NIGHT-TIME TEMPERATURE AND MORTALITY FROM CIRCULATORY CAUSES
Ioannou L.G Tsoutsoubi L., Mantzios K., Samoutis G. Flouris A.D.
FAME Laboratory, School of Exercise Science, University of Thessaly, Greece, Medical School, University of
Nicosia, Nicosia, Cyprus
Introduction:The relationship between temperatures which are located outside the thermoneutral zone and the increase of mortality is well established, but it is unclear if the temperature of the previous night can affect mortality during the next day. The aim of this study was to investigate if the environmental temperature of previous night affects mortality of the people who died because of circulatory cause during the next day.
Methods: To test this aim, we used midnight temperature (00:00) recorded for each district of Cyprus (Nicosia, Limassol, Larnaca, Paphos, and Ammochostos) over the period from 2004 to 2014. The daily meteorological data used were collected from
www.wunderground.com. Also, mortality data for the study period were provided by the Health Monitoring Unit of the Ministry of Health of Cyprus, daily, for each of the five districts of Cyprus. The data included the circulatory-cause of mortality, for people of all ages living permanently in the Republic of Cyprus. In order to execute the statistical analysis, environmental temperatures were
categorized into six ambient temperature categories of 5°C each (less or equal than 8°C, 9-13°C, 14-18°C, 19-23°C, 24-28°C, and equal or over 29°C). In this study, thermoneutral zone was defined the ambient temperature range of 19-23°C.
Results: Mortality was significantly greater above and below thermoneutral zone (p<0.05), for the people who died because of circulatory causes. Also, the Spearman’s rho revealed a statistically significant positive relationship between the temperatures ≥22°C and mortality (r= 0.048, p<.05), and a statistically significant negative relationship between the temperatures ≤22°C and mortality (r= -063, p<0.01).
Conclusion: The number of fatalities from circulatory-causes is increased above and below the thermoneutral zone.