HEALTH EFFECTS OF HOT SUMMER WEATHER IN PATIENTS WITH INTERMEDIATE AND HIGH CARDIOVASCULAR RISK

Background. The potential global warming justifies the need for further investigation of the impact of abnormally hot summer weather on health and the prevention of these negative health effects.

Aim. To study the effects of extreme climatic conditions (hot weather) on hemodynamics, electrolyte metabolism, oxidative stress (OS), and quality of life (QoL) in cardiac patients.

Material and methods. In total, the study included 123 patients (52 men and 76 women) with intermediate (17,3%) and high or very high (82,7%) cardiovascular risk. The following parameters were assessed: office blood pressure (BP), pulse wave velocity (PWV), plasma levels of potassium (K), sodium (Na), oxidized low-density lipoproteins (oxLDL), and malondialdehyde (MDA), erythrocyte activity of superoxide dismutase (SOD), and MDA/SOD ratio. The QoL scale, Shikhan clinical anxiety scale, and a questionnaire specifically designed for this study were also used.

Results. Subjective health deterioration in hot weather was reported by 46,3% of the participants. The number of cardiovascular events (CVE) was higher during the hot weather period, compared to the following period (p=0,009). Hot weather was associated with a reduction in the levels of systolic BP (SAD; p=0,004), diastolic BP (DBP; p=0,04), PWV (p=0,05), and heart rate (HR; p=0,06). The levels of Na were elevated by the second visit (p=0,002). The number of CVE during the hot weather period negatively correlated with the dynamics of PWV (r= –0,304, p<0,001), SBP (r= –0,225, p=0,009), and DBP (r= –0,292, p=0,001) and positively correlated with the Na concentration dynamics. There was a negative correlation between QoL and age (r= –0,202, p=0,03). The hot weather period was characterised by the OS development, with the OS regression during the subsequent colder period.

Conclusion. Hot summer weather, even within the climatic norm range, is associated with increased CVE risk in some cardiac patients. Negative health effects of hot weather were self-reported by 46,3% of participants. Inadequate heat adaptation was linked to OS development, lesser degree of BP and PWV reduction, more pronounced Na elevation, and older age.

1. Climate change and communicable diseases in the EU Member States. Handbook for national vulnerability, impact and adaptation assessments. Eur Centre Dis Prevent Cont 2010; 42 p.

2. Wildfires and heat waves in the Russian Federation. Health recommendations August 19, 2010, 19 p. Russian (Природные пожары и аномальная жара в Российской Федерации. Медико-санитарные рекомендации 19 августа 2010 г., 19 стр).

3. Fouillet A, Rey G, Laurent F, et al. Excess mortality related to the August 2003 heat wave in France. Int Arch Occup Environ Health 2006; 80 (1): 16–24.

4. Bouchama A, Dehbi M, Mohamed G, et al. Prognostic factors in heat wave￾related deaths; a meta-analysis. Arch Intern Med 2007; 167: 2170–6. 5. Curriero F, Heiner KS, Samet JM, et al. Temperature and mortality in 11 cities of the Eastern United States. Am J Epidemiol 2002; 155: 80–7.

5. Lammintausta R, Syvalahti E, Pekkarinen A. The change in hormones reflecting sympathetic activity in the Finnish sauna. Ann Clin Res 1976; 8: 266–71.

6. Karvonen MJ, Friberg 0, Anltila E. Urine flow and water balance in the sauna-bath. Ann Med exp Fenn 1955; 33: 326–36.

7. Finn AL. Effect of aldosterone administration on electrolyte excretion and GFR in the rat. Am J Physiol 1963 (Feb); 204–44.

8. Russian recommendations “Diagnosis and correction of disorderslipid exchangeinthe prevention and treatment of atherosclerosis”, V revision. Moscow 2012, 23p. Russian (Российские рекомендации “Диагностика и коррекция нарушений липидного обмена с целью профилактики и лечения атеросклероза”. V пересмотр. Москва 2012; 23 c).

9. Revitch B. Temperature curves of mortality and the area of thermal comfort: heat waves and mortality: Hot summer of 2010in Moscow ELECTRONIC VERSIONNEWSLETTER “POPULATION AND SOCIETY” INLIT.RU: http://www.polit.ru, available March 13, 2013. Russian (Ревич Б. Температурные кривые смертности и область темпера- турного комфорта: Волны жары и смертность: Горячее лето 2010-го в Москве ЭЛЕКТРОННАЯ ВЕРСИЯ БЮЛЛЕТЕНЯ “НАСЕЛЕНИЕ И ОБЩЕСТВО” ПОЛИТ.РУ: http://www.polit.ru, доступно 13 марта 2013г).

10. Revitch BA, Maleev VV. Climate changeand health of population in Russia: situation analysis and forecasts. M. Lenanl, 2011, 208 p. Russian (Ревич Б. А., Малеев В. В. Изменения климата и здоровье населения России: анализ ситуации и прогнозные оценки. М., Ленанл 2011; 208 с).

11. Great Medical Encyclopedia. Tom 1. The famouseditor Academician Petrovsky, the publishing house “Soviet encyclopedia”. Moscow 1974; 576 p. Russian (Большая медицинская энциклопедия. Том 1. Гл. редактор академик Б. В. Петровский; издательство “Советская энциклопедия”. Москва 1974; 576 с).

12. Umidova ZI. Physiology and pathology of the cardiovascular system in ahotclimate. Tashkent. Gosizdat UzSSSR 1949; 296 p. Russian (Умидова З. И. Физиология и патология сердечно-сосудистой систем в условиях жаркого климата. Ташкент. Госиздат УзСССР 1949; 296 с).

13. Miyata M, Kihara T, Kubozono T, et al. Beneficial effects of Waon therapy on patients with chronic heart failure: Results of a prospective multicenter study. J Cardiology 2008; 52: 79–85.

14. Gora EP. Human Ecology. Dropha 2007; 145 p. Russian (ГораЕ. П. Экология человека. Дрофа 2007; 145 с).

15. Grant PJ, Tate GM, Hughes JR, et al. Davies JA, Prentice CR. Does hypernatraemia promote thrombosis? Thromb Res 1985; 40 (3): 393–9.