Subclinical atherosclerosis and metabolic risk: role of body mass index and waist circumference

A Nomogram for Predicting the Risk of Critical Limb Ischemia in Adults with Hypertension: A Retrospective Study

Purpose

Peripheral arterial disease (PAD) presenting with underlying hypertension (HTN) poses a higher risk of bilateral lower limb amputation than PAD patients without HTN. While the role of HTN management of PAD patients has received limited attention. We analyzed the clinical characteristics of PAD in adults with HTN and explored risk factors for PAD to construct a nomogram for evaluating critical limb ischemia (CLI) and lesion severity.

Methods Patients and Methods

Between January 2014 and December 2019, we retrospectively evaluated 1886 patients with peripheral artery disease with coexisting HTN. Patients were randomly divided into training (n = 1320, 70%) and validation cohorts (n = 566, 30%), and according to the subjective experience of PAD [Fontaine classification (I-II vs III-IV)], patients were further classified into intermittent claudication (IC) and CLI groups. LASSO regression and multivariate Cox proportional hazard analyses were used to construct a nomogram using variables defined in the training cohort, which was validated in the validation cohort. The evaluation of the predictive discriminative, accuracy and clinical application are further analyzed.

Results

In the training cohort, optimal independent factors included age, male sex, body mass index, diabetes mellitus, heart rate, triglyceride, and uric acid (AM-BDHTU), which were included in the nomogram predicting the CLI risk (all P < 0.05). The C-index values for CLI risk in PAD with HTN patients were 0.729 (95% CI: 0.704-0.807) and 0.728 (95% CI: 0.652-0.744) in the training and validation sets, respectively. Calibration curves indicated good consistency between predicted and actual outcomes. DCA confirmed the clinical utility of the diagnostic model.

Conclusion

The AM-BDHTU nomogram, constructed and validated using simple to obtain clinical variables, when combined with the Fontaine classification, effectively predicts the risk of CLI among PAD patients with HTN.

An integrative model of cardiometabolic traits identifies two types of metabolic syndrome

Human diseases arise in a complex ecosystem composed of disease mechanisms and the whole-body state. However, the precise nature of the whole-body state and its relations with disease remain obscure. Here we map similarities among clinical parameters in normal physiological settings, including a large collection of metabolic, hemodynamic, and immune parameters, and then use the mapping to dissect phenotypic states. We find that the whole-body state is faithfully represented by a quantitative two-dimensional model. One component of the whole-body state represents ‘metabolic syndrome’ (MetS) – a conventional way to determine the cardiometabolic state. The second component is decoupled from the classical MetS, suggesting a novel ‘non-classical MetS’ that is characterized by dozens of parameters, including dysregulated lipoprotein parameters (e.g. low free cholesterol in small high-density lipoproteins) and attenuated cytokine responses of immune cells to ex vivo stimulations. Both components are associated with disease, but differ in their particular associations, thus opening new avenues for improved personalized diagnosis and treatment. These results provide a practical paradigm to describe whole-body states and to dissect complex disease within the ecosystem of the human body.

Hypertriglyceridemic Waist: A Simple Marker of High-Risk Atherosclerosis Features Associated With Excess Visceral Adiposity/Ectopic Fat

Background

Subclinical atherosclerosis identification remains challenging; abdominal visceral adiposity may improve risk stratification beyond traditional cardiovascular risk factors. Hypertriglyceridemic waist, a visceral adiposity marker combining elevated triglycerides (≥2 mmol/L) and waist circumference (≥90 cm), has been related to carotid atherosclerosis, although associations with high‐risk features, including lipid‐rich necrotic core (LRNC), remain unknown. We tested the hypothesis that hypertriglyceridemic waist is an independent marker of high‐risk atherosclerosis features.

Methods and Results

In this cross‐sectional study including 467 white men (mean age, 45.9±14.8 years; range 19.4–77.6 years), carotid atherosclerosis characteristics were examined by magnetic resonance imaging and associations with hypertriglyceridemic waist and benefits beyond Framingham Risk Score (FRS) and Pathobiological Determinants of Atherosclerosis in Youth (PDAY) were determined. Subclinical carotid atherosclerosis was present in 61.9% of participants, whereas 50.1% had LRNC. Hypertriglyceridemic waist was associated with carotid maximum wall thickness (P=0.014), wall volume (P=0.025), normalized wall index (P=0.004), and Carotid Atherosclerosis Score (derived from wall thickness and LRNC; P=0.049). Hypertriglyceridemic waist was associated with carotid LRNC volume beyond FRS (P=0.037) or PDAY (P=0.015), contrary to waist circumference alone (both P>0.05). Although 69.7% and 62.0% of participants with carotid atherosclerosis and/or LRNC were not high‐risk by FRS or PDAY, respectively, hypertriglyceridemic waist correctly reclassified 9.7% and 4.5% of them, respectively. Combining hypertriglyceridemic waist with FRS (net reclassification improvement=0.17; P<0.001) or PDAY (net reclassification improvement=0.05; P=0.003) was superior to each score alone in identifying individuals with carotid atherosclerosis and/or LRNC.

Conclusions

Hypertriglyceridemic waist is an independent marker of carotid high‐risk atherosclerosis features in men, improving on FRS and PDAY risk score.

The association between various indices of obesity and severity of atherosclerosis in adults in the north of Iran

Recent observational studies have reported controversial results for the association between different anthropometric indices of obesity and severity of atherosclerosis. The aim of the current study is to determine the associations between anthropometric indices with severity of atherosclerosis in adult population in north of Iran.The cross-sectional study was performed on 610 participants, who were admitted to a hospital for elective angiographyin Rasht, Iran, Anthropometric indices, including waist circumference (WC), waist-to-height ratio (WHtR), conicity index (CI), body mass index (BMI), and hematological factors, were measured using the standard methods. According to angiography reports, severity of atherosclerosis was determined.Sixty-two percent of participants had moderate to severe atherosclerosis. According to BMI, 44% were overweight and 25.8% were obese. Based on WHtR and WC, 90%, and 57% were obese, respectively. The prevalence of moderate to severe atherosclerosis in centrally obese women was significantly higher than in centrally nonobese women (52% vs 28% P = 0.02). According to multivariate adjustment analysis, age, sex, systolic blood pressure, hemoglobin A1c, uric acid, and triglyceride were independently associated with severity of atherosclerosis. BMI, WC, CI, and WHtR had no significant association with severity of atherosclerosis.Our findings showed that anthropometric indices reflective of general and abdominal obesity were not independently related to the severity of atherosclerosis in adults, in northern Iran.

Metabolic fuel utilization and subclinical atherosclerosis in overweight/obese subjects

The utilization of different macronutrients is relevant for the risk of obesity, diabetes, or the appearing of vascular complications. The Respiratory Quotient (RQ) is a parameter measuring the fuel utilizations; in fact, it can indicate the fat stores utilization or lipogenesis activation. Aim of this study was to investigate the link between the RQ and the subclinical carotid atherosclerosis presence in overweight/obese subjects. 132 subjects with body mass index at least 25, at conventional diet, underwent an Indirect Calorimetry for the measurement of the Resting Metabolic Rate as well as the RQ and an evaluation of carotid arteries with ultrasound. Biochemical analyses were also performed. The mean age was 48 ± 12 years. There was a positive relation between carotid intima-media thickness and RQ (p = 0.010), with the high value in the subgroup with high RQ (p = 0.045 vs. group with low RQ). The RQ, an index of fuel utilization, is positively associated to subclinical carotid atherosclerosis in overweight/obese individuals.