Secondhand Smoke Exposure Linked to Migraine, Severe Headache

TOPLINE:
Heavy secondhand smoke (SHS) exposure is associated with severe headache or migraine in adults who have never smoked, with effects of exposure varying depending on body mass index (BMI) and level of physical activity, new research shows.

METHODOLOGY:
Investigators analyzed data on 4560 participants (median age, 43 years; 60% female; 71.5% White) from the 1999-2004 National Health and Nutrition Examination Survey.
Participants were aged 20 years or older and had never smoked.
Migraine headache status was determined by asking whether participants experienced severe headaches or migraines during the previous 3 months.
SHS exposure was categorized as unexposed (serum cotinine levels < 0.05 ng/mL and no smoker in the home), low (0.05 ng/mL ≤ serum cotinine level < 1 ng/mL), or heavy (1 ng/mL ≤ serum cotinine level ≤ 10 ng/mL).
TAKEAWAY:
In all, 919 (20%) participants had severe headaches or migraines.
After adjustment for demographic and lifestyle factors (including medication use), heavy SHS exposure was positively associated with severe headache or migraine (adjusted odds ratio [aOR], 2.02; 95% CI, 1.19-3.43).
No significant association was found between low SHS exposure and severe headaches or migraine (aOR, 1.15; 95% CI, 0.91-1.47).
In participants who were sedentary (P = .016) and those with a BMI < 25 (P = .001), significant associations between SHS and severe headache or migraine were observed.
IN PRACTICE:
Noting a linear dose-response relationship between cotinine and severe headaches or migraine, the investigators write, “These findings underscore the need for stronger regulation of tobacco exposure, particularly in homes and public places.”

SOURCE:
Junpeng Wu, MMc, and Haitang Wang, MD, of Southern Medical University in Guangzhou, China, and their colleagues conducted the study. It was published online November 8 in Headache.

LIMITATIONS:
The study could not establish causal relationships between SHS and migraine or severe headache. In addition, the half-life of serum cotinine is 15-40 hours and thus this measure can reflect only recent SHS exposure.

DISCLOSURES:
The study was not funded. The investigators reported no disclosures.