Unhealthy Lifestyle Doesn't Worsen Stroke Outcome

Pauline Anderson

January 26, 2017

Obesity, smoking, and high alcohol intake are not associated with adverse stroke outcomes, a new study suggests, but being underweight is, as well as being linked to a higher risk for pneumonia after a stroke.

Annette Ingeman, PhD, Department of Clinical Epidemiology, Aarhus University Hospital, Denmark, and colleagues report that "unhealthy lifestyle factors, including obesity, smoking, and high alcohol intake either individually or in combination, were in general not associated with increased risk of adverse early clinical outcomes," particularly among men with stroke.

However, they note, "underweight may be a particular concern because it was associated with an increased risk of adverse outcomes after stroke among both men and women, and further efforts to ameliorate this association seem warranted."

The study was published online January 16 in Stroke.

Health Categories

From national registries, researchers identified 82,597 adult Danish residents, mean age 71.5 years, who were admitted with a first acute stroke to any hospital in the country between January 13, 2003, and December 31, 2011.

Researchers looked at smoking status, obesity, and alcohol intake of patients upon admission. They assessed subjects as being:

  1. Healthy: nonsmoker, drinking 21 or fewer drinks (14 or fewer for women) per week, a body mass index (BMI) more than 18.5 (kg/m2) but less than 24.9;

  2. Moderately healthy: one adverse lifestyle factor (current/former smoker, alcohol intake of more than 21 [14 for women] drinks per week, or BMI less than 18.5 or more than 24.9);

  3. Moderately unhealthy: having two of the three adverse lifestyle factors; or

  4. Unhealthy: having all three adverse lifestyle factors.

About 18% of the patients had a severe stroke (15 to 29 points on the Scandinavian Stroke Scale) or very severe (0 to 14 points on the scale) on admission.

On admission, 7.9% had a healthy lifestyle, 34.4% a moderately healthy lifestyle, 38.0% had a moderately unhealthy lifestyle, and 4.5% had an unhealthy lifestyle.

The researchers found that compared with men with a healthy lifestyle, those with an unhealthy lifestyle had a lower risk for severe stroke outcome (adjusted odds ratio [OR], 0.73; 95% confidence interval [CI], 0.63 - 0.84).

This was not the case for women (adjusted OR, 1.14; 95% CI, 0.85 - 1.55; P for interaction = .01).

Being underweight was the only adverse lifestyle factor associated with a significantly increased risk for poor stroke outcome for both men (adjusted OR, 1.5; 95% CI, 1.34 - 1.70) and women (adjusted OR, 1.34; 95% CI, 1.19 - 1.52).

Obese men and women, as well as current and former smokers of both sexes, had a lower risk for severe stroke.

It's possible, said the authors, that smokers have a particularly strong health constitution that has allowed them to survive to an age where stroke incidence is increased, even with a high-risk lifestyle. They pointed to the so-called obesity paradox to help explain the results vis-à-vis body weight.

Researchers also looked at data on in-hospital pneumonia and urinary tract infections (UTIs), which were available from 11 stroke units. These variables were included because they're relatively common post-stroke complications and are amenable to clinical intervention and prevention, according to the authors.

After admission, 7.8% of patients developed pneumonia and 12.5% a UTI. Because there was no interaction with sex, researchers pooled the analysis without stratifying for sex and found that an unhealthy lifestyle was not associated with a statistically significantly higher risk for pneumonia or UTI.

However, being underweight was associated with a higher risk for pneumonia (adjusted OR, 1.36; 95% CI, 1.10 - 1.69). And high alcohol intake was associated with an increased risk for both pneumonia (adjusted OR, 1.24; 95% CI, 1.14 - 1.36) and UTI (adjusted OR, 1.12; 95% CI, 1.02 - 1.22).

Men with an unhealthy lifestyle had a statistically significant lower risk of dying within 30 days compared with men with a healthy lifestyle (adjusted OR, 0.71; 95% CI, 0.58 - 0.87). This was not so for women with an unhealthy lifestyle; they had an adjusted OR for 30-day mortality of 1.34 (95% CI, 0.90 - 1.99).

Mortality Outcome

Adverse lifestyle factors, such as smoking, obesity, and heavy alcohol use, have been shown to increase the risk for stroke, said Ralph Sacco, MD, professor, Department of Neurology, University of Miami, Florida, who was not involved in the study but was asked to comment on it.

"What this new study is showing is that once you've suffered a stroke, having these lifestyle factors doesn't affect your outcome."

He called the finding of a worse outcome among underweight patients "unique."

"It says to me that we should be keeping people at the right weight, not too low and not too high," he said.

If a patient admitted to hospital is underweight, "there could be something else going on, like an underlying cancer or other chronic conditions, that made them malnourished," he added.

Dr Sacco pointed out that the study did not look at such lifestyle factors as diet and physical activity. He also questioned the reliability of data on smoking status and alcohol intake of patients who have just had a stroke.

"Some people will underestimate and underreport that information, and if someone is very sick with aphasia or is comatose from the stroke and you have to rely on family to get that information, it may or may not be accurate."

And Dr Sacco noted that BMI may not always be the best measure of obesity. Other measures could include waist circumference and waist-to-hip ratio.

This research was supported by a grant from TrygFonden. The authors have disclosed no relevant financial relationships.

Stroke. Published online January 16, 2017. Abstract

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