Hypoglycemia a Greater Threat Than Hyperglycemia in Elderly

May 21, 2014

ORLANDO, Florida — A study showing that hospital admission rates for hypoglycemia now outpace those for hyperglycemia among older adults in the United States, first reported at the American Diabetes Association meeting last year, has been published in JAMA Internal Medicine to coincide with another presentation, this time here at the American Geriatrics Society (AGS) 2014 Annual Scientific Meeting this past weekend.

Severe hypoglycemia is the most common acute adverse effect of glucose-lowering therapy among patients with diabetes mellitus and is associated with poor outcomes, lead author Kasia J. Lipska, MD, of the Yale School of Medicine, New Haven, Connecticut, told Medscape Medical News.

The new paper extends on both conference presentations by including figures on subsequent deaths and readmissions after hospitalizations for both hyperglycemia and hypoglycemia, Dr. Lipska noted.

"What struck me was that hospital admissions for hypoglycemia — in other words, for a low blood sugar reaction, which is typically reversible — were associated with around 20% mortality at 1 year," she noted. "Of course, we can't tell whether hypoglycemia contributes to death in these persons, but I think we can say it really portends a poor prognosis.

"I believe our findings call for a change in current practice," she added. "We have made great strides in reducing hospital admissions for serious hyperglycemia; I think we have to do better with respect to admissions for hypoglycemia."

And in the study, the very elderly — those aged over 75 — and black patients were particularly at risk for hypoglycemia, she stressed, noting that these patients need to be paid closer attention to with regard to this issue.

In an editor's note in the same issue of JAMA Internal Medicine, Rita F. Redberg, MD, says the new data indicate there were "40% more admissions for hypoglycemia than for hyperglycemia over the 12-year period" of Dr. Lipska's study, and the 1-year mortality rate after a hypoglycemia admission was higher than after a hyperglycemia admission [in 2010].

"Our patients are now more likely to experience adverse events related to overtreatment of diabetes mellitus. Striving for too low an HbA1c target level puts patients at risk for this dangerous adverse effect," Dr. Redberg cautions.

Others have also highlighted the danger of hypoglycemia as a result of overtreatment among the elderly; for example, the latest International Diabetes Federation guidelines focusing on care for this patient group have specified this issue is a problem.

Paradigm Shift Required

In their retrospective observational study using data from almost 34 million Medicare fee-for-service beneficiaries 65 years or older from 1999 to 2011, Dr. Lipska and colleagues set out to examine hospital admission for both hyper- and hypoglycemia; both of these are relatively rare, so these data capture the most severe cases, the researchers note.

They also examined 30-day and 1-year mortality rates and 30-day hospital readmission rates and compared the results according to age, sex, and race.

As previously reported, a total of 279,937 patients experienced 302,095 hospitalizations for hyperglycemia and 404,467 experienced 429,850 hospitalizations for hypoglycemia.

During this 12-year period, rates of admissions for hyperglycemia declined by 38.6%, while admissions for hypoglycemia increased by 11.7%.

However, since 2007, admissions for hypoglycemia have declined modestly, but rates among black Medicare beneficiaries and those older than 75 years remain high, say Dr. Lipska and colleagues.

Admission rates for both hyperglycemia and hypoglycemia were 4-fold higher for black patients compared with white patients, and hypoglycemia rates were 2-fold higher for older patients (>75 years) when compared with younger patients (65–74 years)

The 30-day and 1-year mortality and 30-day readmission rates improved during the study period and by 2010 were similar after an index hospitalization for either hyperglycemia (5.4%, 17.1%, and 15.3%, respectively) or hypoglycemia (4.4%, 19.9%, and 16.3%).

Nevertheless, the high rate of death a year after hypoglycemia hospitalization remains a major concern, the researchers stress.

"Hospital admissions for severe hypoglycemia seem to pose a greater health threat than those for hyperglycemia, suggesting new opportunities for improvement in care of persons with diabetes mellitus," they conclude.

Dr. Lipska told Medscape Medical News that better care for diabetic patients can be achieved by shifting "the paradigm that lower glycemic levels are always better." Decisions about treatment of diabetes need to take into account the risk for hypoglycemia, she stressed.

"Many guidelines already call for an individualized approach to treatment, with less aggressive targets for people at risk for hypoglycemia. Our study underscores the need for this shift."

Dr Lipska reports no relevant financial relationships; disclosures for the coauthors are listed in the article.

JAMA Intern Med. Published online May 17, 2014. Article, Editor's Note


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