Objectives Changes in air temperature are associated with an increase in cardiovascular events, but the role of procoagulant and proinflammatory blood markers is still poorly understood. The authors investigated the association between air temperature and fibrinogen, plasminogen activator inhibitor type 1, interleukin-6 and high-sensitivity C reactive protein in two potentially susceptible groups. Methods This prospective panel study was conducted between March 2007 and December 2008 in Augsburg, Germany. The study population comprised 187 participants with type 2 diabetes mellitus or impaired glucose tolerance and 87 participants with genetic polymorphisms on the detoxification and inflammation pathways. Overall, 1766 repeated blood measurements were collected. Hourly meteorology data were available from a central measurement site. The association between temperature and blood markers was analysed with additive mixed models. Results For type 2 diabetes mellitus and impaired glucose tolerance participants, the authors observed immediate, lagged and cumulative increases in fibrinogen (range of percentage changes in geometric mean: 0.6%e0.8%) and plasminogen activator inhibitor type 1 (6.0%e10.1%) in association with a 58C temperature decrement. Participants with a body mass index above 30 kg/m 2 as well as females showed particularly strong fibrinogen effects. In participants with the special genetic background, 58C decreases in the 5-day average of temperature led to a change of 8.0% (95% CI 0.5% to 16.2%) in interleukin-6 and of À8.4% (95% CI À15.8% to À0.3%) in high-sensitivity C reactive protein, the latter driven by physically active individuals. Conclusions The authors observed different temperature effects on blood markers in two potentially susceptible groups probably indicating varying underlying biological mechanisms. This study results might provide a link between temperature and cardiovascular events.

Background: Changes in air temperature are associated with an increase in cardiovascular events, but the role of pro-coagulant and proinflammatory blood markers is poorly understood. Objectives:We investigated the association between air temperature and interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP), fibrinogen, and plasminogen-activator-inhibitor-type 1 (PAI-1) in two potentially susceptible groups.Methods: A prospective panel study was conducted between March, 2007 and December, 2008. The study population comprised 187 participants with type-2 diabetes mellitus (T2D) or impaired glucose tolerance (IGT) and 87 participants with genetic polymorphisms (GEN) on the detoxification or inflammation pathways from Augsburg, Germany. Overall, 1,766 repeated blood measurements were collected. Hourly meteorology and air pollution data were available from a central measurement site. The association between temperature and log-transformed blood markers was analyzed with additive mixed models including random participant effects.Results: For T2D and IGT participants, we observed immediate, delayed and cumulative increases in fibrinogen (range of %-changes in geometric mean: 0.6-0.8%) and PAI-1 (6.0-10.1%) in association with a 5°C-temperature decrement. Participants with a body mass index >30kg/m² and females showed particularly strong fibrinogen effects. In GEN participants, 5°C-decrements in 5-day-average temperature led to a change of 8.0% (95%-confidence interval: [0.5, 16.2]) in IL-6 and of -8.4% [-15.8, -0.3] in hsCRP, the latter driven by physically active individuals. Adjustment for particulate air pollution did not change temperature effects. Conclusions:We observed different temperature effects in the two subgroups possibly indicating different underlying biological mechanisms. Our results might provide a link between temperature and cardiovascular events.