# Effects of temperature and humidity on hospitalizations for metabolic syndrome with cerebral infarction among older adults in Panzhihua: a distributed lag non-linear model analysis

## TL;DR

This study finds that high temperature and humidity may lower hospitalization risk for metabolic syndrome with cerebral infarction in older adults in Panzhihua, but effects vary by subgroup.

## Contribution

The study applies a distributed lag non-linear model to assess temperature and humidity effects on hospitalization risk in a dry-hot valley climate.

## Key findings

- High temperature and humidity were associated with reduced hospitalization risk for MetS with cerebral infarction.
- Men showed reduced risk with high temperature and humidity, while women had reduced risk under low temperature.
- Individuals aged 60–75 showed protective effects, but no significant effects were found in those over 75.

## Abstract

Research on special climatic regions, such as dry-hot valleys and high-altitude areas, is gradually emerging. Taking the dry-hot valley climate of Panzhihua as an example, this study explores the potential relationship between the risk of hospitalization due to metabolic syndrome (MetS) combined with cerebral infarction in the local older population and meteorological factors, specifically temperature and humidity.

Daily meteorological data, air pollution data, and records of hospital admissions for MetS complicated with cerebral infarction at Panzhihua Central Hospital were collected from 2016 to 2020. A distributed lag nonlinear model was applied to analyze the impact of daily mean temperature and relative humidity on admission risk among adults aged over 60.

High temperature was associated with a reduced risk of hospital admission for MetS with cerebral infarction among older adults. The relative risk (RR) reached its minimum at lag day 17 (RR = 0.940, 95% CI: 0.887–0.996). Similarly, relatively high humidity and high humidity also reduced admission risk, with the lowest RR values observed at lag days 19 and 18, respectively. Subgroup analysis revealed that men experienced reduced admission risk when exposed to high temperature and high humidity, whereas women showed reduced risk under low temperature conditions. In the 60–75 age group, protective effects were observed with exposure to relatively high temperature, low humidity, relatively high humidity, and high humidity. However, no statistically significant effects of temperature or humidity exposure were found among individuals over 75 years of age.

High temperature and high humidity may reduce the overall risk of hospital admission for MetS with cerebral infarction among older adults. However, these effects vary across different subgroups. Therefore, public health policies should be tailored to specific demographic groups.