Heavy secondhand smoke exposure was positively associated with a higher risk of developing severe headaches or migraine in adults who never smoked.
Among adults who never smoke, heavy secondhand smoke exposure is positively associated with severe headaches or migraine, according to study findings published in the journal Headache.

To determine if an association exists between secondhand smoke exposure and severe headaches or migraine, validated by serum cotinine levels, among adults who never smoked, researchers conducted a cross-sectional study and collected data via the 1999-2004 National Health and Nutrition Examination Survey (NHANES).
Serum cotinine levels exceeding 10 ng/mL were frequently observed in current smokers, establishing a threshold value.
To be classified as nonsmoker, individuals must have smoked fewer than 100 cigarettes in their lifetime, abstained from nicotine-containing products for the past 5 days, and had serum cotinine levels of 10 ng/mL or less.
The researchers determined migraine headache status by asking participants whether they have experienced severe headaches or migraine during the previous 3 months.
After excluding participants, a total of 4560 individuals (median age, 43; female 60.1%; 71.5% White) who had completed the NHANES survey were included in the final analysis.
Among participants, 919 (20%) self-reported experiencing severe headaches or migraine.
After accounting for relevant covariates, the researchers observed a significant association between high levels of secondhand smoke exposure and an increased risk for severe headaches or migraine (odds ratio [OR], 2.02; 95% CI, 1.19-3.43).
In contrast, low secondhand smoke exposure demonstrated no significant association with severe headaches or migraine (OR, 1.15; 95% CI, 0.91-1.47).
When compared with individuals with no secondhand smoke exposure, those with a body mass index (BMI) less than 25 and those who were sedentary (P =.016) showed a significant association with both low secondhand smoke exposure (OR, 2.15; 95% CI, 1.54-2.99) and heavy secondhand smoke exposure (OR, 2.60, 95% CI; 1.25-5.42) and severe headache or migraine.
Among individuals with a BMI of 25–30, no significant association was found between low secondhand smoke exposure (OR, 0.77; 95% CI, 0.51-1.15) or heavy secondhand smoke exposure (OR, 1.14; 95% CI, 0.47-2.76).
The results indicated a distinct linear association between the natural logarithm of serum cotinine and the occurrence of severe headaches or migraine (P =.335 for nonlinearity).
In sensitivity analyses, which excluded active smokers with serum cotinine concentrations more than 3 ng/mL, participants on specific medications, and after multiple imputations, the association persisted with a slight decrease in the odds ratio value.
The study has several limitations including the inability to establish a causal relationship between secondhand smoke exposure and severe headache or migraine. Moreover, the half-life of serum cotinine is 15-40 hours, which can only reveal recent secondhand smoke exposure.
“These findings underscore the harmful impact of [secondhand smoke] exposure on the nervous system and serve as a reminder to avoid prolonged exposure to tobacco smoke,” the researchers concluded.
This article originally appeared on Neurology Advisor
Comments