# Associations of Long-Term Exposure to Temperature Variability with Glucose Metabolism: Results from KORA F4 and FF4

## TL;DR

Long-term exposure to temperature variability is linked to worse glucose metabolism, which could worsen diabetes trends globally.

## Contribution

This study is the first to explore long-term temperature variability's impact on glucose metabolism using population data.

## Key findings

- Higher temperature variability was associated with increased fasting insulin and insulin resistance.
- Temperature variability correlated with elevated HbA1c and reduced QUICKI, indicating impaired glucose metabolism.
- Findings suggest temperature variability may contribute to metabolic dysfunction and diabetes progression.

## Abstract

The impact of rising temperature variability driven by
climate
change on metabolic health remains understudied, especially considering
the global increase in diabetes prevalence, with long-term effects
on glucose metabolism unexplored. This study investigated associations
between long-term temperature variability exposure and glucose metabolism
in a population-based cohort of 2997 participants (4954 observations)
over a 7-year period from KORA F4 and FF4 cohorts in Augsburg, Germany.
Long-term exposure to temperature variability was estimated as the
standard deviation of the daily mean air temperature over the 365-day
period preceding each examination. We applied generalized estimating
equations to examine the longitudinal associations between long-term
exposure to temperature variability and multiple glucose metabolism
biomarkers: fasting glucose, 2h glucose, fasting insulin, homeostasis
model assessment of insulin resistance (HOMA-IR), homeostasis model
assessment of β-cell function (HOMA-B), quantitative insulin
sensitivity check index (QUICKI), and glycated hemoglobin (HbA1c).
We found that a 1 °C higher temperature variability was significantly
associated with higher fasting insulin, HOMA-IR, and HbA1c with %
changes (95% CI) of 2.62 (0.79; 4.49), 2.81 (0.79; 4.87), and 2.38
(1.97; 2.79), respectively, and lower QUICKI (−0.41 [−0.70;
−0.11]). These findings suggest that increasing temperature
variability exposure may contribute to metabolic dysfunction, potentially
accelerating the global diabetes epidemic.