Healthy “ABCs” Lower CVD Risk in Patients with T2D

A large population-based study of patients with type 2 diabetes (T2D) indicates that achieving a greater number of “ABC” targets (A: HbA1c; B: blood pressure; C: LDL-cholesterol) incrementally reduced the risk of cardiovascular disease (CVD). However, not all ABC risk factors were of equal importance in CVD risk reduction.¹

For adults with T2D, the American Diabetes Association (ADA) recommends maintaining optimal levels of all three ABC risk factors: HbA1c < 7%, blood pressure < 130/80 mm Hg, and LDL-C < 100 mg/dL.² This has proven to be challenging, with only 14.3% of patients in the US and 12% of patients in Canada able to achieve three-factor control.³ Some deterring factors include adverse effects from treatments, excessive polypharmacy, cost, or treatment burden.

Researchers from the Department of Family Medicine and Primary Care at the University of Hong Kong conducted a study to understand the relative effects of the ABC factors, individually and in combination, on the prevention of CVD. Study methods aligned with the aforementioned ABC targets, except for blood pressure, for which the researchers elected to use local Hong Kong guidelines for diabetes care in adults (i.e. blood pressure < 130/90 mm Hg).⁴ By examining patient records at 74 outpatient primary care clinics in the Hong Kong area, the investigators identified more than 144,000 adult patients with T2D who were receiving health services for T2D. The patients were followed from the first time their ABC values were recorded until the occurrence of a CVD event, death, or the last date of the study, whichever occurred first.¹

Major findings include:¹

• Achieving a greater number of ABC targets incrementally reduced the incidence of total CVD and individual disease, including coronary heart disease, stroke, and heart failure
• Those who achieved optimal levels of all three ABC targets reduced their CVD risk by 55%. However, only 9% of patients achieved all three targets
• Among patients achieving only 1 ABC target, LDL-C reduction was associated with the greatest CVD risk reduction (42%), followed by blood pressure reduction (18%), and HbA1c reduction (13%)
• Subgroup analysis revealed that patients diagnosed with T2D for less than 1 year benefited the most from achieving ABC targets, suggesting the importance of early intervention

The sample size of this study was very large, however, the investigators acknowledged that the homogeneity of the cohort comprised Chinese patients from one geographic region. Also noteworthy, the effects of lifestyle factors such as diet and exercise were not assessed in this study.¹

Why is this Clinically Relevant?

• Albeit challenging for most patients with T2D, achieving all three ABC targets led to the greatest CVD risk reduction
• For T2D patients who are unable to improve all three ABC factors, clinicians should consider prioritizing efforts on treatment of LDL-C, followed by blood pressure and HbA1c
• Early prevention efforts to achieve ABC targets in patients diagnosed with T2D is paramount for CVD prevention

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References:

1. Wan EYF, Fung CSC, Yu EYT, et al. Effect of multifactorial treatment targets and relative importance of hemoglobin A1c, blood pressure, and low-density lipoprotein-cholesterol on cardiovascular diseases in Chinese primary care patients with type 2 diabetes mellitus: a population-based retrospective cohort study. J Am Heart Assoc. 2017;6(8):e006400.
2. The American Diabetes Association. Standards of Medical Care in Diabetes-2012. Diabetes Care. 2012;35(Suppl 1):S11-S63.
3. Ali MK, Bullard KM, Gregg EW. Achievement of goals in U.S. diabetes care, 1999-2010. N Engl J Med. 2013;369(3):287-288.
4. Food and Health Bureau HKSAR. Hong Kong reference framework for diabetes care for adults in primary care settings. 2010.