Coronary heart disease (CHD) occurs when plaque builds up on the arteries that supply blood to the heart. The plaque buildup can reduce blood flows to the heart causing chest pain – particularly during strenuous activity. If the plaque bursts a clot can form which can block blood flows to the heart causing a heart attack.

Increased Risk of Coronary Heart Disease in Patients with Primary Fibromyalgia and Those with Concomitant Comorbidity—A Taiwanese Population-Based Cohort Study Chia-Hsien Su, Jiunn-Horng Chen, Joung-Liang Lan, Yu-Chiao Wang, Chun-Hung Tseng, Chung-Yi Hsu, Lichi Huang, Published: September 14, 2015 DOI: 10.1371/journal.pone.0137137​

CHD is the leading cause of death in the U.S. Despite the fact that it typically shows up about ten years later in women than men it is the leading cause of death in the U.S. for women. This is the second Taiwanese study to find an increased risk of coronary heart disease in people with fibromyalgia.

The increased risk of CHD (almost 50%) found was not as high as for diabetes or hypertension, and was described as “moderate”. Another Taiwanese study suggested an increased risk of stroke may be present as well.  Oddly enough, the increased risk of cardiovascular disease was highest when younger people with FM were compared to their peers. (They had a low risk of cardiovascular disease overall but it was increased compared to their peers.)

As a group people with FM had a higher incidence of diabetes, hypertension, hyperlipidemia, congestive heart failure, cerebral vascular diseases, depression, and anxiety than the reference cohort they were compared to.

While those comorbid conditions were more common in FM, the good news was that people with FM who did not have those cardiovascular conditions (diabetes, hypertension, hyperlipidemia, congestive heart failure, cerebral vascular diseases) actually had a somewhat lower risk of heart disease than the reference population.

The authors proposed several hypotheses to explain the increased CHD. They rejected the idea that the high use of NSAIDS, antidepressants and pain killers were contributing to it, and suggested that chronic stress, including early lifetime stressors, increased sympathetic nervous system activity and reduced parasympathetic nervous system activity were likely contributing. They noted the reduced heart variability found in FM is a known risk factor for heart disease.

Oxidative Stress Factors and Lipid Profiles Suggest Increased Cardiovascular Risk

While large-scale cardiovascular risk assessments have not, to my knowledge, been carried out in ME/CFS, similar autonomic nervous system findings are found. Plus studies suggest that some cardiovascular risk factors are increased in both diseases.

Increased levels of oxidative stress have been found in both fibromyalgia and ME/CFS. Plus high levels of oxidative stress factors and/or decreased levels of the protective antioxidants have twice been associated with increased symptoms in ME/CFS and FM.

Several studies have found “unfavorable lipid profiles” that could increase the risk of atherosclerosis in ME/CFS. Fibromyalgia studies have had mixed results with several finding unfavorable lipid profiles and others not.  

Spence’s 2008 ME/CFS study found increased arterial stiffness and significantly increased markers of inflammation and oxidative stress (C-reactive protein, 8-iso-prostaglandin F, isoprostanes, oxidized LDL) which could be damaging the arterial walls. Spence concluded that “inflammation and oxidative stress may result in an increased risk of future cardiovascular events” in ME/CFS.

In 2009 Maes concluded that chronic low grade inflammation, increased oxidative and nitrosative stress, reduced levels antioxidants and healthy fatty acids could predispose people with ME/CFS to cardiovascular issues. A small 2012 study of women with ME/CFS found high levels of “bad” fats (triglycerides), low levels of the “good” fats (HDL cholesterol) and signs of oxidative stress (increased malondialdehyde levels).

High levels of overweight and obesity in fibromyalgia may contribute although they may not be higher than in the population at large.

Risk Factors for Coronary Heart Disease

A look at the risk factors for CHD finds a mixed bag for people with ME/CFS/FM. Some are probably high (triglycerides, lack of physical activity, sleep apnea, stress) while some major ones (unhealthy diet, smoking, alcohol consumption, high blood pressure) are probably low.

• High blood cholesterol and triglyceride (tri-GLIS-er-ide) levels (a type of fat found in the blood)
• High blood pressure
• Diabetes and prediabetes
• Overweight and obesity
• Smoking
• Lack of physical activity
• Unhealthy diet
• Sleep apnea.
• Stress.
• Preeclampsia (pre-e-KLAMP-se-ah)

Reduced Physical Activity

Reduced physical activity is important risk factor but the authors of the paper did not suggest it was a factor. The US Guidelines for the amount of aerobic exercise needed to maintain health and ward off illness, however, are probably rarely met by people with fibromyalgia and almost never by people with ME/CFS.

The U.S. breaks activity levels into four categories:

• Inactive is no activity beyond baseline activities of daily living.
• Low activity is activity beyond baseline but fewer than 150 minutes (2 hours and 30 minutes) of moderate-intensity physical activity a week or the equivalent amount (75 minutes, or 1 hour and 15 minutes) of vigorous-intensity activity.
• Medium activity is 150 minutes to 300 (5 hours) minutes of moderate-intensity activity a week (or 75 to 150 minutes of vigorous-intensity physical activity a week). In scientific terms, this range is approximately equivalent to 500 to 1,000 metabolic equivalent (MET) minutes a week.
• High activity is more than the equivalent of 300 minutes of moderate-intensity physical activity a week.

Aerobic Activity

Guidelines state the following amounts of aerobic activity are needed to maintain health and ward off illness. Moderate (such as brisk walking or tennis) or intense (jogging or swimming) should be done in episodes of at least 10 minutes and, if possible, spread out through the week.

• 150 minutes (2 hours and 30 minutes) each week of moderate-intensity aerobic physical activity (such as brisk walking or tennis)
• 75 minutes (1 hour and 15 minutes) each week of vigorous-intensity aerobic physical activity (such as jogging or swimming laps)
• An equivalent combination of moderate- and vigorous-intensity aerobic physical activity

For even greater health benefits, they recommend

• Increase moderate-intensity aerobic physical activity to 300 minutes (5 hours) each week
• Increase vigorous-intensity aerobic physical activity for 150 minutes (2 hours and 30 minutes) each week

Is Heart Disease in Chronic Fatigue Syndrome (ME/CFS) and Fibromyalgia Patients Future?

Despite some negative risk factors – not necessarily. The CDC estimates that about 7% of the entire population and about 17% of people over 65 have it. Women have lower rates of CHD (@ 5%) than men but may be more severely affected by it when it does occur.

That suggests that even a 50% increase in the risk factor for CHD would leave the vast majority of middle-aged women with FM (>90%) without it. FM and ME/CFS patients with increased risk factors (depression, anxiety, obesity, increased blood pressure, sleep apnea) would have a higher incidence.

Coronary heart disease is something to think about, though, given the reports of decreased heart rate variability, increased oxidative stress, poor  lipid profiles, possible arterial stiffness, the lack of activity, etc. in ME/CFS/FM but it’s certainly not a forgone outcome. More study is clearly needed regarding the long term effects of these diseases.

In the meantime a heart healthy diet, stress reduction, whatever exercise can be done, strategies to reduce inflammation and sleep studies to assess sleep apnea are probably good ideas.