Rising temperature tied to risk of complications and hospitalization among diabetes patients

With global warming, studies have shown a rise in extreme heat events. Heat exposure has been associated with adverse health outcomes, including mortality. Patients with diabetes, because of their pathological conditions such as impaired thermoregulation and dehydration risk, are specifically vulnerable to heat exposure.

Heat exposure in an ambient temperature is tied to all-cause hospitalization and all-cause diabetes mortality in patients with diabetes. However, there is no clarity in the association between heat exposure and hospitalization for hyperglycemic emergencies, such as HHS, DKA, and hypoglycemia.

Considering the above, Takeo Fujiwara, Department of Global Health Promotion, Tokyo Medical and Dental University, Tokyo, Japan, and colleagues conducted the study to clarify the stance of heat exposure on the hospitalization for HHS, DKA, and hypoglycemia.

The researchers used distributed nonlinear lag model to evaluate heat exposure's nonlinear and lagged effects on hospitalization for hyperglycemic emergencies. For this purpose, the researchers extracted data on daily hospitalizations for hypoglycemia and hyperglycemic emergencies (i.e., HHS or DKA) from a nationwide administrative database in Japan. They linked it with temperature in each prefecture in Japan from the period 2012–2019.

Based on the study, the authors reported the following findings:

• The pooled relative risk (RR) for hyperglycemic emergencies of heat exposure and extreme heat effect over 0–3 lag days, respectively, was 1.27 and 1.64.
• The pooled RR for heat effect on hypoglycemia and extreme heat effect hospitalization over 0–3 lag days was 1.33 and 1.65.
• These associations were consistent by type of diabetes and type of hyperglycemic emergencies and were generally consistent by regions.

"To the best of our conscience, this is the first study that demonstrates the association between ambient temperature and hyperglycemic emergencies and hypoglycemia through utilizing distributed nonlinear lag model, which allows the assessment of the nonlinear and lag effects of ambient temperature," the researchers wrote. "The results from the previous studies examining the effects of ambient temperature on diabetes patients were limited to all-cause hospitalization and all-cause mortality.

"Our findings suggest that heat exposure is tied to an increased hospitalization risk of HHS, DKA, and hypoglycemia. The study may be helpful to guide preventive action for the risk of hypoglycemia and fatal hyperglycemic emergencies," they conclude.

Reference:

Miyamura K, Nawa N, Nishimura H, Fushimi K, Fujiwara T. Association between heat exposure and hospitalization for diabetic ketoacidosis, hyperosmolar hyperglycemic state, and hypoglycemia in Japan. Environ Int. 2022 Sep;167:107410. doi: 10.1016/j.envint.2022.107410. Epub 2022 Jul 13. PMID: 35868079