European Journal of Cardiovascular Medicine

Metabolic Syndrome (MetS) is a cluster of interrelated metabolic abnormalities that significantly increase the risk of cardiovascular disease (CVD), type 2 diabetes mellitus (T2DM), and all-cause mortality worldwide. It is characterized by central obesity, dyslipidemia, hypertension, and insulin resistance or glucose intolerance. The prevalence of MetS is rapidly increasing globally, driven mainly by urbanization, sedentary lifestyles, unhealthy dietary habits, and rising obesity rates. This escalating burden of MetS poses a substantial challenge to public health systems, particularly in developing countries where healthcare resources may be limited.^[1]

Dyslipidemia is a core component of MetS and plays a pivotal role in the pathogenesis of atherosclerosis and cardiovascular complications. Typically, the lipid abnormalities associated with MetS include elevated triglycerides (TG), reduced high-density lipoprotein cholesterol (HDL-C), increased low-density lipoprotein cholesterol (LDL-C), and often increased total cholesterol (TC). The altered lipid profile seen in MetS patients promotes endothelial dysfunction, inflammation, and oxidative stress, thereby accelerating vascular damage and increasing cardiovascular risk.^[2]

Understanding the lipid profile abnormalities in patients with MetS is essential for early diagnosis, risk stratification, and management. Numerous studies have demonstrated that targeting dyslipidemia in MetS patients can substantially reduce the incidence of cardiovascular events and improve patient outcomes. However, the pattern and severity of lipid abnormalities may vary depending on genetic predisposition, lifestyle factors, and ethnic differences, which necessitates population-specific studies.^[3]

Comparative cross-sectional studies between individuals with MetS and healthy controls help to delineate the extent and nature of lipid abnormalities attributable to MetS. Such studies also aid clinicians in tailoring treatment strategies aimed at correcting lipid derangements and preventing adverse cardiovascular outcomes. Despite the recognized significance of lipid abnormalities in MetS, there remains a need for more detailed epidemiological data, particularly in the Indian population, where MetS prevalence is rising and the phenotype may differ from Western populations.^[4]

The pathophysiology of lipid abnormalities in MetS involves complex interactions between adipose tissue, insulin resistance, and lipid metabolism pathways. Insulin resistance impairs the activity of lipoprotein lipase, an enzyme responsible for hydrolyzing triglycerides in lipoproteins, leading to hypertriglyceridemia. Additionally, insulin resistance is associated with increased hepatic production of very-low-density lipoprotein (VLDL) particles and reduced clearance of LDL, resulting in atherogenic dyslipidemia. Low HDL cholesterol levels, another hallmark of MetS, reduce reverse cholesterol transport and further increase atherosclerotic risk.^[5]

Aim

To compare lipid profile abnormalities between metabolic syndrome patients and healthy controls in a cross-sectional study.

Objectives

1. To assess the levels of serum total cholesterol, triglycerides, LDL cholesterol, and HDL cholesterol in metabolic syndrome patients.
2. To compare the lipid profile parameters of metabolic syndrome patients with age- and sex-matched healthy controls.
3. To determine the prevalence of dyslipidemia among patients diagnosed with metabolic syndrome.

Source of Data: The data for this study were collected from patients attending the outpatient and inpatient departments, who were diagnosed with metabolic syndrome based on standardized criteria. Healthy controls were recruited from the general population matched for age and sex.

Study Design: This was a comparative cross-sectional study conducted to analyze and compare the lipid profiles of metabolic syndrome patients and healthy controls.

Study Location: The study was carried out at the Department of Biochemistry and affiliated clinical departments of Tertiary Medical College.

Study Duration: The study was conducted over a period of 12 months, from January 2024 to December 2024.

Sample Size: A total of 200 participants were enrolled, including 100 diagnosed metabolic syndrome patients and 100 age- and sex-matched healthy controls.

Inclusion Criteria:

• Patients aged between 30 and 65 years.
• Diagnosed with metabolic syndrome as per the International Diabetes Federation (IDF) criteria.
• Willing to provide informed consent.
• Controls without metabolic syndrome or related comorbidities.

Exclusion Criteria:

• Patients on lipid-lowering therapy or other medications affecting lipid metabolism.
• Known cases of hypothyroidism, nephrotic syndrome, liver disease, or other chronic systemic illnesses.
• Pregnant or lactating women.
• Patients with a history of alcohol abuse or substance use.

Procedure and Methodology: After obtaining informed consent, a detailed clinical history and physical examination were performed. Metabolic syndrome diagnosis was confirmed using IDF criteria which include central obesity plus any two of the following: raised triglycerides ≥150 mg/dL, reduced HDL cholesterol (<40 mg/dL in males, <50 mg/dL in females), raised blood pressure (≥130/85 mmHg), and raised fasting plasma glucose (≥100 mg/dL).

Venous blood samples were collected from all participants after an overnight fast of 10-12 hours. Samples were allowed to clot and then centrifuged to separate serum for biochemical analysis. Serum lipid profile parameters measured included total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C). LDL-C was calculated using the Friedewald formula when triglyceride levels were below 400 mg/dL.

Sample Processing: Serum samples were analyzed using enzymatic colorimetric methods on an automated biochemical analyzer [Model and Manufacturer]. Quality control was maintained by running standard controls with each batch of samples. Lipid parameters were interpreted according to the guidelines provided by the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III).

Statistical Methods: Data were entered and analyzed using SPSS version 24.0 (IBM Corp.). Continuous variables were expressed as mean ± standard deviation (SD), and categorical variables as percentages. Comparisons between metabolic syndrome patients and controls were performed using Student’s t-test for continuous variables and Chi-square test for categorical variables. A p-value of less than 0.05 was considered statistically significant.

Data Collection: All clinical, demographic, and biochemical data were recorded on a pre-designed proforma by trained investigators. Patient confidentiality was maintained throughout the study. Data were double-checked for accuracy and completeness prior to analysis.

Source of Data: The data for this study were collected from patients attending the outpatient and inpatient departments, who were diagnosed with metabolic syndrome based on standardized criteria. Healthy controls were recruited from the general population matched for age and sex.

Study Design: This was a comparative cross-sectional study conducted to analyze and compare the lipid profiles of metabolic syndrome patients and healthy controls.

Study Location: The study was carried out at the Department of Biochemistry and affiliated clinical departments of Tertiary Medical College.

Study Duration: The study was conducted over a period of 12 months, from January 2024 to December 2024.

Sample Size: A total of 200 participants were enrolled, including 100 diagnosed metabolic syndrome patients and 100 age- and sex-matched healthy controls.

Inclusion Criteria:

• Patients aged between 30 and 65 years.
• Diagnosed with metabolic syndrome as per the International Diabetes Federation (IDF) criteria.
• Willing to provide informed consent.
• Controls without metabolic syndrome or related comorbidities.

Exclusion Criteria:

• Patients on lipid-lowering therapy or other medications affecting lipid metabolism.
• Known cases of hypothyroidism, nephrotic syndrome, liver disease, or other chronic systemic illnesses.
• Pregnant or lactating women.
• Patients with a history of alcohol abuse or substance use.

Procedure and Methodology: After obtaining informed consent, a detailed clinical history and physical examination were performed. Metabolic syndrome diagnosis was confirmed using IDF criteria which include central obesity plus any two of the following: raised triglycerides ≥150 mg/dL, reduced HDL cholesterol (<40 mg/dL in males, <50 mg/dL in females), raised blood pressure (≥130/85 mmHg), and raised fasting plasma glucose (≥100 mg/dL).

Venous blood samples were collected from all participants after an overnight fast of 10-12 hours. Samples were allowed to clot and then centrifuged to separate serum for biochemical analysis. Serum lipid profile parameters measured included total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C). LDL-C was calculated using the Friedewald formula when triglyceride levels were below 400 mg/dL.

Sample Processing: Serum samples were analyzed using enzymatic colorimetric methods on an automated biochemical analyzer [Model and Manufacturer]. Quality control was maintained by running standard controls with each batch of samples. Lipid parameters were interpreted according to the guidelines provided by the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III).

Statistical Methods: Data were entered and analyzed using SPSS version 24.0 (IBM Corp.). Continuous variables were expressed as mean ± standard deviation (SD), and categorical variables as percentages. Comparisons between metabolic syndrome patients and controls were performed using Student’s t-test for continuous variables and Chi-square test for categorical variables. A p-value of less than 0.05 was considered statistically significant.

Data Collection: All clinical, demographic, and biochemical data were recorded on a pre-designed proforma by trained investigators. Patient confidentiality was maintained throughout the study. Data were double-checked for accuracy and completeness prior to analysis.

Table 1: Demographic and Clinical Profile of Study Participants (n=200)

The study included a total of 200 participants divided equally between metabolic syndrome patients (n=100) and healthy controls (n=100). The demographic and clinical profiles of both groups were comparable with respect to age and gender distribution. The mean age of metabolic syndrome patients was 47.6 ± 8.3 years compared to 46.8 ± 7.9 years in controls, with no statistically significant difference (t = 0.64, p = 0.52). Similarly, the proportion of males was similar in both groups (56% vs. 53%, χ² = 0.18, p = 0.67). However, metabolic syndrome patients exhibited significantly higher body mass index (BMI) and waist circumference, with mean BMI of 29.7 ± 4.1 kg/m² versus 23.4 ± 3.2 kg/m² (t = 13.45, p < 0.001) and waist circumference of 102.3 ± 9.7 cm compared to 83.5 ± 8.2 cm in controls (t = 20.23, p < 0.001). Additionally, the prevalence of hypertension was markedly higher in the metabolic syndrome group (68%) than in controls (12%), which was statistically significant (χ² = 65.18, p < 0.001). Fasting blood glucose levels were also significantly elevated in metabolic syndrome patients (116.7 ± 18.4 mg/dL) compared to healthy individuals (89.4 ± 12.7 mg/dL, t = 15.82, p < 0.001).

Table 2: Lipid Profile Levels in Metabolic Syndrome Patients (n=100)

Regarding lipid profiles in metabolic syndrome patients, the mean total cholesterol level was 220.6 ± 38.5 mg/dL, exceeding the normal reference of <200 mg/dL, with 72% of patients exhibiting hypercholesterolemia. Mean triglycerides were elevated at 186.9 ± 54.3 mg/dL, above the normal cutoff of 150 mg/dL, with 65% of patients affected. LDL cholesterol levels averaged 140.4 ± 31.2 mg/dL, with 58% showing elevated values above 130 mg/dL. Conversely, HDL cholesterol, the protective lipid fraction, was notably low at 38.7 ± 8.9 mg/dL, with 79% of metabolic syndrome patients having HDL levels below the recommended thresholds (>40 mg/dL for males and >50 mg/dL for females).

Table 3: Comparison of Lipid Profile Parameters Between Metabolic Syndrome Patients and Healthy Controls (n=200)

A comparative analysis of lipid profiles between metabolic syndrome patients and healthy controls revealed significant differences across all parameters. Total cholesterol was significantly higher in metabolic syndrome patients (220.6 ± 38.5 mg/dL) compared to controls (182.4 ± 29.7 mg/dL, t = 8.17, p < 0.001). Triglyceride levels showed a pronounced difference, with patients having a mean of 186.9 ± 54.3 mg/dL versus 111.3 ± 41.5 mg/dL in controls (t = 10.53, p < 0.001). Similarly, LDL cholesterol was elevated in patients (140.4 ± 31.2 mg/dL) relative to controls (108.7 ± 26.1 mg/dL, t = 8.06, p < 0.001). HDL cholesterol was significantly reduced in metabolic syndrome patients (38.7 ± 8.9 mg/dL) compared to controls (52.3 ± 9.6 mg/dL, t = -9.74, p < 0.001), underscoring the characteristic dyslipidemic pattern associated with metabolic syndrome.

Table 4: Prevalence of Dyslipidemia Among Metabolic Syndrome Patients (n=100)

The prevalence of dyslipidemia within the metabolic syndrome cohort was notably high. Hypercholesterolemia was present in 72% (95% CI: 62.5–80.1%), hypertriglyceridemia in 65% (95% CI: 55.0–74.1%), and elevated LDL cholesterol in 58% (95% CI: 48.0–67.4%). Low HDL cholesterol was the most prevalent lipid abnormality, affecting 79% of patients (95% CI: 69.9–86.1%). Overall, 91% (95% CI: 83.3–95.8%) of metabolic syndrome patients had at least one form of dyslipidemia, highlighting the critical role of lipid abnormalities in this condition.

The present study assessed the demographic, clinical, and lipid profile characteristics of 100 patients with metabolic syndrome (MetS) compared to 100 healthy controls. The mean age and gender distribution were comparable between the two groups, ensuring that differences observed in metabolic and lipid parameters were less likely due to age or sex bias. Similar findings were reported by Ko SH et al.(2020)[6], where age and gender matched controls were used to analyze metabolic syndrome characteristics, strengthening the internal validity of such comparative studies.

Body mass index (BMI) and waist circumference were significantly higher in MetS patients, consistent with the central role of obesity, particularly visceral adiposity, in the pathogenesis of metabolic syndrome Gisondi P et al.(2018)^[7] & Srikanthan K et al.(2016)[8]. The significantly increased waist circumference (102.3 cm vs. 83.5 cm, p < 0.001) aligns with the findings of Bussler S et al.(2017)^[9], who emphasized abdominal obesity as a key diagnostic criterion for MetS due to its association with insulin resistance and dyslipidemia. The high prevalence of hypertension (68% in MetS patients vs. 12% in controls, p < 0.001) and elevated fasting blood glucose further confirm the clustering of cardiovascular risk factors typical of metabolic syndrome Castro-Barquero S et al.(2020)^[10].

Lipid profile analysis revealed pronounced dyslipidemia among MetS patients. Total cholesterol, triglycerides, and LDL cholesterol were significantly elevated, while HDL cholesterol was markedly reduced compared to controls. The mean total cholesterol of 220.6 ± 38.5 mg/dL and triglycerides of 186.9 ± 54.3 mg/dL exceeded normal reference ranges, mirroring the dyslipidemic pattern described in the Adult Treatment Panel III (ATP III) guidelines and other epidemiological studies et al.(20)^[11]. The predominance of low HDL cholesterol (79% prevalence) observed is particularly important as it represents atherogenic dyslipidemia, strongly linked to increased cardiovascular morbidity in metabolic syndrome Mahalingaiah S et al.(2015)^[12].

When compared directly with healthy controls, the differences in lipid parameters were statistically significant with large effect sizes. These findings are consistent with those of Bovolini A et al.(2021)^[13], who reported elevated triglycerides and LDL, along with reduced HDL levels, in South Asian populations with metabolic syndrome. The increased LDL cholesterol, averaging 140.4 mg/dL, may contribute to accelerated atherosclerosis in this patient group, as supported by evidence from studies like Chan TF et al.(2014)^[14].

Prevalence data from this study underscore the burden of dyslipidemia in MetS patients: 72% had hypercholesterolemia, 65% hypertriglyceridemia, 58% elevated LDL, and 79% low HDL cholesterol. Notably, 91% had at least one lipid abnormality, highlighting the near-universal presence of dyslipidemia in this condition. These rates are comparable to findings by Rani V et al.(2016)^[15], who reported high prevalence rates of lipid abnormalities in metabolic syndrome across diverse populations. The high prevalence of low HDL, in particular, emphasizes the need for focused lipid management strategies in MetS to reduce cardiovascular risk.

Overall, these results align with the pathophysiological understanding that insulin resistance and central adiposity drive a proatherogenic lipid profile in metabolic syndrome patients, as elucidated by Rochlani Y et al.(2017)^[16]. The findings reinforce the importance of routine lipid screening and comprehensive cardiovascular risk assessment in MetS patients to enable timely intervention.

This comparative cross-sectional study demonstrated that patients with metabolic syndrome exhibit significant lipid profile abnormalities characterized by elevated total cholesterol, triglycerides, and LDL cholesterol, along with markedly reduced HDL cholesterol levels compared to healthy controls. These dyslipidemic alterations are strongly associated with the pathophysiology of metabolic syndrome and contribute substantially to the heightened cardiovascular risk observed in this population. Early identification and management of lipid abnormalities in metabolic syndrome patients are essential to mitigate cardiovascular morbidity and improve long-term outcomes.

1. The study employed a cross-sectional design, which limits the ability to infer causality between metabolic syndrome and lipid abnormalities.
2. The sample size, though adequate, was restricted to a single center, which may limit the generalizability of findings to broader populations.
3. The study did not assess other lipid parameters such as apolipoproteins or lipoprotein particle size, which could provide more detailed insights into dyslipidemia in metabolic syndrome.
4. Lifestyle factors such as diet, physical activity, and socioeconomic status were not extensively evaluated, which might influence lipid profiles.
5. Medication history regarding lipid-lowering agents or other drugs that affect lipid metabolism was a basis for exclusion but could still introduce residual confounding if self-reported inaccurately.

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