Influence of neighbourhood‐level crowding on sleep‐disordered breathing severity: mediation by body size

SummaryNeighbourhood‐level crowding, a measure of the percentage of households with more than one person per room, may impact the severity of sleep‐disordered breathing. This study examined the association of neighbourhood‐level crowding with apnoea–hypopnoea index in a large clinical sample of diverse adults with sleep‐disordered breathing. Sleep‐disordered breathing severity was quantified as the apnoea–hypopnoea index calculated from overnight polysomnogram; analyses were restricted to those with apnoea–hypopnoea index ≥5. Neighbourhood‐level crowding was defined using 2000 US Census tract data as percentage of households in a census tract with >1 person per room. Multivariable linear mixed models were fit to examine the associations between the percentage of neighbourhood‐level crowding and apnoea–hypopnoea index, and a causal mediation analysis was conducted to determine if body mass index acted as a mediator between neighbourhood‐level crowding and apnoea–hypopnoea index. Among 1789 patients (43% African American; 68% male; 80% obese), the mean apnoea–hypopnoea index was 29.0 ± 25.3. After adjusting for race, age, marital status and gender, neighbourhood‐level crowding was associated with apnoea–hypopnoea index; for every one‐unit increase in percentage of neighbourhood‐level crowding mean, the apnoea–hypopnoea index increased by 0.40 ± 0.20 (P = 0.04). There was a statistically significant indirect effect of neighbourhood‐level crowding through body mass index on the apnoea–hypopnoea index (P < 0.001). Neighbourhood‐level crowding is associated with severity of sleep‐disordered breathing. Body mass index partially mediated the association between neighbourhood‐level crowding and sleep‐disordered breathing. Investigating prevalent neighbourhood conditions impacting breathing in urban settings may be promising.