PracticeUpdate Diabetes June 2019

AACE 2019 17

Clustered Metabolic Approach Helps Stratify Cardiovascular Risk in Type 2 Diabetes The approach can help lead to intensive, targeted therapies to prevent complications and improve outcomes. A clustered metabolic approach has been shown to help stratify cardio- vascular risk in patients with type 2 diabetes, reports an analysis of arterial health including cardiovascular risk. and arterial stiffness as assessed by the aortic augmentation index demonstrated a potentially useful, convenient tool to enable better decision-making regard- ing therapy.

Dr. Chawla explained that the co-asso- ciation of diabetes with hypertension is known to increase aortic stiffness and pulse pressure. Arterial stiffness increases as the elastic fibers in the lamina media of the aorta are destroyed and replaced by collagen fibers, causing a substantial increase in aortic impedance and pulse wave velocity. The augmentation index is a more indirect measure of arterial stiffness, a measure of pulse wave reflection that calculates how much of the central pulse pressure is accounted for by the reflected pulse wave. The augmentation index depends on arte- rial stiffness and reflective properties of the arteries, that is the amplitude of the reflected wave and the reflectance point. Pulse wave velocity is the gold stand- ard for measuring arterial stiffness, though correlated pulse wave velocity and augmentation index are two differ- ent measurements of the properties of the arterial tree that cannot be used interchangeably. The augmentation index is less time con- suming and easier to measure than pulse wave velocity. In contrast to pulse wave velocity, the augmentation index can be modified by medication in subjects with hypertension, as shown in the 2006 CAFE (Conduit Artery Function Evaluation) study. 1 Dr. Chawla concluded that the clustered metabolic marker approach is a novel tool to identify and stratify patients with diabe- tes based on metabolic risk. The tool can help provide intensive, tar- geted therapies to prevent complications and improve outcomes. Reference 1. Williams B, Lacy PS, Thom SM, et al. Differential impact of blood pressure-lowering drugs on central aortic pressure and clinical outcomes: principal results of the Conduit Artery Function Evaluation (CAFE) study. Circulation 2006;113(9):1213-1225. www.practiceupdate.com/c/82553

Rajeev Chawla, MD, of the North Delhi Diabetes Centre in New Delhi, India, and colleagues set out to investigate the asso- ciation of grade of glycemic control with aortic augmentation index as a routine tool by using an analysis of arterial health including cardiovascular risk analysis. Dr. Chawla told Elsevier’s PracticeUpdate , “Ideally, patients with comorbidities such as dyslipidemia, hypertension, and poor glycemic control should be screened for increased arterial stiffness so intervention can begin early to reduce cardiovascu- lar risk.” The cardiovascular risk analyzer was used to estimate functional vascular age in 200 consecutive patients for 3 months. The generated cardiovascular interpretations formed the basis for comparison of the metabolically healthy group vs the meta- bolically unhealthy group. HbA1c was >7% and <7% in 53 and 147 patients, respectively. Mean age was 53.3 years. The comorbid profile (n=200 [n=117 males; n=83 females]) revealed mean low-density lipoprotein values as <100, 100–150, or >150 mg/dL in 138, 52, and 10 patients, respectively. Total cholesterol was >150 mg/dL in 132 patients. Overall, 51 patients suffered from hypertension, peripheral neuropathy was reported in 45 patients, and 19 patients were heavy smokers. The clustered triad for the co-associa- tion of HbA1c, hypertension status, and parameters of arterial stiffness differed statistically significantly when the met- abolically healthy were compared with 23 metabolically unhealthy patients (P = .0457). Aortic augmentation index corrected for heart rate at 75 beats per minute is a spe- cific marker for evaluation of arterial health and correlated with the grade of glyce- mic control. Correlates of the clustered triad marker for the association of HbA1c, blood pressure,

Standard metrics used in these trials showed that A1c was reduced by a 7% rel- ative decrease (from 7.4% to 6.9%; P < .001). Time in hypoglycemia (<70 mg/dL) was reduced by 44% in 124 adults/adolescents. In 105 children, A1c was reduced by a 5% relative decrease (from 7.9% to 7.5%; P < .001). Time in hypoglycemia (<70 mg/dL) was reduced by 36% (from 4.7% to 3.0%; P < .001). Dr. Vigersky’s team is looking beyond A1c because A1c provides no information about hypoglycemia, hyperglycemia, or glycemic variability. The relationship of A1c to mean glucose is individualized, and a variety of clinical conditions, such as hemoglobinopathies, anemia, uremia and pregnancy affect its accuracy. Dr. Vigersky concluded that results of the Medtronic MiniMed™ 670G system piv- otal trials as assessed using the novel hypo-triad and comprehensive glucose pentagon demonstrated more robust and clinically relevant improvement in overall glycemic control than using standard met- rics, such as A1c. He added, “Since patients may understand a picture such as that depicted by the com- prehensive glucose pentagon better than an abstract number like A1c, this approach may help them and their health care provid- ers better appreciate changes in diabetes control.” www.practiceupdate.com/c/82602

VOL. 3 • NO. 2 • 2019