The time-dependent adverse effects of a high-fat diet on sperm parameters.

Abstract

Studies indicate a relationship between a high-fat diet (HFD) and sperm quality. However, the time-dependent adverse effects of a HFD on sperm parameters and the underlying mechanisms remain unclear. The present study was designed to determine the effects of a HFD on sperm quality at various time points in order to assess whether a HFD causes cumulative damage to sperm. Male C57BL/6 mice were fed a normal diet (the ND group) or a HFD (the HFD group) for 16, 30 or 42 weeks (n = 6 for each group). Body weight, lipid profile, sperm parameters, testicular morphology, and testicular oxidative stress levels were evaluated alongside the proliferation, DNA damage and rate of germ cell apoptosis. Sperm quality was reduced in HFD-fed animals in a time-dependent manner, which was demonstrated by a decline in sperm density, motility and progressive motility. Further analysis showed a progressive deterioration of the testicular histoarchitecture of HFD-fed mice, which was accompanied by a decrease in DEAD-box helicase 4 (DDX4) expression and superoxide dismutase (SOD) levels, increased malondialdehyde (MDA) levels and gamma-H2A histone family member X (γ-H2AX) expression, and increased apoptosis of germ cells. These findings demonstrate that a HFD exerted adverse effects on sperm quality, and the deteriorating effect was progressive with long-term feeding. The inhibited proliferation and apoptosis of germ cells, and the increased oxidative stress levels and DNA damage may be the underlying mechanisms.