Type 2 Diabetes among Older Adults

Speaker: Graydon Meneilly, MD, Professor and Department Head, Medicine Department, Faculty of Medicine, University of British Columbia, Vancouver, BC.

Dr. Graydon Meneilly introduced his discussion of type 2 diabetes among older adults by emphasizing the condition’s underestimated prevalence. One in four older adults over age 60 has diabetes, yet ~50% are unaware they have the disease, underscoring the need for improved screening protocols.

Glycemic Control in Older Adults with Diabetes
The British Geriatrics Society, in conjunction with the European Association for the Study of Diabetes, established two sets of therapeutic goals for older people, the first of which applies to healthy, active older persons with diabetes. Their fasting glucose is targeted between 4-7 mM; the 2-hour postmeal sugar at 7-10 mM, and HbA1c at <7%. The forthcoming Canadian Diabetes Association (CDA) guidelines may offer a more aggressive HbA1c target; however, Dr. Meneilly does not recommend that HbA1c be targeted lower than 6.5% in older adults, as aggressive lowering has been associated with adverse events.

Evidence suggests that fasting glucose is a poor predictor of diabetes risk among older adults; postprandial glucose has better predictive value. The target should be <8 mmol/L; at this level, the risk of cardiovascular disease (CVD) and mortality are reduced when compared with postprandial glucose levels of >11, even among patients with good fasting glucose levels.

Glycemic Goals for Frail Patients
The second set of glycemic control goals apply to frail patients and target fasting glucose from 7-9 mM, the 2-hour postprandial sugar at 10-13 mM, and HbA1c at <8.5%. The renal threshold for glucose increases with age, so patients will not develop glucosuria at these glucose levels. It is not known whether this level of hyperglycemia could increase the risk of infection, worsen cognitive function, or adversely affect important health parameters for this patient segment. Some feel more stringent criteria should apply, but data are insufficient and cannot support a recommendation.

Controlling blood sugar appropriately in frail patients is key. Many doctors outside of geriatric medicine do not know how to modify the medical approach to diabetes that frailty requires.

Treatment of Other Risk Factors
Dr. Meneilly emphasized that treatment of hypertension in older adults with diabetes significantly modifies CVD and mortality risk.¹

European guidelines recommend a target of less than 140/90 mm Hg. The benefits of reduced hypertension are clearly established but level off with increasingly aggressive treatment; benefits are less once BP targets are aimed <140. Comparably, with HbA1c, there is a great effect if patients drop from 9 to 8, but a reduced health yield with a reduction from 7 to 6. Treatment that achieves a systolic BP ≤140 is the best approach, Dr. Meneilly stated.
A second pillar of sound risk factor modification targets hypercholesterolemia with statins. Data from the Heart Protection Study show that persons over 65 with diabetes treated with statins experience a reduced risk of CV events by 20%; treatment of hyperlipidemia with statins in diabetics strongly benefits vascular outcomes.²

As for specific lipid targets, European guidelines aim for an LDL of ≤2.5; forthcoming CDA targets may be more aggressive. The benefit curve for LDL seems to flatten out below 3, he observed, adding among very old adults, the higher the patient’s cholesterol, the greater the longevity benefit. Dr. Meneilly does not test lipids in patients over age 85, or alter treatment if the patient has been stable on a statin for years.

Significant progress must