Constipation, Cardiovascular Disease, and the Connection

Abstract & Commentary

By Rahul Gupta, MD, MPH, FACP, Clinical Assistant Professor, West Virginia University School of Medicine, Charleston, WV. Dr. Gupta reports no financial relationship relevant to this field of study.

Synopsis: In postmenopausal women, constipation is associated with having major risk factors for cardiovascular disease and increased cardiovascular risk.

Source: Salmoirago-Blotcher E, et al. Constipation and risk of cardiovascular disease among postmenopausal women. Am J Med 2011;124:714-723.

Constipation is one of the most common presenting complaints in a primary care practice. Estimates of population-based studies conducted in North America reveal that up to 27% of individuals may experience constipation, with most estimates ranging from 12% to 19%.1 Managing constipation is often frustrating and associated with substantial economic costs to the health care system.2 Constipation is often treated on the basis of a patient's impression that there is a disturbance in bowel function. However, I must admit that I have often enjoyed having medical students and residents struggle with attempting to define something as simple as constipation. This is because constipation often has wide-ranging interpretations for most people. In clinical practice, constipation is generally defined as fewer than three bowel movements per week. While the rates for constipation are on the rise, especially in women and the elderly, very little is understood about the pathophysiology of this common clinical disorder.3 Many of the risk factors associated with constipation, such as diabetes mellitus, hormonal abnormalities, and neurologic diseases, also contribute to cardiovascular disease. Therefore, it is reasonable to explore whether there may be a direct link between constipation and cardiovascular disease in the adult population.

In their study, Salmoirago-Blotcher et al conducted an analysis in 93,676 women enrolled in the observational arm of the Women's Health Initiative. The duration of follow-up in this group of postmenopausal women was between 6 and 10 years and information about constipation was collected by means of a self-administered questionnaire. For this study, the authors defined constipation as "difficulty having bowel movements" over the previous 4 weeks, and this was rated using a scale ranging from none (symptom did not occur), mild (symptom did not interfere with usual activities), moderate (symptom interfered somewhat with usual activities), to severe (symptom was so bothersome that usual activities could not be performed). The study outcomes, identified by self-report, were coronary heart disease, stroke, breast and colorectal cancer, osteoporotic fractures, diabetes, and total mortality.

Due to exclusions, the final analysis included 73,047 women. Researchers found that women with moderate and severe constipation experienced more cardiovascular events (14.2 and 19.1 events/1000 person-years, respectively) compared with women with no constipation (9.6/1000 person-years). Researchers also found that constipation was associated with the following factors: increased age, African American and Hispanic descent, smoking, diabetes, high cholesterol, family history of myocardial infarction, hypertension, obesity, lower physical activity levels, lower fiber intake, and depression. However, after adjusting for these factors, constipation was no longer associated with an increased risk of cardiovascular events, except for the severe constipation group, which had a 23% higher risk of cardiovascular events.

The authors conclude that in postmenopausal women, while evidence for an independent association or for a causal association between constipation and cardiovascular disease was not found, constipation is a marker for the major risk factors for cardiovascular disease and increased cardiovascular risk. Thus, they state that because constipation is easily evaluated in a primary care setting, it may be a helpful tool to identify postmenopausal women who may be at increased cardiovascular risk.

Commentary

We know that although constipation is a common condition, only a proportion of the affected individuals will seek health care for their symptoms. However, this does not stop people from utilizing health care resources to attempt to self-treat the condition. On the other hand, cardiovascular disease remains one of the leading causes of morbidity and mortality in women in the United States. Women fare less well than men after a myocardial infarction or cardiac interventions. Their short- and long-term prognosis is worse and the likelihood for adverse events is higher than in men. The postmenopausal state itself renders a woman at higher likelihood for cardiovascular disease.

While the results of this study are not conclusive enough to warrant definitive recommendations, they may provide valuable information regarding health and lifestyle choices of the patients being seen. Along with recommending diet and lifestyle changes, physicians can potentially use constipation in postmenopausal women as another opportunity to discuss cardiovascular risks with the patients as well as to conduct an evaluation for factors such as hypertension, hyperlipidemia, obesity, and smoking status.

References

1. Higgins PD, Johanson JF. Epidemiology of constipation in North America: A systematic review. Am J Gastroenterol 2004;99:750-759.

2. Singh G, et al. Use of health care resources and cost of care for adults with constipation. Clin Gastroenterol Hepatol 2007;5:1053.

3. Shah N, et al. Ambulatory care for constipation in the United States, 1993-2004. Am J Gastroenterol 2008; 103:1746-1753.