Excess weight is associated with numerous health problems including polycystic ovary syndrome (PCOS) in women. This common problem induces a wide range of symptoms that affect a woman’s quality of life. Weight gain is also an issue for patients with PCOS, but it proves to be a complicated matter. The question is – does weight gain cause PCOS or vice versa? The main objective of this post is to give you the answer. Read on to see which comes first, PCOS or weight gain.
What is PCOS?
Polycystic ovary syndrome (PCOS) is a condition that affects hormone levels in women of reproductive age. Women with this hormonal disorder tend to have elevated levels of androgen (male) hormones and their ovaries may form plenty of small collections of fluid i.e. follicles and thereby fail to release eggs.
The condition was first described in 1935 and today it is the most prevalent endocrine pathology in reproductive-age females worldwide (1). Despite the high prevalence, PCOS is largely underdiagnosed and it may take several visits to a doctor’s office to get identified.
According to the CDC, this multifactorial disease is one of the most common causes of female infertility. About 6% to 12% of US women of reproductive age have PCOS. In other words, at least five million women have this hormonal disorder. That being said, PCOS is a lifelong condition that remains long after childbearing age (2).
What Causes PCOS?
The exact cause of PCOS is unknown. Factors that play a role in the development of this condition include (3):
- Heredity – PCOS may run in families (4). Evidence shows multiple genes contribute to the condition, not just one (5)
- Excess insulin or insulin resistance – up to 70% of women with PCOS have insulin resistance meaning their body is unable to use insulin properly (6)
- Long-term low-grade inflammation – chronic inflammation contributes to the pathogenesis of this hormonal disorder (7)
- Excess androgen – androgens in excess, working through androgen receptors, play a key role in the origins of PCOS (8)
Symptoms of PCOS
In some women, the symptoms of PCOS may appear around their first period. Others discover they have PCOS later in life. The most common symptoms of PCOS include:
- Irregular periods
- Heavy bleeding during periods
- Hair growth on the face, back, belly, and chest
- Weight gain
- Male-pattern baldness
- Dark patches of the skin in body creases such as those on the neck, under the breasts, in the groin
Relationship Between PCOS and Excess Weight
As seen above, weight gain is a common symptom of polycystic ovary syndrome. Does weight gain lead to PCOS, or maybe this condition makes you more prone to putting on a few pounds? The relationship between two conditions (PCOS and overweight/obesity) is too complex, which is why we’re going to discuss it in detail below.
Does Excess Weight Play A Role in PCOS Development?
Several studies have explored the potential role of weight gain in the risk of developing PCOS. A review from the Journal of Clinical Endocrinology and Metabolism analyzed data from two consecutive populational studies assessing the prevalence of PCOS as well as a database of untreated patients with this condition at a university clinic from 1987 to 2002. More precisely, the review included 746 patients with PCOS and 675 women from populational studies. The results showed the prevalence of PCOS in women of different body weight was as follows:
- 8.2% in underweight women
- 9.8% in normal-weight women
- 9.9% in overweight women
- 9.0% in obese women
The average BMI of patients with this hormonal disorder was 37.3, which is considered obese. Scientists concluded their study confirming excess weight increases the risk of PCOS, but minimally. They also explained obesity in PCOS reflects environmental factors to a great extent (9).
Although modest, the role of excess weight in PCOS may stem from the endocrine function of the adipose tissue. You see, adipose tissue is an endocrinologically active organ that produces products such as adipokines (cytokines secreted by adipose tissue) and peptides that may act as cytokines, growth factors, chemokines (very small cytokines), and neutrally active hormones. For that reason, it is possible that adipokines including leptin (a hormone that regulates appetite) diminish insulin sensitivity and thereby pave the way to weight gain.
When discussing the potential impact of excess weight on PCOS it is important to clarify that reproductive disturbances are more common in overweight/obese women regardless of whether they have this hormonal disorder or not. Obese or overweight women tend to be more likely to experience problems such as menstrual irregularity and fertility struggles than normal-weight women. Even though reproductive abnormalities are more common in obese women, most women with excess weight don’t develop hyperandrogenemia and do not have PCOS.
In obese women, elevated production of androgen hormones has been observed particularly in females with upper-body obesity. That being said, androgen clearance rates are also higher which is why circulating bioavailable androgens remain in a normal or healthy range. However, in PCOS levels of bioavailable androgens are increased. This only confirms that being obese doesn’t automatically lead to PCOS and the risk of developing this hormonal disorder due to excess weight is modest.
That said, excess weight can worsen the abnormality with increased bioavailable androgens. Central obesity is a big problem here primarily because levels of sex hormone-binding globulin (SHBG) are decreased in this state due to elevated insulin. As a reminder, the role of SHBG is to transport androgens and estrogens in blood and regulate their access to target tissues.
It’s also useful to mention PCOS is indicated by abnormalities in the gonadotropin-releasing hormone (GnRH), which are independent of obesity. The role of GnRH is to act on the pituitary gland and trigger a release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). These two hormones act on the ovaries to release two hormones directly involved in menstruation (estrogen and progesterone).
A lot more research is necessary to uncover, in detail, the mechanism behind the potential impact of excess weight on PCOS, even in a modest amount. Several mechanisms are involved including:
- Insulin Resistance and Fat Distribution: As seen above, most women with PCOS are insulin resistant, but the understanding of insulin resistance in this condition is poor. Excess weight can worsen insulin resistance and features of metabolic syndrome. By increasing insulin resistance and affecting insulin pathways, excess weight may form a central component of PCOS pathogenesis thus underlying the link between weight gain and this condition. Additionally, women with PCOS manifest global adiposity, but visceral fat is still important in PCOS as a contributor to insulin resistance. Global adiposity
- Obstructive Sleep Apnea (OSA): Patients with OSA are at a higher risk of developing insulin resistance (10). At the same time, being overweight or obese makes you more susceptible to developing sleep apnea. Therefore, excess weight may lead to OSA thus contributing to insulin resistance and the development of PCOS
- Steroidogenesis: A multistep process for the biosynthesis of steroid hormones from cholesterol. Insulin resistance and excess insulin are the driving force behind the elevated steroidogenesis in women with PCOS. Increased steroidogenesis leads to amplified androgen levels and androgenic features. Excess weight and obesity, through the effects on insulin resistance, may enhance steroidogenesis and thereby contribute to PCOS.
To sum up this part: weight gain is a risk factor for PCOS, but the risk is modest and involves several mechanisms. Further research is necessary to learn more about the impact of overweight/obesity on the pathogenesis of polycystic ovary syndrome.
Does PCOS Lead to Weight Gain?
The relationship between PCOS and weight gain appears to be a two-way street. While weight gain can contribute to the development of PCOS and aggravate its symptoms, this hormonal disorder may also lead to weight gain.
First, it is important to keep in mind androgen hormones have an important role in the determination of body composition. For instance, men tend to have less body fat with higher fat distribution in the upper part of the body (android obesity). On the flip side, women usually have more body fat than men and tend to accumulate fat in the lower portion of the body (gynoid obesity). Interestingly, the prevalence of hypertension, diabetes, and atherosclerosis tends to be higher in females with an android than gynoid obesity.
Women with android obesity tend to have problems such as excess hair growth on the face, back, stomach, and chest. Android or upper-body obesity in women is associated with reduced insulin sensitivity and a higher risk of cardiovascular disease and diabetes. Regardless of BMI, women with polycystic ovary syndrome have a high prevalence of android obesity. This type of obesity is characterized by increased waist circumference and waist-to-hip ratio compared to other women with the same BMI.
Moreover, chronic exposure to high testosterone levels in women with this hormone disorder could modify the distribution of body fat. As a result, a woman with PCOS could be more prone to accumulating central fat i.e. gaining more weight in this specific area (11).
What we always need to bear in mind is that PCOS is a complex condition. For that reason, its relationship with body weight is also complex. It is of huge importance to discuss mechanisms that could make a woman with PCOS more prone to weight gain. These mechanisms include (12):
- Energy Expenditure: Your metabolic rate is significant for weight loss or management. Women with PCOS tend to have lower thermogenesis than their counterparts. That’s not all, the level of insulin resistance correlates with a decrease in thermogenesis. More data on this subject is necessary, but this could be a small component through which PCOS could lead to weight gain.
- Androgen-mediated Lipolysis: Lipolysis is the process wherein fats are broken down through enzymes and water. The process takes part in adipose tissue stores. PCOS is associated with abnormalities in the lipolytic function of fat cells (adipocytes) (13). Studies show androgens have a stimulatory effect on lipolysis, but also impair insulin signaling and differentiation of adipocytes (14). Even though further studies are required on androgen-mediated lipolysis and its relation to weight gain in PCOS, this process may contribute to metabolic dysfunction in women with this condition.
- Mental Health Problems: Women with PCOS often experience unpleasant and uncomfortable symptoms that affect their quality of life and self-esteem. That’s why it’s no surprise women with this condition are prone to mental health problems. In one study women with PCOS had increased anxiety, depression, and negative body image compared to their counterparts without this hormone disorder (15). Mental health problems such as anxiety and depression could hinder attempts at lifestyle modification and successful weight loss. After all, PCOS is a complicated problem that requires effective lifestyle strategies to tackle the symptoms. This can affect a woman’s mental health, lead to failing to adhere to lifestyle implementations, and contribute to weight gain.
- Sedentary Lifestyle: Physical activity is crucial for the management of both overweight/obesity and PCOS. Regular exercise helps you slim down, lowers waist circumference, improves insulin sensitivity, may regulate hormones, among other things. A sedentary lifestyle is widely prevalent, even in women with PCOS. Lack of physical activity in females with PCOS has an emotional and physical background. As mentioned above, PCOS is associated with mental health problems. For that reason, women with PCOS may experience more physical barriers in physical activity including emotional barriers, fear of injury, and physical limitations. Lack of regular physical activity has a negative effect on body weight, insulin sensitivity, mental health.
Which Comes First Then: Weight Gain or PCOS?
It would be impossible to have a specific answer to this question. The reason is simple – PCOS is a complicated disorder and its relationship with weight gain goes both ways. While excess weight increases the risk of polycystic ovary disorder, PCOS can lead to weight gain. Multiple mechanisms of action are involved here including the rise of androgen hormones and their impact on several processes in a woman’s body, including fat distribution. Insulin resistance plays a major role in both PCOS and overweight/obesity. For that reason, an overweight woman can develop PCOS (although not every overweight woman has it), but at the same time, a woman with PCOS may be more prone to weight gain.
Lifestyle modifications that focus on weight loss and maintaining weight in a healthy range are crucial for the management of PCOS. This is particularly important if we bear in mind excess weight may aggravate symptoms of polycystic ovary syndrome.
Throughout this post, we aimed to explore the complex relationship between weight gain and polycystic ovary syndrome. The link between two conditions is so complex it is impossible to say one comes before another in all women. You see, weight gain is a risk factor for PCOS. But, not every overweight or obese woman has PCOS. So this risk is modest but existent. At the same time, having PCOS could make you more susceptible to gaining weight which then goes on to aggravate other symptoms you experience. See your doctor regularly and modify your lifestyle to maintain weight in a healthy range.