How Does BMI And Waist Circumference Affect Semen Quality In Men?
A lot of people wonder if body size, shape, weight and basal metabolism has any effect on the reproductive health? Scientists at Department of Urology, Stanford University School of Medicine conducted an extensive study on 501 couples over a period of four years to find the answer to this question.
Details Of The Study
During 2005-2009, about 501 couples were recruited from Texas and Michigan region to study if lifestyle choices and environment has any effect on the semen quality and sexual health. The majority of the sample was over-weight or obese (with 82% of the cohort having the body mass index higher than 25kg/m2). In addition, more than 58% participants reported physical activity of less than 1 session per week. When lab investigations were performed, it was observed that a significant chunk of sample (about 8.6%) was oligospermic. After careful correlation and regression analysis; investigators discovered that:
- The volume of ejaculate decreases in a linear fashion with increasing BMI (suggesting an inverse relationship).
- The sperm quality and viability declines with increasing waist circumference.
Investigators also discovered that quality of semen decreases (such as sperm viability, motility, semen volume) with increasing body size; however, no relationship was observed between sperm DNA fragmentation index and physical activity or obesity.
Sub-fertility or impaired reproductive health shatters the parenthood dream of about 15% couples in the United States (1). Various research and clinical studies suggests that subfertility in men is multifactorial i.e. several factors can impact the quality of reproductive health. However, with lifestyle modifications and overall improved physical health, the chances of conception can be significantly improved.
The pathophysiology of abnormal BMI and male has been a topic of debate and research for past few decades. For example:
- Abnormal sperm production: Study conducted by Jensen and associates (2) suggested that abnormal BMI is very strongly linked to impaired sperm production. One of the many reasons is, abnormal metabolism of testosterone (which plays a key role in the production of healthy and viable sperms).
- Abdominal obesity and risk of metabolic disorders: According to a new study reported in the Human Reproduction (3), investigators provided statistical evidence that abnormal BMI and abdominal obesity is very strongly linked to a number of health issues (such as cardiovascular dysfunction, atherosclerosis, type 2 diabetes, hypertension and others). Needless to say that these health issues have a deleterious effect on the sexual health regardless of the body-mass index (or BMI).
- Obesity, physical activity and testosterone: Testosterone levels tends to decline in males who have a sedentary lifestyle. Various research and clinical studies indicates that aerobic activity or exercise can improve testosterone metabolism in males significantly.
What Are Some Interventions That May Help In Improving Fertility In Obese Men?
Fertility in obese men can be improved significantly by following interventions:
- Healthy weight loss: Incorporating a healthy lifestyle is the key. Obese individuals should incorporate moderate physical activity and exercise in their daily lifestyle. In addition, maintain the intake of low-calories, balanced diet to minimize the risk of complications. It is also very important to avoid starving or severe calorie restriction as it may have more deleterious effects on the reproductive health.
- Do not go for surgeries: A lot of obese men finds it hard to shed significant amount of weight with diet and exercise alone. All such men should know that bariatric surgeries or sudden weight loss can have adverse effects on your fertility. Study reported in the Reproductive Biomedicine Online journal (4), suggested that sperm parameters worsens after massive and sudden weight loss and bariatric surgeries. Based on the laboratory investigations obtained from the three cases, it was observed that male patients develops oligoasthenoteratozoospermia and impaired fertility. In all such patients IVF and intracytoplasmic sperm injection can be used until normal spermatogenesis is resumed (which in some cases may take up to two-three years).
Last but not the least, speak to a registered dietitian in addition to a fertility expert in order to make healthy choices and suitable decisions.
1. Eisenberg, M. L., Kim, S., Chen, Z., Sundaram, R., Schisterman, E. F., & Louis, G. M. B. (2014). The relationship between male BMI and waist circumference on semen quality: data from the LIFE study. Human Reproduction, 29(2), 193-200.
2. Jensen, T. K., Andersson, A. M., Jørgensen, N., Andersen, A. G., Carlsen, E., & Skakkebæk, N. E. (2004). Body mass index in relation to semen quality and reproductive hormonesamong 1,558 Danish men. Fertility and sterility, 82(4), 863-870.
3. Hammiche, F., Laven, J. S., Twigt, J. M., Boellaard, W. P., Steegers, E. A., & Steegers-Theunissen, R. P. (2012). Body mass index and central adiposity are associated with sperm quality in men of subfertile couples. Human reproduction, 27(8), 2365-2372.
4. Sermondade, N., Massin, N., Boitrelle, F., Pfeffer, J., Eustache, F., Sifer, C., … & Lévy, R. (2012). Sperm parameters and male fertility after bariatric surgery: three case series. Reproductive biomedicine online, 24(2), 206-210.