ASSOCIATION BETWEEN OBESITY AND INFERTILITY: A CLINICAL AND HORMONAL PERSPECTIVE

Abstract

Background: Infertility in both men and women is increasingly linked to obesity, which has become a major global public health concern. Overweight causes insulin resistance, chronic inflammation, hormonal imbalance, and disruption of the hypothalamic-pituitary-gonadal axis, all of which have a negative impact on reproductive function. Improving reproductive outcomes requires an understanding of the clinical and hormonal mechanisms connecting obesity and infertility.

Objective: To ascertain whether obesity and infertility are related from a clinical and hormonal standpoint in adults of reproductive age who visit the Department of Endocrinology and Diabetes, Ward-6, Jinnah Postgraduate Medical Centre (JPMC), Karachi.

Methodology: From January 2025 to January 2026, a comparative cross-sectional study was carried out at the Department of Endocrinology and Diabetes, Ward-6, Jinnah Postgraduate Medical Centre (JPMC), Karachi, Pakistan. Through consecutive sampling, 240 infertile men and women between the ages of 20 and 45 were recruited and divided into two groups: obese (BMI ≥30 kg/m²) and non-obese (BMI 18.5–24.9 kg/m²). Anthropometric measurements, reproductive history, follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, estradiol, progesterone, testosterone, anti-Müllerian hormone (AMH), thyroid-stimulating hormone (TSH), fasting insulin, and fasting glucose were all evaluated. SPSS version 26.0 was used to analyse the data. Independent sample t-tests and Chi-square tests were used to compare groups, and multivariable logistic regression was used to find independent predictors of infertility. Statistical significance was defined as a p-value of less than 0.05.

Result: Of the 240 participants, 110 (45.8%) were not obese and 130 (54.2%) were. Menstrual irregularities (61.5% vs. 27.3%), polycystic ovary syndrome (38.5% vs. 15.5%), insulin resistance (69.2% vs. 24.5%), and metabolic syndrome (35.4% vs. 12.7%) were all significantly more common in obese participants (p<0.001). Serum levels of LH, total testosterone, prolactin, fasting insulin, and HOMA-IR were significantly higher in obese female participants than in non-obese females, while AMH levels were significantly lower (p<0.05). Male obesity was associated with significantly lower serum testosterone levels and worse semen quality, including lower sperm motility and concentration (p<0.05). Obesity (Adjusted OR=2.84, 95% CI: 1.67–4.82), insulin resistance (Adjusted OR=2.41, 95% CI: 1.39–4.18), and elevated testosterone in women (Adjusted OR=1.96, 95% CI: 1.12–3.42) were found to be independent predictors of infertility using multivariable logistic regression.

Conclusion: Through a variety of clinical and hormonal mechanisms that impact both male and female reproductive function, obesity is closely linked to infertility. To improve reproductive outcomes, infertility management should include the early detection of endocrine abnormalities and the application of weight reduction techniques.