Why is it important to evaluate the cardiovascular system in patients with polycystic ovary syndrome?

#MedTwitter #medstudenttwitter #Tweetorial #PCOS #Cardiology #Science @USFQ_Ecuador
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Polycystic ovary syndrome (PCOS) is the most common endocrine-metabolic disorder in reproductive-age women, with a prevalence between 6 and 20%, depending on how it is defined.

nature.com/articles/nrend…
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The most common definition is Rotterdam Criteria, with 2 out of 3 of the following features:
- Hyperandrogenism
- Ovulatory dysfunction
- Polycystic ovarian morphology

nejm.org/doi/full/10.10… https://www.nature.com/arti...
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However, PCOS is not only acne, hirsutism and menstrual irregularities: it can also double or even triple the rate for the development of metabolic syndrome, type 2 diabetes, and cardiovascular disorders (CVD).

nature.com/articles/nrend…
journals.lww.com/greenjournal/A…
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PCOS is often associated with
- Insulin resistance (IR)/hyperinsulinemia
- Hypertension
- Dyslipidemia
- Obesity

However, does PCOS represent a real cardiovascular risk in patients?
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Evidence of PCOS having a real risk of CVD and mortality is controversial. Nevertheless, some of the markers used suggest that this problem exist, such as:
- Carotid intima-media thickness (CIMT)
- Flow-mediated dilatation (FMD)
- Quantification of coronary artery calcium
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- FMD predicts occult coronary artery disease and endothelial dysfunction

- CIMT helps to predict CV events

- Quantification of coronary artery calcium shows coronary atherosclerosis.

pubmed.ncbi.nlm.nih.gov/28457146/
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All of these markers have shown, in multiple studies, an increased risk of CVD in older PCOS patients. Endothelial dysfunction is the first step for these outcomes.

pubmed.ncbi.nlm.nih.gov/28457146/ https://pubmed.ncbi.nlm.nih...
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So, with this information we can now try to elucidate the possible mechanisms by which PCOS represents a higher CV risk. Which one do you think it is?
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70% of PCOS patients have:
- Low HDL
- High triglyceride
- High total cholesterol and LDL

All of the above are known for being independent risk factors for CVD, specially for atherosclerosis.

nature.com/articles/nrend…
sciencedirect.com/science/articl… Image
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Prevalence of obesity in PCOS ranges between 30 and 60%, this seems to be related to hyperandrogenism’s major role on abdominal visceral adiposity and hyperlipidemia

nature.com/articles/nrend…
journals.lww.com/greenjournal/A…
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Hyperandrogenism can be clinical (hirsutism, acne, baldness in male pattern), biochemical (high androgens in labs) or both. https://journals.lww.com/gr...
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80% of PCOS cases present increased androgen levels

PCOS with hyperandrogenism have worst CV outcomes than PCOS without it.

sciencedirect.com/science/articl….
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A positive correlation has been shown between hyperandrogenism with “blood pressure (BP), obesity, hyperinsulinemia, and endothelial dysfunction”.

These are major risk factors for CVD.

sciencedirect.com/science/articl….
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Studies in animals have revealed that high testosterone levels seemed to be associated with accelerated atheromatous plaque formation.

sciencedirect.com/science/articl…
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Besides, it’s been observed in rats that:

- testosterone stimulates renal angiotensinogen expression

- dihydrotestosterone (DHT) stimulates renin expression in adrenal glands

Both of these phenomena can lead to a rise in BP.

sciencedirect.com/science/articl….
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Similarly, increased angiotensinogen is due to high androgens levels

This can increase angiotensin II, that itself increases endothelin, leading to hypertension and a higher CV risk.

sciencedirect.com/science/articl….
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Also, it’s been seen that BP is increased by “supraphysiological concentrations of DHT that stimulate aldosterone secretion in adrenal glands via calmodulin/calmodulin-dependent protein kinase and protein kinase C”, contributing to elevated BP.

sciencedirect.com/science/articl….
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Worth mentioning that hyperinsulinemia contributes to hyperandrogenism by stimulating theca cells in the ovary, which stimulates testosterone production.

ncbi.nlm.nih.gov/pmc/articles/P…. https://www.nejm.org/doi/fu...
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Hyperinsulinemia has other effects apart from hyperandrogenism. It can evolve into type 2 diabetes, a disease known for its CV risk.

ncbi.nlm.nih.gov/pmc/articles/P….
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This IR leads to:
- Rise of proinflammatory mediators
- Impaired endothelial function
- Reduction in vasoreactivity
- Subclinical atherosclerosis

nature.com/articles/nrend…
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Hyperinsulinemia also generates:
- Hypertrophy of vascular smooth muscle with reduced compliance
- Abnormalities in endothelium-dependent vasodilatation mechanisms
- Interference with the activation of the RAA system and Na retention.

ncbi.nlm.nih.gov/pmc/articles/P….
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This leads to a chronic inflammation that is linked to hyperglycemia as this generates an elevation in reactive oxygen species (ROS) concentration.
ROS activates NFkB and this stimulates the synthesis of inflammatory factors; which enhances IR and results in hyperandrogenism Text source: https://www.nc...
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As it is shown, PCOS has a direct connection at the cardiovascular system by different mechanisms, hence why its profound study and prevention is important as more than just a hormonal abnormality. Image
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Teaching points:
- PCOS has a abnormal lipid profile
- Hyperandrogenism and IR contribute to CVD by enhancing each other but also by other mechanisms
- There is a chronic inflammatory state
- CV study in PCOS is very important and further studies need to be done

Thank you!

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