Sleep fragmentation and sleep-disordered breathing in individuals living close to main roads: results from a population-based study.
BACKGROUND
Nighttime traffic noise is associated with sleep disturbances, but sleep fragmentation and sleep-disordered breathing (SDB) have not been demonstrated in individuals living near busy roads.


METHODS
We asked 1383 participants to answer a health questionnaire and to undergo 24-h electrocardiogram (ECG). Nocturnal ECG records were used to calculate the very low frequency index (VLFI) interval, a surrogate marker of sleep fragmentation. Distances of participants' addresses to roadways were calculated using the VECTOR25© Swisstopo roads classification, a traffic noise proxy. Distances of homes within 100 or 50 m of major roads defined proximity to busy roads. Adjusted multivariate logistic regressions analyzed associations between the distance of home to main roads and VLFI or self-reported SDB.


RESULTS
Distance of participants' homes to main roads was significantly associated with the VLFI in women (odds ratio [OR], 1.58 [confidence interval {CI}, 1.03-2.42]; P = .038) but not in men (OR, 1.35 [CI, 0.77-2.35]; P = .295). Women under hormonal replacement therapy (HRT) were at higher risk for increased VLFI when living close to main roads (OR, 2.10 [CI, 1.20-3.68]; P = .01) than untreated women (P = .584). Associations with self-reported SDB were not statistically relevant.


CONCLUSIONS
In our large population, women living close to main roads were at significantly higher risk for sleep fragmentation than men. The 2-fold higher risk for menopausal women under HRT underscores the vulnerability of this group.
Division of Pulmonary Medicine, University Hospitals of Geneva, Geneva, Switzerland. Electronic address: margaret.gerbase@hcuge.ch.
M W
MW
Gerbase
Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
J
J
Dratva
Division of Pulmonary Medicine, University Hospitals of Geneva, Geneva, Switzerland.
M
M
Germond
Centre Valaisan de Pneumologie, Montana, Switzerland.
J M
JM
Tschopp
University Joseph Fournier, INSERM U 1042, Laboratory HP2, Hypoxia Physiopathology, Locomotion, Reeducation and Physiology Pole, CHU of Grenoble, Grenoble, France.
J L
JL
Pépin
Division of Cardiology, University Hospitals of Geneva, Geneva, Switzerland.
D
D
Carballo
Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
N
N
Künzli
Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
N M
NM
Probst-Hensch
Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
M
M
Adam
Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
E
E
Zemp Stutz
Department of Clinical Physiology and Exercise, Faculty of Medicine Jacques Lisfranc, University Jean Monnet, Saint-Etienne, France.
F
F
Roche
Division of Pulmonary Medicine, University Hospitals of Geneva, Geneva, Switzerland.
T
T
Rochat
D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D018986:Motor Vehicles; D009622:Noise / Q000009:adverse effects*; D012737:Sex Factors; D012891:Sleep Apnea Syndromes / Q000209:etiology*; D012892:Sleep Deprivation / Q000209:etiology*; D011795:Surveys and Questionnaires
Cohort studies; Gender; Heart rate variability; Sleep fragmentation; Sleep-disordered breathing; Traffic noise