Individualizing Treatment of Hyperglycemia in Type 2 Diabetes

This article examines key issues faced by primary care providers when managing hyperglycemia in patients with T2DM and outlines a stepwise approach to determining the optimal antihyperglycemic agent(s) ( Table 1) .

Confirm Diagnosis of T2DM

It can be difficult to distinguish between type 1 diabetes mellitus and T2DM in some individuals due to overlapping characteristics. However, correctly classifying a patient’s diabetes at the outset is essential, as the classification helps determine the best treatment regimen and is rarely reconsidered [4,8]. Considerable evidence suggests that misclassification of diabetes occurs frequently [9,10], resulting in patients receiving inappropriate treatment. Clinical characteristics suggestive of T2DM include older age and features of insulin resistance such as obesity, hyper-tension, hypertriglyceridemia, and low high-density lipoprotein cholesterol. When these features are not present, an alternate diagnosis should be entertained.

Establish Glycemic Goal

Research over the past decade has led to a growing appreciation of the enormous complexity of hyperglycemia management. During the 1990s, landmark trials such as the Diabetes Control and Complications Trial (DCCT) [11] and UK Prospective Diabetes Study (UKPDS) [12] demonstrated that improving glucose control could reduce the incidence of microvascular complications [11,12], prompting a lower-is-better philosophy regarding glucose targets. Despite limited evidence to support such thinking, this viewpoint was adopted by the developers of many guidelines. During the following decade more research was devoted to determining whether aggressively lowering a patient’s glucose could also improve macrovascular outcomes. Table 2 summarizes microvascular and macrovascular effects of intensive glycemic control seen in major trials [11–23]. After several major trials [20,22] found only mild cardiovascular benefits and even suggested harm [18], experts and policy makers began to reconsider the value of tightly controlling glucose levels [24]. Since then, other studies have demonstrated that the potential benefits and risks of glucose control are strongly related to individual patient factors, such as age and duration of diabetes, and associated comorbidities, such as CVD and impaired renal function [6].

A one-size-fits-all glycemic goal is no longer recommended. Personalization is necessary, balancing the potential benefits and risks of treatments required to achieve that goal. Whereas an A1C of < 7% is an appropriate target for some individuals with diabetes, glycemic targets may be more or less stringent based on patient features including life expectancy, duration of diabetes, comorbidities, and patient attitude and support system ( Table 3 ) [4].

A particular group in which less stringent goals should be considered is older patients, especially those with complex or poor health status [4,25]. The risk of intensive glycemic control may exceed the benefits in these patients, as they are at higher risk of hypoglycemia and polypharmacy [26]. A goal A1C of 7% to 7.5% is now recommended for healthy older adults, and less stringent A1C goals of 7.5% to 8% and 8% to 8.5% should be considered based on the presence and severity of multiple coexisting chronic illnesses, decreased self-care ability, or cognitive impairment [4,25]. Unfortunately, overtreatment is frequently seen in this group. In a recent study of patients over age 65 years, about 40% of those with complex or poor health status had tight glycemic control with A1C below 6.5% [26]. An analysis of U.S. Veterans Affairs administration data showed that only 27% of 12,917 patients older than 65 with very low A1C (< 6%) and about 21% of those with A1C of 6% to 6.5% underwent treatment deintensification [27].