Air pollution related prothrombotic changes in persons with diabetes.
BACKGROUND
Population studies suggest that persons with diabetes are more sensitive to the effects of particulate matter (PM) air pollution. However, the biological mechanisms of a possible prothrombotic effect underlying this enhanced susceptibility remain largely unknown.


OBJECTIVE
We hypothesized that exposure to PM causes prothrombotic changes in persons with diabetes, possibly via systemic inflammation.


METHODS
Our study included 137 nonsmoking adults with diabetes who were outpatients at the University Hospital Leuven. Recent exposure (2 hr before examination) to ambient PM was measured at the entrance of the hospital. Individual chronic exposure to PM was assessed by measuring the area occupied by carbon in airway macrophages obtained by sputum induction. Platelet function was measured ex vivo with the PFA-100 platelet function analyzer, which simulates a damaged blood vessel; we analyzed the function of platelets in primary hemostasis under high shear conditions. Total and differential blood leukocytes were counted.


RESULTS
Independent of antiplatelet medication, an interquartile range (IQR) increase of 39.2 microg/m3 in PM10 (PM with aerodynamic diameter <or= 10 microm) concentration measured 2 hr before the clinical examination (recent exposure) was associated with a decrease of 21.1 sec [95% confidence interval (CI), 35.3 to 6.8] in the PFA-100 closure time (i.e., increased platelet activation) and an increase in blood leukocytes of 512 per microliter of blood (95% CI, 45.2979). Each area increase of 0.25 microm2 (IQR) in carbon load of airway macrophages (chronic exposure) was associated with an increase of 687 leukocytes per microliter of blood (95% CI, 2241,150).


CONCLUSIONS
A relevant increase in recent PM exposure was associated with a change in platelet function toward a greater prothrombotic tendency. The magnitude of the change was about two-thirds (in the opposite direction) of the average effect of antiplatelet medication. Diabetic patients showed evidence of proinflammatory response to both recent and chronic exposure to PM air pollution.
Jacobs
Lotte
L
Occupational and Environmental Medicine, Unit of Lung Toxicology, Katholique Universiteit Leuven, Leuven, Belgium.
Emmerechts
Jan
J
Mathieu
Chantal
C
Hoylaerts
Marc F
MF
Fierens
Frans
F
Hoet
Peter H
PH
Nemery
Benoit
B
Nawrot
Tim S
TS
D000328:Adult; D000368:Aged; D000397:Air Pollution / Q000009:adverse effects*; D001792:Blood Platelets / Q000187:drug effects* / Q000502:physiology; D003920:Diabetes Mellitus / Q000097:blood* / Q000276:immunology / Q000378:metabolism*; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D006801:Humans; D007249:Inflammation / Q000139:chemically induced; D007962:Leukocytes / Q000187:drug effects / Q000502:physiology; D008297:Male; D008875:Middle Aged; D052638:Particulate Matter / Q000009:adverse effects; D010979:Platelet Function Tests
D052638:Particulate Matter