations of the four other loci are independent of adiposity. The GCKR locus was found associated with multiple metabolic traits in previous GWAS and the CCNL1 locus with birth weight. Knockdown experiments in mouse adipose tissue explants show convincing evidence for adipogenin, a regulator of adipocyte differentiation, as the novel causal gene in the SLC32A1 locus influencing leptin levels. Our findings provide novel insights into the regulation of leptin production by adipose tissue and open new avenues for examining the influence of variation in leptin levels on adiposity and metabolic health

Genome-wide physical activity interactions in adiposity : a meta-analysis of 200 452 adults

Physical activity (PA) may modify the genetic effects that give rise to increased risk of obesity. To identify adiposity loci whose effects are modified by PA, we performed genomewide interaction meta-analyses of BMI and BMI-adjusted waist circumference and waist-hip ratio from up to 200,452 adults of European (n = 180,423) or other ancestry (n = 20,029). We standardized PA by categorizing it into a dichotomous variable where, on average, 23% of participants were categorized as inactive and 77% as physically active. While we replicate the interaction with PA for the strongest known obesity-risk locus in the FTO gene, of which the effect is attenuated by ~30% in physically active individuals compared to inactive individuals, we do not identify additional loci that are sensitive to PA. In additional genome-wide meta-analyses adjusting for PA and interaction with PA, we identify 11 novel adiposity loci, suggesting that accounting for PA or other environmental factors that contribute to variation in adiposity may facilitate gene discover

Multi-ancestry genome-wide association study accounting for gene-psychosocial factor interactions identifies novel loci for blood pressure traits

Publisher Copyright: © 2020 The Author(s)Psychological and social factors are known to influence blood pressure (BP) and risk of hypertension and associated cardiovascular diseases. To identify novel BP loci, we carried out genome-wide association meta-analyses of systolic, diastolic, pulse, and mean arterial BP, taking into account the interaction effects of genetic variants with three psychosocial factors: depressive symptoms, anxiety symptoms, and social support. Analyses were performed using a two-stage design in a sample of up to 128,894 adults from five ancestry groups. In the combined meta-analyses of stages 1 and 2, we identified 59 loci (p value < 5e−8), including nine novel BP loci. The novel associations were observed mostly with pulse pressure, with fewer observed with mean arterial pressure. Five novel loci were identified in African ancestry, and all but one showed patterns of interaction with at least one psychosocial factor. Functional annotation of the novel loci supports a major role for genes implicated in the immune response (PLCL2), synaptic function and neurotransmission (LIN7A and PFIA2), as well as genes previously implicated in neuropsychiatric or stress-related disorders (FSTL5 and CHODL). These findings underscore the importance of considering psychological and social factors in gene discovery for BP, especially in non-European populations.Peer reviewe

Composite trait Mendelian randomization reveals distinct metabolic and lifestyle consequences of differences in body shape

Obesity is a major risk factor for a wide range of cardiometabolic diseases, however the impact of specific aspects of body morphology remains poorly understood. We combined the GWAS summary statistics of fourteen anthropometric traits from UK Biobank through principal component analysis to reveal four major independent axes: body size, adiposity, predisposition to abdominal fat deposition, and lean mass. Mendelian randomization analysis showed that although body size and adiposity both contribute to the consequences of BMI, many of their effects are distinct, such as body size increasing the risk of cardiac arrhythmia (b = 0.06, p = 4.2 ∗ 10 &lt;sup&gt;-17&lt;/sup&gt; ) while adiposity instead increased that of ischemic heart disease (b = 0.079, p = 8.2 ∗ 10 &lt;sup&gt;-21&lt;/sup&gt; ). The body mass-neutral component predisposing to abdominal fat deposition, likely reflecting a shift from subcutaneous to visceral fat, exhibited health effects that were weaker but specifically linked to lipotoxicity, such as ischemic heart disease (b = 0.067, p = 9.4 ∗ 10 &lt;sup&gt;-14&lt;/sup&gt; ) and diabetes (b = 0.082, p = 5.9 ∗ 10 &lt;sup&gt;-19&lt;/sup&gt; ). Combining their independent predicted effects significantly improved the prediction of obesity-related diseases (p &lt; 10 &lt;sup&gt;-10&lt;/sup&gt; ). The presented decomposition approach sheds light on the biological mechanisms underlying the heterogeneity of body morphology and its consequences on health and lifestyle

Multi-Ancestry Sleep-by-SNP Interaction Analysis in 126,926 Individuals Reveals Lipid Loci Stratified by Sleep Duration

Both short and long sleep are associated with an adverse lipid profile, likely through different biological pathways. To elucidate the biology of sleep-associated adverse lipid profile, we conduct multi-ancestry genome-wide sleep-SNP interaction analyses on three lipid traits (HDL-c, LDL-c and triglycerides). In the total study sample (discovery + replication) of 126,926 individuals from 5 different ancestry groups, when considering either long or short total sleep time interactions in joint analyses, we identify 49 previously unreported lipid loci, and 10 additional previously unreported lipid loci in a restricted sample of European-ancestry cohorts. In addition, we identify new gene-sleep interactions for known lipid loci such as LPL and PCSK9. The previously unreported lipid loci have a modest explained variance in lipid levels: most notable, gene-short-sleep interactions explain 4.25% of the variance in triglyceride level. Collectively, these findings contribute to our understanding of the biological mechanisms involved in sleep-associated adverse lipid profiles

Multi-Ancestry Genome-Wide Association Study Accounting for Gene-Psychosocial Factor Interactions Identifies Novel Loci for Blood Pressure Traits

Psychological and social factors are known to influence blood pressure (BP) and risk of hypertension and associated cardiovascular diseases. To identify novel BP loci, we carried out genome-wide association meta-analyses of systolic, diastolic, pulse, and mean arterial BP, taking into account the interaction effects of genetic variants with three psychosocial factors: depressive symptoms, anxiety symptoms, and social support. Analyses were performed using a two-stage design in a sample of up to 128,894 adults from five ancestry groups. In the combined meta-analyses of stages 1 and 2, we identified 59 loci (p value \u3c 5e−8), including nine novel BP loci. The novel associations were observed mostly with pulse pressure, with fewer observed with mean arterial pressure. Five novel loci were identified in African ancestry, and all but one showed patterns of interaction with at least one psychosocial factor. Functional annotation of the novel loci supports a major role for genes implicated in the immune response (PLCL2), synaptic function and neurotransmission (LIN7A and PFIA2), as well as genes previously implicated in neuropsychiatric or stress-related disorders (FSTL5 and CHODL). These findings underscore the importance of considering psychological and social factors in gene discovery for BP, especially in non-European populations

Decision Aids for Prostate Cancer Screening Choice: A Systematic Review and Meta-analysis

Key PointsQuestionWhat is the association of decision aids vs usual care with shared decision-making in men deciding whether to undergo prostate cancer screening? FindingsThis systematic review and meta-analysis of 19 randomized clinical trials comparing decision aids for prostate cancer screening (12781 men) found that decision aids are probably associated with a small reduction in decisional conflict and are possibly associated with an increase in knowledge. Decision aids are possibly not associated with whether physicians and patients discuss prostate cancer screening and are possibly not associated with actual screening decisions. MeaningRandomized clinical trials have failed to provide compelling evidence for the use of decision aids for men contemplating prostate cancer screening that have, up to now, undergone rigorous testing to determine their outcome. ImportanceUS guidelines recommend that physicians engage in shared decision-making with men considering prostate cancer screening. ObjectiveTo estimate the association of decision aids with decisional outcomes in prostate cancer screening. Data SourcesMEDLINE, Embase, PsycINFO, CINAHL, and Cochrane CENTRAL were searched from inception through June 19, 2018. Study SelectionRandomized trials comparing decision aids for prostate cancer screening with usual care. Data Extraction and SynthesisIndependent duplicate assessment of eligibility and risk of bias, rating of quality of the decision aids, random-effects meta-analysis, and Grading of Recommendations, Assessment, Development and Evaluations rating of the quality of evidence. Main Outcomes and MeasuresKnowledge, decisional conflict, screening discussion, and screening choice. ResultsOf 19 eligible trials (12781 men), 9 adequately concealed allocation and 8 blinded outcome assessment. Of 12 decision aids with available information, only 4 reported the likelihood of a true-negative test result, and 3 presented the likelihood of false-negative test results or the next step if the screening test result was negative. Decision aids are possibly associated with improvement in knowledge (risk ratio, 1.38; 95% CI, 1.09-1.73; I-2=67%; risk difference, 12.1; low quality), are probably associated with a small decrease in decisional conflict (mean difference on a 100-point scale, -4.19; 95% CI, -7.06 to -1.33; I-2=75%; moderate quality), and are possibly not associated with whether physicians and patients discuss prostate cancer screening (risk ratio, 1.12; 95% CI, 0.90-1.39; I-2=60%; low quality) or with men's decision to undergo prostate cancer screening (risk ratio, 0.95; 95% CI, 0.88-1.03; I-2=36%; low quality). Conclusions and RelevanceThe results of this study provide moderate-quality evidence that decision aids compared with usual care are associated with a small decrease in decisional conflict and low-quality evidence that they are associated with an increase in knowledge but not with whether physicians and patients discussed prostate cancer screening or with screening choice. Results suggest that further progress in facilitating effective shared decision-making may require decision aids that not only provide education to patients but are specifically targeted to promote shared decision-making in the patient-physician encounter. This systematic review and meta-analysis of 19 randomized clinical trials estimates the association of decision aids with decisional outcomes in prostate cancer screening.Peer reviewe