High Temperatures Linked to Increased Hospitalizations for People with Diabetes

Results of a new study should serve as a warning related to the impact of rising temperatures on risk of adverse outcomes in patients with diabetes, according to investigators.

As climate change continues to touch each corner of the earth, results of the study, which leveraged data from nationwide administrative databases in Japan from 2012-2019, suggest extreme heart was linked to a more than 60% increase in risk of a hyperglycemic emergency in the next 3 days, which investigates indicate was consistent across different types of hyperglycemic emergencies and type of diabetes.

“Relative risks for standard and extreme heat effect on emergency hospitalization for hypoglycemia were found to be 1.33 and 1.65, respectively, and similar risks were found for hyperglycemia. In most regions, the higher the temperature, the higher the relative risk,” said lead investigator Takeo Fujiwara, MD, PhD, MPH, in a statement.

With extreme heat linked to an uptick in adverse health outcomes, and in the wake of recent data illustrating this effect in patients with diabetes, the current study was launched by investigators in the Department of Global Health Promotion at Tokyo Medical and Dental University. With the intent of estimating the associations between heat exposure and hospitalization in patients with diabetes, investigators designed the present study as an analysis of data from daily hospitalizations extracted from a nationwide administrative database in Japan linked with temperature in each region from 2012-2019. Investigators noted a distributed lag non-linear model was used to assess nonlinear and lagged effects of heat exposure on hospitalization, with events of interest defined as diabetic ketoacidosis, hyperosmolar hyperglycemic state, and hypoglycemia.

From the dates, investigators identified 45,482 hospitalizations for hyperglycemic emergencies and 62,042 hospitalizations for hypoglycemia during the study period. The most common form of hyperglycemic emergency was diabetic ketoacidosis, which accounted for 84.9% of all hyperglycemic emergencies included in the trial. Investigators pointed out 52.8% of hyperglycemic emergencies occurred in patients with type 2 diabetes and the majority occurred among patients aged 15 years or older (94.6%). Investigators also pointed out the majority of patients who experienced hospitalization (65.8%) were older than 65 years old.

Upon analysis, results indicated the pooled relative risk of heat effect (90th percentile of temperature vs 75th percentile of temperature) and extreme heat effect (99th percentile of temperature vs 75th percentile of temperature) for hyperglycemic emergencies over 0-3 lag days were 1.27 (95% CI, 1.16-1.39) and 1.64 (95% CI, 1.38-1.93), respectively. Further analysis suggested the pooled relative risk for heat effect and extreme heat effect on hospitalization for hypoglycemia were 1.33 (95% CI, 1.17-1.52) and 1.65 (95% CI, 1.29-2.10), respectively. Investigators also pointed out these associations appeared to be consistent by type of hyperglycemic emergencies and type of diabetes.

“To the best of our knowledge, this is the first study to show the association between ambient temperature and hyperglycemic emergencies and hypoglycemia using distributed lag non-linear model, which allows us to assess the nonlinear and lag effects of ambient temperature. The findings of previous studies evaluating the effects of ambient temperature on diabetic patients were limited to all-cause mortality and all-cause hospitalization,” investigators added.

This study, “Association between heat exposure and hospitalization for diabetic ketoacidosis, hyperosmolar hyperglycemic state, and hypoglycemia in Japan,” was published in Environmental International.