Association of ultra-processed food consumption with cardiovascular risk factors among patients with type-2 diabetes mellitus

Type-2 diabetes mellitus (T2DM) is a major global health concern, significantly increasing the risk of cardiovascular diseases (CVDs) due to comorbidities like hypertension and hyperlipidemia. Unhealthy lifestyles and diets contribute significantly to T2DM and CVD prevalence. Ultra-processed foods (UPFs), characterized by high energy density and low nutrient content, are increasingly linked to various health problems, including diabetes and CVDs. The NOVA classification system categorizes foods based on the extent of processing, with UPFs representing those undergoing extensive industrial processing. Numerous studies have associated higher UPF consumption with increased risks of diabetes, CVDs, obesity, and hypertension. While previous research has explored the link between UPFs and CVD risk in general populations, limited research has focused on the high-risk T2DM population. This study aimed to address this gap by investigating the association between UPF consumption and novel CVD risk factors, including Castelli risk indices (CRI-I and II), the atherogenic index of plasma (AIP), lipid accumulation product (LAP), and cholesterol index (CI), as well as anthropometric indices like body shape index (ABSI), body roundness index (BRI), and abdominal volume index (AVI), in a cohort of T2DM patients.

Existing literature extensively documents the negative health consequences associated with high consumption of ultra-processed foods (UPFs). Studies consistently demonstrate a link between UPF intake and an increased risk of developing type-2 diabetes mellitus (T2DM) and cardiovascular diseases (CVDs). These studies often highlight the high energy density and low nutrient profile of UPFs as contributing factors. The NOVA classification system, widely used to categorize foods based on processing levels, provides a framework for understanding the potential health impacts of different food groups. Research suggests that UPFs contribute to hypertriglyceridemia, reduced high-density lipoprotein (HDL) cholesterol, and elevated low-density lipoprotein (LDL) cholesterol. In addition to these established CVD risk factors, research has also investigated the association between UPF consumption and emerging risk indicators such as the Castelli risk indices (CRI-1 and CRI-2), the atherogenic index of plasma (AIP), lipid accumulation product (LAP), and cholesterol index (CI). Anthropometric indicators like body shape index (ABSI), body roundness index (BRI), and abdominal volume index (AVI) have also been linked to cardiovascular risk. However, a comprehensive study examining the relationship between UPF consumption and these novel CVD risk factors specifically in T2DM patients remained lacking before this study, highlighting a significant research gap in this high-risk population.

This cross-sectional study enrolled 490 type-2 diabetes mellitus (T2DM) patients aged 35–80 years from the Endocrine and Metabolism Research Institute's diabetes research center. Participants were recruited between May 2021 and September 2022. Exclusion criteria included insulin use, pregnancy/breastfeeding, estrogen hormone therapy, autoimmune diseases, acute gastrointestinal or renal diseases, liver cancer, or dietary energy reports outside the 800-4200 kcal/day range. Data collection involved a validated 168-item semi-quantitative food frequency questionnaire (FFQ) to assess dietary intake, with UPF consumption categorized using the NOVA classification. Cardiovascular risk factors (CRI-I, CRI-II, AIP, LAP, CI) were calculated from laboratory test results (LDL-C, HDL-C, total cholesterol, triglycerides). Anthropometric measurements (weight, height, waist circumference, hip circumference) were taken to calculate BMI, ABSI, BRI, and AVI. Socioeconomic status was assessed using a dedicated questionnaire. Statistical analysis involved classifying subjects into UPF consumption tertiles, comparing baseline variables across tertiles using ANOVA and chi-square tests, and exploring associations between UPF consumption and CVD risk factors/anthropometric indices using linear and binary logistic regression. The linear regression models were adjusted for energy intake, socioeconomic status, age, sex, and smoking. Binary logistic regression analyzed categorical risk factors and indices. SPSS version 26 was used for all analyses, with p<0.05 considered statistically significant.

The study population consisted predominantly of females (59%) with a mean age of 62.6 ± 9.8 years. Significant differences were observed across UPF consumption tertiles for age, sex, socioeconomic status, smoking status, and several biochemical and anthropometric indices. Specifically, higher UPF consumption tertiles were associated with higher total cholesterol (TC) levels (p=0.03), CRI-I (p=0.03), and CRI-II (p=0.05). Significant increases were also observed in weight, BMI, waist circumference (WC), and AVI (p<0.05 for all). Linear regression analysis revealed that each 20-gram increase in UPF consumption was associated with a significant elevation in serum TC levels [B (SE): 1.214 (0.537); 95% CI: 0.159–2.269] and a non-significant decrease in HDL levels in the fully adjusted model. In the crude model, increases in UPF intake were associated with significant increases in CRI-1, CRI-2, and AIP. Tertile analysis showed significant associations between the highest UPF consumption tertile and various CVD risk factors and anthropometric indices, even for some indices not significant in the linear regression with 20g increments. Logistic regression further revealed significant associations between UPF tertiles and certain risk factors, such as AVI, further emphasizing the influence of UPF consumption on CVD risk. Dietary intake analysis indicated that the highest tertile consumed significantly higher amounts of UPFs (117.37 g/day), with higher percentages of energy from UPFs (12.94%) compared to lower tertiles.

This study provides evidence supporting a strong association between higher ultra-processed food (UPF) consumption and increased cardiovascular disease (CVD) risk in type-2 diabetes mellitus (T2DM) patients. The findings demonstrate a dose-response relationship, with the highest UPF consumption tertile exhibiting significantly elevated CVD risk factors compared to lower tertiles. The significant association between UPF intake and total cholesterol (TC), along with the trends observed in other CVD risk indices, highlights the potential mechanisms linking UPF consumption to adverse lipid profiles. While the study observed significant associations with certain anthropometric indices in higher tertiles, these associations were not consistently demonstrated in the linear regression model using a 20g increment. This difference may stem from the different sensitivity of linear and logistic models or from non-linear associations which could be captured better by tertile analysis. The inconsistencies among different analyses and with other studies in the literature may also be related to the confounding effects of medication and existing chronic diseases on the lipid profile of the patients, highlighting the unique challenges of studying CVD risk factors in a T2DM population. Future longitudinal studies are crucial to confirm causality and to further investigate the complex interplay between UPF consumption, lifestyle factors, and CVD risk in T2DM patients.

This study's findings underscore the importance of reducing ultra-processed food (UPF) consumption in managing cardiovascular disease (CVD) risk among type-2 diabetes mellitus (T2DM) patients. The observed associations between increased UPF intake and unfavorable lipid profiles and anthropometric indices highlight the need for dietary interventions focused on limiting UPF consumption. Future prospective studies are warranted to definitively establish causality and further elucidate the underlying mechanisms connecting UPF intake to CVD risk in this high-risk population. Further research should also explore the effectiveness of dietary interventions targeting UPF reduction in improving cardiovascular health outcomes in T2DM patients.

The cross-sectional nature of this study limits the ability to establish causality. The reliance on self-reported dietary data through a food frequency questionnaire (FFQ) may introduce recall bias. The influence of medication on lipid profiles in the T2DM patients could have masked some associations, and the sample may not be fully representative of all T2DM populations.