Cold weather-related cardiorespiratory symptoms predict higher morbidity and mortality
Highlights
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3–5 bullet points (max 85 charaters/bullet point).
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Low temperature elicits physiological responses that aggravate a disease condition.
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Cold weather symptoms may indicate an undiagnosed disease.
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Cold-related cardiorespiratory symptoms relate to higher morbidity and mortality.
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Pre-emptive measures can aid reducing and preventing adverse health effects in winter.
Abstract
Background
Symptoms perceived in cold weather reflect physiological responses to body cooling and may worsen the course of a pre-existing disease or precipitate disease events in ostensibly healthy individuals. However, the associations between cold-related symptoms and their health effects have remained unknown. We examined whether cold-related cardiac and respiratory symptoms perceived in cold weather predict future morbidity and mortality. Methods: Cold-related symptoms were inquired in four national FINRISK surveys conducted in 1997, 2002, 2007, 2012 in Finland including altogether 17 040 respondents. A record linkage was made to national hospital discharge and cause-of-death registers. The participants were followed up until the first hospital admission due to a cardiovascular or respiratory disease or death, or until the end of 2015. The individual follow-up times ranged from 0 to 18 years (mean 11 years). The association of cold-related symptoms with morbidity and mortality was examined by Kaplan-Meyer and Cox-regression analyses. Results: Cold-related cardiac [hazard ratio (HR), 1.76 and its 95% confidence interval (95% CI), 1.44–2.15] and combined cardiac and respiratory symptoms [1.50 (1.29–1.73)] were associated with hospitalization due to cardiovascular causes. The respective HRs for admissions due to respiratory causes were elevated for cold-related respiratory [1.22 (1.07–1.40)], cardiac [1.24 (0.88–1.75)] and cardiorespiratory [1.82 (1.50–2.22)] symptoms. Cold-related cardiorespiratory symptoms were associated with deaths from all natural [1.38 (1.11–1.72)], cardiovascular [1.77 (1.28–2.44)] and respiratory [2.19 (0.95–5.06)] causes. Interpretation: Cold weather-related symptoms predict a higher occurrence of hospital admissions and mortality. The information may prove useful in planning measures to reduce cold-related adverse health effects.