Fatty acid intake in relation to reproductive hormones and testicular volume among young healthy men

Emerging evidence suggests that dietary fats may influence testicular function. However, most of the published literature on this field has used semen quality parameters as the only proxy for testicular function. We examined the association of fat intake with circulating reproductive hormone levels and testicular volume among healthy young Spanish men. This is a cross-sectional study among 209 healthy male volunteers conducted between October 2010 and November 2011 in Murcia Region of Spain. Participants completed questionnaires on lifestyle, diet, and smoking, and each underwent a physical examination, and provided a blood sample. Linear regression was used to examine the association between each fatty acid type and reproductive hormone levels and testicular volumes. Monounsaturated fatty acids intake was inversely associated with serum blood levels of calculated free testosterone, total testosterone, and inhibin B. A positive association was observed between the intake of polyunsaturated fatty acids, particularly of omega-6 polyunsaturated fatty acids, and luteinizing hormone concentrations. In addition, the intake of trans fatty acids was associated with lower total testosterone and calculated free testosterone concentrations （Ptrend = 0.01 and 0.02, respectively）. The intake of omega-3 polyunsaturated fatty acids was positively related to testicular volume while the intake of omega-6 polyunsaturated fatty acids and trans fatty acids was inversely related to testicular volume. These data suggest that fat intake, and particularly intake of omega 3, omega 6, and trans fatty acids, may influence testicular function.

Decline in semen concentration of healthy Chinese adults： evidence from 9357 participants from 2010 to 2015

The present study aims to analyze sperm concentration trends among young and healthy Chinese adults in Wuhan, Central China, from 2010 to 2015. Semen analysis data from 9357 participants were collected and analyzed using a general linear model and the Cochran-Armitage trend test. A significant decline was observed in sperm concentration （β [standard deviation]： -1.53 [0.16]; P 〈 0.001）. In addition, a decline in sperm density was observed by stratifying student versus nonstudent sperm donors and by analyzing the year of birth or birth year cohort of the participants. Furthermore, the percentage of participants with sperm densities of over 40×10^6 ml^-1 significantly decreased with year. Notably, a dramatic decline in sperm density was recorded over the first 5 years of study.

Changing Tendency Analysis of Chinese Normal Male's Semen Quality in Recent 25 Years:Samples from Chinese Documents

Objective To analyze the trend of change in semen quality of Chinese healthy men over recent 25 years. Methods A total of 115 reports were collected on quality inspection of semen of healthy Chinese men between 1985-2009 through literature search, which involved 23 126 persons from 69 counties and cities. Trend of change in semen parameters was analyzed by linear regression model and rank sum test. Results Sperm concentration and non-progressive motility （c%） declined, and the linear equation was of statistics value. Linear equations include y=2.968-0. 004x （P〈0.05） and y=3.204-0.026x （P〈0.05）. As the results of K-S rank sum test showed, the difference of sperm concentration and total sperm count in the three groups, i.e., the group for 1985-1989, the group for 1990-1999 and the group for 2000-2009 was of statistics value. Conclusion The semen concentration decline over recent 25 years （P〈0.05）. of healthy Chinese men appears a possible