Air pollution and incidence of hypertension and diabetes mellitus in black women living in Los Angeles.
BACKGROUND
Evidence suggests that longer-term exposure to air pollutants over years confers higher risks of cardiovascular morbidity and mortality than shorter-term exposure. One explanation is that the cumulative adverse effects that develop over longer durations lead to the genesis of chronic disease. Preliminary epidemiological and clinical evidence suggests that air pollution may contribute to the development of hypertension and type 2 diabetes mellitus.


RESULTS
We used Cox proportional hazards models to assess incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for incident hypertension and diabetes mellitus associated with exposure to fine particulate matter (PM(2.5)) and nitrogen oxides in a cohort of black women living in Los Angeles. Pollutant levels were estimated at participants' residential addresses with land use regression models (nitrogen oxides) and interpolation from monitoring station measurements (PM(2.5)). Over follow-up from 1995 to 2005, 531 incident cases of hypertension and 183 incident cases of diabetes mellitus occurred. When pollutants were analyzed separately, the IRR for hypertension for a 10-μg/m(3) increase in PM(2.5) was 1.48 (95% CI, 0.95-2.31), and the IRR for the interquartile range (12.4 parts per billion) of nitrogen oxides was 1.14 (95% CI, 1.03-1.25). The corresponding IRRs for diabetes mellitus were 1.63 (95% CI, 0.78-3.44) and 1.25 (95% CI, 1.07-1.46). When both pollutants were included in the same model, the IRRs for PM(2.5) were attenuated and the IRRs for nitrogen oxides were essentially unchanged for both outcomes.


CONCLUSIONS
Our results suggest that exposure to air pollutants, especially traffic-related pollutants, may increase the risk of type 2 diabetes mellitus and possibly of hypertension.
Slone Epidemiology Center at Boston University, 1010 Commonwealth Ave., Boston, MA 02215, USA. pcoogan@bu.edu
Patricia F
PF
Coogan
Laura F
LF
White
Michael
M
Jerrett
Robert D
RD
Brook
Jason G
JG
Su
Edmund
E
Seto
Richard
R
Burnett
Julie R
JR
Palmer
Lynn
L
Rosenberg
D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data*; D000368:Aged; D000397:Air Pollution / Q000009:adverse effects* / Q000706:statistics & numerical data; D015331:Cohort Studies; D016001:Confidence Intervals; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology* / Q000208:ethnology; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology* / Q000208:ethnology; D015994:Incidence; D015141:Los Angeles / Q000453:epidemiology; D008875:Middle Aged; D009589:Nitrogen Oxides / Q000009:adverse effects* / Q000032:analysis; D009622:Noise / Q000009:adverse effects; D052638:Particulate Matter / Q000009:adverse effects* / Q000032:analysis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D014505:Urban Population / Q000706:statistics & numerical data; D001335:Vehicle Emissions; D055815:Young Adult
D009589:Nitrogen Oxides; D052638:Particulate Matter; D001335:Vehicle Emissions