Evaluation of Micronutrients and Components of Macronutrients Intake in Cardiac Patients: A Cross-sectional Study of Cardiovascular Nutritional Risk in Lahore, Pakistan

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Introduction

According to the World Health Organization (WHO), cardiovascular diseases (CVDs) are the leading cause of death worldwide. In 2022 alone, an estimated 19.8 million deaths were attributed to CVDs, accounting for approximately 32% of global mortality[1]. Furthermore, global CVD prevalence increased from 0.061% in 2010 to 0.070% in 2019 [2]. In the European region, over 60 million potential years of life are lost annually to CVDs, with mortality higher among women than men [3]. A particularly notable surge has been observed in South Asia, where prevalence rose from 3304.2 to 4944.1 cases per 100,000 population between 1990 and 2019, an increase of about 49.6% [4]. In Pakistan, data from the 2019 Global Burden of Disease study indicate an age-standardized CVD incidence of 918.18 per 100,000 people, markedly higher than the global average of 684.33 per 100,000 [5].

Nutritionally poor diets have a significant adverse impact on cardiovascular health, whereas nutritionally rich diets and their functional food components are effective in preventing and reducing CVD risk [6]. Multiple studies suggest that more than 90% of myocardial infarctions could be prevented through improved nutrition and environmental factors [6-8]. Adequate and balanced intake of various vitamins, including A, B-complex, C, D, E, and K, plays a preventive role in human health. Vitamin A, for instance, supports immune function, growth, and mucosal integrity, thereby contributing to improved cardiovascular outcomes [9]. Vitamin D modulates cardiac muscle function [10], while vitamin E exerts anti-oxidative properties that may prevent cardiovascular cancers [11]. Vitamin C, in turn, protects vascular endothelial function [12]. Furthermore, B-complex vitamins play a significant protective role in the prevention of cardiovascular diseases [13]. In addition to vitamins, several minerals are key to CVD prevention. Potassium regulates blood pressure and reduces the risk of coronary heart disease and stroke.[14] Low magnesium levels are an established predictor of CVDs,[15] whereas calcium is involved in cardiac muscle contraction and the bone–heart axis [16]. Adequate selenium and zinc support normal cardiovascular function, [17] and balanced iron levels are vital for cardiovascular well-being[16].

Macronutrient components, including sugars, fiber, protein, saturated fats, trans fats, and unsaturated fats—also influence cardiovascular health. Saturated and trans fats adversely affect cardiovascular outcomes, while unsaturated fats (both monounsaturated and polyunsaturated) are beneficial[19]. Dietary fiber within carbohydrates demonstrates positive cardiovascular effects, whereas high sugar intake contributes to vascular damage[20]. Although recent evidence shows no direct effect of protein on heart health, optimal protein intake is necessary to reduce CVD-related mortality [21]. Several nutritional risk assessment tools are used in cardiac patients, with the Subjective Global Assessment (SGA) and Mini Nutritional Assessment (MNA) being the most prominent. The MNA categorizes patients into three groups: 1) normal nutritional status, 2) at risk of malnutrition, and 3) malnourished. Similarly, the SGA classifies patients into Stage A (well-nourished), Stage B (moderately malnourished), and Stage C (severely malnourished) [22-24]. This study aims to promote better cardiovascular health by evaluating nutrient intake patterns in cardiac patients, with a focus on assessing micronutrient intake and macronutrient composition to identify nutritional deficiencies that may contribute to cardiovascular risk. These deficiencies could also serve as nutritional risk factors associated with the national burden of CVDs. Limited data are currently available on nutrient intake among cardiac patients in Pakistan, particularly in Lahore.

Methods

Study population and characteristics A simple random sampling technique was used after identifying the target population from the cardiac wards of the facility. The study population consisted of cardiac patients aged 18–50 years, admitted to the inpatient department of a tertiary-care public cardiology facility. A sample of 222 participants (N = 222) was calculated using OpenEpi with a 5% margin of error, a CVD prevalence of 17.5% in Punjab, Pakistan,²⁵ and a design effect of 1.0 for a random sample. Both male and female patients were included if they had a clinical diagnosis of cardiac disease and had received treatment for at least one day as inpatients. Patients with comorbid systemic or psychiatric conditions, such as bipolar disorder, schizophrenia, dementia, or other mental disorders—were excluded, as these conditions could impede their ability to provide accurate study-related information.

Data collection and study design A cross-sectional design was employed to obtain a snapshot of the prevailing nutritional risk among patients with CVD. Data were collected using a self-designed demographic survey and the Mini Nutritional Assessment—Short Form (MNA-SF). Dietary intake was assessed using a weekly Food Frequency Questionnaire (FFQ) with estimated portion sizes based on household food measures. Nutrient values were estimated using Cronometer, an application designed to accurately quantify calories, macronutrients, and micronutrients. Data collection took place over approximately five months, from January 3, 2024, to May 30, 2024. Prior to data collection, approval was obtained from the Institutional Review Committee (letter no. 0299/IRC/BMR). Informed consent was obtained from each participant to ensure ethical adherence and transparency.

Statistical analysis Data were analyzed using IBM SPSS version 25.0. Descriptive statistics, including mean (M), standard deviation (SD), frequency (f), and percentage (%) were applied after confirming normality assumptions. Bivariate analysis using the Chi-square test was performed on non-parametric variables. Additionally, multivariate analysis of variance (MANOVA) was conducted to examine group differences and maintain statistical rigor.

Results

Table 2: Chi-square analysis between BMI and gende Gender BMI Female Male Chi-square (χ²) p-value Underweight 38 25 9.767 .021* Normal 39 37 Overweight 30 33 Obese 17 3 Total 124 98 Note: p < 0.05*, p < 0.01** Gender-stratified BMI data were presented in Table 2. Female participants included 38 underweight, 39 normal weight, 30 overweight, and 17 obese individuals. Male participants included 25 underweight, 37 normal weight, 33 overweight, and 3 obese individuals. A statistically significant association was found between gender and BMI (χ² = 9.767, p < .05), indicating that gender significantly influenced BMI distribution in this study.

Table 3: Chi-square analysis between gender and nutritional risk Gender Nutritional risk Female Male Chi-square (χ²) p-value Normal nutritional status 5 4 7.836 .020* At risk of malnutrition 58 28 Malnourished 61 66 Total 124 98 Note: p < 0.05*, p < 0.01** Nutritional risk status by gender was displayed in Table 3. Among females, 5 were well-nourished, 58 were at risk of malnutrition, and 61 were malnourished. Among males, 4 were well-nourished, 28 were at risk, and 66 were malnourished. A significant relationship was observed between gender and nutritional risk (χ² = 7.836, p < .05). While the proportion of females at risk of malnutrition was notably higher, the malnourished category included comparable numbers of males and females.

Table 5: Descriptive statistics of B-vitamins intake by nutritional risk Nutritional risk B9 (µg) 501.86±42.84 380.21±163.28 206.40±146.99 B12 (µg) 3.05±0.42 2.13±1.37 1.97±1.92 A significant multivariate effect of nutritional risk status on B-vitamin intake was observed (Wilk’s Λ = 0.52, F(14, 424) = , p < .001) (Table 5). The effect size was large (partial η² = 0.275), with observed power of 1.00, indicating robust results. Well-nourished individuals had the highest mean B-vitamin intake, followed by those at risk of malnutrition; the lowest intake was observed in malnourished individuals.

Discussion

As evident from the findings of this study, the prevalence of being underweight, having a normal BMI, and being overweight was higher among the studied population of cardiac patients. Interestingly, female participants took part in the study in greater numbers, while males were less represented. This finding deviated from the cultural and hospital setting, where women were typically less able to speak freely with male healthcare professionals without the presence of family members. These results also contrasted with a previous cross-sectional study, in which women were underrepresented compared to men [²⁵]. Another prospective stability trial reported that both underweight BMI (<20 kg/m²) and very high BMI (>35 kg/m²) were strong markers of risk for poor prognosis [26].

Moreover, findings from the Chi-square analysis demonstrated that more females were in the underweight and obese categories, whereas both genders had similar numbers in the normal and overweight categories. A significant relationship (χ² = 9.767, p < 0.05) was observed between BMI and cardiovascular diseases. A previous systematic review and meta-analysis supported these findings, reporting a J-shaped relationship between BMI and mortality in cardiac patients, suggesting an inverse association of mortality risk with BMI [27]. Another study reported increased incidences of cardiac mortality among obese individuals [28]. Additionally, the chi-square analysis of nutritional risk revealed that female participants were at higher risk of malnutrition; however, both genders had higher numbers in the malnourished state. A statistically significant relationship was established between gender and nutritional risk (χ² = 7.836, p < .05). A previous study reported persistent gaps in food security between men and women, which kept women at higher risk of malnourishment [29]. Contrarily, a retrospective analysis indicated that both underweight status and risk of malnutrition directly predicted the odds of in-hospital mortality in men, but not in women with cardiac diseases [30].

Furthermore, findings from the MANOVA test demonstrated significant differences among nutritional risk groups regarding macronutrient intake. The sample size was sufficient to determine the effect size for nutrient intake across the groups. Intake of dietary fiber was highest in subjects with normal nutritional status and gradually declined in those at risk of malnutrition and those who were malnourished. Similarly, starch intake also declined progressively across groups from normal nutritional status to malnourished state. Lower intake of fiber and higher intake of refined carbohydrates could result in cardio-metabolic complications in patients with cardiac diseases. A previous study reported a negative association between higher fiber intake, lower refined carbohydrate intake, and cardio-metabolic complications such as diabetes and hypertension [31]. The current study also illustrated that high sugar intake was more prevalent in malnourished individuals compared to those with normal nutritional status or at risk of malnutrition. Meanwhile, no significant difference was observed in trans fat intake among the groups; however, saturated fat intake steadily declined from the normal to the malnourished group. A probable explanation for these patterns may be reduced food intake following admission to cardiac inpatient wards. Another study demonstrated that lower fat intake coupled with higher carbohydrate consumption was associated with adverse lipid profiles, while higher saturated fat intake was linked to poorer outcomes [32].

Additionally, a steady decline was observed in the intake of all analyzed B vitamins, including B1, B2, B3, B4, B5, B6, B9, and B12. Every B vitamin intake was lowest in the malnourished group and highest in the normal group. Lower intake of these vitamins from food sources may exacerbate the severity of cardiac disease symptoms. Conversely, adequate vitamin B complex intake may play a protective role in preventing cardiovascular diseases. These findings are supported by a systematic review and meta-analysis in which higher intakes of B vitamins were associated with lower cardiovascular risk.³³ Another study reported that vitamin B complex reduced the risk of metabolic syndrome, a known complication in cardiovascular diseases [34]. Concomitantly, intake of fat-soluble vitamins (A, D, E, and K) declined progressively from normal nutritional status to malnourished status, whereas the water-soluble vitamin C was surprisingly higher in the at-risk group. Poor nutritional intake may explain the persistent decline in fat-soluble vitamin levels from normal to malnourished patients. These findings align with a cross-sectional study that reported persistently lower caloric and macronutrient intake among patients with congestive heart failure, leading to reduced micronutrient intake [35]. As reported in previous studies, fat-soluble vitamins, especially vitamin K (specifically K2), play a protective role in heart health [36, 37]. Regarding vitamin C intake, another study confirmed its beneficial effect on improving lipid profiles in patients with cardiovascular disease [38].

Finally, findings from mineral intake analysis revealed that individuals with normal nutritional status had the highest intake of calcium, copper, iron, magnesium, manganese, phosphorus, potassium, selenium, sodium, and zinc. Those at risk of malnutrition and in a malnourished state had lower intakes of these essential minerals. Cardiac patients with lower mineral intake may face a higher likelihood of severe complications and mortality risk. These findings are consistent with previous research in which lower mineral intake was associated with higher mortality rates, increased hospitalization costs, longer hospital stays, and greater complication rates [39]. Another study reported that mineral intake was negatively associated with the risk of all-cause cardiovascular mortality across different BMI categories [⁴⁰].

Limitations

The overall sample size was adequate to support replication and generalization of the findings; however, future work with a larger sample is needed to establish a causal relationship between nutritional risk and cardiac outcomes. Additionally, this study was not designed to establish a causal association between nutritional risk factors and the incidence of cardiac diseases. These limitations could be addressed through longitudinal cohort studies, with a focus on determining the causal role of nutrient intake in the development of cardiac diseases.

Conclusion

The results of this study suggested that nutritional risk was increased with reduced food consumption among individuals with cardiovascular disease. Substantial micronutrient deficiencies were evident among those categorized as malnourished. Further studies are recommended to establish causal relationships between specific vitamins, minerals, and cardiovascular disease incidence, which may provide deeper insight into underlying pathophysiological mechanisms. Such research could inform the development of policies and preventive approaches aimed at reducing the global burden of cardiovascular disease.

Acknowledgement

The authors acknowledge Ms. Marriam Ahmed for her continuous support and assistance in obtaining the ethical approval letter and for her guidance during manuscript preparation. Her contributions were instrumental in the smooth completion of this manuscript.

Declarations

Authors’ contributions Muteeba Komal and Muhammd Jawad designed the study, did conceptualization, collected data and wrote original manuscript, Zainab Malik and Shaheer Ahmed performed statistical analysis, and interpretation of the data, Maham Shafique and Manahil Afzal prepared the final document, critically revised it and validate methodology, Faran Khan did supervision, validation and proofreading of the final document, Izza Shahzad and Muhammad Saad critically revised the manuscript and approved the final version.

Ethical Approval This study was approved by the Institutional Review Committee (IRC) for Biomedical Research of University of South Asia Lahore under the letter no. 0299/IRC/BMR.

Conflict of Interest

All authors declare no conflict of interest for this study at any point.

Funding

No funding was received to perform this research. This work is the collaborative effort of all the authors. All authors are based in low-middle-income country.