Effect of High Temperatures on Daily Counts of Mortality from Diseases of Circulatory System in Astana, Kazakhstan

Andrej M. Grjibovski^{1, 2}, Nassikhat Nurgaliyeva^{3, 4}, Aliya Kosbayeva⁴, Altay Sharbakov³, Telman Seysembekov³, Bettina Menne⁵

¹Department of International Public Health, Norwegian Institute of Public Health, Norway, ²International School of Public Health, Northern State Medical University, Russia, ³Medical University of Astana, Kazakhstan, ⁴WHO Office in Kazakhstan, Kazakhstan, ⁵WHO European Centre for Environment and Health, Bonn Office, Germany

Key words: cardiovascular mortality; hypertension; cerebrovascular mortality; temperature; Central Asia.

Summary. Background and Objective. Associations between hot temperatures and both overall and cardio- and cerebrovascular mortality have been observed in many European, North American, and Southeastern Asian cities. However, the effects varied among the settings with limited evidence from the countries with arid and semiarid climates. The aim of this study was to assess the effect of air temperature on deaths from the selected diseases of the circulatory system in the city of Astana, Kazakhstan.

Material and Methods. The daily counts of deaths from hypertensive diseases (ICD-10 codes, I10–I15), cerebrovascular diseases (ICD-10 codes, I60–I69), and ischemic heart disease (ICD-10 codes, I20–I25) during the warm seasons (April-September) of 2000–2001 and 2006–2010 were obtained from the City Registry Office. The associations between the maximum apparent temperature (average of lags 0–3) and mortality were assessed by a first-order autoregressive Poisson regression with the adjustment for barometric pressure (average of lags 0–3), wind speed, and effects of month, year, holidays, and weekends.

Results. Altogether, there were 282, 1177, and 2994 deaths from hypertensive diseases, cerebrovascular diseases, and ischemic heart disease, respectively. The maximum effective temperature varied between –2.2°C and 44.5°C. An increase in temperature by 1°C was associated with a 1.9% (95% CI, 0.3–3.5) increase in the daily number of deaths from cerebrovascular diseases and with a 3.1% (95% CI, 0.2–6.1) decrease in the number of deaths from hypertensive diseases among women.

Conclusions. The results suggest a positive association between the maximum apparent temperature and the daily counts of deaths from cerebrovascular diseases and an inverse association between temperature and mortality from hypertensive diseases, but only among women.

Correspondence to A. M. Grjibovski, Department of International Public Health, Norwegian Institute of Public Health, Postbox 4404 Nydalen, 0403 Oslo, Norway. E-mail: angr@fhi.no

Received 3 September 2012, accepted 30 December 2012