Skin cancers are the most frequent cancers in fair-skinned populations, but we can prevent them

Cancers of the skin are the most commonly occurring cancers in humans. In fair-skinned populations, up to 95% of keratinocyte skin cancers and 70-95% of cutaneous melanomas are caused by ultraviolet radiation and are thus theoretically preventable. Currently, however, there is no comprehensive global advice on practical steps to be taken to reduce the toll of skin cancer. To address this gap, an expert working group comprising clinicians and researchers from Africa, America, Asia, Australia, and Europe, together with learned societies (European Association of Dermato-Oncology, Euromelanoma, Euroskin, European Union of Medical Specialists, and the Melanoma World Society) reviewed the extant evidence and issued the following evidence-based recommendations for photoprotection as a strategy to prevent skin cancer. Fair skinned people, especially children, should minimise their exposure to ultraviolet radiation, and are advised to use protective measures when the UV index is forecast to reach 3 or higher. Protective measures include a combination of seeking shade, physical protection (e.g. clothing, hat, sunglasses), and applying broad-spectrum, SPF 30 + sunscreens to uncovered skin. Intentional exposure to solar ultraviolet radiation for the purpose of sunbathing and tanning is considered an unhealthy behaviour and should be avoided. Similarly, use of solaria and other artificial sources of ultraviolet radiation to encourage tanning should be strongly discouraged, through regulation if necessary. Primary prevention of skin cancer has a positive return on investment. We encourage policymakers to communicate these messages to the general public and promote their wider implementation.

Age group-specific changes in keratinocyte cancer treatment rates in Australia, 2012-2021: a retrospective cohort study based on MBS claims data

OBJECTIVES

To examine recent changes in the numbers of Medicare-subsidised keratinocyte cancer excisions, particularly for younger people exposed to primary prevention campaigns since the early 1980s.

STUDY DESIGN

Retrospective cohort study; analysis of administrative data.

SETTING, PARTICIPANTS

Analysis of Medicare Benefits Schedule (MBS) claims data for procedures related to the diagnosis and treatment of keratinocyte cancer in Australia, 2012-2021.

MAIN OUTCOME MEASURES

Age-standardised rates for MBS-subsidised claims for first surgical squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) excisions, Mohs surgery, surgical excisions of benign lesions, skin biopsies, and cryotherapy or serial curettage of premalignant and malignant lesions, overall, and by sex, state/territory, and age group; average annual percentage change in rate for time intervals determined by joinpoint regression.

RESULTS

In men, the age-standardised rate of BCC/SCC excisions increased by 1.9% (95% confidence interval [CI], 1.4-2.4%) per year during 2012-2019 (from 2931 to 3371 per 100 000 men) and then declined by 3.8% (95% CI, 0.5-7.0%) per year during 2019-2021 (to 3152 per 100 000). In women, the age-standardised rate increased by 2.2% (95% CI, 1.7-2.8%) per year during 2012-2019 (from 1798 to 2093 per 100 000 women); the decline to 1967 excisions per 100 000 women in 2021 was not statistically significant. BCC/SCC excision rates declined for men under 55 years of age (by 1.0-3.4% per year) and women under 45 years of age (by 1.7-2.3% per year). Age-standardised biopsy rates increased during 2012-2021 in all age groups (by 2.8-6.9% per year).

CONCLUSIONS

Rates of MBS-subsidised treatment for keratinocyte cancers increased during 2012-2019, but BCC/SCC treatment rates declined among younger Australians, who have probably been exposed to less sunlight than earlier generations because of public health interventions and population-wide lifestyle changes related to technology use.

Genetic predisposition to childhood obesity does not influence the risk of developing skin cancer in adulthood

The relationship between body mass index (BMI) and melanoma and other skin cancers remains unclear. The objective of this study was to employ the Mendelian randomization (MR) approach to evaluate the effects of genetically predicted childhood adiposity on the risk of developing skin cancer later in life. Two-sample MR analyses were conducted using summary data from genome-wide association study (GWAS) meta-analyses of childhood BMI, melanoma, cutaneous squamous cell carcinoma (cSCC), and basal cell carcinoma (BCC). We used the inverse-variance-weighted (IVW) methods to obtain a pooled estimate across all genetic variants for childhood BMI. We performed multiple sensitivity analyses to evaluate the potential influence of various assumptions on our findings. We found no evidence that genetically predicted childhood BMI was associated with risks of developing melanoma, cSCC, or BCC in adulthood (OR, 95% CI: melanoma: 1.02 (0.93-1.13), cSCC 0.94 (0.79-1.11), BCC 0.97 (0.84-1.12)). Our findings do not support the conclusions from observational studies that childhood BMI is associated with increased risks of melanoma, cSCC, or BCC in adulthood. Intervening on childhood adiposity will not reduce the risk of common skin cancers later in life.

The effect of three years of vitamin D supplementation on erectile dysfunction: Results from the randomized placebo-controlled D-Health Trial

BACKGROUND & AIMS

Erectile dysfunction is common among older men and has been associated with low serum 25-hydroxy vitamin D concentration. However, this association may be due to uncontrolled confounding, and there is a paucity of evidence from interventional studies. We aimed to examine the effect of vitamin D supplementation on the prevalence of erectile dysfunction, in an exploratory analysis using data from a large randomized controlled trial.

METHODS

The D-Health Trial recruited Australians aged 60-84 years between January 2014 and May 2015 and randomly assigned them to supplementation with 60,000 IU of vitamin D or placebo per month for up to 5 years. Blood samples were collected annually from randomly selected participants (total N = 3943). We assessed erectile dysfunction at the end of the third year of follow-up. We used log-binomial regression to examine the effect of vitamin D on the prevalence of erectile dysfunction overall, and within sub-groups.

RESULTS

Of the 11,530 men enrolled, 8920 (77.4 %) completed the erectile dysfunction question and were included in the analysis. After three years of supplementation, the mean serum 25-hydroxy vitamin D concentration was 76 nmol/L (standard deviation (SD) 24.94) in the placebo group and 106 nmol/L (SD 26.76) in the vitamin D group (p < 0.0001). The prevalence of erectile dysfunction was 58.8 % and 59.0 % in the vitamin D and placebo groups, respectively (prevalence ratio 1.00, 95 % CI 0.97, 1.03); there was no evidence of an effect of vitamin D in any subgroup analyses.

CONCLUSION

Supplementing older men with vitamin D is unlikely to prevent or improve erectile dysfunction.

CLINICAL TRIALS REGISTRY

(ACTRN12613000743763).

International patterns and trends in the incidence of melanoma and cutaneous squamous cell carcinoma, 1989-2020

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) and melanoma have different associations with sun exposure.

OBJECTIVES

To compare trends in the incidence rates of cSCC and melanoma, to provide insight into changing patterns of exposure to ultraviolet radiation (UVR).

METHODS

We compared trends in the incidence of cSCC and melanoma in seven susceptible populations residing at mid-to-high latitudes: Finland, Norway, Sweden, Denmark, Scotland, the Netherlands and Tasmania (Australia). We fitted Joinpoint models to describe trends in age-standardized incidence rates for melanoma and cSCC and calculated the average annual percentage rate of change for the period 1989-2020 (1989-2018 for Tasmania). We calculated the incident rate ratio (IRR) as the ratio of the age-standardized rates (European Standard Population) for cSCC to melanoma and conducted age-period-cohort modelling to compare age, period and cohort effects.

RESULTS

The ratio of cSCC-to-melanoma incidence increased with proximity to the equator and over time. In the most recent time period, the incidence of cSCC was higher than the incidence of melanoma for men and women in all seven populations. While the ratio of cSCC-to-melanoma incidence was higher for men vs. women, in most countries the cSCC-to-melanoma IRR increased over time to a greater extent in women than in men. Melanoma incidence was higher among younger people and cSCC incidence was higher among older people; the age at which the incidence of cSCC overtook the incidence of melanoma was progressively younger with proximity to the equator.

CONCLUSIONS

Despite concerted international efforts to preserve the ozone layer over the past four decades resulting in significant reductions in surface ultraviolet B at mid-latitudes, the incidence of skin cancer, particularly cSCC, continues to rise in those regions. Our findings are consistent with a stronger association with age-associated cumulative sun exposure for cSCC vs. melanoma and suggest that women are currently receiving greater UV radiation exposure than in the past.

Genetic Analysis of Perceived Youthfulness Reveals Differences in How Men's and Women's Age Is Assessed

Skin aging is a natural process that occurs over time but can be accelerated by sun exposure. Measuring skin age in a large population can provide insight into the extent of skin damage from sun exposure and skin cancer risk. Understanding the genetics of skin aging, within and across sexes (males and females), could improve our understanding of the genetic drivers of both skin aging and skin cancer. We used UK Biobank data to examine the genetic overlap between perceived youthfulness and traits relevant to actinic photoaging. Our GWAS identified 22 genome-wide significant loci for women and 43 for men. The genetic correlation (rg) between perceived youthfulness in men and women was significantly less than unity (rg = 0.75, 95% confidence interval = 0.69-0.80), suggesting a gene-by-sex interaction. In women, perceived youthfulness was modestly correlated with keratinocyte cancer (rg = -0.19) and skin tanning (rg = 0.18). In men, perceived youthfulness was correlated with male-pattern baldness (rg = -0.23). This suggests that the genetic architecture of perceived youthfulness may differ between sexes, with genes influencing skin tanning and skin cancer susceptibility driving the difference in women, whereas genes influencing male-pattern baldness and other puberty-related traits drive the difference in men. We recommend that future genetic analysis of skin aging include a sex-stratified component.

Balancing the risks and benefits of sun exposure: A revised position statement for Australian adults

OBJECTIVE

To describe the development of a new position statement regarding balancing the risks and benefits of sun exposure for Australian adults.

METHODS

We conducted a Sun Exposure Summit in March 2021, with presentations from invited experts and a workshop including representation from academic, clinical, policy, and patient stakeholder organisations. The group considered advice about balancing the risks and benefits of sun exposure for Australian adults and developed a revised consensus position statement.

RESULTS

The balance of risks and benefits of sun exposure is not the same for everybody. For people at very high risk of skin cancer, the risks of exposure likely outweigh the benefits; sun protection is essential. Conversely, people with deeply pigmented skin are at low risk of skin cancer but at high risk of vitamin D deficiency; routine sun protection is not recommended. For those at intermediate risk of skin cancer, sun protection remains a priority, but individuals may obtain sufficient sun exposure to maintain adequate vitamin D status.

CONCLUSIONS

The new position statement provides sun exposure advice that explicitly recognises the differing needs of Australia's diverse population.

IMPLICATIONS FOR PUBLIC HEALTH

Mass communication campaigns should retain the focus on skin cancer prevention. The new position statement will support the delivery of personalised advice.

Genome-wide association study meta-analysis of dizygotic twinning illuminates genetic regulation of female fecundity

STUDY QUESTION

Which genetic factors regulate female propensity for giving birth to spontaneous dizygotic (DZ) twins?

SUMMARY ANSWER

We identified four new loci, GNRH1, FSHR, ZFPM1, and IPO8, in addition to previously identified loci, FSHB and SMAD3.

WHAT IS KNOWN ALREADY

The propensity to give birth to DZ twins runs in families. Earlier, we reported that FSHB and SMAD3 as associated with DZ twinning and female fertility measures.

STUDY DESIGN, SIZE, DURATION

We conducted a genome-wide association meta-analysis (GWAMA) of mothers of spontaneous dizygotic (DZ) twins (8265 cases, 264 567 controls) and of independent DZ twin offspring (26 252 cases, 417 433 controls).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Over 700 000 mothers of DZ twins, twin individuals and singletons from large cohorts in Australia/New Zealand, Europe, and the USA were carefully screened to exclude twins born after use of ARTs. Genetic association analyses by cohort were followed by meta-analysis, phenome wide association studies (PheWAS), in silico and in vivo annotations, and Zebrafish functional validation.

MAIN RESULTS AND THE ROLE OF CHANCE

This study enlarges the sample size considerably from previous efforts, finding four genome-wide significant loci, including two novel signals and a further two novel genes that are implicated by gene level enrichment analyses. The novel loci, GNRH1 and FSHR, have well-established roles in female reproduction whereas ZFPM1 and IPO8 have not previously been implicated in female fertility. We found significant genetic correlations with multiple aspects of female reproduction and body size as well as evidence for significant selection against DZ twinning during human evolution. The 26 top single nucleotide polymorphisms (SNPs) from our GWAMA in European-origin participants weakly predicted the crude twinning rates in 47 non-European populations (r = 0.23 between risk score and population prevalence, s.e. 0.11, 1-tail P = 0.058) indicating that genome-wide association studies (GWAS) are needed in African and Asian populations to explore the causes of their respectively high and low DZ twinning rates. In vivo functional tests in zebrafish for IPO8 validated its essential role in female, but not male, fertility. In most regions, risk SNPs linked to known expression quantitative trait loci (eQTLs). Top SNPs were associated with in vivo reproductive hormone levels with the top pathways including hormone ligand binding receptors and the ovulation cycle.

LARGE SCALE DATA

The full DZT GWAS summary statistics will made available after publication through the GWAS catalog (https://www.ebi.ac.uk/gwas/).

LIMITATIONS, REASONS FOR CAUTION

Our study only included European ancestry cohorts. Inclusion of data from Africa (with the highest twining rate) and Asia (with the lowest rate) would illuminate further the biology of twinning and female fertility.

WIDER IMPLICATIONS OF THE FINDINGS

About one in 40 babies born in the world is a twin and there is much speculation on why twinning runs in families. We hope our results will inform investigations of ovarian response in new and existing ARTs and the causes of female infertility.

STUDY FUNDING/COMPETING INTEREST(S)

Support for the Netherlands Twin Register came from the Netherlands Organization for Scientific Research (NWO) and The Netherlands Organization for Health Research and Development (ZonMW) grants, 904-61-193, 480-04-004, 400-05-717, Addiction-31160008, 911-09-032, Biobanking and Biomolecular Resources Research Infrastructure (BBMRI.NL, 184.021.007), Royal Netherlands Academy of Science Professor Award (PAH/6635) to DIB, European Research Council (ERC-230374), Rutgers University Cell and DNA Repository (NIMH U24 MH068457-06), the Avera Institute, Sioux Falls, South Dakota (USA) and the National Institutes of Health (NIH R01 HD042157-01A1) and the Genetic Association Information Network (GAIN) of the Foundation for the National Institutes of Health and Grand Opportunity grants 1RC2 MH089951. The QIMR Berghofer Medical Research Institute (QIMR) study was supported by grants from the National Health and Medical Research Council (NHMRC) of Australia (241944, 339462, 389927, 389875, 389891, 389892, 389938, 443036, 442915, 442981, 496610, 496739, 552485, 552498, 1050208, 1075175). L.Y. is funded by Australian Research Council (Grant number DE200100425). The Minnesota Center for Twin and Family Research (MCTFR) was supported in part by USPHS Grants from the National Institute on Alcohol Abuse and Alcoholism (AA09367 and AA11886) and the National Institute on Drug Abuse (DA05147, DA13240, and DA024417). The Women's Genome Health Study (WGHS) was funded by the National Heart, Lung, and Blood Institute (HL043851 and HL080467) and the National Cancer Institute (CA047988 and UM1CA182913), with support for genotyping provided by Amgen. Data collection in the Finnish Twin Registry has been supported by the Wellcome Trust Sanger Institute, the Broad Institute, ENGAGE-European Network for Genetic and Genomic Epidemiology, FP7-HEALTH-F4-2007, grant agreement number 201413, National Institute of Alcohol Abuse and Alcoholism (grants AA-12502, AA-00145, AA-09203, AA15416, and K02AA018755) and the Academy of Finland (grants 100499, 205585, 118555, 141054, 264146, 308248, 312073 and 336823 to J. Kaprio). TwinsUK is funded by the Wellcome Trust, Medical Research Council, Versus Arthritis, European Union Horizon 2020, Chronic Disease Research Foundation (CDRF), Zoe Ltd and the National Institute for Health Research (NIHR) Clinical Research Network (CRN) and Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust in partnership with King's College London. For NESDA, funding was obtained from the Netherlands Organization for Scientific Research (Geestkracht program grant 10000-1002), the Center for Medical Systems Biology (CSMB, NVVO Genomics), Biobanking and Biomolecular Resources Research Infrastructure (BBMRI-NL), VU University's Institutes for Health and Care Research (EMGO+) and Neuroscience Campus Amsterdam, University Medical Center Groningen, Leiden University Medical Center, National Institutes of Health (NIH, ROI D0042157-01A, MH081802, Grand Opportunity grants 1 RC2 Ml-1089951 and IRC2 MH089995). Part of the genotyping and analyses were funded by the Genetic Association Information Network (GAIN) of the Foundation for the National Institutes of Health. Computing was supported by BiG Grid, the Dutch e-Science Grid, which is financially supported by NWO. Work in the Del Bene lab was supported by the Programme Investissements d'Avenir IHU FOReSIGHT (ANR-18-IAHU-01). C.R. was supported by an EU Horizon 2020 Marie Skłodowska-Curie Action fellowship (H2020-MSCA-IF-2014 #661527). H.S. and K.S. are employees of deCODE Genetics/Amgen. The other authors declare no competing financial interests.

TRIAL REGISTRATION NUMBER

N/A.

Comprehensive Sex-Stratified Genetic Analysis of 28 Blood Biomarkers and Depression Reveals a Significant Association between Depression and Low Levels of Total Protein in Females

Introduction

Major depression (MD) is more common amongst women than men, and MD episodes have been associated with fluctuations in reproductive hormones amongst women. To investigate biological underpinnings of heterogeneity in MD, the associations between depression, stratified by sex and including perinatal depression (PND), and blood biomarkers, using UK Biobank (UKB) data, were evaluated, and extended to include the association of depression with biomarker polygenic scores (PGS), generated as proxy for each biomarker.

Method

Using female (N = 39,761) and male (N = 38,821) UKB participants, lifetime MD and PND were tested for association with 28 blood biomarkers. A GWAS was conducted for each biomarker and genetic correlations with depression subgroups were estimated. Using independent data from the Australian Genetics of Depression Study, PGS were constructed for each biomarker, and tested for association with depression status (n [female cases/controls] = 9,006/6,442; n [male cases/controls] = 3,106/6,222). Regions of significant local genetic correlation between depression subgroups and biomarkers highlighted by the PGS analysis were identified.

Results

Depression in females was significantly associated with levels of twelve biomarkers, including total protein (OR = 0.90, CI = [0.86, 0.94], p = 3.9 × 10-6) and vitamin D (OR = 0.94, CI = [0.90, 0.97], p = 2.6 × 10-4), and PND with five biomarker levels, also including total protein (OR = 0.88, CI = [0.81, 0.96], p = 4.7 × 10-3). Depression in males was significantly associated with levels of eleven biomarkers. In the independent Australian Genetics of Depression Study, PGS analysis found significant associations for female depression and PND with total protein (female depression: OR = 0.93, CI = [0.88, 0.98], p = 3.6 × 10-3; PND: OR = 0.91, CI = [0.86, 0.96], p = 1.1 × 10-3), as well as with vitamin D (female depression: OR = 0.93, CI = [0.89, 0.97], p = 2.0 × 10-3; PND: OR = 0.92, CI = [0.87, 0.97], p = 1.4 × 10-3). The male depression sample did not report any significant results, and the point estimate of total protein (OR = 0.98, CI = [0.92-1.04], p = 4.7 × 10-1) did not indicate any association. Local genetic correlation analysis highlighted significant genetic correlation between PND and total protein, located in 5q13.3 (rG = 0.68, CI = [0.33, 1.0], p = 3.6 × 10-4).

Discussion and Conclusion

Multiple lines of evidence from genetic analysis highlight an association between total serum protein levels and depression in females. Further research involving prospective measurement of total protein and depressive symptoms is warranted.

Does genetic risk modify the effect of skin screening on melanoma detection rates?

BACKGROUND

Skin screening is associated with higher melanoma detection rates, a potential indicator of overdiagnosis, but it remains possible that this effect is due to confounding by genetic risk.

OBJECTIVES

To compare melanoma incidence among screened vs. unscreened participants within tertiles of genetic risk.

METHODS

We investigated melanoma incidence in the QSkin study, a prospective cohort study which for this analysis comprised 15 283 participants aged 40-69 years with genotype data and no prior history of melanoma. We calculated a polygenic score (PGS) for melanoma. We first calculated the age-standardized rate (ASR) of melanoma within PGS tertiles, and then measured the association between skin examination and melanoma detection by calculating the hazard ratio (HR) and 95% confidence interval (95% CI), overall and within PGS tertiles.

RESULTS

Melanoma incidence increased with PGS (ASR per 100 000 per year): tertile 1 = 442; tertile 2 = 519; tertile 3 = 871. We found that the HRs for all melanomas (i.e. in situ and invasive) associated with skin examination differed slightly across PGS tertiles [age- and sex-adjusted tertile 1 HR 1.88 (95% CI 1.26-2.81); tertile 2 HR 1.70 (95% CI 1.20-2.41); tertile 3 HR 1.96 (95% CI 1.43-2.70); fully adjusted tertile 1 HR 1.14 (95% CI 0.74-1.75); tertile 2 HR 1.21 (95% CI 0.82-1.78); tertile 3 HR 1.41 (95% CI 1.00-1.98)], but these differences were not statistically significant. HRs for in situ melanoma associated with skin examination were similar across PGS tertiles. For invasive melanomas, the point estimates appeared to be highest in PGS tertile 3 in both the minimally adjusted (age, sex) and fully adjusted models; however, these apparent differences were also not statistically significant.

CONCLUSIONS

Genetic risk predicts subsequent melanoma incidence, and is weakly associated with screening behaviour, but it does not explain the higher rate of melanoma detection between screened and unscreened people.

Meta-Analyses of Genome-Wide Association Studies for Postpartum Depression

OBJECTIVE

Postpartum depression (PPD) is a common subtype of major depressive disorder (MDD) that is more heritable, yet is understudied in psychiatric genetics. The authors conducted meta-analyses of genome-wide association studies (GWASs) to investigate the genetic architecture of PPD.

METHOD

Meta-analyses were conducted on 18 cohorts of European ancestry (17,339 PPD cases and 53,426 controls), one cohort of East Asian ancestry (975 cases and 3,780 controls), and one cohort of African ancestry (456 cases and 1,255 controls), totaling 18,770 PPD cases and 58,461 controls. Post-GWAS analyses included 1) single-nucleotide polymorphism (SNP)-based heritability ([Formula: see text]), 2) genetic correlations between PPD and other phenotypes, and 3) enrichment of the PPD GWAS findings in 27 human tissues and 265 cell types from the mouse central and peripheral nervous system.

RESULTS

No SNP achieved genome-wide significance in the European or the trans-ancestry meta-analyses. The [Formula: see text] of PPD was 0.14 (SE=0.02). Significant genetic correlations were estimated for PPD with MDD, bipolar disorder, anxiety disorders, posttraumatic stress disorder, insomnia, age at menarche, and polycystic ovary syndrome. Cell-type enrichment analyses implicate inhibitory neurons in the thalamus and cholinergic neurons within septal nuclei of the hypothalamus, a pattern that differs from MDD.

CONCLUSIONS

While more samples are needed to reach genome-wide levels of significance, the results presented confirm PPD as a polygenic and heritable phenotype. There is also evidence that despite a high correlation with MDD, PPD may have unique genetic components. Cell enrichment results suggest GABAergic neurons, which converge on a common mechanism with the only medication approved by the U.S. Food and Drug Administration for PPD (brexanolone).

GWAS of Dizygotic Twinning in an Enlarged Australian Sample of Mothers of DZ Twins

Female fertility is a complex trait with age-specific changes in spontaneous dizygotic (DZ) twinning and fertility. To elucidate factors regulating female fertility and infertility, we conducted a genome-wide association study (GWAS) on mothers of spontaneous DZ twins (MoDZT) versus controls (3273 cases, 24,009 controls). This is a follow-up study to the Australia/New Zealand (ANZ) component of that previously reported (Mbarek et al., 2016), with a sample size almost twice that of the entire discovery sample meta-analysed in the previous article (and five times the ANZ contribution to that), resulting from newly available additional genotyping and representing a significant increase in power. We compare analyses with and without male controls and show unequivocally that it is better to include male controls who have been screened for recent family history, than to use only female controls. Results from the SNP based GWAS identified four genomewide significant signals, including one novel region, ZFPM1 (Zinc Finger Protein, FOG Family Member 1), on chromosome 16. Previous signals near FSHB (Follicle Stimulating Hormone beta subunit) and SMAD3 (SMAD Family Member 3) were also replicated (Mbarek et al., 2016). We also ran the GWAS with a dominance model that identified a further locus ADRB2 on chr 5. These results have been contributed to the International Twinning Genetics Consortium for inclusion in the next GWAS meta-analysis (Mbarek et al., in press).

Health care service use by people diagnosed with invasive melanoma in Queensland: a benefit incidence analysis

OBJECTIVE

To quantify differences, by residential remoteness and socio-economic status, in health care service use by people diagnosed with invasive melanoma in Queensland.

DESIGN

Benefit incidence analysis of CancerCostMod data, comprising Queensland Cancer Registry data linked with Queensland Hospital Admitted Patient Data Collection (QHAPDC), Medicare Benefits Schedule (MBS), and Pharmaceutical Benefits Scheme (PBS) data.

SETTING, PARTICIPANTS

Adults (18 years or older) newly diagnosed with invasive melanoma in Queensland during 1 July 2011 - 31 June 2015 and alive three years after diagnosis.

MAIN OUTCOME MEASURES

Concentration curves and indices quantifying differences by residential postcode-based remoteness (Australian Statistical Geography Standard - Remoteness Area) and socio-economic disadvantage (Index of Relative Socioeconomic Disadvantage) in hospital admissions (overall and by type) and use of MBS (overall and by type) and PBS services during the three years following diagnosis of invasive melanoma.

RESULTS

A total of 13 145 adults diagnosed with invasive melanoma during 2011-15 were alive three years after the diagnosis. Public hospital admissions were more frequent for people living in areas of greater socio-economic disadvantage (concentration index, -0.15; 95% confidence interval [CI], -0.19 to -0.12) or outside major cities (concentration index, -0.10; 95% CI, -0.13 to -0.06); private hospital admissions (concentration index, 0.11; 95% CI, 0.07-0.15) and specialist consultations (concentration index, 0.08; 95% CI, 0.07-0.10) were more frequent in areas of lesser disadvantage and in major cities (private hospital admissions: 0.10; 95% CI, 0.06-0.13; specialist services: 0.07; 95% CI, 0.06-0.09). Differences in other melanoma health care service use by residential remoteness and socio-economic disadvantage were not statistically significant.

CONCLUSIONS

Variation in health care service use by Queenslanders with primary diagnoses of invasive melanoma by residential socio-economic disadvantage and remoteness were generally minor. Our analysis suggests that access to health care for people with melanoma is fairly equitable in Queensland.

The Effect of Vitamin D Supplementation on Hypothyroidism in the Randomized Controlled D-Health Trial

Background: Hypothyroidism is common, and in iodine-sufficient areas, it is primarily caused by autoimmune destruction of the thyroid gland. Observational studies have consistently shown an inverse association between serum 25-hydroxyvitamin D concentration and autoimmune diseases; however, there is a lack of evidence from randomized controlled trials to support a benefit of vitamin D supplementation, particularly for autoimmune thyroid diseases. We, therefore, aimed to assess the effect of vitamin D supplementation on the incidence of hypothyroidism. Methods: We analyzed data from the D-Health Trial (n = 21,315), a randomized double-blind placebo-controlled trial of 60,000 international units per month of supplemental vitamin D3 among Australians aged 60 years and over. Hypothyroidism, a tertiary outcome of the D-Health Trial, was defined by treatment with levothyroxine, ascertained through linkage with the Australian Pharmaceutical Benefits Scheme. The outcome was time to first prescription of levothyroxine. We began follow-up at 12 months after randomization; people who had died or who had been dispensed levothyroxine during the first year were excluded. Flexible parametric survival models were used to assess the effect of vitamin D supplementation on hypothyroidism, overall and within strata defined by age, sex, body mass index, and predicted baseline vitamin D status. Results: We included 17,851 participants in the main analysis (vitamin D = 8939; placebo = 8912). During a median follow-up of 4.1 years (interquartile range 4.1-4.1), 293 participants developed hypothyroidism (vitamin D = 138 [1.5%]; placebo = 155 [1.7%]). Vitamin D supplementation did not significantly reduce the incidence of hypothyroidism (overall hazard ratio [HR] 0.89; 95% confidence interval [CI] 0.71-1.12). There was some suggestion of an effect in females (overall HR 0.78; CI 0.58-1.06) but not in males (overall HR 1.06; CI 0.74-1.50; p interaction 0.20). Conclusions: Vitamin D supplementation did not reduce the incidence of hypothyroidism overall; however, the possible beneficial effect observed in females warrants further investigation. Clinical Trial Registration: Australian New Zealand Clinical Trials Registry: ACTRN12613000743763.

Comparative age-period-cohort analysis

BACKGROUND

Cancer surveillance researchers analyze incidence or mortality rates jointly indexed by age group and calendar period using age-period-cohort models. Many studies consider age- and period-specific rates in two or more strata defined by sex, race/ethnicity, etc. A comprehensive characterization of trends and patterns within each stratum can be obtained using age-period-cohort (APC) estimable functions (EF). However, currently available approaches for joint analysis and synthesis of EF are limited.

METHODS

We develop a new method called Comparative Age-Period-Cohort Analysis to quantify similarities and differences of EF across strata. Comparative Analysis identifies whether the stratum-specific hazard rates are proportional by age, period, or cohort.

RESULTS

Proportionality imposes natural constraints on the EF that can be exploited to gain efficiency and simplify the interpretation of the data. Comparative Analysis can also identify differences or diversity in proportional relationships between subsets of strata ("pattern heterogeneity"). We present three examples using cancer incidence from the United States Surveillance, Epidemiology, and End Results Program: non-malignant meningioma by sex; multiple myeloma among men stratified by race/ethnicity; and in situ melanoma by anatomic site among white women.

CONCLUSIONS

For studies of cancer rates with from two through to around 10 strata, which covers many outstanding questions in cancer surveillance research, our new method provides a comprehensive, coherent, and reproducible approach for joint analysis and synthesis of age-period-cohort estimable functions.

Genetic variants for smoking behaviour and risk of skin cancer

Observational studies have suggested that smoking may increase the risk of cutaneous squamous cell carcinoma (cSCC) while decreasing the risks of basal cell carcinoma (BCC), and melanoma. However, it remains possible that confounding by other factors may explain these associations. The aim of this investigation was to use Mendelian randomization (MR) to test whether smoking is associated with skin cancer, independently of other factors. Two-sample MR analyses were conducted to determine the causal effect of smoking measures on skin cancer risk using genome-wide association study (GWAS) summary statistics. We used the inverse-variance-weighted estimator to derive separate risk estimates across genetic instruments for all smoking measures. A genetic predisposition to smoking initiation was associated with lower risks of all skin cancer types, although none of the effect estimates reached statistical significance (OR 95% CI BCC 0.91, 0.82-1.01; cSCC 0.82, 0.66-1.01; melanoma 0.91, 0.82-1.01). Results for other measures were similar to smoking initiation with the exception of smoking intensity which was associated with a significantly reduced risk of melanoma (OR 0.67, 95% CI 0.51-0.89). Our findings support the findings of observational studies linking smoking to lower risks of melanoma and BCC. However, we found no evidence that smoking is associated with an elevated risk of cSCC; indeed, our results are most consistent with a decreased risk, similar to BCC and melanoma.

Uncovering the complex relationship between balding, testosterone and skin cancers in men

Male-pattern baldness (MPB) is related to dysregulation of androgens such as testosterone. A previously observed relationship between MPB and skin cancer may be due to greater exposure to ultraviolet radiation or indicate a role for androgenic pathways in the pathogenesis of skin cancers. We dissected this relationship via Mendelian randomization (MR) analyses, using genetic data from recent male-only meta-analyses of cutaneous melanoma (12,232 cases; 20,566 controls) and keratinocyte cancers (KCs) (up to 17,512 cases; >100,000 controls), followed by stratified MR analysis by body-sites. We found strong associations between MPB and the risk of KC, but not with androgens, and multivariable models revealed that this relationship was heavily confounded by MPB single nucleotide polymorphisms involved in pigmentation pathways. Site-stratified MR analyses revealed strong associations between MPB with head and neck squamous cell carcinoma and melanoma, suggesting that sun exposure on the scalp, rather than androgens, is the main driver. Men with less hair covering likely explains, at least in part, the higher incidence of melanoma in men residing in countries with high ambient UV.

GWAS Meta-Analysis of Suicide Attempt: Identification of 12 Genome-Wide Significant Loci and Implication of Genetic Risks for Specific Health Factors

OBJECTIVE

Suicidal behavior is heritable and is a major cause of death worldwide. Two large-scale genome-wide association studies (GWASs) recently discovered and cross-validated genome-wide significant (GWS) loci for suicide attempt (SA). The present study leveraged the genetic cohorts from both studies to conduct the largest GWAS meta-analysis of SA to date. Multi-ancestry and admixture-specific meta-analyses were conducted within groups of significant African, East Asian, and European ancestry admixtures.

METHODS

This study comprised 22 cohorts, including 43,871 SA cases and 915,025 ancestry-matched controls. Analytical methods across multi-ancestry and individual ancestry admixtures included inverse variance-weighted fixed-effects meta-analyses, followed by gene, gene-set, tissue-set, and drug-target enrichment, as well as summary-data-based Mendelian randomization with brain expression quantitative trait loci data, phenome-wide genetic correlation, and genetic causal proportion analyses.

RESULTS

Multi-ancestry and European ancestry admixture GWAS meta-analyses identified 12 risk loci at p values <5×10-8. These loci were mostly intergenic and implicated DRD2, SLC6A9, FURIN, NLGN1, SOX5, PDE4B, and CACNG2. The multi-ancestry SNP-based heritability estimate of SA was 5.7% on the liability scale (SE=0.003, p=5.7×10-80). Significant brain tissue gene expression and drug set enrichment were observed. There was shared genetic variation of SA with attention deficit hyperactivity disorder, smoking, and risk tolerance after conditioning SA on both major depressive disorder and posttraumatic stress disorder. Genetic causal proportion analyses implicated shared genetic risk for specific health factors.

CONCLUSIONS

This multi-ancestry analysis of suicide attempt identified several loci contributing to risk and establishes significant shared genetic covariation with clinical phenotypes. These findings provide insight into genetic factors associated with suicide attempt across ancestry admixture populations, in veteran and civilian populations, and in attempt versus death.

Patterns and cost of care according to keratinocyte cancer risk stratification in a volunteer population screening clinic: Real-world data from the TRoPICS study

BACKGROUND

Risk prediction tools have been developed for keratinocyte cancers (KCs) to effectively categorize individuals with different levels of skin cancer burden. Few have been clinically validated nor routinely used in clinical settings.

OBJECTIVES

To assess whether risk prediction tool categories associate with interventions including chemoprophylaxis for skin cancer, and health-care costs in a dermatologist-run screening clinic.

METHODS

Adult participants who presented to a walk-in screening facility were invited to participate. A self-completed KC risk prediction tool was used to classify participants into one of the five risk categories. Participants subsequently underwent full skin examination by a dermatologist. Dermatological interventions and skin cancer-related medical prescriptions were documented. Total health-care costs, both to the health-care system and patients were evaluated.

RESULTS

Of the 507 participants recruited, 5-fluorouracil cream and nicotinamide were more frequently prescribed in the higher risk groups as chemoprophylaxis (p < 0.005). A significant association with high predicted risk was also observed in the use of cryotherapy and curettage and cautery (p < 0.05). The average health-care costs associated with a skin check visit increased from $90 ± 37 (standard deviation) in the lowest risk group to $149 ± 97 in the highest risk group (p < 0.0001).

CONCLUSIONS

We observed a positive association between higher predicted risk of skin cancer and the prescription of chemoprophylaxis and health-care costs involved with opportunistic community skin cancer screening. A clinical use of risk stratification may be to provide an opportunity for clinicians to discuss skin cancer prevention and chemoprophylaxis with individual patients.

High-risk Prognostic Tumor Features of Squamous Cell Carcinomas in Organ Transplant Recipients Compared With the General Population

Importance

The extent to which major high-risk features of squamous cell carcinomas (SCCs) in organ transplant recipients (OTRs) differ from SCCs in the general population is not known.

Objective

To quantify the relative frequency of perineural invasion, invasion below the dermis, lack of cellular differentiation, and tumor diameter greater than 20 mm in SCCs in OTRs and the general population, by anatomic site.

Design, Setting, and Participants

This dual-cohort study in Queensland, Australia, included a cohort of OTRs at high risk of skin cancer ascertained from 2012 to 2015 (Skin Tumours in Allograft Recipients [STAR] study) and a population-based cohort ascertained from 2011 (QSkin Sun and Health Study). The STAR study comprised population-based lung transplant recipients and kidney and liver transplant recipients at high risk of skin cancer recruited from tertiary centers and diagnosed with histopathologically confirmed SCC from 2012 to 2015. The QSkin participants were recruited from Queensland's general adult population, and primary SCCs diagnosed from 2012 to 2015 were ascertained through Medicare (national health insurance scheme) and linked with histopathology records. Data analysis was performed from July 2022 to April 2023.

Main Outcomes and Measures

Prevalence ratio (PR) of head/neck location, perineural invasion, tumor invasion to/beyond subcutaneous fat, poor cellular differentiation, and tumor diameter greater than 20 mm among SCCs in OTRs vs the general population.

Results

There were 741 SCCs excised from 191 OTRs (median [IQR] age, 62.7 [56.7-67.1] years; 149 [78.0%] male) and 2558 SCCs from 1507 persons in the general population (median [IQR] age, 63.7 [58.0-68.8] years; 955 [63.4%] male). The SCCs developed most frequently on the head/neck in OTRs (285, 38.6%), but on arms/hands in the general population (896, 35.2%) (P < .001). After adjusting for age and sex, perineural invasion was more than twice as common in OTRs as in population cases (PR, 2.37; 95% CI, 1.70-3.30), as was invasion to/beyond subcutaneous fat (PR, 2.37; 95% CI, 1.78-3.14). Poorly vs well-differentiated SCCs were more than 3-fold more common in OTRs (PR, 3.45; 95% CI, 2.53-4.71), and prevalence of tumors greater than 20 mm vs 20 mm or smaller was moderately higher in OTRs (PR, 1.52; 95% CI, 1.08-2.12).

Conclusions and Relevance

In this dual-cohort study, SCCs in OTRs had significantly worse prognostic features than SCCs in the general population, reinforcing the necessity of early diagnosis and definitive management of SCCs in OTRs.

Vitamin D supplementation and major cardiovascular events: D-Health randomised controlled trial

OBJECTIVE

To investigate whether supplementing older adults with monthly doses of vitamin D alters the incidence of major cardiovascular events.

DESIGN

Randomised, double blind, placebo controlled trial of monthly vitamin D (the D-Health Trial). Computer generated permuted block randomisation was used to allocate treatments.

SETTING

Australia from 2014 to 2020.

PARTICIPANTS

21 315 participants aged 60-84 years at enrolment. Exclusion criteria were self-reported hypercalcaemia, hyperparathyroidism, kidney stones, osteomalacia, sarcoidosis, taking >500 IU/day supplemental vitamin D, or unable to give consent because of language or cognitive impairment.

INTERVENTION

60 000 IU/month vitamin D₃ (n=10 662) or placebo (n=10 653) taken orally for up to five years. 16 882 participants completed the intervention period: placebo 8270 (77.6%); vitamin D 8552 (80.2%).

MAIN OUTCOME MEASURES

The main outcome for this analysis was the occurrence of a major cardiovascular event, including myocardial infarction, stroke, and coronary revascularisation, determined through linkage with administrative datasets. Each event was analysed separately as secondary outcomes. Flexible parametric survival models were used to estimate hazard ratios and 95% confidence intervals.

RESULTS

21 302 people were included in the analysis. The median intervention period was five years. 1336 participants experienced a major cardiovascular event (placebo 699 (6.6%); vitamin D 637 (6.0%)). The rate of major cardiovascular events was lower in the vitamin D group than in the placebo group (hazard ratio 0.91, 95% confidence interval 0.81 to 1.01), especially among those who were taking cardiovascular drugs at baseline (0.84, 0.74 to 0.97; P for interaction=0.12), although the P value for interaction was not significant (<0.05). Overall, the difference in standardised cause specific cumulative incidence at five years was -5.8 events per 1000 participants (95% confidence interval -12.2 to 0.5 per 1000 participants), resulting in a number needed to treat to avoid one major cardiovascular event of 172. The rate of myocardial infarction (hazard ratio 0.81, 95% confidence interval 0.67 to 0.98) and coronary revascularisation (0.89, 0.78 to 1.01) was lower in the vitamin D group, but there was no difference in the rate of stroke (0.99, 0.80 to 1.23).

CONCLUSIONS

Vitamin D supplementation might reduce the incidence of major cardiovascular events, although the absolute risk difference was small and the confidence interval was consistent with a null finding. These findings could prompt further evaluation of the role of vitamin D supplementation, particularly in people taking drugs for prevention or treatment of cardiovascular disease.

TRIAL REGISTRATION

ACTRN12613000743763.

Vitamin D supplementation and cognition-Results from analyses of the D-Health trial

BACKGROUND

Observational studies have consistently found a link between low serum 25-hydroxyvitamin D concentration and higher risk of cognitive impairment. Results from randomized controlled trials have been mixed, and few have been conducted in the general population.

METHODS

We recruited 21,315 community-dwelling Australians aged between 60 and 84 years to participate in the D-Health Trial, a randomized, double-blind, placebo-controlled trial. The intervention was monthly oral doses of 60,000 international units of vitamin D or placebo for 5 years. We assessed cognitive function in a randomly sampled group of participants aged ≥70 years using the Telephone Interview for Cognitive Status (TICS) at 2 and 5 years after randomization. The primary outcome for this analysis was TICS score; the secondary outcome was the proportion of people who had cognitive impairment (defined as TICS score ≤25). We analyzed data using mixed models (linear and logistic).

RESULTS

We interviewed 3887 participants at year 2 and 3614 participants at year 5. The mean TICS score at these time points was 32.3 and 32.2, respectively. Vitamin D supplementation did not affect cognitive function as measured by TICS score (mean difference between vitamin D and placebo groups 0.04; 95% CI -0.14 to 0.23), or alter risk of cognitive impairment (odds ratio 1.00; 95% CI 0.75 to 1.33).

CONCLUSIONS

Monthly bolus doses of vitamin D supplementation neither enhanced nor hindered cognitive function among older adults. Population-wide vitamin D supplementation of older adults that are largely vitamin D replete is unlikely to substantially benefit cognition.

The diagnosis and initial management of melanoma in Australia: findings from the prospective, population-based QSkin study

OBJECTIVES

To determine the proportions of newly diagnosed melanomas treated by different medical specialist types, to describe the types of excisions performed, and to investigate factors associated with treating practitioner specialty and excision type.

DESIGN, SETTING

Prospective cohort study; analysis of linked data: baseline surveys, hospital, pathology, Queensland Cancer Register, and Medical Benefits Schedule databases.

PARTICIPANTS

Random sample of 43 764 Queensland residents aged 40-69 years recruited during 2011, with initial diagnoses of in situ or invasive melanoma diagnosed to 31 December 2019.

MAIN OUTCOME MEASURES

Treating practitioner type and treatment modality for first incident melanoma; second and subsequent treatment events for the primary melanoma.

RESULTS

During a median follow-up of 8.4 years (interquartile range, 8.3-8.8 years), 1683 eligible participants (720 women, 963 men) developed at least one primary melanoma (in situ melanoma, 1125; invasive melanoma, 558), 1296 of which (77.1%) were initially managed in primary care; 248 were diagnosed by dermatologists (14.8%), 83 by plastic surgeons (4.9%), 43 by general surgeons (2.6%), and ten by other specialists (0.6%). The most frequent initial procedures leading to histologically confirmed melanoma diagnosis were first excision (854, 50.7%), shave biopsy (549, 32.6%), and punch biopsy (178, 10.6%); 1339 melanomas (79.6%) required two procedures, 187 (11.1%) three. Larger proportions of melanomas diagnosed by dermatologists (87%) or plastic surgeons (71%) were in people living in urban areas than of those diagnosed in primary care (63%); larger proportions of melanomas diagnosed by dermatologists or plastic surgeons than of those diagnosed in primary care were in people with university degrees (45%, 42% v 23%) or upper quartile clinical risk scores (63%, 59% v 47%).

CONCLUSIONS

Most incident melanomas in Queensland are diagnosed in primary care, and nearly half are initially managed by partial excision (shave or punch biopsy). Second or third, wider excisions are undertaken in about 90% of cases.

Basal cell carcinomas in organ transplant recipients versus the general population: clinicopathologic study

Organ transplant recipients (OTRs) are at greater risk of basal cell carcinomas (BCCs) than non-OTRs, but histopathologic differences between BCCs in OTRs and the general population are largely unknown. We compared clinicopathologic features of BCCs in OTRs vs the general population in Queensland, Australia. Details of BCC tumors (site, size, level of invasion, subtype, biopsy procedure) were collected from histopathology reports in two prospective skin cancer studies, one in OTRs and one general-population-based. We used log-binomial regression models to estimate age- and sex-adjusted prevalence ratios (PR) with 95% confidence intervals (CIs) for BCC features. Overall, there were 702 BCCs in 200 OTRs and 1725 BCCs in 804 population cases. Of these, 327 tumors in 128 OTRs were higher risk BCCs (any head and neck BCC; ≥ 2 cm on trunk/extremities), more per person than 703 higher risk BCCs in 457 cases in the general population (chi-square p = 0.008). Among head/neck BCCs, OTRs were more likely than general population cases to have BCCs on scalp/ear than on face/lip/neck (PR = 1.5, 95%CI 1.2-1.8). Although aggressive subtypes were less common among higher risk BCCs in OTRs, BCCs invading beyond the dermis were almost twice as prevalent in OTRs (PR = 1.8, 95% CI 1.3-2.6) than the general population.

GWAS meta-analysis of 16 790 patients with Barrett's oesophagus and oesophageal adenocarcinoma identifies 16 novel genetic risk loci and provides insights into disease aetiology beyond the single marker level

OBJECTIVE

Oesophageal cancer (EC) is the sixth leading cause of cancer-related deaths. Oesophageal adenocarcinoma (EA), with Barrett's oesophagus (BE) as a precursor lesion, is the most prevalent EC subtype in the Western world. This study aims to contribute to better understand the genetic causes of BE/EA by leveraging genome wide association studies (GWAS), genetic correlation analyses and polygenic risk modelling.

DESIGN

We combined data from previous GWAS with new cohorts, increasing the sample size to 16 790 BE/EA cases and 32 476 controls. We also carried out a transcriptome wide association study (TWAS) using expression data from disease-relevant tissues to identify BE/EA candidate genes. To investigate the relationship with reported BE/EA risk factors, a linkage disequilibrium score regression (LDSR) analysis was performed. BE/EA risk models were developed combining clinical/lifestyle risk factors with polygenic risk scores (PRS) derived from the GWAS meta-analysis.

RESULTS

The GWAS meta-analysis identified 27 BE and/or EA risk loci, 11 of which were novel. The TWAS identified promising BE/EA candidate genes at seven GWAS loci and at five additional risk loci. The LDSR analysis led to the identification of novel genetic correlations and pointed to differences in BE and EA aetiology. Gastro-oesophageal reflux disease appeared to contribute stronger to the metaplastic BE transformation than to EA development. Finally, combining PRS with BE/EA risk factors improved the performance of the risk models.

CONCLUSION

Our findings provide further insights into BE/EA aetiology and its relationship to risk factors. The results lay the foundation for future follow-up studies to identify underlying disease mechanisms and improving risk prediction.

The effect of monthly vitamin D supplementation on fractures: a tertiary outcome from the population-based, double-blind, randomised, placebo-controlled D-Health trial

BACKGROUND

Low serum 25-hydroxy vitamin D concentration is associated with increased fracture risk. It is uncertain whether vitamin D supplementation reduces fractures, or whether intermittent doses are harmful. We aimed to investigate if supplementing adults living in Australia with monthly doses of 60 000 international units (IU) vitamin D₃ for 5 years or less altered the rate of fractures.

METHODS

We did a population-based, double-blind, randomised, placebo-controlled trial of oral vitamin D₃ supplementation (60 000 IU per month) for up to 5 years in adults aged 60-84 years living in Australia. We randomly assigned (1:1) 21 315 participants to either vitamin D or placebo. We ascertained fractures through linkage with administrative datasets. The main outcome was total fractures. Additional outcomes were non-vertebral, major osteoporotic (hip, wrist, proximal humerus, and spine), and hip fractures. We excluded participants (989 [4·6%]) without linked data, and estimated hazard ratios (HRs) and 95% CIs using flexible parametric survival models. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12613000743763, and the trial intervention ended in February, 2020.

FINDINGS

Between Feb 14, 2014, and June 17, 2015, we recruited 21 315 participants. For the current analysis, we included 20 326 participants (vitamin D 10 154 [50·0%]; placebo 10 172 [50·0%]). 9295 (45·7%) of 20 326 participants were women and the mean age was 69·3 years (SD 5·5). Over a median follow-up of 5·1 years (IQR 5·1-5·1), 568 (5·6%) participants in the vitamin D group and 603 (5·9%) in the placebo group had one or more fractures. There was no effect on fracture risk overall (HR 0·94 [95% CI 0·84-1·06]), and the interaction between randomisation group and time was not significant (p=0·14). However, the HR for total fractures appeared to decrease with increasing follow-up time. The overall HRs for non-vertebral, major osteoporotic, and hip fractures were 0·96 (95% CI 0·85-1·08), 1·00 (0·85-1·18), and 1·11 (0·86-1·45), respectively.

INTERPRETATION

These findings do not support concerns that bolus doses of vitamin D administered monthly increase fracture risk. Long-term supplementation might reduce the incidence of total fractures, but additional research is needed to clarify this effect.

FUNDING

Australian National Health and Medical Research Council.

Oral HPV infection and HPV vaccination in an Australian cohort

Human papillomavirus (HPV)-related oropharyngeal cancer (OPC) is increasing in incidence, yet very little is known about oral HPV infection in the general population. In this Australian-based study we assess oral HPV prevalence according to HPV vaccination status. Participants of the Oral Diversity Study were Australian residents, aged 18-70 years, who filled out a questionnaire about lifestyle and sexual behaviour, and donated a saliva sample in 2020-21. We obtained permission to access HPV vaccination status through record linkage with the Australian Immunisation Register. Saliva samples were DNA extracted, DNA quality checked and analysed for HPV. We recruited 1023 participants to the Oral Diversity Study. 921 returned a saliva sample for analysis, 911 passed the DNA quality check and were included in the study. 7.2% had an oral HPV infection, which was strongly associated with sexual behaviours. We identified 27 different HPV types; 53% of participants carried high-risk HPV types, with no difference between the vaccinated and the unvaccinated groups (53% both, P = 0.979). 230 participants (26%) were HPV vaccinated. The oral prevalence of the nine HPV types included in the nonavalent HPV vaccine was significantly lower in the vaccinated participants compared to the unvaccinated (0.9% vs 3.4%; P = 0.022). These findings suggest that a sizeable minority of Australian residents harbor oral HPV infections, and many of these are high-risk subtypes. We found some evidence that HPV vaccination resulted in lower prevalence of oral HPV infections of vaccine-specific types. Larger surveys are required to confirm these findings. This article is protected by copyright. All rights reserved.

The ethical implications of opportunistic detection of melanoma in clinical care

We sought to explore several ethical ethical issues relating to opportunistic detection of melanoma, given current controversies in melanoma control. We suggest these should be considered in conjunction with the quantitative yardsticks that accompany decision-making about disease detection. Researchers should focus on capturing and providing evidence to support decision-making for patients and their doctors.

Vitamin D Supplementation and the Incidence of Cataract Surgery in Older Australian Adults

PURPOSE

Observational studies suggest that higher serum 25-hydroxy vitamin D (25(OH)D) concentration may be associated with lower risk of cataract. However, no randomized controlled trials have assessed the effect of vitamin D supplementation on the incidence of cataract. We aimed to assess whether vitamin D supplementation reduces the incidence of cataract surgery.

DESIGN

We conducted an ancillary study of the D-Health Trial, a randomized, double-masked, placebo-controlled trial of monthly vitamin D conducted from 2014 through 2020 within the Australian general population.

PARTICIPANTS

We invited 421 207 men and women 60 to 84 years of age to participate; including an additional 1896 volunteers, 40 824 expressed interest. Those with hypercalcemia, hyperparathyroidism, kidney stones, osteomalacia, or sarcoidosis or those who were taking more than 500 international units (IU) supplemental vitamin D per day were excluded. A total of 21 315 were randomized, and 1390 participants did not fulfil the eligibility criteria for this analysis (linked data available, no cataract within first 6 months), leaving 19 925 included. The median follow-up was 5 years.

METHODS

Participants took 60 000 IU of vitamin D₃ (n = 10 662) or placebo (n = 10 653) orally once per month for a maximum of 5 years.

MAIN OUTCOME MEASURES

The primary outcome for this analysis was the first surgical treatment for cataract, ascertained through linkage to universal health insurance records and hospital data.

RESULTS

Among 19 925 participants eligible for this analysis (mean age, 69.3 years; 46% women) 3668 participants (18.4%) underwent cataract surgery during follow-up (vitamin D: n = 1841 [18.5%]; placebo: n = 1827 [18.3%] ). The incidence of cataract surgery was similar between the two groups (incidence rate, 41.6 and 41.1 per 1000 person-years in the vitamin D and placebo groups, respectively; hazard ratio, 1.02; 95% confidence interval, 0.95-1.09). In prespecified subgroup analyses, the effect of vitamin D supplementation on the incidence of cataract surgery was not modified by age, sex, body mass index, predicted serum 25(OH)D concentration, or ambient ultraviolet radiation.

CONCLUSIONS

Routinely supplementing older adults who live in an area with a low prevalence of vitamin D deficiency with high-dose vitamin D is unlikely to reduce the need for cataract surgery.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

The genetic basis of endometriosis and comorbidity with other pain and inflammatory conditions

Endometriosis is a common condition associated with debilitating pelvic pain and infertility. A genome-wide association study meta-analysis, including 60,674 cases and 701,926 controls of European and East Asian descent, identified 42 genome-wide significant loci comprising 49 distinct association signals. Effect sizes were largest for stage 3/4 disease, driven by ovarian endometriosis. Identified signals explained up to 5.01% of disease variance and regulated expression or methylation of genes in endometrium and blood, many of which were associated with pain perception/maintenance (SRP14/BMF, GDAP1, MLLT10, BSN and NGF). We observed significant genetic correlations between endometriosis and 11 pain conditions, including migraine, back and multisite chronic pain (MCP), as well as inflammatory conditions, including asthma and osteoarthritis. Multitrait genetic analyses identified substantial sharing of variants associated with endometriosis and MCP/migraine. Targeted investigations of genetically regulated mechanisms shared between endometriosis and other pain conditions are needed to aid the development of new treatments and facilitate early symptomatic intervention.

Vitamin D and Sun Exposure: A Community Survey in Australia

Sun exposure carries both harms and benefits. Exposing the skin to the sun is the main modifiable cause of skin cancers, which exert a considerable health and economic burden in Australia. The most well-established benefit of exposure to ultraviolet (UV) radiation is vitamin D production. Australia has the highest incidence of skin cancer in the world but, despite the high ambient UV radiation, approximately one quarter of the population is estimated to be vitamin D deficient. Balancing the risks and benefits is challenging and requires effective communication. We sought to provide a snapshot of public knowledge and attitudes regarding sun exposure and vitamin D and to examine the associations between these factors and sun protective behaviors. In 2020 we administered an online survey; 4824 participants with self-reported fair or medium skin color were included in this analysis. Only 25% and 34% of participants were able to identify the amount of time outdoors needed to maintain adequate vitamin D status in summer and winter, respectively and 25% were concerned that sunscreen use inhibits vitamin D synthesis. This lack of knowledge was associated with suboptimal sun protection practices. Public education is warranted to prevent over-exposure, while supporting natural vitamin D production.

Identification of Novel, Replicable Genetic Risk Loci for Suicidal Thoughts and Behaviors Among US Military Veterans

Importance

Suicide is a leading cause of death; however, the molecular genetic basis of suicidal thoughts and behaviors (SITB) remains unknown.

Objective

To identify novel, replicable genomic risk loci for SITB.

Design, Setting, and Participants

This genome-wide association study included 633 778 US military veterans with and without SITB, as identified through electronic health records. GWAS was performed separately by ancestry, controlling for sex, age, and genetic substructure. Cross-ancestry risk loci were identified through meta-analysis. Study enrollment began in 2011 and is ongoing. Data were analyzed from November 2021 to August 2022.

Main Outcome and Measures

SITB.

Results

A total of 633 778 US military veterans were included in the analysis (57 152 [9%] female; 121 118 [19.1%] African ancestry, 8285 [1.3%] Asian ancestry, 452 767 [71.4%] European ancestry, and 51 608 [8.1%] Hispanic ancestry), including 121 211 individuals with SITB (19.1%). Meta-analysis identified more than 200 GWS (P < 5 × 10-8) cross-ancestry risk single-nucleotide variants for SITB concentrated in 7 regions on chromosomes 2, 6, 9, 11, 14, 16, and 18. Top single-nucleotide variants were largely intronic in nature; 5 were independently replicated in ISGC, including rs6557168 in ESR1, rs12808482 in DRD2, rs77641763 in EXD3, rs10671545 in DCC, and rs36006172 in TRAF3. Associations for FBXL19 and AC018880.2 were not replicated. Gene-based analyses implicated 24 additional GWS cross-ancestry risk genes, including FURIN, TSNARE1, and the NCAM1-TTC12-ANKK1-DRD2 gene cluster. Cross-ancestry enrichment analyses revealed significant enrichment for expression in brain and pituitary tissue, synapse and ubiquitination processes, amphetamine addiction, parathyroid hormone synthesis, axon guidance, and dopaminergic pathways. Seven other unique European ancestry-specific GWS loci were identified, 2 of which (POM121L2 and METTL15/LINC02758) were replicated. Two additional GWS ancestry-specific loci were identified within the African ancestry (PET112/GATB) and Hispanic ancestry (intergenic locus on chromosome 4) subsets, both of which were replicated. No GWS loci were identified within the Asian ancestry subset; however, significant enrichment was observed for axon guidance, cyclic adenosine monophosphate signaling, focal adhesion, glutamatergic synapse, and oxytocin signaling pathways across all ancestries. Within the European ancestry subset, genetic correlations (r > 0.75) were observed between the SITB phenotype and a suicide attempt-only phenotype, depression, and posttraumatic stress disorder. Additionally, polygenic risk score analyses revealed that the Million Veteran Program polygenic risk score had nominally significant main effects in 2 independent samples of veterans of European and African ancestry.

Conclusions and Relevance

The findings of this analysis may advance understanding of the molecular genetic basis of SITB and provide evidence for ESR1, DRD2, TRAF3, and DCC as cross-ancestry candidate risk genes. More work is needed to replicate these findings and to determine if and how these genes might impact clinical care.

Vitamin D supplementation and hospitalization for infection in older adults: A post-hoc analysis of data from the Australian D-Health Trial

BACKGROUND

Evidence suggests that vitamin D influences the immune system. Recent studies indicate that vitamin D supplementation may reduce the severity of infections, but this has not been confirmed.

OBJECTIVES

The objective of this study was to assess the effect of vitamin D supplementation on hospitalization for infection.

METHODS

The D-Health Trial was a randomized, double-blind, placebo-controlled trial of monthly 60,000 international units of vitamin D₃ for 5 y among 21,315 Australians aged 60-84 y. Hospitalization for infection, ascertained through linkage with hospital admitted patient data, is a tertiary outcome of the trial. The primary outcome for this post-hoc analysis was hospitalization for any infection. Secondary outcomes were extended hospitalization for infection (length of stay >3 d and >6 d) and hospitalization for respiratory tract, skin, and gastrointestinal infections. We used negative binomial regression to estimate the effect of vitamin D supplementation on outcomes.

RESULTS

Participants (46% women, mean age: 69 y), were followed up for a median of 5 y. Vitamin D supplementation had little or no effect on the incidence of hospitalization for any infection [incidence rate ratio (IRR): 0.95; 95% CI: 0.86, 1.05], respiratory tract (IRR: 0.93; 95% CI: 0.81, 1.08), skin (IRR: 0.95; 95% CI: 0.76, 1.20), gastrointestinal infections (IRR: 1.03; 95% CI: 0.84, 1.26), or hospitalizations lasting >3 d (IRR: 0.94; 95% CI: 0.81, 1.09), with all CIs consistent with a null finding. People supplemented with vitamin D had fewer hospitalizations lasting >6 d (IRR: 0.80; 95% CI: 0.65, 0.99).

CONCLUSIONS

We did not find a protective effect of vitamin D on hospitalization for infection, but it reduced the number of extended hospitalizations. In populations where few people are vitamin D deficient, the effect of population-wide supplementation is likely to be small, but these findings support previous studies suggesting that vitamin D plays a role in infectious disease. The D-Health Trial is registered at the Australian New Zealand Clinical Trials Registry as ACTRN12613000743763.

Is the disease risk and penetrance in Leber hereditary optic neuropathy actually low?

Pedigree analysis showed that a large proportion of Leber hereditary optic neuropathy (LHON) family members who carry a mitochondrial risk variant never lose vision. Mitochondrial haplotype appears to be a major factor influencing the risk of vision loss from LHON. Mitochondrial variants, including m.14484T>C and m.11778G>A, have been added to gene arrays, and thus many patients and research participants are tested for LHON mutations. Analysis of the UK Biobank and Australian cohort studies found more than 1 in 1,000 people in the general population carry either the m.14484T>C or the m.11778G>A LHON variant. None of the subset of carriers examined had visual acuity at 20/200 or worse, suggesting a very low penetrance of LHON. Haplogroup analysis of m.14484T>C carriers showed a high rate of haplogroup U subclades, previously shown to have low penetrance in pedigrees. Penetrance calculations of the general population are lower than pedigree calculations, most likely because of modifier genetic factors. This Matters Arising Response paper addresses the Watson et al. (2022) Matters Arising paper, published concurrently in The American Journal of Human Genetics.

Common Germline Risk Variants Impact Somatic Alterations and Clinical Features across Cancers

Aggregation of genome-wide common risk variants, such as polygenic risk score (PRS), can measure genetic susceptibility to cancer. A better understanding of how common germline variants associate with somatic alterations and clinical features could facilitate personalized cancer prevention and early detection. We constructed PRSs from 14 genome-wide association studies (median n = 64,905) for 12 cancer types by multiple methods and calibrated them using the UK Biobank resources (n = 335,048). Meta-analyses across cancer types in The Cancer Genome Atlas (n = 7,965) revealed that higher PRS values were associated with earlier cancer onset and lower burden of somatic alterations, including total mutations, chromosome/arm somatic copy-number alterations (SCNA), and focal SCNAs. This contrasts with rare germline pathogenic variants (e.g., BRCA1/2 variants), showing heterogeneous associations with somatic alterations. Our results suggest that common germline cancer risk variants allow early tumor development before the accumulation of many somatic alterations characteristic of later stages of carcinogenesis.

SIGNIFICANCE

Meta-analyses across cancers show that common germline risk variants affect not only cancer predisposition but the age of cancer onset and burden of somatic alterations, including total mutations and copy-number alterations.

Effects of Vitamin D Supplementation on Telomere Length: An Analysis of Data from the Randomised Controlled D-Health Trial

OBJECTIVES

Observational studies have suggested that a higher 25-hydroxyvitamin D concentration may be associated with longer telomere length; however, this has not been investigated in randomised controlled trials. We conducted an ancillary study within a randomised, double-blind, placebo-controlled trial of monthly vitamin D (the D-Health Trial) for the prevention of all-cause mortality, conducted from 2014 to 2020, to assess the effect of vitamin D supplementation on telomere length (measured as the telomere to single copy gene (T/S) ratio).

DESIGN, SETTING, PARTICIPANTS, AND INTERVENTION

Participants were Australians aged 60-84 years and we randomly selected 1,519 D-Health participants (vitamin D: n=744; placebo: n=775) for this analysis. We used quantitative polymerase chain reaction to measure the relative telomere length (T/S ratio) at 4 or 5 years after randomisation. We compared the mean T/S ratio between the vitamin D and placebo groups to assess the effect of vitamin D supplementation on relative telomere length, using a linear regression model with adjustment for age, sex, and state which were used to stratify the randomisation.

RESULTS

The mean T/S ratio was 0.70 for both groups (standard deviation 0.18 and 0.16 for the vitamin D and placebo groups respectively). The adjusted mean difference (vitamin D minus placebo) was -0.001 (95% CI -0.02 to 0.02). There was no effect modification by age, sex, body mass index, or predicted baseline 25-hydroxyvitamin D concentration.

CONCLUSION

In conclusion, routinely supplementing older adults, who are largely vitamin D replete, with monthly doses of vitamin D is unlikely to influence telomere length.

The effect of vitamin D supplementation on the gut microbiome in older Australians - Results from analyses of the D-Health Trial

Observational studies suggest a link between vitamin D and the composition of the gut microbiome, but there is little evidence from randomized controlled trials of vitamin D supplementation. We analyzed data from the D-Health Trial, a randomized, double-blind, placebo-controlled trial. We recruited 21,315 Australians aged 60-84 y and randomized them to 60,000 IU of vitamin D₃ or placebo monthly for 5 y. Stool samples were collected from a sample of 835 participants (417 in the placebo and 418 in the vitamin D group) approximately 5 y after randomization. We characterized the gut microbiome using 16S rRNA gene sequencing. We used linear regression to compare alpha diversity indices (i.e. Shannon index (primary outcome), richness, inverse Simpson index), and the ratio of Firmicutes to Bacteroidetes between the two groups. We analyzed between-sample (beta) diversity (i.e. Bray Curtis distance and UniFrac index) using principal coordinate analysis and used PERMANOVA to test for significant clustering according to randomization group. We also assessed the difference in the abundance of the 20 most abundant genera between the two groups using negative binomial regression model with adjustment for multiple testing. Approximately half the participants included in this analysis were women (mean age 69.4 y). Vitamin D supplementation did not alter the Shannon diversity index (mean 3.51 versus 3.52 in the placebo and vitamin D groups, respectively, p = 0.50). Similarly, there was little difference between the groups for other alpha diversity indices, the abundance of different genera, and the Firmicutes-to-Bacteroidetes ratio. We did not observe clustering of bacterial communities according to randomization group. In conlusion, monthly doses of 60,000 IU of vitamin D supplementation for 5 y did not alter the composition of the gut microbiome in older Australians.

Risk Factors Associated With First and Second Primary Melanomas in a High-Incidence Population

Importance

An increasing number of people develop more than 1 primary melanoma, yet to date, no population-based prospective cohort studies have reported on risk factors for developing first vs second primary melanomas.

Objective

To compare the clinical characteristics of first and second melanomas and then to estimate the relative risks of developing 1 vs multiple melanomas associated with demographic, phenotypic, sun exposure, and genetic factors.

Design, Setting, and Participants

This population-based prospective cohort study included men and women aged 40 to 69 years recruited in 2011 and followed up until December 2018 in Queensland, Australia. Data analysis was performed from February to July 2022.

Exposures

Self-reported information about demographic, phenotypic, and sun exposure measures captured using a survey completed at baseline, and polygenic risk score for melanoma.

Main Outcomes and Measures

Incident first or second primary melanoma diagnosis, and histologic and clinical characteristics thereof. The Wei-Lin-Weissfeld model for recurrent events was used to estimate the association of each factor with the risks of first and second primary melanoma.

Results

A total of 38 845 patients (mean [SD] age at baseline, 56.1 [8.2] years; 17 775 men and 21 070 women) were included in the study. During a median follow-up period of 7.4 years, 1212 (3.1%) participants had a single primary melanoma diagnosis, and 245 (0.6%) had a second primary melanoma diagnosis. Second melanomas were more likely than first melanomas to be in situ; for invasive tumors, second melanomas were more likely to be thin (ie, ≤1 mm) than first melanomas. Having many moles at age 21 years (self-reported using visual scoring tool) was more strongly associated with second (hazard ratio [HR], 6.36; 95% CI, 3.77-10.75) than first primary melanoma (HR, 3.46; 95% CI, 2.72-4.40) (P value for difference between the HRs = .01). A high genetic predisposition (ie, polygenic risk score in tertile 3) was also more strongly associated with second (HR, 3.28; 95% CI, 2.06-5.23) than first melanoma (HR, 2.06; 95% CI, 1.71-2.49; P = .03). Second melanomas were more strongly associated with a history of multiple skin cancer excisions (HR, 2.63; 95% CI, 1.80-3.83) than first melanomas (HR, 1.86; 95% CI, 1.61-2.16; P = .05). For all other phenotypic characteristics and sun exposure measures, similarly elevated associations with first vs second melanomas were observed.

Conclusions and Relevance

Findings of this cohort study suggest that within the general population, the presence of many nevi and having a high genetic predisposition to melanoma were associated with the highest risks of developing second primary melanomas.

Effect of vitamin D supplementation on depression in older Australian adults

OBJECTIVES

To investigate whether vitamin D supplementation reduces depressive symptoms and incidence of antidepressant use.

METHODS

We used data from the D-Health Trial (N = 21,315), a randomized double-blind placebo-controlled trial of monthly vitamin D₃ for the prevention of all-cause mortality. Participants were Australians aged 60-84 years. Participants completed the Patient Health Questionnaire (PHQ-9) at 1, 2 and 5 years after randomization to measure depressive symptoms; national prescribing records were used to capture antidepressant use. We used mixed models and survival models.

RESULTS

Analyses of PHQ-9 scores included 20,487 participants (mean age 69·3 years, 46% women); the mean difference (MD) in PHQ-9 score (vitamin D vs. placebo) was 0·02 (95% CI -0·06, 0·11). There was negligible difference in the prevalence of clinically relevant depression (PHQ-9 score ≥10) (odds ratio 0·99; 95% CI 0·90, 1·08). We included 16,670 participants in the analyses of incident antidepressant use (mean age 69·4 years, 43% women). Incidence of antidepressant use was similar between the groups (hazard ratio [HR] 1·04; 95% CI 0·96, 1·12). In subgroup analyses, vitamin D improved PHQ-9 scores in those taking antidepressants at baseline (MD -0·25; 95% CI -0·49, -0·01; p-interaction = 0·02). It decreased risk of antidepressant use in participants with predicted 25(OH)D concentration <50 nmol/L (HR 0·88; 95% CI 0·75, 1·02; p-interaction = 0·01) and increased risk in those with predicted 25(OH)D ≥ 50 nmol/L (HR 1·10; 95% CI 1·01, 1·20).

CONCLUSION

Monthly supplementation with high-dose vitamin D₃ was not of benefit for measures of depression overall, but there was some evidence of benefit in subgroup analyses.

CLINICAL TRIAL REGISTRATION

The trial is registered on the Australian New Zealand Clinical Trials Registry: ACTRN12613000743763. https://www.anzctr.org.au/.

A multi-phenotype analysis reveals 19 susceptibility loci for basal cell carcinoma and 15 for squamous cell carcinoma

Basal cell carcinoma and squamous cell carcinoma are the most common skin cancers, and have genetic overlap with melanoma, pigmentation traits, autoimmune diseases, and blood biochemistry biomarkers. In this multi-trait genetic analysis of over 300,000 participants from Europe, Australia and the United States, we reveal 78 risk loci for basal cell carcinoma (19 previously unknown and replicated) and 69 for squamous cell carcinoma (15 previously unknown and replicated). The previously unknown risk loci are implicated in cancer development and progression (e.g. CDKL1), pigmentation (e.g. TPCN2), cardiometabolic (e.g. FADS2), and immune-regulatory pathways for innate immunity (e.g. IFIH1), and HIV-1 viral load modulation (e.g. CCR5). We also report an optimised polygenic risk score for effective risk stratification for keratinocyte cancer in the Canadian Longitudinal Study of Aging (794 cases and 18139 controls), which could facilitate skin cancer surveillance e.g. in high risk subpopulations such as transplantees.

Global Biobank Meta-analysis Initiative: Powering genetic discovery across human disease

Biobanks facilitate genome-wide association studies (GWASs), which have mapped genomic loci across a range of human diseases and traits. However, most biobanks are primarily composed of individuals of European ancestry. We introduce the Global Biobank Meta-analysis Initiative (GBMI)-a collaborative network of 23 biobanks from 4 continents representing more than 2.2 million consented individuals with genetic data linked to electronic health records. GBMI meta-analyzes summary statistics from GWASs generated using harmonized genotypes and phenotypes from member biobanks for 14 exemplar diseases and endpoints. This strategy validates that GWASs conducted in diverse biobanks can be integrated despite heterogeneity in case definitions, recruitment strategies, and baseline characteristics. This collaborative effort improves GWAS power for diseases, benefits understudied diseases, and improves risk prediction while also enabling the nomination of disease genes and drug candidates by incorporating gene and protein expression data and providing insight into the underlying biology of human diseases and traits.

Common Genetic Variation and Age of Onset of Anorexia Nervosa

Background

Genetics and biology may influence the age of onset of anorexia nervosa (AN). The aims of this study were to determine whether common genetic variation contributes to age of onset of AN and to investigate the genetic associations between age of onset of AN and age at menarche.

Methods

A secondary analysis of the Psychiatric Genomics Consortium genome-wide association study (GWAS) of AN was performed, which included 9335 cases and 31,981 screened controls, all from European ancestries. We conducted GWASs of age of onset, early-onset AN (<13 years), and typical-onset AN, and genetic correlation, genetic risk score, and Mendelian randomization analyses.

Results

Two loci were genome-wide significant in the typical-onset AN GWAS. Heritability estimates (single nucleotide polymorphism-h 2) were 0.01-0.04 for age of onset, 0.16-0.25 for early-onset AN, and 0.17-0.25 for typical-onset AN. Early- and typical-onset AN showed distinct genetic correlation patterns with putative risk factors for AN. Specifically, early-onset AN was significantly genetically correlated with younger age at menarche, and typical-onset AN was significantly negatively genetically correlated with anthropometric traits. Genetic risk scores for age of onset and early-onset AN estimated from independent GWASs significantly predicted age of onset. Mendelian randomization analysis suggested a causal link between younger age at menarche and early-onset AN.

Conclusions

Our results provide evidence consistent with a common variant genetic basis for age of onset and implicate biological pathways regulating menarche and reproduction.