Anti-ApoA-1 IgG has emerged as a noteworthy biomarker associated with cardiovascular disease (CVD) and mortality [19]. Several studies stated that anti-ApoA-1 autoantibodies may be present in the general population but in low titers (up to 6.5%) and may be related to the vascular and immune aging processes [16].

Our study focused on a cohort of Egyptian obese patients to investigate the impact of metabolic bariatric surgery on the follow-up 12 months postoperatively on anti-apolipoprotein A-1 (anti-ApoA-1 IgG) auto-antibody titers and associated changes in lipid parameters.

Based on our findings, there was a reduction in the number of seropositive patients from 28 (38.9%) preoperatively to 8 (11.1%) postoperatively. Moreover, there was an overall significant statistical postoperative reduction in anti-apolipoprotein A-1 antibody levels. This trend aligned with the results of a study conducted by Adam et al. [20] and Adam et al. [21]. However, the prevalence of autoantibody positivity status at baseline in our study (38.9%) was greater than that conducted by Adam et al. (2022), which was 25%.

The study showed that the individuals with positive autoantibody status exhibited significantly lower baseline body weight and were younger. Notably, our findings indicate a higher %TWL in patients who tested negative for autoantibodies postoperatively compared to those who tested positive, although it was not statistically significant.

Also, patients who were anti-ApoA-1 antibody seropositive showed a significant preoperative increase in LDL-C (P-value = 0.023) and a postoperative increase in systolic blood pressure and total cholesterol (P-value = 0.003, 0.024), respectively. These findings suggested a higher cardiovascular risk in individuals with positive autoantibody status.

Interestingly, in the current study, CRP levels were higher in patients whose antibody status was positive (16.54 ± 3.56) compared to negative (6.95 ± 2.92) with preoperative statistical significance (P-value =  < 0.001). However, postoperative CRP levels showed no statistical significance (P-value = 0.050).

CRP has been used as a biomarker of cardiovascular risk. At CVD risk, individuals can be classified according to the level of CRP into three groups: (1) low risk when CRP levels are below 1 mg/L, moderate risk when CRP levels are between 1 and 3 mg/L, and high risk when CRP levels exceed 3 mg/L [22, 23].

Several studies investigated the impact of MBS on cardiovascular risk by examining various cardiovascular biomarkers. It is known that obesity alters HDL metabolism, affecting ApoA-1 [24], and this could explain the presence of anti-ApoA-1 antibodies and therefore increased CVD risk.

In the present study, we assumed that MBS was responsible for the reduction in anti-ApoA-1 antibody levels with significant improvements in blood pressure, BMI, insulin resistance, hyperglycemia, inflammation, and the lipid profile, which supported the idea that MBS induces positive changes in cardiovascular biomarkers, resulting in a healthier lipid profile and reduced cardiovascular risk, as demonstrated in the studies by Adam et al. (21), Gómez et al. [24], Farias et al. [25], Doumouras et al. [26], and Adam et al. [21].

We demonstrated, at baseline, a positive correlation between anti-ApoA-1 IgG levels on one side and total cholesterol, LDL-C, total cholesterol to HDL ratios, non-HDL cholesterol, and CRP on the other side. However, there was a positive correlation between anti-ApoA-1 antibodies and total cholesterol.

A study by Bridge et al. [27] determined that the correlation analysis showed an inverse relationship between anti-ApoA-1 autoantibody responses and total cholesterol concentration (r =  − 0.32; p = 0.005) in HCV patients, in contrast to ours, which showed a positive correlation between anti-ApoA-1 IgG levels on one side and total cholesterol pre- and postoperatively. Moreover, the study agreed with our study that there is no correlation between anti-ApoA-1 antibodies and TG/HDL-C. However, in contrast to ours, it showed no correlation between total cholesterol to HDL ratios and anti-ApoA-1 antibodies.

Our results showed partial agreement with Adam et al. [18], which stated no correlation was found between anti-ApoA-1 IgG and lipid profile. Another study by Antiochos et al. [10] showed an inverse correlation between anti-ApoA-1 IgG and HDL-C; however, we showed no correlation between them.

Our study demonstrated a positive correlation with the % change before and after surgery between anti-ApoA-1 antibodies and triglycerides, while no significant correlation was observed with % change between anti-ApoA-1 antibodies and other parameters such as BMI, systolic and diastolic blood pressure, total cholesterol, HDL-C, LDL-C, TG-Gly index, TG/HDL ratio, total cholesterol to HDL, HBA1C, fasting glucose, HOMA-IR, and CRP.

These results demonstrated an association between anti-ApoA-1 autoantibodies and cardiovascular risk, and these are consistent with El-Lebedy et al. [16], who demonstrated this association in diabetic patients.

It is worth noting that the current study demonstrated a positive correlation between HOMA-IR and TG-Gly index preoperatively and postoperatively. In accordance with these findings, a study by Liu et al. [28] showed an elevation of the TyG index with a more severe IR, and a study by Hegab et al. [29] demonstrated a significant association between the TG-Gly index and HOMA-IR and might be applied as eligible indices of IR among overweight and/or obese Egyptians.