Diabetes in the Desert: What Do Patients Know about the Heat?
From ENDO 2010 The Endocrine Society Annual Meeting, San Diego, June 19-22, 2010
Living with diabetes in hot climates poses unique care challenges. Increasing awareness about the interaction between heat and diabetes should be a priority as more patients are living in regions with high temperatures. Data are sparse on what diabetes patients understand concerning heat or what precautions they should take under extreme heat conditions. A survey of patients attending a Southwestern US diabetes clinic was conducted to gauge types of personal protective measures taken against the heat, knowledge of safe temperatures and exposure times, comprehension of weather data and sources of weather information. From November 30 to December 31, 2009 data were collected in 169 completed patient questionnaires. The mean patient age was 66 years, diabetes duration 15 years, 52% were men, 85% had type 2 diabetes, 62% were non-Hispanic white, 67% took insulin by injection, and 6% were on insulin pumps. Mean HgA1c was 7.9%, 38% had a hemoglobin A1c value ≥8.0%, and nearly 40% had values ≥8.0% during the hottest summer months (July and August). Patients employed a variety of personal protective measures, and 68% limited heat exposure to less than one hour. While respondents typically took steps to protect their diabetes equipment and medication (eg, carrying items in a cooler), 36% simply left medications or supplies at home. Although 72% of respondents indicated they had received information regarding the effects of heat on insulin, a minority of patients acknowledged having received information about the effect of heat on oral medications (40%), on glucose monitors (41%), and on glucose monitoring strips (38%). There was considerable variability in temperatures at which patients would consider taking protective measures. Even though 82% knew the correct definition of humidity, only 55% knew the definition of the heat index. Overall, television was the primary source for weather information (89%).
Many patients had suboptimal glycemic control that placed them at risk for dehydration during the hottest months; as well, they used a medication (insulin) particularly susceptible to heat damage. Most respondents had awareness as to the importance of heat in relation to their diabetes, although knowledge gaps were evident. Increased public awareness of this important topic is needed, and diabetes education should include information about the heat, where regionally appropriate.
Nassar AA, Childs RD, Boyle ME, et al. Mayo Clinic Arizona, Scottsdale, Arizona, USA and National Weather Service, Silver Spring, Maryland, USA
In a recent paper, Westphal and collegaues1 reviewed MEDLINE publications from 1966 to 2009 that cross-referenced diabetes mellitus, hot temperature, heat, desert, and insulin. It was found that persons with diabetes might have greater susceptibility to adverse effects from heat (ie, increased number of emergency department visits and hospitalizations, increased occurrence of dehydration and electrolyte abnormalities, and higher death rate) than persons without diabetes. Alterations in glucose homeostasis could also occur, and changes in insulin kinetics and stability were possible. The impact of heat exposure on equipment performance (eg, glucose meters) must be considered. The authors concluded that having diabetes places a person at risk for heat-related health problems. Physicians must be aware of possible complications that diabetic patients may encounter in summer heat to prevent problems. Adolescents with type 1 diabetes mellitus may spend the summer at the beach, and they should be aware of the increased risk, particularly those who are not well controlled. Patient educational materials should be developed relating to self-management skills in the heat, and the topic should be included in standard diabetes education programs when applicable.
As the climate changes, many more people are being subjected to increasing extremes in weather, thus additional education on the health effects of heat on disease and treatment regimens is important. Reid and colleagues have studied the community determinants of heat vulnerability.2 Four factors explained over 75% of the potential vulnerability variables: a) social/environmental vulnerability (combined education/poverty/race/green space), b) social isolation, c) air conditioning prevalence, and d) proportion of elderly people, and those with diabetes. In the US, a higher vulnerability was found in individuals residing in the Northeast and Pacific Coast and the lowest in the Southeast. Urban areas and inner cities showed the highest vulnerability to heat.
Fima Lifshitz, MD
References - (linked to )