Does plasma insulin level affect ovarian response to exogenous administration of follicle-stimulating hormone in women without polycystic ovary syndrome?

Association of HOMA-IR with Ovarian Sensitivity Index in Women Undergoing IVF/ICSI: A Retrospective Cohort Study

BACKGROUND

Insulin resistance (IR) may adversely impact the in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) outcomes. However, the association of IR with ovarian sensitivity during controlled ovarian hyperstimulation (COH) remains controversial.

PURPOSE

We aimed to explore the association between homeostasis model assessment of insulin resistance (HOMA-IR) and ovarian sensitivity index (OSI).

PATIENTS AND METHODS

In this retrospective cohort study, 7836 patients aged between 20 and 39 years with good ovarian reserve were included consecutively between June 2018 and May 2022. HOMA-IR was calculated to evaluate the degree of IR and OSI was used to measure ovarian sensitivity. Owing to skewed distribution, HOMA-IR and OSI were log e transformed to Ln HOMA-IR and Ln OSI. Smoothing splines were generated by generalized additive models to explore the correlation between Ln HOMA-IR and Ln OSI. Then, the relationship between Ln HOMA-IR and Ln OSI was tested with multivariable linear regression model after adjustments for the potential confounders.

RESULTS

We observed negative association between Ln HOMA-IR and Ln OSI after adjustment for potential confounders by using smoothing spline fitting curves in generalized additive model. In the multivariable linear regression model, after full adjustments, each one unit increase in Ln HOMA-IR was related to reduced Ln OSI values (β = -0.12, 95% CI, -0.15, -0.09). As sensitivity analysis, those who had HOMA-IR of quartile 3 (HOMA-IR 2.33-3.43) and quartile 4 (HOMA-IR ≥3.43) had decreases in Ln OSI values (β = -0.07, 95% CI -0.11, -0.03 and β = -0.18, 95% CI -0.22, -0.13, respectively) when compared with patients in the quartile 1 (HOMA-IR <1.63). Furthermore, stratified and interaction analysis showed a strong inverse association of Ln HOMA-IR with Ln OSI in subgroups of PCOS patients and overweight/obese populations (P-value for interaction <0.0001).

CONCLUSION

HOMA-IR value was negatively associated with the ovarian sensitivity assessed by OSI. Among the PCOS and overweight/obese populations, this inverse relationship may be strong. These findings will increase the understanding of the contribution of IR to the development of decreased ovarian sensitivity within the assisted reproductive technology (ART) setting. It may have implications for optimizing gonadotropin dose manipulation in patients with IR undergoing IVF/ICSI.

Role of hormonal and inflammatory alterations in obesity-related reproductive dysfunction at the level of the hypothalamic-pituitary-ovarian axis

BACKGROUND

Besides being a risk factor for multiple metabolic disorders, obesity could affect female reproduction. While increased adiposity is associated with hormonal changes that could disrupt the function of the hypothalamus and the pituitary, compelling data suggest that obesity-related hormonal and inflammatory changes could directly impact ovarian function.

OBJECTIVE

To review the available data related to the mechanisms by which obesity, and its associated hormonal and inflammatory changes, could affect the female reproductive function with a focus on the hypothalamic-pituitary-ovarian (HPO) axis.

METHODS

PubMed database search for publications in English language until October 2017 pertaining to obesity and female reproductive function was performed.

RESULTS

The obesity-related changes in hormone levels, in particular leptin, adiponectin, ghrelin, neuropeptide Y and agouti-related protein, are associated with reproductive dysfunction at both the hypothalamic-pituitary and the ovarian levels. The pro-inflammatory molecules advanced glycation end products (AGEs) and monocyte chemotactic protein-1 (MCP-1) are emerging as relatively new players in the pathophysiology of obesity-related ovarian dysfunction.

CONCLUSION

There is an intricate crosstalk between the adipose tissue and the inflammatory system with the HPO axis function. Understanding the mechanisms behind this crosstalk could lead to potential therapies for the common obesity-related reproductive dysfunction.