Prevalence of the Metabolic Syndrome in Patients With Type B Aortic Dissection

Background/Objective: The aim of this study is to detect the prevalence of metabolic syndrome (MS) and its components in type B aortic dissection patients. This study assessed the association of MS and its component with type B aortic dissection in Chinese patients. Methods: This cross-sectional prospective observation study consisted of 445 patients who were rst diagnosed with type B aortic dissection. Demographic information, clinical symptoms and laboratory parameters were collected using a standard form. Results: Among the 445 TBAD patients 38.4% had MS. Hypertension was present in 78.2% of all TBAD patients. Hypertension, high fasting glucose and obesity were the most common combination of metabolic abnormalities (93%, 79.5% and 63.2%) in the TBAD patients, and a same phenomenon was seen in acute TBAD patients. But among chronic TBAD patients the most frequent individual components were hypertension, hyper- triglyceride and high fasting glucose (92.6%, 75%, and 70.6%). Presence of two or more components of the metabolic syndrome was common: 22.7% had one component, 31.9% had two components, 24.9% had three components, 10.8% had four components and 3.1% had ve components. In TBAD, hypertension, obesity, triglycerides and FBG (fasting blood-glucose) were main risk factors for MS. This is the rst study provided information on the prevalence and components of MS in the initial TBAD patients. Hypertension, high fasting glucose and obesity were the most common combination of metabolic abnormalities in TBAD patients.


Background
Aortic dissection (AD) is a life-threatening cardiovascular disease associated with high morbidity and mortality rates, and it remains a challenge to clear its causation. The anatomical classi cation is basis on the location of the dissection and/or origin of the intimal tear and the extent of the dissection, as Stanford type A aortic dissections (TAAD) involve the ascending aorta, and Stanford type B dissections (TBAD) involve the descending aorta. Acute AD is diagnosed within two weeks of onset of symptoms, and chronic phage is diagnosed after eight weeks, the middle period is de ned subacute AD [1]. According to the International Registry of Acute Aortic Dissection (IRAD), 33% patients presented with type B aortic dissection (TBAD) and 63% were treated medically [2]. In uence factors associated with TBAD include hypertension, diabetes mellitus (DM), obesity, and hyperlipidemia, which are also common components of MS. As estimated, approximately 80% of patients who develop an aortic dissection have hypertension, 31% of patients have atherosclerosis [3][4]. Nevertheless, the role of association diabetes mellitus, obesity, triglyceride and high-density lipoprotein cholesterol in TBAD remains unclear with controversial or scarce research ndings [5].
Metabolic syndrome (MS) is characterized by a cluster of metabolic risk factors including obesity, elevated blood pressure, hyperglycemia, high triglyceride and low high-density lipoprotein cholesterol [6]. However, there is no uniform de nition of MS, even though several diagnostic criteria of MS were proposed in the past few years, including the World Health Organization criteria in 1998, the Evaluation and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III), and the CDS criteria by cooperation group of Chinese diabetes society in 2004, the International Diabetes Federation (IDF) in 2005 and so on [7][8][9][10].
These criteria generally share the similar components although they vary somewhat in some speci c elements. For example, the CDS used body mass index (BMI) rather than waist circumference (WC) to de ne obesity and the cut-offs for other components are different from those in the revised NCEP ATPIII except for the cut-off of triglycerides. The synergistic effect of the components of MS may cause or accelerate the progression of vascular dysregulation. Individuals with MS are at increased risk for developing cardiovascular related diseases, and the relevant had well documented. However, to data, limited information is available on the association of AD with MS and its components. This study collected a relative large sample to evaluate the correlation between MS and AD in TBAD patients.

Participants
For the present study, a cross-sectional evaluation, analyses were based on the screening period of 1 January 2016 to 31 December 2019. Inclusion criteria: patients were initial TBAD and whom complete data were available. Height, weight and blood pressure was measured at admission as well as laboratory test (

De nitions
The CDS criteria (Metabolic syndrome study cooperation group of Chinese diabetes society, 2004) was used to de ne MS in this study. Patients meting three or more of the following conditions were de ned as having the MS. Besides, patients took anti-hypertensive or antidiabetic drugs were considered to satisfy the criteria even though with normal blood pressure or FBG.

Statistical analysis
Continuous variable was expressed as mean ± SD, median and interquartile range according to its distribution. Student t test or nonparametric test were used to examine the difference between two groups. Categorical variable was shown as percentage, and the Chi-square test was used to examine the difference between groups. Multiple Logistic regression analysis was preformed to identify the risk of metabolic syndrome development in TBAD patients. Statistical analyses were performed using IBM SPSS 23.0. The reported p-value was two-tailed, and p 0.05 was considered to be statistically signi cant.

Results
Demographics and baseline characteristics of the study population are summarized in Table 1. A total of 445 patients with con rmed TBAD were included in this study. The overall prevalence of MS was 38.4%. 37.3% in acute TBAD and 40.2% in Chronic TBAD. The mean age was 60±13.6 years, 59.98 ±12.16 in MS group and 60.47±14.44 in Non-MS group. The majority of the patients were male (78.7%). Chest-back pain was the most common syndrome (62.5%). Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were higher in patients with MS than Non-MS (P < 0.001). The mean height and weight were signi cantly (P < 0.001) different between both groups. (P=0.006). Among the MS group the value of lipid related indicators were higher than Non-MS, including total cholesterol, triglyceride, HDL-C and LDL-C. Fasting serum glucose signi cantly (P < 0.001) higher in patients with MS (7.1) than those without metabolic syndrome (5.7). Proportion of patients with elevated serum uric acid levels was signi cantly higher in MS group than in Non-MS (P=0.016). Table 2 displays the prevalence of the MS and its components in TBAD patients. Among those patients, a total of 171(38.4%) were also diagnosed with MS, 103(37.3%) in acute TBAD patients, and 68(40.2%) in chronic TBAD patients. Hypertension was present in 78.2% of all TBAD patients, 69% and 93% in Non-MS and MS patients, respectively. Hypertension, high fasting glucose and obesity were the most common combination of metabolic abnormalities (93%, 79.5% and 63.2%) in the TBAD patients, and a same phenomenon was seen in acute TBAD patients. But among chronic TBAD patients the most frequent individual components were hypertension, hyper-triglyceride and high fasting glucose (92.6%, 75%, and 70.6%).
Presence of two or more components of the metabolic syndrome was common: 22.7% had one component, 31.9% had two components, 24.9% had three components, 10.8% had four components and 3.1% had ve components. (Table 3) Multiple logistic regression showed that the MS was 1.131times more common in acute phage compared to chronic phage (1.131(0.764-1.674)). In TBAD, hypertension, obesity, triglycerides and FBG (fasting blood-glucose) were main risk factors for MS as Table 4 showed.

Discussion
This is the rst cross-sectional study explore the relationship between MS and TBAD with a large sample size. The overall prevalence of MS was 38.4%. 37.3% in acute TBAD and 40.2% in Chronic TBAD. Presence of two or more components of the MS was common in the TBAD patients. Hypertension, high fasting glucose and obesity were the most common combination of metabolic abnormalities.
The prevalence of the metabolic syndrome in abdominal aortic aneurysm (AAA) patients was 45% in study conducted by Jobien et al [11]. In their study, MS was diagnosed according to the Adult Treatment Panel III criteria. Individual variability and the use of different diagnostic criteria for the MS are, at least in part, reasons for differences in prevalence rate. The incidence of MS has regional and demographic characteristics, and we believe that the Chinese standard is more suitable for Chinese population [12][13][14].
Hypertension is an established risk factor of aortic dissection, as estimated that about 80% aortic dissection patients had hypertension, that's why hypertension was the most common component in MS group [15]. The role of associated diabetic conditions in aortic dissection is controversial [16]. Approximate 80% of the patients with type 2 diabetes mellitus, the MS was present. Our results showed FBG was the second frequent component among TBAD patients, which suggested the relationship between diabetes mellitus and TBAD [17]. Several studies showed obesity was related to the prognostic of AD, however limit information about the relationship between TBAD and obesity [18][19]. This study was, however, subject to several limitations. This is a cross-sectional retrospective study that can't draw causal conclusions. In the present study, only taking anti-hypertension and anti-diabetic were included and lipid-lowing drugs was not evaluated. As a result, this may lower the rate of MS in TBAD patients.

Conclusion
This study aimed at the evaluation of the presentation of MS on TBAD patients from a single center admission records. The present study provided the information on the prevalence and components of MS in the initial TBAD patients. The prevalence of MS in the present study was 38%. Previous study showed MS was a risk factor of AAA. The present study observations suggest that hypertension, diabetes mellitus, hypertriglyceridemia, hyperuricemia, and reduced HDL were prominently associated with the increased risk of developing metabolic syndrome in patients with TBAD. Declarations Ethics approval and consent to participate

Abbreviations
The study was approved by the Changhai Hospital medical ethic committee, a liated to Navy Medical University. The study was a retrospective study, samples involved in this study had discharged from our hospital. Then verbal consent was obtained from each subject by telephone consultation and was approved by the Changhai Hospital medical ethics committee.

Consent for publication
Not applicable Availability of data and materials All data generated or analyzed during this study are included in the article.

Competing interests
The authors declare that they have no competing interests.

Funding
This work is supported by the National Natural Science Foundation of China (81700430, the funder is the corresponding author of study) and by Changhai hospital Youth Start-up Fund (CH201804, the funder is the rst author of study). The funding bodies were involved in the study design, data collection, data analysis and formation this article. No relationship with industry, and without competing interests.
Authors' contributions SSL analyzed data and wrote the manuscript. JD and JY contributed to data collection. RLG and RF contributed to the data analysis. JZ and ZPJ contributed to the design and revised the manuscript. All authors read and approved the nal manuscript.
[20] Gorter Petra M,Olijhoek Jobien K,van der Graaf Yolanda et al. Prevalence of the metabolic syndrome in patients with coronary heart disease, cerebrovascular disease, peripheral arterial disease or abdominal aortic aneurysm.    Figure 1 Prevalence of the number of components of the metabolic syndrome in TBAD