Zinc deficiency deteriorates ovarian follicle development and function by inhibiting mitochondrial function.

Zinc (Zn) is a crucial trace element essential for human growth and development, particularly for reproductive health. Previous research has shown a decrease in serum zinc concentration with age and individuals with conditions such as polycystic ovary syndrome (PCOS) and diabetes mellitus. However, the specific effects of zinc deficiency on the female reproductive system, especially ovarian function, are not fully understood. In our study, we observed a significant reduction in the total number of follicles and mature follicles in the zinc deficiency group. This reduction correlated with decreased level of anti-Mullerian hormone (AMH) and abnormal gene expression affecting hormone secretion regulation. Furthermore, we found that zinc deficiency disrupted mitochondrial dynamics, leading to oxidative stress in the ovaries, which further inhibited autophagy and increased ovarian apoptosis. These changes ultimately resulted in the failure of germinal vesicle breakdown (GVBD) and reduced oocyte quality. Meanwhile, administration of zinc glycine effectively alleviated the oocyte meiotic arrest caused by dietary zinc deficiency. In conclusion, our findings demonstrated that dietary zinc deficiency can affect hormone secretion and follicle maturation by impairing mitochondrial function and autophagy.

[Correlation of insulin resistance with male reproductive hormone levels and semen parameters].

OBJECTIVE: To investigate the influence of insulin resistance on male reproductive hormones and semen quality. METHODS: Using the electrochemiluminescence method, we measured the levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), estradiol (E2) and testosterone (T) in the serum of 83 infertile males. We detected the levels of fasting plasma glucose (FPG) and fasting insulin (FINS) and calculated the insulin resistance index presented as homeostasis model assessment of insulin resistance (HOMA-IR). Based on HOMA-IR, we divided the patients into three tertile groups, T1 (HOMA-IR 0.36－0.55, n = 27), T2 (HOMA-IR 0.56－0.80, n = 28) and T3 (HOMA-IR 0.81－1.97, n = 28), obtained their semen parameters by computer-assisted semen analysis (CASA) and analyzed the correlation of HOMA-IR with male reproductive hormone levels and semen parameters. RESULTS: With the elevation of HOMA-IR, the patients of the T1, T2 and T3 groups showed significant decreases in the serum T level (ï¼»14,26 ± 4.27ï¼½ vs ï¼»14.75 ± 5.00ï¼½ vs ï¼»11.62 ± 3.68ï¼½ nmol/L, P <0.05) and the percentage of progressively motile sperm (PMS) (ï¼»51.04 ± 15.10ï¼½% vs ï¼»48.04 ± 16.24ï¼½% vs ï¼»37.84 ± 18.23ï¼½%, P <0.05). HOMA-IR was correlated negatively with the serum T level (r = －0.333, P = 0.002), semen volume (r = －0.23, P = 0.029) and PMS (r = －0.27, P = 0.015), and so was FINS with the serum T level (r = －0.327, P = 0.003) and PMS (r = －0.315, P = 0.004), while the semen volume was correlated positively with the levels of serum T (r = 0.221, P = 0.048) and FSH (r = 0.222, P = 0.047). Multivariate linear regression analysis showed that HOMA-IR was an independent influencing factor for PMS and the body mass index (BMI) was that for the semen volume and total sperm count. CONCLUSIONS: Insulin resistance may reduce semen quality by changing the levels of male reproductive hormones.

[Correlation of reproductive hormone levels and seminal plasma oxidative stress with semen quality in obese males].

OBJECTIVE: To investigate the correlation of the levels of reproductive hormones and oxidative stress in the seminal plasma with semen parameters in obese males. METHODS: Based on the body mass index (BMI), we divided 138 infertile men into three groups: normal (BMI <24 kg/m2, n = 48), overweight (24 kg/m2≤BMI<28 kg/m2, n = 47), and obesity (BMI ≥28 kg/m2, n = 43). We determined the concentrations of follicle-stimulating hormone (FSH), luteotropic hormone (LH), prolactin (PRL), testosterone (T) and estradiol (E2) in the serum by electrochemiluminescence and measured the levels of superoxide dismutase (SOD), glutathione-S-transferases (GSTs), reactive oxygen species (ROS) and malondialdehyde (MDA) in the seminal plasma by ELISA, compared the above indexes among the three groups, and analyzed their correlation with the semen volume, sperm concentration, total sperm count, and percentage of progressively motile sperm (PMS). RESULTS: The semen volume was significantly lower in the obesity than in the normal group (ï¼»2.63 ± 0.74ï¼½ vs ï¼»3.37 ± 1.00ï¼½ ml, P < 0.05), and so was the percentage of PMS in the overweight and even lower in the obesity than in the normal group (ï¼»47.91 ± 12.89ï¼½ and ï¼»41.27 ± 15.77ï¼½ vs ï¼»54.04 ± 13.29ï¼½%, P < 0.05). Compared with the normal group, both the overweight and obesity groups showed markedly decreased levels of serum T (ï¼»4.83 ± 1.42ï¼½ vs ï¼»3.71 ± 1.22ï¼½ and ï¼»3.49 ± 1.12ï¼½ ng/ml, P<0.05), T/LH ratio (1.53 ± 0.57 vs 1.19 ± 0.54 and 0.97 ± 0.51, P<0.05), SOD (ï¼»112.05 ± 10.54ï¼½ vs ï¼»105.85 ± 6.93ï¼½ and ï¼»99.33 ± 8.39ï¼½ U/ml, P<0.05), and GSTs (ï¼»31.75±6.03ï¼½ vs ï¼»29.54±5.78ï¼½ and ï¼»29.02±4.52ï¼½ U/L, P<0.05), but remarkably increased seminal plasma ROS (ï¼»549.93±82.41ï¼½ vs ï¼»620.61±96.13ï¼½ and ï¼»701.47±110.60ï¼½ IU/ml, P<0.05) and MDA (ï¼»7.46 ± 2.13ï¼½ vs ï¼»8.72 ± 1.89ï¼½ and ï¼»10.47 ± 2.10ï¼½ nmol/L, P<0.05). BMI was correlated positively with ROS and MDA, but negatively with the semen volume, PMS, T, T/LH, SOD and GSTs (P<0.05); LH negatively with sperm concentration, total sperm count and GSTs (P<0.05); PRL negatively GSTs (P<0.05); E2 positively with SOD (P<0.05); T positively with SOD (P<0.05) but negatively with MDA (P<0.05); T/LH positively with PMS and SOD (P<0.05) but negatively with ROS and MDA (P<0.05); SOD positively with semen volume, PMS and GSTs (P<0.05) but negatively with ROS and MDA (P<0.05); GSTs negatively with sperm concentration; total sperm count and MDA (P<0.05); ROS positively with MDA (P<0.01) but negatively with PMS (P<0.05); and MDA negatively with semen volume (P<0.05). Multivariate logistic regression analysis showed that the independent factors influencing the semen volume were BMI and GSTs, those influencing the total sperm count were BMI and T, and those influencing PMS were BMI and MDA. CONCLUSIONS: Increased BMI induces changes in the levels of male reproductive hormones and seminal plasma oxidative stress and affects semen quality, which may be associated with male infertility.

[Correlation of the levels of seminal plasma homocysteine, folate and cobalamin with semen parameters in obese men].

OBJECTIVE: To investigate the correlation of seminal plasma homocysteine (Hcy) and its metabolic factors folate (FA) and cobalamin (VB12) with semen quality in obese men. METHODS: We randomly selected 83 male patients with idiopathic infertility for this study and, according to the body mass index (BMI), divided them into a normal BMI (n = 28), an overweight (n = 28) and an obesity group (n = 27). We determined the levels of Hcy, FA and VB12 in the seminal plasma by ELISA and analyzed their correlation with the semen parameters of the patients in different groups. RESULTS: Compared with the normal BMI group, the obese males showed significant decreases in the semen volume (ï¼»3.23 ± 0.86ï¼½ vs ï¼»2.58 ± 0.77ï¼½ ml, P < 0.05), total sperm count (ï¼»191.35 ± 103.00ï¼½ vs ï¼»121.55 ± 88.08ï¼½ ×106, P < 0.05), percentage of progressively motile sperm (ï¼»52.88 ± 15.58ï¼½ % vs ï¼»38.97 ± 16.52ï¼½ %, P < 0.05), seminal plasma Hcy (ï¼»7.41 ± 1.29ï¼½ vs ï¼»6.62 ± 0.85ï¼½ µmol/L, P < 0.05), and VB12 (ï¼»282.41 ± 30.38ï¼½ vs ï¼»230.07 ± 37.75ï¼½ pmol/L, P < 0.05). There were no statistically significant differences in the semen parameters between the overweight group and the normal BMI or the obese group (P > 0.05), or in sperm concentration or the FA level among the three groups of patients (P > 0.05). The levels of seminal plasma Hcy and VB12 were correlated positively with the semen volume (r = 0.281 and 0.242, P < 0.05) and total sperm count (r = 0.229 and 0.258, P < 0.05) but negatively with BMI (r = －0.293 and －0.238, P < 0.05). No correlation, however, was found either between sperm concentration and the percentage of progressively motile sperm (P > 0.05) or between the FA level and BMI or semen parameters (P > 0.05). CONCLUSIONS: The levels of seminal plasma Hcy and VB12 are correlated with BMI, semen volume and total sperm count, which suggests that the concentrations of seminal plasma Hcy and VB12 may be associated with the fertility of obese men.