Long-term exposure to fine particulate matter and incidence of type 2 diabetes mellitus in a cohort study: effects of total and traffic-specific air pollution

Table 1 Baseline characteristics of the study population (N = 3607) stratified by diabetes status at follow up

	Participants without diabetes N = 3276	Participants with incident diabetes N = 331
Variable
Men, %	47	56
Age [years], mean (SD)	58.8 (7.6)	60.5 (7.5)
BMI [kg/m²], mean (SD)	27.2 (4.2)	29.8 (4.7)
BMI > 25, %	69	87
BMI > 30, %	22	44
Hypertension^a, %	50	66
Non-Smokers, %	44	39
Smokers, %	22	21
Ex-smokers, %	34	40
Exercise >3 times per week, %	26	22
% unemployment rate in neighbourhood mean (SD)	12.4 (3.4)	12.6 (3.4)
Mülheim, %	38	37
Essen, %	34	33
Bochum, %	29	31
Occupational status
Employed, %	45	34
Inactive, %	15	13
Pensioner, %	35	45
Unemployed, %	6	8
Education ^b
Highest, %	13	6
High, %	23	21
Middle, %	55	63
Low, %	10	10
PM10 total [μg/m³], mean (SD)	20.8 (2.3)	20.9 (2.4)
PM2.5 total [μg/m³], mean (SD)	16.7 (1.4)	16.8 (1.5)
PM10 traffic [μg/m³], mean (SD)	0.8 (0.2)	0.9 (0.2)
PM2.5 traffic [μg/m³], mean (SD)	0.8 (0.2)	0.9 (0.2)
Distance to major road [m], mean (SD)	1021.4 (805.1)	1034.6 (830.5)

N number of individuals, SD standard deviation,
^aHypertension is defined as systolic blood pressure ≥ 140 mmHg or diastolic blood pressure ≥ 90 mmHg or intake of hypertensive medication
^bEducation: low: ≤10 years, middle 11–13 years, high: 14–17 years, highest:≥18 years

ISSN: 1476-069X