Reply to the comments of Saleh et al. on “Coexistence of high visceral fat area and sarcopenia and atherosclerotic markers in old-old patients with diabetes: Is there an association?”

Abstract

We thank Saleh et al.¹ for their interest in and constructive and critical comments on our recent study² on sarcopenia obesity and atherosclerosis markers in the older patient with diabetes.

We would like to respond to the point about the site where the carotid intima-media thickness (cIMT) was measured. We agree that ideally, cIMT should be measured in all common carotid arteries, carotid sinuses, and the internal carotid arteries; subsequently, their maximum values should be used as the maximum value of cIMT (IMTmax). However, we believe that adopting the maximum value of cIMT in the common carotid artery as the IMTmax in our study was reasonable and appropriate for the following reasons. First, the cIMT measured in the common carotid artery has been used in many studies and is accepted as an indicator of atherosclerosis because it is associated with cardiovascular disease or cerebral stroke^3-7. Second, cIMT measured in the internal carotid arteries is inadequately assessed in 20% of cases⁸. In addition, it is often challenging to measure the cIMT in the internal carotid arteries using carotid echocardiography in Japanese patients because the carotid bifurcation is often located above the angle of the mandible^{8, 9}.

Next, we would like to respond to the point about cIMT measurement under electrocardiographic (ECG) synchronization. As Saleh et al. pointed out, the diameter of the carotid artery varies with the cardiac cycle. Nevertheless, this is not the case for atherosclerotic lesions such as cIMT, and measurements of cIMT under ECG synchronization are not necessary when evaluating atherosclerotic lesions⁸, including cIMT. Instead, ECG synchronization is recommended when measuring vessel diameter⁸. Accordingly, we believe that it is unlikely that measuring cIMT without ECG synchronization caused significant measurement errors in this study.

Take together, we are confident that the protocol for measuring cIMT in this study was appropriate despite some limitations. As indicated by Saleh et al., accurate and rigorous measurement protocols for cIMT are important for the reliability of the study results; therefore, we need to pay as much attention as possible to the measurement protocols when using cIMT in clinical research.

Araki A received speaker honoraria from Sumitomo Pharma Co., Ltd., Ono Pharmaceutical Co., Ltd., and Novo Nordisk Pharma Ltd. The other authors declare no conflicts of interest.

Approval of the research protocol: This study was conducted in accordance with the Declaration of Helsinki, and the study protocol was approved by the Ethics Committee of the Tokyo Metropolitan Geriatric Hospital (R21-012).

Informed consent: Since the Ethics Committee determined that written patient consent was not required, the study was conducted using an opt?out method, and consent was not obtained directly from the participants.

Registry and the registration no. of the study/trial: June 22, 2021 and R21-012.

Animal studies: N/A.