Introduction

Insulin resistance (IR) is patho-physiologically linked to metabolic syndrome (MetS). Previous study showed a correlation between MetS and a reduced male fertility potential. We aimed to investigate whether men with IR are at higher risk of decreased reproductive health

Methods

Complete demographic, clinical and laboratory data from 272 consecutive infertile men (infertility defined according to the WHO definition) were considered for this analysis. Azoospermia was defined as the absence of sperm in 2 consecutive semen analyses. Health-significant comorbidities were scored with the Charlson Comorbidity Index (CCI). Glucose and insulin levels were measured for every man after a 12-h overnight fast, and homeostasis model assessment-estimated insulin resistance (HOMA-IR) index was then calculated. HOMA-IR was classified using the 2.6 cut-off, previously shown to be an accurate predictor of IR (Ascaso et al. Diabetes Care 2003). Logistic regression models tested the odds (OR, 95%CI) of non-obstructive azoospermia (NOA) after adjusting for age, BMI, comorbidities (CCI>0), FSH, testicular volume, and HOMA-IR >2.6.

Results

Mean (interquartile range) patient age was 38 (IQR 35-42) years. Median BMI 25 (IQR 23-27) kg/m2. Of 272, 16 (6%) men had a CCI≥1. A HOMA-IR suggestive for IR was found in 47 (17%) men. Overall, NOA was found in 64 (24%) men. Compared to men without IR, men with IR were older [median age 41 (IQR 37-44) vs. 38 (IQR 35-42) years], had higher median BMI [27 (IQR 25-29) vs. 25 (IQR 23-26) kg/m2]; and, a higher rate of NOA [14/47 (30%) vs. 50/225 (22%)]. At multivariable logistic regression analysis, men with IR were at higher risk of NOA [OR 2.46 (CI: 1.06-5.72)], after accounting for patient age, BMI, CCI, FSH values, and testicular volume.

Conclusions

A consistent proportion of infertile men (17%) showed a HOMA-IR suggestive for IR. This finding is worrying not only in terms of general health, but also considering male fertility potential, since men with IR have a more than doubled risk of NOA.

Funding

none