Body Mass Index Is Associated with Impaired Semen Characteristics and Reduced Levels of Anti-Müllerian Hormone across a Wide Weight Range.

There is still controversy as to how body mass index (BMI) affects male reproduction. We investigated how BMI is associated with semen quality and reproductive hormones in 166 men, including 38 severely obese men. Standard semen analysis and sperm DNA integrity analysis were performed, and blood samples were analysed for reproductive hormones.

Genetic variations associated with the effect of testicular cancer treatment on gonadal hormones.

Study Question: Do genetic variations in the testosterone pathway genes modify the effect of treatment on the levels of testosterone and LH in long-term testicular cancer (TC) survivors (TCSs)?

Summary Answer: Variations in LH receptor (LHR) and in 5α-reductase II (SRD5A2) genes may modify the effect of TC treatment on testosterone levels, whereas genetic variations in the androgen receptor (AR) may modify the effect on LH levels.

What Is Known Already: TCSs experience variable degrees of long-term reduction in gonadal function after treatment. This variability can in part be explained by treatment intensity, but may also be due to individual variations in genes involved in the function and metabolism of reproductive hormones.

Investigation of six testicular germ cell tumor susceptibility genes suggests a parent-of-origin effect in SPRY4.

Recent genome-wide association studies have identified single-nucleotide polymorphisms (SNPs) associated with testicular germ cell tumor (TGCT) risk in the genes ATF7IP, BAK1, DMRT1, KITLG, SPRY4 and TERT. In the present study, we validate these associations in a Scandinavian population, and explore effect modification by parental sex and differences in associations between the major histological subtypes seminoma and non-seminoma. A total of 118 SNPs in the six genes were genotyped in a population-based Swedish-Norwegian sample comprising 831 TGCT case-parent triads, 474 dyads, 712 singletons and 3919 population controls.

Genetic variation in AKT1, PTEN and the 8q24 locus, and the risk of testicular germ cell tumor.

Study Question: Is there an association between testicular germ cell tumor (TGCT) and genetic polymorphisms in AKT1, PTEN and the 8q24 locus?

Summary Answer: Our findings suggest that genetic variation in PTEN may influence the risk of TGCT.

What Is Known Already: There is strong evidence that genetic variation influences the risk of TGCT. The oncogene, AKT1, the tumor suppressor gene, PTEN and the chromosome 8q24 locus play important roles in cancer development in general.

Variations in testosterone pathway genes and susceptibility to testicular cancer in Norwegian men.

Imbalance between the oestrogen and androgen levels in utero is hypothesized to influence testicular cancer (TC) risk. Thus, variation in genes involved in the action of sex hormones may contribute to variability of an individual's susceptibility to TC. Mutations in testosterone pathway genes may alter the level of testosterone in vivo and hypothetically the risk of developing TC.