Tailored Targets – When to loosen the reins on glucose control

Some people with type 2 diabetes may reach glucose targets through lifestyle modification alone, especially in the early years after diagnosis. Diabetes being a progressive disease, however, most of these patients come to rely on glucose-lowering medications, as do all patients witih type 1 diabetes. Some of these medications—especially insulin—incur a substantial risk of hypoglycaemia and its potentially serious consequences. For certain populations, a slavish adherence to strict glucose targets may cause more harm than good and may thus constitute overtreatment.

The American Diabetes Association (ADA) and European Association for the Study of Diabetes (EASD) recognized the need to individualize glucose targets in a 2012 joint position statement. The authors of the document maintained that glucose targets “should be considered within the context of the needs, preferences, and tolerances of each patient and that “individualization of treatment is the cornerstone of success.”¹

In my experience, however, time pressures and other barriers—especially in busy practices with patients presenting with multimorbid conditions—make it a challenge to individualize therapy. At worst, therapeutic inertia may set in and obscure patients’ changing needs.

Vulnerable populations

When setting glucose targets, factors to consider include age, disease duration, risk of hypoglycaemia and chronic comorbidities. Tight glucose control tends to increase the risk of hypoglycaemia, and recent studies suggest that older adults, in particular, incur significant risks from hypoglycaemic episodes. Indeed, hypoglycaemia accounts for more hospitalizations than hyperglycaemia in older US adults receiving Medicare.² 

Despite this very real risk, older people are often encouraged to pursue the same targets as their younger counterparts. In a cross-sectional analysis of over 1,000 subjects with diabetes from the National Health and Nutrition Examination Survey (NHANES), the proportion with a HbA1C less than 7% did not differ based on health status.² Similarly, health status did not have a bearing on the proportion being treated with insulin or sulfonylureas—medications associated with hypoglycaemia.²

Patients with recurrent hypoglycaemia constitute an especially vulnerable group. Repeated hypoglycaemic episodes promote impaired awareness of hypoglycaemia (IAH), a condition characterized by lack of subjectively perceived hypoglycaemia symptoms. In a study of 153 unselected patients with type 1 diabetes, asymptomatic hypoglycaemic events were tightly correlated with the risk of severe hypoglycaemia, indicating that this group of patients merits particular consideration in clinical practice.³

Patient preferences and attitudes also come into play. In a study estimating the effect of HbA1C reduction on diabetes outcomes and quality-adjusted life years (QALYs), investigators concluded that for most patients over 50 with a HbA1C below 9% on metformin, further glycaemic treatment offers only modest benefits, which are contingent on patient perceptions of the treatment burden.⁴ By the same token, even small adverse treatment effects may result in net harm in this group.⁴

My own practice includes nurse practitioners who have more time to spend with patients and who take a holistic approach that considers not just target HbA1c, but patient circumstances and preferences. I have found this approach to support patient motivation and adherence.

A patient-centred approach

Despite the evidence and guideline recommendations for glucose targets, many clinicians delay treatment intensification, resulting in suboptimal glucose control.⁵ At the other end of the spectrum are those patients being treated to lower targets than required. When individualizing therapy, clinicians need to take into account the risks of hypoglycaemia in groups such as the elderly, the frail, those with IAH, and those with chronic co-morbidities. Patient preferences and quality-of-life issues must also be given reasonable consideration.⁶

Health providers who manage patients with diabetes need to know not only when to escalate therapy but also to recognize those patients who will get more harm than benefits from tight glucose control. Failure to de-intensify therapy in these patients is as much a form of “therapeutic inertia” as failure to intensify therapy.⁷ Clinician awareness and education can help counter these tendencies.