Elderly new onset diabetes a new sub group of diabetes

Elderly patients with new-onset diabetes and poor sugar control (HbA1c of 7.5% or higher) are linked with increased mortality risk. There is no U-shaped risk pattern, unlike that reported for elderly patients with long-standing diabetes.

In a study published in July edition of Diabetes Care, patients with the highest levels of HbA1c also were least likely to undergo a coronary revascularization procedure.

The findings are totally different from the results in elderly with long-standing diabetes.

The researchers conducted a retrospective observational study of data from a cohort of 2994 individuals (48% males) living in the Sharon-Shomron District, Israel, who were insured by a large provider.

The study subjects were 65 years or older when they were newly diagnosed with diabetes in 2003 or 2004. The patients were assumed to have type 2 diabetes, since type 1 diabetes is very rare at this age, and only 0.1% to 3% of the patients were receiving insulin therapy.

The patients were followed for 7 years or until they reached a study outcome: coronary revascularization — PCI or CABG — or mortality.

At baseline, patients had a mean age of 75.6 years. They were stratified into 4 groups, based on their average HbA1c levels during follow-up: less than 6.5% (n=1580), 6.5% to 6.99% (n=611), 7% to 7.49% (n=367), and 7.5% or greater (n=436).

During a mean follow-up of 5.54 years, 1173 participants (39.17%) died. All-cause mortality rates were 41%, 32%, 36%, and 46%, in the 4 groups.

Compared with participants in the group at lowest risk of dying (those with an average HbA1c level of 6.5% to 6.99%), patients in the group with the highest HbA1c levels (>7.5%) had a significant increased mortality risk.

These findings differ from a previous large, retrospective cohort study of patients older than 50 who had long-standing diabetes and intensive hypoglycemic treatment, where researchers reported finding a U-shaped risk pattern, and an HbA1c level of about 7.5% was associated with the lowest all-cause mortality (Lancet. 2010;375:481-489).

The difference in mortality patterns between our finding and the aforementioned study underscores the need to differentially treat elderly patients with new-onset [diabetes] and elderly patients with long-standing disease.

During follow-up, 285 participants (9.51%) underwent PCI or CABG. The rate of coronary revascularization was highest in the patients with an average HbA1c level of 6.5% to 6.99% and lowest in the patients with an HbA1c level of 7.5% or higher.

This inverse relationship may be the result of a protective effect of revascularization against mortality, or the patients with the highest levels of HbA1c may have received suboptimal medical treatment for various reasons. (Source Medscape)