Egg and Dietary Cholesterol Consumption and the Prevalence of Metabolic Syndrome: Findings from a Population-Based Nationwide Cohort

The Association Between Egg and Egg-Derived Cholesterol Consumption, and Their Change Trajectories, with Obesity Among Chinese Adults: Results from the China Health and Nutrition Survey

Background/Objectives: As a widely consumed, nutritious, and affordable food, eggs and their derivatives' impacts on obesity remain inconclusive. In this study, we aimed to determine the association between egg and egg-derived cholesterol consumption, and their change trajectories, with obesity among Chinese adults. Methods: Longitudinal data collected by the China Health and Nutrition Survey from 1997 to 2015 were analyzed. The latent growth mixture model was used to identify eggs and egg-derived cholesterol consumption trajectories. Cox proportional hazard models with shared frailty were used to analyze the association between egg and egg-derived cholesterol consumption, and their change trajectories, with obesity. Results: Data from 10,971 and 9483 participants aged ≥18 years old were used for the analyses of general obesity and central obesity, respectively. Compared to participants with an average egg intake of 0.1-50.0 g/d during the follow-up period, adults who never consumed eggs or those with an average egg intake of 50.1-100.0 g/d and >100.0 g/d had a higher risk of general obesity, with hazard ratios (HRs) and 95% confidence intervals (CIs) of 1.31 (1.08, 1.58), 1.30 (1.07, 1.60), and 1.98 (1.17, 3.35), respectively, and had a higher risk of central obesity, with HRs (95% CIs) of 1.17 (1.04, 1.31), 1.31 (1.14, 1.50), and 1.64 (1.15, 2.36), respectively. Participants with a "Baseline Low-Significant Rising Pattern" or a "Baseline High-Rising then Falling Pattern" of egg consumption trajectories during the follow-up period had a higher risk of general obesity, with HRs (95% CIs) of 1.56 (1.25, 1.93) and 1.38 (1.13, 1.69), respectively, and central obesity, with HRs (95% CIs) of 1.47 (1.29, 1.68) and 1.52 (1.34, 1.72), respectively. Compared to the second quartile (Q2) group of the average egg-derived cholesterol intake during the follow-up period, Q1, Q3, and Q4 groups had a higher risk of general obesity, with HRs (95% CIs) of 1.28 (1.06,1.54), 1.21 (1.02, 1.44), and 1.43 (1.19, 1.71), respectively, and a higher risk of central obesity, with HRs (95% CIs) of 1.20 (1.08, 1.33), 1.11 (1.01, 1.23), and 1.32 (1.19, 1.46), respectively. Participants with a "Baseline Low-Significant Rising Pattern" or with a "Baseline High-Rising then Falling Pattern" of egg-derived cholesterol consumption during the follow-up period had a higher risk of general obesity, with HRs (95% CIs) of 1.54 (1.25, 1.92) and 1.37 (1.15, 1.64), respectively, and a higher risk of central obesity, with HRs (95% CIs) of 1.46 (1.28, 1.68) and 1.47 (1.32, 1.64), respectively. Conclusions: Both the insufficient and excessive intake of eggs and egg-derived cholesterol tended to be associated with a higher risk of general and central obesity. Suddenly increasing or consistently high levels of egg and egg-derived cholesterol intake seemed to be associated with a higher risk of obesity. To prevent obesity, people should consume a moderate amount of eggs and egg-derived cholesterol.

Influence of dietary cholesterol on metabolic syndrome risk in middle-aged Korean adults: using the Korean Genome and Epidemiology Study (KoGES)

BACKGROUND

The association between dietary cholesterol and metabolic diseases remains controversial. However, the majority of studies focus on egg intake, and there is a limitation in the availability of prospective cohort studies. Our study examined the association between dietary cholesterol and the incidence risk of metabolic syndrome (MetS) in middle aged adults using large prospective cohort study in Republic of Korea.

METHODS

The Health Examinees cohort from the Korean Genome and Epidemiology Study was used from baseline to follow-up. Dietary cholesterol intake was assessed by the validated semi-quantitative food frequency questionnaire. Participants were classified as quintile groups according to adjusted dietary cholesterol for total energy intake. MetS was defined as more than 3 of the 5 components of MetS. Hazard ratio (HR) and 95% confidence intervals (CI) for MetS were evaluated by multivariable cox regression analyses.

RESULTS

Of the total 40,578 participants, metabolic syndrome developed in 4,172 (10.28%) individuals during an average follow-up period of approximately 4.76 years. Dietary cholesterol did not exhibit a significant association with the risk of MetS after adjusting for potential confounding factors, but a trend was observed indicating an increased risk with higher intake (p for trend = 0.044). Among the components of MetS, the incidence risk of high waist circumference (HR: 1.164, 95% CI: 1.049-1.290), high blood pressure (HR: 1.188, 95% CI: 1.075-1.313), high serum triglyceride (HR: 1.132, 95% CI: 1.044-1.227) and high fasting blood glucose (HR: 1.217, 95% CI: 1.132-1.308) in the group that consumed the highest dietary cholesterol intake was increased compared with the group that consumed the lowest dietary cholesterol intake. Dose-response relationship suggested a positive linear association between dietary cholesterol intake and the risk of high waist circumference (p-linearity = 0.004), blood pressure (p-linearity = 0.012), and triglycerides (p-linearity = 0.005).

CONCLUSION

This study suggests a positive association between dietary cholesterol intake and the risk of MetS and its components (abdominal obesity, hypertension, hypertriglyceridemia, and hyperglycemia) in middle-aged Korean adults.

Machine Learning Identification of Nutrient Intake Variations across Age Groups in Metabolic Syndrome and Healthy Populations

This study undertakes a comprehensive examination of the intricate link between diet nutrition, age, and metabolic syndrome (MetS), utilizing advanced artificial intelligence methodologies. Data from the National Health and Nutrition Examination Survey (NHANES) spanning from 1999 to 2018 were meticulously analyzed using machine learning (ML) techniques, specifically extreme gradient boosting (XGBoost) and the proportional hazards model (COX). Using these analytic methods, we elucidated a significant correlation between age and MetS incidence and revealed the impact of age-specific dietary patterns on MetS. The study delineated how the consumption of certain dietary components, namely retinol, beta-cryptoxanthin, vitamin C, theobromine, caffeine, lycopene, and alcohol, variably affects MetS across different age demographics. Furthermore, it was revealed that identical nutritional intakes pose diverse pathogenic risks for MetS across varying age brackets, with substances such as cholesterol, caffeine, and theobromine exhibiting differential risks contingent on age. Importantly, this investigation succeeded in developing a predictive model of high accuracy, distinguishing individuals with MetS from healthy controls, thereby highlighting the potential for precision in dietary interventions and MetS management strategies tailored to specific age groups. These findings underscore the importance of age-specific nutritional guidance and lay the foundation for future research in this area.

Nutrient patterns in relation to metabolic health status and serum levels of brain-derived neurotrophic factor (BDNF) and adropin in adults

The present study aimed to investigate the association of nutrient patterns (NPs) with metabolic health status and serum levels of brain-derived neurotrophic factor (BDNF) and adropin in Iranian adults. This cross-sectional survey was performed on 527 adults aged 20-60 years in Isfahan, Iran. To evaluate dietary intake, a validated 168-item semi-quantitative food frequency questionnaire (FFQ) was used. Participants were categorized as metabolically healthy (MH) and metabolically unhealthy (MU) according to their glycemic and lipid profile, insulin resistance (IR), and inflammation status. An overnight fasting blood sample was collected from each participant and serum levels of BDNF and adropin were assessed. A total of 42.50% of participants were recognized as MU. Three NPs were recognized by factor analysis that labeled as "high animal protein" (NP1), "high vegetable" (NP2), and "high carbohydrate" (NP3) patterns. Moderate adherence to NP2 was related to a lower risk of MU (ORT2 vs. T1 = 0.38, 95% CI: 0.18-0.76). Moreover, high adherence of NP2 (T3 vs. T1) was inversely associated with hypertriglyceridemia (OR = 0.27, 95% CI: 0.11-0.65; P-trend < 0.001) and high hs-CRP values (OR = 0.29, 95% CI: 0.09-1.00; P-trend = 0.03). No significant association was observed between adherence of NP1 and NP3 with MU in crude and adjusted models. However, negative associations were found between moderate adherence to NP3 and insulin resistance (IR) (OR = 0.23, 95% CI: 0.06-0.91) as well as high adherence to NP1 and hypertension (OR = 0.23, 95% CI: 0.09-0.61; P-trend < 0.001). NPs were not associated with serum BDNF and adropin values.

Association between Dietary Patterns and Metabolic Syndrome and Modification Effect of Altitude: A Cohort Study of Tibetan Adults in China

Little is known about the longitudinal association between dietary patterns (DPs) and metabolic disorders in people living at high altitude areas, such as Tibetans. We constructed the first open cohort, with 1832 Tibetans, and collected data in 2018 and in 2022. The metabolic syndrome (MetS) prevalence was 30.1% (32.3% in men and 28.3% in women). Three different DPs were identified: modern DP (pulses, poultry, offal, and processed meat), urban DP (vegetables, refined grain, beef/mutton, and eggs), and pastoral DP (Tibetan cheese, tsamba, butter/milk tea, and desserts). Participants within the third tertile of the urban DP had a 3.42-fold (95% CI 1.65-7.10) higher risk of MetS than those with the first tertile. Modern DP was positively associated with elevated blood pressure (BP) and elevated triglycerides (TAG), while it was inversely associated with low HDL-C. The urban DP was associated with a higher risk of low HDL-C, but a lower risk of impaired fasting blood glucose (FBG). The pastoral DP was a risk factor for impaired FBG, but protective for central obesity and elevated BP. Associations of modern DP with elevated BP, and pastoral DP with low HDL-C, were modified by altitude. In conclusion, among Tibetan adults, DPs were associated with MetS and its components, and the associations were modified by altitude among Tibetans.

Association of egg intake with risks of cardiometabolic factors among adults in China

Objective

To explore the association between egg intake and cardiometabolic factors (CMFs) in Chinese adults.

Method

The subjects were 6,182 adults aged 18-64 who had complete survey data and had no CMFs at baseline. Egg intake was assessed with 3 days-24 h dietary recalls in all waves of the China Health and Nutrition Survey (CHNS). Multivariate Cox proportional risk regression model and restricted cubic spline (RCS) model were used to analyze the association and dose-response relationship between egg intake and CMFs.

Results

Of the 6,182 participants who did not have metabolic syndrome (MetS) at baseline, 1,921 developed this disease during an average follow-up of 5.71 years, with an incidence of 31.07%. Central obesity, elevated TG, decreased HDL-C, elevated blood pressure and elevated plasma glucose were 38.65, 26.74, 30.21, 40.64, and 30.64%, respectively. After adjusting for demographic characteristics, lifestyle, energy and BMI, using the lowest quintile (Q1) as a reference, the risk of central obesity, elevated TG, decreased HDL-C, and elevated plasma glucose in the highest quintile (Q5) were reduced by 15% (HR = 0.85, 95% CI = 0.73-0.98, P = 0.16), 33% (HR = 0.67, 95% CI = 0.57-0.78), 25% (HR = 0.75, 95% CI = 0.63 0.90, p = 0.05), and 28% (HR = 0.72, 95% CI = 0.63-0.83, p < 0.05), respectively. The risk of elevated blood pressure was reduced by 26% in the fourth quintile (HR = 0.74, 95% CI = 0.64-0.85, P = 0.85). RCS analysis show that the overall correlation and nonlinear relationship between egg intake and CMFs were statistically significant (P < 0.05). When the intake was lower than 20 g/days, the risk of MetS, central obesity, elevated blood pressure and elevated plasma glucose were negatively correlated with egg intake, while elevated TG was negatively correlated with eggs when the intake was lower than 60 g/days. There was no statistically significant association between egg intake and CMFs at higher egg intake.

Conclusion

There was a U-shaped association between egg intake and CMFs in Chinese adults.