Air temperature and inflammatory and coagulation responses in men with coronary or pulmonary disease during the winter season

Background and Objective Air temperature changes are associated
with increased cardiovascular and respiratory risk, but the roles
of inflammatory and coagulation markers are not well understood. We
investigated the associations between temperature and several blood
markers in patients with coronary heart disease (CHD) and pulmonary
disease (PD). Methods Two studies were conducted in Erfurt,
Germany, over two successive winters. 578 and 381 repeated blood
measurements were collected from 57 CHD and 38 PD patients,
respectively. Data on patient characteristics and disease history
were gathered at baseline. Meteorological data were collected from
existing networks. Associations were analysed using additive mixed
models with random patient effects. Effect modification by diabetes
status was investigated only in CHD patients, as only two PD
patients had diabetes. Results Mean daily air temperature varied
between -13 degrees C and 16 degrees C in both study periods. A 10
degrees C decrease in the 5-day temperature average before blood
withdrawal led to an increase in platelet counts (% change from the
mean: 3.0%, 95% CI 0.6% to 5.5%) and fibrinogen (5.5%, 1.3% to
9.7%), no change in C-reactive protein in PD patients, and a
decrease in C-reactive protein in CHD patients. A 2-day delayed
increase in factor VII associated with temperature decrease was
seen in CHD patients (4.9%; 0.7% to 9.2%), while PD patients showed
no effect. `Effects in CHD patients without diabetes' into `Effects
on factor VII in CHD patients without diabetes'. Conclusions This
study suggests that temperature decrease is associated with change
in several blood parameters. The complex interplay of blood markers
at low temperature may contribute to the observed association
between cold and cardiovascular mortality and morbidity.