Sex differences in temperature-related all-cause mortality in the Netherlands

Mireille A Folkerts,Mike L Martinius,Peter Bröde,Nicola Gerrett,Carel N Harmsen,Hein A M Daanen,W J Wouter Botzen

doi:10.1007/s00420-021-01721-y

Abstract

PurposeOver the last few decades, a global increase in both cold and heat extremes has been observed with significant impacts on human mortality. Although it is well-identified that older individuals (> 65 years) are most prone to temperature-related mortality, there is no consensus on the effect of sex. The current study investigated if sex differences in temperature-related mortality exist in the Netherlands.MethodsTwenty-three-year ambient temperature data of the Netherlands were combined with daily mortality data which were subdivided into sex and three age classes (< 65 years, 65–80 years, ≥ 80 years). Distributed lag non-linear models were used to analyze the effect of ambient temperature on mortality and determine sex differences in mortality attributable to the cold and heat, which is defined as mean daily temperatures below and above the Minimum Mortality Temperature, respectively.ResultsAttributable fractions in the heat were higher in females, especially in the oldest group under extreme heat (≥ 97.5th percentile), whilst no sex differences were found in the cold. Cold- and heat-related mortality was most prominent in the oldest age group (≥ 80 years) and to a smaller extent in the age group between 65–80 years. In the age group < 65 years temperature-related mortality was only significant for males in the heat.ConclusionMortality in the Netherlands represents the typical V- or hockey-stick shaped curve with a higher daily mortality in the cold and heat than at milder temperatures in both males and females, especially in the age group ≥ 80 years. Heat-related mortality was higher in females than in males, especially in the oldest age group (≥ 80 years) under extreme heat, whilst in the cold no sex differences were found. The underlying cause may be of physiological or behavioral nature, but more research is necessary.

Highlights

A global increase in heat waves and cold spells have been observed over the last few decades and this increase is expected to continue due to climate change (Alexander et al 2006; Meehl and Tebaldi 2004; Rahmstorf and Coumou 2011)
Daily mortality per 100,000 residents of the same sex and similar age provides a better overview of sex differences in temperature-related mortality
In the cold there was an increase in mortality from the Mortality Temperature (MMT) to the 2.5th percentile for males of 14.7% and for females of 18.3%

Summary

Introduction

A global increase in heat waves and cold spells have been observed over the last few decades and this increase is expected to continue due to climate change (Alexander et al 2006; Meehl and Tebaldi 2004; Rahmstorf and Coumou 2011). International Archives of Occupational and Environmental Health elderly population are most at risk for temperature-related morbidity and mortality, as their thermoregulatory function is impaired, they are often less physically fit and have more chronic illnesses and diseases (Koppe et al 2004; Worfolk 2000). Males and females differ from each other in their physiology, anthropometric characteristics, body composition and social behavior, which impact their thermoregulation (Gagnon and Kenny 2012; Kaciuba-Uscilko and Grucza 2001). Females are at a slight advantage due to their greater body fat content which functions as insulation (Kaciuba-Uscilko and Grucza 2001; McArdle et al 1992). A higher heat-related mortality for females and a higher cold-related mortality for males is expected due to the aforementioned physiological differences

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