SUMMARY The extent to which low-frequency (minor allele frequency [MAF] between 1–5%) and rare (MAF ≤ 1%) variants contribute to complex traits and disease in the general population is largely unknown. Bone mineral density (BMD) is highly heritable, is a major predictor of osteoporotic fractures and has been previously associated with common genetic variants1–8, and rare, population-specific, coding variants9. Here we identify novel non-coding genetic variants with large effects on BMD (ntotal = 53,236) and fracture (ntotal = 508,253) in individuals of European ancestry from the general population. Associations for BMD were derived from whole-genome sequencing (n=2,882 from UK10K), whole-exome sequencing (n= 3,549), deep imputation of genotyped samples using a combined UK10K/1000Genomes reference panel (n=26,534), and de-novo replication genotyping (n= 20,271). We identified a low-frequency non-coding variant near a novel locus, EN1, with an effect size 4-fold larger than the mean of previously reported common variants for lumbar spine BMD8 (rs11692564[T], MAF = 1.7%, replication effect size = +0.20 standard deviations [SD], Pmeta = 2×10−14), which was also associated with a decreased risk of fracture (OR = 0.85; P = 2×10−11; ncases = 98,742 and ncontrols = 409,511). Using an En1Cre/flox mouse model, we observed that conditional loss of En1 results in low bone mass, likely as a consequence of high bone turn-over. We also identified a novel low-frequency non-coding variant with large effects on BMD near WNT16 (rs148771817[T], MAF = 1.1%, replication effect size = +0.39 SD, Pmeta = 1×10−11). In general, there was an excess of association signals arising from deleterious coding and conserved non-coding variants. These findings provide evidence that low-frequency non-coding variants have large effects on BMD and fracture, thereby providing rationale for whole-genome sequencing and improved imputation reference panels to study the genetic architecture of complex traits and disease in the general population.

HPV infection is highly prevalent in sexually active men and can be detected by use of a variety of specimens and methods. There have been few natural-history studies and no transmission studies of HPV in men. The information that we have reviewed may be useful for future natural-history studies and for modeling the potential impact of a prophylactic HPV vaccine.

Male sexual behavior influences the rates of cervical dysplasia and invasive cervical cancer, as well as male human papillomavirus (HPV) infection and disease. Unfortunately, little is known regarding male HPV type distribution by age and across countries. In samples combined from the coronal sulcus, glans penis, shaft, and scrotum of 1,160 men from Brazil, Mexico, and the United States, overall HPV prevalence was 65.2%, with 12.0% oncogenic types only, 20.7% nononcogenic types only, 17.8% both oncogenic and nononcogenic, and 14.7% unclassified infections. Multiple HPV types were detected in 25.7% of study participants. HPV prevalence was higher in Brazil (72.3%) than in the United States (61.3%) and Mexico (61.9%). HPV16 (6.5%), HPV51 (5.3%), and HPV59 (5.3%) were the most commonly detected oncogenic infections, and HPV84 (7.7%), HPV62 (7.3%), and HPV6 (6.6%) were the most commonly detected nononcogenic infections. Overall HPV prevalence was not associated with age. However, significant associations with age were observed when specific categories of HPV, nononcogenic, and unclassified HPV infections were considered. Studies of HPV type distribution among a broad age range of men from multiple countries is needed to fill the information gap internationally with respect to our knowledge of HPV infection in men.

The last five years have witnessed a remarkable renaissance in vitamin D research and a complete re-evaluation of its benefits to human health. Two key factors have catalyzed these changes. First, it now seems likely that localized, tissue-specific, conversion of 25-hydroxyvitamin D (25OHD) to 1,25-dihydroxyvitamin D (1,25(OH)2D) drives many of the newly recognized effects of vitamin D on human health. The second key factor concerns the ongoing discussion as to what constitutes adequate or optimal serum vitamin D (25OHD) status, with the possibility that vitamin D-deficiency is common to communities across the globe. These two concepts appear to be directly linked when low serum concentrations of 25OHD compromise intracrine generation of 1,25(OH)2D within target tissues. But, is this an over-simplification? Pro-hormone 25OHD is a lipophilic molecule that is transported in the circulation bound primarily to vitamin D binding protein (DBP). While the association between 25OHD and DBP is pivotal for renal handling of 25OHD and endocrine synthesis of 1,25(OH)2D, what is the role of DBP for extra-renal synthesis of 1,25(OH)2D? We hypothesize that binding to DBP impairs delivery of 25OHD to the vitamin D-activating enzyme 1α-hydroxylase in some target cells. Specifically, it is unbound, ‘free’ 25OHD that drives many of the non-classical actions of vitamin D. Levels of ‘free’ 25OHD are dependent on the concentration of DBP and alternative serum binding proteins such as albumin, but will also be influenced by variations in DBP binding affinity for specific vitamin D metabolites. The aim of this review will be to discuss the merits of ‘free 25OHD’ as an alternative marker of vitamin D status, particularly in the context of non-classical responses to vitamin D.

Low areal BMD (aBMD) is associated with increased risk of hip fracture, but many hip fractures occur in persons without low aBMD. Finite element (FE) analysis of QCT scans provides a measure of hip strength. We studied the association of FE measures with risk of hip fracture in older men. A prospective case-cohort study of all first hip fractures (n = 40) and a random sample (n = 210) of nonfracture cases from 3549 community-dwelling men !65 yr of age used baseline QCT scans of the hip (mean follow-up, 5.6 yr). Analyses included FE measures of strength and load-to-strength ratio and BMD by DXA. Hazard ratios (HRs) for hip fracture were estimated with proportional hazards regression. Both femoral strength (HR per SD change = 13.1; 95% CI: 3.9-43.5) and the load-to-strength ratio (HR = 4.0; 95% CI: 2.7-6.0) were strongly associated with hip fracture risk, as was aBMD as measured by DXA (HR = 5.1; 95% CI: 2.8-9.2). After adjusting for age, BMI, and study site, the associations remained significant (femoral strength HR = 6.5, 95% CI: 2.3-18.3; load-to-strength ratio HR = 4.3, 95% CI: 2.5-7.4; aBMD HR = 4.4, 95% CI: 2.1-9.1). When adjusted additionally for aBMD, the load-to-strength ratio remained significantly associated with fracture (HR = 3.1, 95% CI: 1.6-6.1). These results provide insight into hip fracture etiology and demonstrate the ability of FE-based biomechanical analysis of QCT scans to prospectively predict hip fractures in men.

To increase our understanding of the genetic basis of adiposity and its links to cardiometabolic disease risk, we conducted a genome-wide association meta-analysis of body fat percentage (BF%) in up to 100,716 individuals. Twelve loci reached genome-wide significance (P<5 × 10−8), of which eight were previously associated with increased overall adiposity (BMI, BF%) and four (in or near COBLL1/GRB14, IGF2BP1, PLA2G6, CRTC1) were novel associations with BF%. Seven loci showed a larger effect on BF% than on BMI, suggestive of a primary association with adiposity, while five loci showed larger effects on BMI than on BF%, suggesting association with both fat and lean mass. In particular, the loci more strongly associated with BF% showed distinct cross-phenotype association signatures with a range of cardiometabolic traits revealing new insights in the link between adiposity and disease risk.

Reference ranges generated in a community-based sample of men provide a rational basis for categorizing testosterone levels as low or normal. Men with low TT or FT by these criteria had higher prevalence of physical dysfunction, sexual dysfunction, and diabetes. These reference limits should be validated prospectively in relation to incident outcomes and in randomized trials.

Background. Human papillomavirus (HPV) infection in men contributes to infection and cervical disease in women as well as to disease in men. This study aimed to determine the optimal anatomic site(s) for HPV detection in heterosexual men.Methods. A cross-sectional study of HPV infection was conducted in 463 men from 2003 to 2006. Urethral, glans penis/coronal sulcus, penile shaft/prepuce, scrotal, perianal, anal canal, semen, and urine samples were obtained. Samples were analyzed for sample adequacy and HPV DNA by polymerase chain reaction and genotyping. To determine the optimal sites for estimating HPV prevalence, site-specific prevalences were calculated and compared with the overall prevalence. Sites and combinations of sites were excluded until a recalculated prevalence was reduced by <5% from the overall prevalence.Results. The overall prevalence of HPV was 65.4%. HPV detection was highest at the penile shaft (49.9% for the full cohort and 47.9% for the subcohort of men with complete sampling), followed by the glans penis/coronal sulcus (35.8% and 32.8%) and scrotum (34.2% and 32.8%). Detection was lowest in urethra (10.1% and 10.2%) and semen (5.3% and 4.8%) samples. Exclusion of urethra, semen, and either perianal, scrotal, or anal samples resulted in a <5% reduction in prevalence.Conclusions. At a minimum, the penile shaft and the glans penis/coronal sulcus should be sampled in heterosexual men. A scrotal, perianal, or anal sample should also be included for optimal HPV detection.