Nerve and kidney damage, taking beta blockers, alcohol use and the length of time with type 1 diabetes are all factors that can contribute to more frequent incidents of severe hypoglycemia.
Researchers in the Netherlands based this observation on results of a questionnaire filled out by nearly 200 people with diabetes. The questionnaire asked how many times in the previous year the people had experienced hypoglycemia that required the assistance of another person. Other questions addressed complications, medications taken and personal habits.
The results, reported in the October 2000 issue of Diabetes Care, divided the respondents’ hypoglycemia into two categories:
- Severe hypoglycemia – when episodes did not involve coma, seizure or treatment with glucagon or intravenous dextrose.
- Hypoglycemia coma.
Some 40.5 percent of those responding said they had experienced at least one episode of severe hypoglycemia in the past year, and half of those said that a coma or seizure had accompanied one or more hypoglycemic episodes.
Patients who experienced severe hypoglycemia without coma were more likely to have:
- Kidney disease;
- A threshold for hypoglycemic symptoms at more than 54 mg/dl; and
- A daily insulin dose 0.1 unit per kilogram in weight higher than those without severe hypoglycemia.
In the coma group, researchers found:
- A longer duration of diabetes;
- A higher proportion of patients with long-term diabetes complications such as neuropathy, micro- or macroalbuminuria, retinopathy or macrovascular disease;
- A higher proportion of patients who took beta-blockers; and
- A higher proportion of patients who had more than two alcoholic drinks per week.
Patients who had experienced hypoglycemic coma tended to set their target ranges for treatment higher than those who had not experienced a coma, for a mean level of 99 mg/dl versus 83 mg/dl.
Researchers say, “Our studies suggest that the presence of long-term complications may serve as a useful clinical risk indicator of severe hypoglycemia.”