Fuks, K; Hertel, S; Viehmann, A; Nonnemacher, M; Moebus, S; Jakobs, H; Kessler, C; Erbel, R; Joeckel, K; Hoffmann, B
Rationale
Recent studies show an association between short-term air pollution levels and acute changes in blood pressure (BP). Most of these studies have been performed on selected populations. Up to date, only one study has investigated medium-term effects up to 60 days on BP in the general population. We aim to investigate the association of residential long-term particulate matter (PM) exposure on arterial BP in an urban population of Western Germany, independently of short-term effects.
Methods
We used baseline data (2000-2003) from the Heinz Nixdorf Recall Study, a population-based cohort study (n=4814). The yearly average exposure to PM and PM (µg/m³) was assessed using a dispersion and chemistry transport model. Arterial BP was measured according 2.5 10 to the standardized protocol of the World Health Organization, using an automated oscillometric device. Linear regression and generalized additive models were used, adjusting for meteorology, time trend, short-term exposure to PM, and personal characteristics.
Results
We included 4352 participants with non-missing information on exposure, outcome, and covariates. Mean yearly concentrations of PM2.5 and PM were 16.7 µg/m³ (interquartile range (IQR) 2.4 µg/m³) and 20.7 µg/m³ (IQR 4.0 µg/m³), respectively. Mean systolic BP was 132.7 10mmHg, mean diastolic BP was 81.2 mmHg. We found increases in arterial BP in association with an interquartile raise in yearly exposure to PM, higher after adjustment for covariates. For PM (multivariate model), mean systolic BP increased by 1.7 mmHg (95%CI: 0.7-2.7 mmHg), diastolic BP by 0.8 mmHg (95%CI: 0.3-1.4 2.5mmHg). Results for PM were similar: increase of 1.6 mmHg (95%CI: 0.6-2.6 mmHg) in mean systolic BP, and of 0.8 mmHg (95%CI: 0.3-1.3 10mmHg) in mean diastolic BP. Stronger effects were found in women (Figure 1).
[Figure 1. Absolute change in arterial BP by gender (mmHg, 95% CI) for an interquartile increase in mean annual exposure to PM2.5 and PM10.]
1. Adjusted for short-term exposure, temperature, season, age, gender, education, economical activity, body-mass index, smoking, environmental tobacco smoke, alcohol consumption, cardiovascular disease, diabetes, antihypertensive medication, sport activity. 2. Mean values of systolic and diastolic BP in men: 137.6 mmHg and 83.7 mmHg; in women: 127.8 mmHg and 78.7 mmHg, respectively.
Conclusions
Even small variations in long-term exposure to fine and coarse PM may increase arterial BP, independently of short-term levels of airpollution. This effect can already be observed at PM levels below current regulatory standards. Our finding has substantial public health relevance, due to the important role of BP as a risk factor for atherogenesis and cardiovascular disease.
