Triglycerides/Glucose Index Is Associated with Sperm Parameters and Sperm DNA Fragmentation in Primary Infertile Men: A Cross-Sectional Study

Abstract

Study question: we aimed to investigate the relationship between the tyg index and both semen and hormonal characteristics in a cohort of primary infertile men. Summary answer: almost one in two primary infertile men presented with a triglycerides/glucose index (tyg) suggestive of insulin resistance (ir). overall, patients with tyg suggestive of ir showed worse clinical, hormonal, and semen parameters. What is already known: male factor infertility (MFI) is often associated with metabolic disorders such as diabetes mellitus and metabolic syndrome, where insulin resistance (IR) plays a relevant pathological role. Recently, TyG has been suggested as a user-friendly IR marker. Study Design: serum hormones and the sperm DNA fragmentation index (SDF) were measured in every patient. The semen analysis was based on 2010 WHO reference criteria. Glucose and insulin levels were measured for every man after a 12-h overnight fast, and the homeostatic model assessment index (HOMA-IR) was then calculated and categorized using a 2.6 threshold. Similarly, fasting glucose and triglycerides levels were measured and the TyG index was calculated and categorized using an 8.1 threshold. Descriptive statistics and logistic regression models tested the association between the TyG and semen and hormonal characteristics. Participants: complete demographic, clinical, and laboratory data from 726 consecutive white European primary infertile men were considered for this analysis. Main results and the role of chance: the median (IQR) age was 39 (35–43) years. A TyG and HOMA suggestive for IR was found in 339 (46.6%) and 154 (21.2%) men, respectively. During the Spearman’s test, the TyG index was highly correlated with HOMA-IR (rho = 0.46, p < 0.001). Compared to men with a normal TyG, men with TyG > 8.1 were older, had greater BMI and CCI scores, and lower total testosterone and sperm concentration, but higher DFI, and presented a greater proportion of NOA (all p < 0.01). The multivariable logistic regression analysis showed that men with TyG > 8.1 were at higher risk of SDF > 30 (OR 1.92 (CI: 1.2–2.9)) and NOA (OR 1.78 (CI: 1.1–2.8)). Wider implications of the findings: the Tyng index may act as a reliable marker of IR in the clinical work-up of primary infertile men in real-life settings.

The Triglycerides and Glucose Index is not superior to HOMA‐IR in predicting testosterone deficiency among adult males

“…37 A higher TyG index was also associated with more serious sperm DNA fragmentation (OR = 1.92, 95% CI = 1.2, 2.9) and a higher risk of nonobstructive azoospermia (OR = 1.78, 95% CI = 1.1, 2.8). 38 However, the results of ROC analysis indicated that the TyG index was inferior to HOMA-IR in predicting testosterone deficiency occurrence in NHANES participants, which was not in accordance with a previous study carried out on 4299 Chinese men. 39 The reason for this discordance was not clear, but it might derive from different population settings, races, or laboratory protocols.…”

“…reported that the TyG index could be used as a predictive marker of unfavorable prognostic factors of radical prostatectomy 37 . A higher TyG index was also associated with more serious sperm DNA fragmentation (OR = 1.92, 95% CI = 1.2, 2.9) and a higher risk of nonobstructive azoospermia (OR = 1.78, 95% CI = 1.1, 2.8) 38 . However, the results of ROC analysis indicated that the TyG index was inferior to HOMA‐IR in predicting testosterone deficiency occurrence in NHANES participants, which was not in accordance with a previous study carried out on 4299 Chinese men 39 .…”

Kidney function impairment in men with primary infertility: A case–control analysis

“…Third, for the definition of CKD, we used the threshold set by the KDIGO guidelines (i.e., defining kidney function impairment as eGFR < 90 mL/min per 1.73 m 2 and CKD as eGFR < 60 mL/min per 1.73 m 2 ); however, evidence exists that the threshold for CKD should be set at higher eGFR levels for younger individuals, 41 thus potentially increasing the proportion of men with initial kidney function impairment among young men with primary infertility. Finally, although an association between impaired renal function and semen parameters was not observed, we did not examine alterations in the sperm quality profile that could be even more sensitive to alterations in the state of overall men's health, such as an increase in the percentage of sperm DNA fragmentation 42–44 . In addition, we included a very selected group of infertile men, that is, those with availability of eGFR evaluation in a tertiary referral center; therefore, the study of association of putative risk factors such as impaired kidney function with impaired semen analysis might be biased by information and selection bias.…”

“…Finally, although an association between impaired renal function and semen parameters was not observed, we did not examine alterations in the sperm quality profile that could be even more sensitive to alterations in the state of overall men's health, such as an increase in the percentage of sperm DNA fragmentation. [42][43][44] In addition, we included a very selected group of infertile men, that is, those with availability of eGFR evaluation in a tertiary referral center; therefore, the study of association of putative risk factors such as impaired kidney function with impaired semen analysis might be biased by information and selection bias. Further studies with larger cohorts are certainly needed.…”

Interpretable machine learning framework to predict gout associated with dietary fiber and triglyceride-glucose index

“…According to Belladelli F et al [ 23 ], the TyG index is calculated as ln [triglycerides (mg/dL) × fasting glucose (mg/dL)/2]. Huang X et al concluded that the TyG- BMI has the same novel index of IR as the TyG index, which is a better indicator of IR than the HOMA-IR, and its calculation formula is TyG-BMI = TyG index × BMI [ 24 ].…”