The Relation of Insulin Resistance With Free Androgen Index and Endothelial Dysfunction Marker YKL-40 and Its Effect on Male Infertility: A Prospective Study.

Purpose: In this study, the effects of insulin resistance and the role of the endothelial dysfunction marker YKL-40 in male infertility were investigated.

Methods: This study was conducted with male patients who underwent fertility investigations in the in vitro fertilization (IVF) unit of a tertiary center. Semen samples were evaluated after two to five days of sexual abstinence. The hormonal and lipid profiles, fasting glucose and insulin levels, and YKL-40 values of the patients were assessed. The Homeostatic Model Assessment (HOMA) index was calculated, and those with a score of 2.5 and above were considered insulin resistant (IR).

Results: In total, 75 patients, 34 with IR and 41 without IR, were included. The groups had similar ages, heights, weights, and BMIs. Additionally, the semen parameters were similar between the groups. The median fasting glucose and insulin levels were significantly greater in the insulin-resistant group (p=0.008 and p<0.00, respectively). There were no significant differences in terms of the serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), thyroid stimulating hormone (TSH), sex hormone binding globulin (SHBG), high-density lipoprotein (HDL), or low-density lipoprotein LDL) levels. Total testosterone levels were lower in the IR group than in the group without IR (p<0.001). Both the total serum cholesterol and triglyceride levels were greater in the IR patients (p=0.031 and p=0,002, respectively). Compared with the patients without IR, the IR patients had a lower free androgen index. The serum YKL-40 levels were similar between the groups, and there were no correlations between YKL-40 and the other parameters.

Conclusion: This initial study investigating the serum YKL-40 level in men with and without IR revealed no relationship between YKL-40 levels and IR. Nonetheless, higher total serum cholesterol and triglyceride levels and lower total serum testosterone and free androgen indices were found in participants with IR.