Psoriasis is a chronic inflammatory skin disease associated with a higher incidence of major adverse cardiovascular events (MACE).1–9 However, it is necessary to identify easily obtainable metabolic and hematological parameters to predict the development of MACE in clinical practice.10–16

The triglyceride-glucose (TyG) index is a simple indicator of insulin resistance, associated with the development of cardiovascular events that predicts metabolic disorders (e.g., diabetes mellitus) better than its individual components.17–20

The objective of this study is to analyze whether the TyG index is a predictor of MACE in psoriatic patients who required biological or systemic treatment.

We selected patients with psoriasis from the Dermatology Department of Hospital Clínico Universitario de Valencia (Valencia, Spain) with data collected retrospectively from their electronic health records. Psoriatic patients who had received biological or systemic therapy from 2017 through 2022, aged over 18 and under 90, were included. Patients without TyG index information or without repeated annual measurements were excluded.

The primary endpoint of the study was the development of MACE at the follow-up, which included acute myocardial infarction and stroke.

Demographic information and clinical data of the included patients were collected at each visit. Body mass index was calculated as weight in kilograms divided by the square of height in meters. Lab test results, including biochemical values and complete blood count values, were obtained from routine blood tests performed during clinical follow-up. The TyG index was calculated at baseline using the logarithmic product of fasting glucose and serum triglyceride levels divided by 2. The unit of measurement for the TyG index calculation is mg/dL for triglycerides and glucose. The severity of psoriasis in patients was measured using routine clinical scales (PASI, BSA, and DLQI). Systemic or biological therapies received by patients at the time of TyG determination were recorded.

Data from 150 psoriatic patients with a mean age (±standard deviation) of 50.76±13.44 and 58.7% men were recorded. The median follow-up was 17 months (8.75–45.90). At the end of follow-up, a total of 12 MACE (11 acute myocardial infarctions and 1 stroke) were found, resulting in an incidence of 8%.

Age, age at psoriasis diagnosis, and body mass index in men were more likely to increase across TyG index quartiles. The incidence of hypertension, type 2 diabetes, mellitus hyperlipidemia, and chronic obstructive pulmonary disease also increased proportionally in the higher TyG index quartiles. Additionally, higher quartiles showed higher frequencies of positive QuantiFERON tests. Glucose, triglyceride, total cholesterol, and HDL-cholesterol index values increased in proportion to TyG index quartiles. Finally, the incidence of MACE increased significantly in the upper quartiles. Regarding treatments, only statins were increasingly used across TyG index quartiles. Data for each TyG index quartile are shown in Table 1 and Table S1 (see supplementary data).

In the crude Cox regression model, the HR for the highest TyG index quartile was 9.33 (95%CI, 1.1–78.9) (Table S2 of the supplementary data). In none of the models adjusted for statin use, age, age at diagnosis, hypertension, diabetes, dyslipidemia, chronic obstructive pulmonary disease, acute myocardial infarction, and glucose were statistically significant differences in HRs across TyG index quartiles found, taking the 1st quartile as the reference group (Tables S3 and S4 of the supplementary data). However, the HR progressively increased across the higher TyG index quartiles. In the Pearson correlation analysis, no significant correlation was observed between the TyG index and psoriasis severity measured with the PASI index (r=0.085, p>0.05). In the ROC curve analysis, we found an AUC of 0.75 (95%CI, 0.60–0.90, p=0.001) (Fig. 1).

Figure 1.

Receiver-operating characteristic curve for the triglyceride-glucose index model.

(0.23MB).

Psoriasis is a prevalent skin disease associated with an elevated cardiovascular risk.1–4 However, to date, there are no simple biochemical parameters that allow clinicians to establish a cardiovascular risk level in their patients, which would enable them to adapt prevention strategies and adjust treatments.6,7

Recently, Xie et al.19 have published a positive correlation between the TyG index and carotid atherosclerosis in patients with psoriatic arthritis, regardless of traditional cardiovascular risk factors and psoriasis-related factors.

In our study, we found consistent results in terms of patient characteristics and MACE incidence with other published TyG index series to date.10,11 However, no studies have been published specifically analyzing the relationship between the TyG index and the development of MACE in psoriatic patients.

Of note, the incidence of MACE increases statistically significantly (p=0.015) across TyG index quartiles, indicating that this parameter is very likely related to the development of cardiovascular events in psoriatic patients.

Additionally, although we did not find statistical significance in any of the adjusted Cox regression models, all showed an upward trend in HRs across the higher TyG index quartiles. This lack of statistical significance is likely due to the small sample size in our analysis, which is an important limitation of our study and leaves the door open for future studies to confirm this association.

Recently, O’Hagan et al.18 demonstrated that the TyG index correlates with well-established markers of insulin resistance and subclinical atherosclerosis in their cohort of 284 psoriatic patients, concluding that larger studies are needed to evaluate the clinical utility and better understand the relationship of the TyG index with other known risk factors, demonstrating the clinical potential of the TyG index in assessing cardiometabolic risk in psoriasis.

Sánchez-Íñigo et al.17 studied the ability of the TyG index to predict cardiovascular events in a cohort of 5014 healthy patients and concluded that the TyG index – which is a simple and widely used measure – could be useful for early identification of individuals at high risk of developing a cardiovascular event. In their prediction models, they found AUCs of ROC curves of 0.71 (0.68–0.73) for the Framingham model and 0.72 (0.70–0.74) for the Framingham+TyG index model (p=0.014). In our psoriatic population, the result of a significant AUC value of 0.75 (0.61–0.89, p=0.001) is striking and consistent with their results. Therefore, we propose that although the TyG index is a good predictor of MACE in our psoriatic population, it is probably not superior to its value in the general population. Thus, more studies are needed to evaluate its clinical utility in psoriatic patients.

The TyG index is a simple and widely available metabolic parameter useful for predicting cardiovascular events in psoriatic patients. This study highlights the clinical potential of the TyG index for early identification of psoriatic patients at high risk of developing a cardiovascular event.

Leopoldo Fernández Domper was responsible for data collection, manuscript drafting, and literature search and analysis.

María Morales Suarez-Varela was responsible for data analysis, reviewed the manuscript, and approved the final version.

José María Martin Hernández, Jose Antonio Páramo, Leopoldo Fernández Alonso, and Ángeles Revert Fernández reviewed the manuscript and approved the final version.

This study was approved by Hospital Clínico Universitario de Valencia Ethics Committee.

This research was supported by Hospital Clínico Universitario de Valencia Dermatology Department.

None declared.