UK Health Security Agency                            HRSC0065

Supplementary written evidence submitted by the UK Health Security Agency

Q1.               Why is there insufficient academic and scientific information about the effects of heatwaves on the menopause?

Response:

Everyone is at risk from the health consequences of hot weather as high heat directly compromise the body’s ability to regulate its internal temperature. There are certain factors that increase an individual’s risk during a heatwave; for instance, concurrent risk factors for cardiovascular disease and greater difficulty cooling down.

Pathways to differences in thermoregularity between sexes could include variations in sweat volume, core body temperature, body mass and hormonal fluctuations associated with the reproductive cycle and menopause. Dessapt and Goudy (2012) suggest that post-menopausal women are at increased risk of cardiovascular disease due to the reduction of oestrogen hormone in the body and the protective effect the hormone has on cardiovascular disease risk.

The first iteration of UKHSA’s (2023a) Adverse Weather and Health Plan (AWHP): Supporting Evidence document highlights pregnant women as a key group at risk from hot weather and presents the associated evidence base. The document does not currently include the effects of hot weather on menopausal health. Nevertheless, this will be considered in the second edition which is due to be published on 22nd February 2024, as well as the Adverse Weather and Health Plan Equity Review, to be published on 16th November 2023, as one of the areas that will need further research in the UK.

Q2.              The Office for National Statistics (ONS) said in 2022 that there were more excess deaths among women as compared to men during 2022, but there did not seem to be much mention about the impact of heatwaves on women.

Response:

There are some plausible physiological and social factors that could be attributed to observed differences in risk by sex. For example, the age distribution of the population by sex also suggests that the population size of older woman is larger than the comparable age groups for males, and evidence suggests that the risk increases with age. Therefore, it is possible that the increased mortality number is more associated with age than sex.

Analysis of previous episodes of heatwaves and epidemiological evidence suggests that older females are perhaps at higher risk than older males. A literature review published in 2019 (van Steen et al, 2019) which aimed to investigate the difference in risk by sex after heatwaves in Europe concluded that more research is needed to fully understand any physiological mechanisms that may be at play, and the role of social factors that may increase risk of older females. Age and sex together are likely to be important factors to consider, and how they interact to increase the likelihood of other potential heat risk factors. Evidence is limited but this demonstrates the complexities involved. Although no strong evidence of this exists in the UK, the UKHSA plans – as part of the Adverse Weather and Health Plan (UKHSA, 2023b) – to provide disaggregated relevant data by region, sex, and age on relevant indicators, such as mortality.

October 2023