Does Obesity Contribute to Male Infertility?
Dr. Kate Dudek • November 2, 2019 • 5 min read
According to the World Health Organisation, over 650 million adults worldwide are obese. With prevalence rates increasing rapidly across developed countries, obesity is becoming a major public health concern. Across the Arab world, it is estimated that approximately 30% of the population are obese. Obesity predisposes males and females to many potential health issues, including infertility.
How is obesity measured?
A person’s Body Mass Index (BMI) is used to determine whether they are obese. BMI is a measure of body fat using height and weight measurements; weight in KG divided by height in metres squared (m2):
BMI = KG/m2
The general consensus is that adults with a BMI in the range of 25 – 29.9 KG/m2 are overweight, and those with a BMI of ⩾30.0 KG/m2 are obese.
Having a high BMI puts an individual at greater risk of various serious health issues, including type 2 diabetes, high blood pressure, high cholesterol and cancer. It also affects a person’s quality of life, often having a negative impact on their self-esteem and confidence.
In females, the effect of obesity on infertility has been well studied and it is widely known that a high BMI can result in menstrual cycle irregularities. The impact of obesity on a male’s ability to conceive has been less extensively studied. However, it is likely to have an effect as an increased BMI is associated with lower testosterone production, poor semen quality and reduced fertility.
How obesity affects male fertility:
Endocrine dysregulation
Typically, obese, infertile men have lower testosterone levels and higher circulating oestrogen. The reduction in androgens, primarily testosterone, is proportional to the degree of obesity. Increased peripheral aromatisation of androgens causes higher levels of oestrone and oestradiol. Obesity results in more white adipose tissue, which also increases oestrogen levels. Alterations in the testosterone/oestrogen ratio have a negative effect on the hypothalamic-pituitary-gonadal (HPG) axis, disrupting the negative feedback loop and resulting in diminished sperm counts.
Other hormones are also implicated; men with a high BMI have lower levels of Sex Hormone Binding Globulin (SHBG). SHBG is involved in spermatogenesis and Sertoli cell function. Obese, infertile men often have elevated leptin and, interestingly, levels are less high in obese men who are not infertile. Leptin is secreted by white adipose tissue into the bloodstream. Therefore, the serum levels of this hormone correlate with the body’s fat stores. High leptin inhibits the production of testosterone from the leydig cells.
Insulin resistance
Obese men with type 2 diabetes often have secondary hypogonadism due to their insulin resistance. It is thought that insulin resistance triggers disruption of the HPG axis, although the mechanisms are not fully understood. Insulin resistance also results in reduced testosterone levels. Obesity is a major risk factor for development of type 2 diabetes, with difficulties in conceiving being just one of the associated health risks.
Oxidative stress
Obesity results in an increase in the production of reactive oxygen species (ROS), which cause damage to the DNA located within sperm cells. Men with a higher BMI exhibit increased oxidative stress and, as a result, more ROS.
Metabolic syndrome
Metabolic syndrome (MetS) is triggered, in part by obesity. Other contributory factors include high blood pressure, high plasma glucose and high cholesterol. MetS increases the risk of type 2 diabetes, and is also linked to the development of hypogonadism and erectile dysfunction. Not all men who experience erectile dysfunction are infertile, but difficulties in sustaining an erection are more common in men who are struggling to conceive. One study found that 27% of infertile men experienced erectile dysfunction. Furthermore, those who report erectile difficulties are significantly more likely to be overweight or obese. Obese men with MetS frequently present with hyperinsulinaemia and hyperglycaemia, which can have a detrimental effect on sperm quantity and quality.
Hyperthermia
The process of spermatogenesis is highly heat sensitive, with the optimal temperature being 34-35°C. Increased adipose tissue in the scrotal area can have a detrimental effect on gonadal temperature and damage the developing sperm cells. The consequences of this include reduced sperm motility and increased DNA fragmentation, both of which hinder a man’s ability to conceive.
Environmental and psychological factors
There are many environmental pollutants and endocrine disruptors that have been shown to affect male fertility. A lot of toxins are fat soluble and therefore, tend to accumulate in fatty tissue. This suggests that obese men, who have more fat reserves, are at greater risk of suffering the harmful effects caused by a build up of these toxins.
Obese men are also more prone to sleep apnea. This is a disorder characterised by pauses in breathing during periods of sleep and one of the consequences is disrupted testosterone production. Levels of testosterone are particularly low immediately after waking. The condition can also reduce a man’s interest in partaking in sexual activity.
It is important not to under-estimate the psychological burden of obesity. Obese individuals are more likely to consider themselves unattractive and undesirable than their non-obese counterparts. They may be emotionally unwilling, or physically unable to engage in regular intercourse. They might experience a lack of desire and implement avoidance strategies, particularly if they find the process uncomfortable or are ashamed of their body. There is limited data suggesting that obese men have intercourse less frequently; however, whether this is due to psychological factors, or a physical barrier, such as erectile dysfunction, is not clear. Further work is needed in order to validate and better understand these findings.
To conclude, obesity does appear to contribute to male infertility; probably due to multiple factors interacting and exacerbating the negative effects of lower testosterone levels and poorer semen quality in males with a high BMI.
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Get in touch if you have any questions about this article or any aspect of women’s health. We’re here for you.
Sources:
- Hammoud, Ahmad O., et al. “Impact of Male Obesity on Infertility: a Critical Review of the Current Literature.” Fertility and Sterility, vol. 90, no. 4, Oct. 2008, pp. 897–904., doi:10.1016/j.fertnstert.2008.08.026.
- Hofny, Eman R.m., et al. “Semen Parameters and Hormonal Profile in Obese Fertile and Infertile Males.” Fertility and Sterility, vol. 94, no. 2, July 2010, pp. 581–584., doi:10.1016/j.fertnstert.2009.03.085.
- Katib, Atif. “Mechanisms Linking Obesity with Male Infertility.” Central European Journal of Urology, vol. 68, no. 1, 13 Mar. 2015, pp. 79–85., doi:10.5173/ceju.2015.01.435.
- “Obesity and Overweight.” World Health Organization, https://www.who.int/en/news-room/fact-sheets/detail/obesity-and-overweight.
- “Managing Overweight and Obesity in Adults: Systematic Evidence Review from the Obesity Expert Panel.” National Heart Lung and Blood Institute, U.S. Department of Health and Human Services, https://www.nhlbi.nih.gov/health-topics/managing-overweight-obesity-in-adults.
- Morrison, Christopher D., and Robert E. Brannigan. “Metabolic Syndrome and Infertility in Men.” Best Practice & Research Clinical Obstetrics & Gynaecology, vol. 29, no. 4, May 2015, pp. 507–515., doi:10.1016/j.bpobgyn.2014.10.006.
- Salam, Mohamed Ahmed Abd El. “Obesity, An Enemy of Male Fertility: A Mini Review.” Oman Medical Journal, vol. 33, no. 1, Jan. 2018, pp. 3–6., doi:10.5001/omj.2018.02.
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Causes of Female Infertility – Autoimmune and Immune-Mediated Disorders
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[Causes of Female](https://nabtahealth.com/causes-of-female-infertility-infection) [Infertility](https://nabtahealth.com/glossary/infertility/) – Infection ([PID](https://nabtahealth.com/glossary/pid/) and [HPV](https://nabtahealth.com/glossary/hpv/)) [Causes of Female](https://nabtahealth.com/causes-of-female-infertility-environmental-lifestyle-factors) [Infertility](https://nabtahealth.com/glossary/infertility/) – Environmental/Lifestyle Factors Nabta is reshaping women’s healthcare. We support women with their personal health journeys, from everyday wellbeing to the uniquely female experiences of fertility, pregnancy, and [menopause](https://nabtahealth.com/glossary/menopause/). Get in [touch](/cdn-cgi/l/email-protection#671e060b0b062709060513060f02060b130f4904080a) if you have any questions about this article or any aspect of women’s health. We’re here for you. **Sources:** * Brazdova, A, et al. “Immune Aspects of Female [Infertility](https://nabtahealth.com/glossary/infertility/).” International Journal of Fertility & Sterility , vol. 10, no. 1, 2016, pp. 1–10. * Domniz, N and Meirow, D, “Premature ovarian insufficiency and autoimmune diseases” Best Practice & Research Clinical Obstetrics & Gynaecology, vol 60, Oct 2019, pp 42-55. doi.org/10.1016/j.bpobgyn.2019.07.008. * Hickman, R A, and C Gordon. “Causes and Management of [Infertility](https://nabtahealth.com/glossary/infertility/) in Systemic [Lupus](https://nabtahealth.com/glossary/lupus/) Erythematosus .” Rheumatology, vol. 50, no. 9, Sept. 2011, pp. 1551–1558., doi:10.1093/rheumatology/ker105. * Khizroeva, J et al, “[Infertility](https://nabtahealth.com/glossary/infertility/) in women with systemic autoimmune diseases” Best Practice & Research Clinical Endocrinology & [Metabolism](https://nabtahealth.com/glossary/metabolism/), vol 33, Dec 2019, doi.org/10.1016/j.beem.2019.101369. * Kim, N Y et al. “Thyroid autoimmunity and its association with cellular and humoral immunity in women with reproductive failures.” American Journal of reproductive immunology, vol. 65, no. 1, Jan. 2011, pp. 78-87. doi: 10.1111/j.1600-0897.2010.00911.x. * Lebovic and Naz, “Premature ovarian failure: Think ‘autoimmune disorder’”, Sexuality, Reproduction & [Menopause](https://nabtahealth.com/glossary/menopause/), vol. 2, no. 4, Dec 2004, pp.230-233. https://doi.org/10.1016/j.sram.2004.11.010. * McCulloch, F. “Natural Treatments for Autoimmune [Infertility](https://nabtahealth.com/glossary/infertility/) Concerns.” American College for Advancement in Medicine, 29 Jan. 2014, [www.acam.org/blogpost/1092863/179527/Natural-Treatments-for-Autoimmune-](http://www.acam.org/blogpost/1092863/179527/Natural-Treatments-for-Autoimmune-Infertility-Concerns)[Infertility](https://nabtahealth.com/glossary/infertility/)\-Concerns. * Romitti, M et al. “Association between [PCOS](https://nabtahealth.com/glossary/pcos/) and autoimmune thyroid disease: a systematic review and meta-analysis.” Endocrine connections, vol 7, no. 11, Oct 2018, pp 1158-1167. doi: 10.1530/EC-18-0309. * Shigesi, N et al, “The association between [endometriosis](https://nabtahealth.com/glossary/endometriosis/) and autoimmune diseases: a systematic review and meta-analysis.” Human Reproduction Update, vol. 25, no. 4, Jul 2019, pp 486-503. doi: 10.1093/humupd/dmz014. * “What Are Some Possible Causes of Female [Infertility](https://nabtahealth.com/glossary/infertility/)? .” National Institutes of Health, [www.nichd.nih.gov/health/topics/](http://www.nichd.nih.gov/health/topics/infertility/conditioninfo/causes/causes-female)[infertility](https://nabtahealth.com/glossary/infertility/)/conditioninfo/causes/causes-female.
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The best time to record BBT is first thing in the morning before undertaking any physical activity. Ideally, BBT measurements should be taken after at least 3-4 hours sleep. BBT can be affected by increased stress, illness, medication use, alcohol consumption and changes in time zone/circadian rhythm. It is not recommended to take measurements if you are using hormonal contraceptives, as the synthetic hormones will disrupt the normal ovulatory cycle. #### What can you use basal body temperature for? As a means of contraception, recording BBT is not without its drawbacks. At best it predicts peak fertility, with the rise in temperature indicating that [ovulation](https://nabtahealth.com/glossary/ovulation/) has occurred. To completely avoid pregnancy, a female would need to abstain from intercourse from the start of menstruation until 3-4 days after the rise in BBT. The most valuable use for BBT plotting is perhaps as a tool for determining the best time to have intercourse if trying to conceive. For those women who have regular periods, measuring BBT for 3-4 cycles can give a fairly accurate prediction of which days they are most fertile. Male [sperm](https://nabtahealth.com/glossary/sperm/) can survive for 5-7 days inside the female reproductive tract, but once [ovulation](https://nabtahealth.com/glossary/ovulation/) triggers the release of the female egg from the [ovaries](https://nabtahealth.com/glossary/ovaries/), the egg only has a 24 hour period of viability. This means that a female is fertile from 5 days before [ovulation](https://nabtahealth.com/glossary/ovulation/), to 2 days afterwards. Outside of this window, she cannot conceive. By the time the BBT spike is seen, the female is reaching the end of her fertile period for that month. #### Can measuring basal body temperature help fertility? The major benefits to using BBT to identify [ovulation](https://nabtahealth.com/glossary/ovulation/) are that it is low-cost, easily accessible (the only equipment you need are a thermometer and chart paper to plot your readings) and non-invasive. One means of improving the efficacy of BBT is to combine it with other fertility awareness-based methods, such as the cervical mucus method. This method is based on the theory that cervical secretions change throughout the menstrual cycle. Using these two approaches in combination is known as the symptothermal approach. BBT can also be tracked alongside using our [OvuSense device](https://nabtahealth.com/products/ovusense/), which is a realtime fertility monitor, aimed to predict [ovulation](https://nabtahealth.com/glossary/ovulation/) with 99% accuracy. The benefits of tracking your basal body temperature ---------------------------------------------------- Tracking your basal body temperature (BBT) is a simple and effective way to gain insights into your menstrual cycle and fertility. BBT is the lowest body temperature that you experience during a 24-hour period, and it can be measured using a basal body thermometer. By taking your temperature every morning at the same time and recording it, you can create a chart that shows any changes in your BBT throughout your menstrual cycle. **There are several benefits to tracking your BBT, including:** 1. Identifying [ovulation](https://nabtahealth.com/glossary/ovulation/): Your BBT typically rises slightly during [ovulation](https://nabtahealth.com/glossary/ovulation/), which is when an egg is released from the [ovaries](https://nabtahealth.com/glossary/ovaries/) and can be fertilized. By tracking your BBT, you can identify when you are most likely to be ovulating, which can help you plan or avoid pregnancy. 2. Monitoring your menstrual cycle: By charting your BBT over time, you can get a better understanding of your menstrual cycle and how it varies from month to month. This can be helpful for identifying any changes or irregularities in your cycle, which can be a sign of underlying health issues. 3. Assessing your fertility: Your BBT can provide valuable insights into your fertility, and tracking it over time can help you and your doctor assess your overall reproductive health. For example, if your BBT remains consistently high over several cycles, it could indicate that you are not ovulating, which can affect your ability to conceive. 4. Predicting [ovulation](https://nabtahealth.com/glossary/ovulation/): By tracking your BBT and identifying when it rises, you can predict when you are most likely to ovulate and plan accordingly. This can be helpful for those who are trying to conceive or avoid pregnancy. The [Nabta App](https://nabtahealth.com/our-platform/nabta-app/) can be used to record the Basal Body Temperature and store and plot the data. Nabta is reshaping women’s healthcare. We support women with their personal health journeys, from everyday wellbeing to the uniquely female experiences of fertility, pregnancy, and [menopause](https://nabtahealth.com/glossary/menopause/). Get in [touch](/cdn-cgi/l/email-protection#a1d8c0cdcdc0e1cfc0c3d5c0c9c4c0cdd5c98fc2cecc) if you have any questions about this article or any aspect of women’s health. We’re here for you. Don’t forget you can register [here](https://nabtahealth.com/my-account) to become a Nabta member free of charge. **Sources:** * NHS Choices, _NHS_, [https://www.nhs.uk/conditions/contraception/natural-family-planning/](https://www.nhs.uk/conditions/contraception/natural-family-planning/). * “Fertility Awareness-Based Methods of Family Planning.” ACOG, _Women’s Health Care Physicians_, [https://www.acog.org/Patients/FAQs/Fertility-Awareness-Based-Methods-of-Family-Planning](https://www.acog.org/Patients/FAQs/Fertility-Awareness-Based-Methods-of-Family-Planning). * Pallone, S. R., and G. R. Bergus. “Fertility Awareness-Based Methods: Another Option for Family Planning.” _The Journal of the American Board of Family Medicine_, vol. 22, no. 2, 2009, pp. 147–157., doi:10.3122/jabfm.2009.02.080038. * Su, Hsiu-Wei, et al. “Detection of [Ovulation](https://nabtahealth.com/glossary/ovulation/), a Review of Currently Available Methods.” _Bioengineering & Translational Medicine_, vol. 2, no. 3, 16 May 2017, pp. 238–246., doi:10.1002/btm2.10058.