European Journal of Cardiovascular Medicine

Cardiovascular diseases (CVD) rank as the top cause of death globally. In 2019, CVD accounted for 17.9 million fatalities or 32% death worldwide, out of which 85% were attributed to coronary artery disease (CAD) and stroke. CVD can be prevented by addressing behavioural and environmental risk factors such as tobacco smoke exposure, unhealthy diet, obesity, physical inactivity and alcoholism. In addition to this, the effect of globalization, urbanization, occupational stress and premature ageing along with hereditary factors constitute the underlying determinants of CVD.^[1] In earlier times, Indian women were mainly confined to the kitchen, preparing traditional meals. Nowadays, an increasing number of women remain engaged in different occupations which demand odd and long working hours leading to irregular eating habit characterized by convenience and fast foods rich in simple sugars, trans fats; and deficient in fiber.^[2] This shift has made them susceptible to obesity, hypertension, diabetes, CVD and cancer. Literature review has indicated a scarcity of research on distribution of various risk factors for CVD in women of the state of West Bengal, India, during their reproductive period when the protective effect of estrogen persists. It has been observed that women balance work and home without taking adequate care of health. Homemakers, too, remain engrossed with family and children. They deny themselves healthy living, either knowingly or unknowingly. In a cross-sectional study among rural and urban population across four geographical regions spanning 18 states of India; three major dietary patterns - ‘cereals-savoury foods’, ‘fruit-veg-sweets-snacks’ and ‘animal food’, were identified through principal components analysis (PCA). High intake of the ‘animal food’ pattern was associated with high levels of fasting plasma glucose (FPG), low density lipoprotein-cholesterol (LDL-C), and very low-density lipoprotein-cholesterol (VLDL-C) as well as systolic (SBP) and diastolic blood pressure (DBP).^[3] In a systematic analysis for the Global Burden of Disease Study 2019; among 87 risk factors studied in 204 countries and territories between 1990 and 2019, high FPG, body mass index, SBP and tobacco smoke exposure were identified as largest contributor to global mortality.^[4] A sedentary lifestyle and increasing consumption of high-calorie, high-protein, high-fat, and less fibrous foods result in vulnerability to non-communicable diseases. In another study, Anjana RM et al, in collaboration with ICMR, reported that sedentary lifestyle and CVD were directly linked with each other and suggested that creating awareness to increase energy expenditure and implementation of intervention strategies would ameliorate the risk.^[5] Saberinia A et al reviewed stress at the workplace as one of the risk factors of CVD.^[6]

Theoretical framework in a conceptual figure:

In this background, the present study was conducted to find out the relationship between food habits and occupation with risk factors of cardiovascular diseases among the study participants. It also aimed to evaluate cardiovascular disease status between working women and homemakers, as well as between different occupational groups

Study design and setting:

This cross-sectional, community-based study, carried out from April 2017 to March 2023 (one year extension of study duration due to COVID-19 pandemic), involved women of the reproductive age group aged between 25 and 45 years. Study participants were selected from fifteen different wards out of one hundred forty-four wards of the Kolkata Municipal Corporation (KMC) based on the latest census data, using a purposive sampling technique. Additionally, study participants were also selected from five neighbouring districts: South 24 Parganas, North 24 Parganas, Nadia, Howrah, and Hooghly in West Bengal.

Study participants and sampling:

Mukherjee D et al in their study in rural and urban areas of West Bengal found the prevalence of CVD as 6.86-15.81%.^[7] Hence, the anticipated population proportion [P] was taken as 10% [0.10], the confidence level [1─α] was 95%, and the standard value of the function of confidence level (z 1-α/2) =1.96 (where α α= significance level of the test, z = number of standard errors from the mean). Absolute precision, which is a measure of how close an estimate is to the true value of a population parameter (5% - 15%) [d] was taken as 5 percentage points [0.05]. Sample size was calculated by using this formula, N = (z _1-α/2)² × P (1-P) / d².^[8] Hence, total sample size (N) came out to be 138 [{(1.96)² × 0.10 × 0.90} / (0.05)²]. In the present study 10% of 138 i.e., 13.8 was added to 138 (in anticipation of dropout) to have the final sample size which comes to 151.8 ≈ 152, but a larger sample consisting of 400 women study participants divided into two groups, one group consisting of 200 working women and another group consisting of 200 nonworking women (homemakers) was taken into consideration. The working women were subdivided into nine categories according to their professional status. Twenty participants in each category of profession were selected, except academician which constituted forty participants as follows: (1) Doctors from two city based and two district based state hospitals, (2) Police personnel from a city and a district-based police Commissionerate, (3) Lawyers from two city based and two district based major courts, (4) Nurses from two city based and two district based state hospitals, (5) Information Technology (IT) professionals from Kolkata based IT industries, (6) Clerks from banks, academic institutions, post offices, and hospitals, (7) Academicians from two city based and two district based academic institutions, (8) Fitness experts from different fitness hubs and (9) House maids from the study area. They were clubbed into four major categories as (i) Professionals, which include academician, doctor, lawyer and IT; (ii) Associate professionals comprising police, nurse and fitness expert; (iii) Service workers consisting of clerk and (iv) Domestic helper or housemaid for the convenience of statistical analysis.^[9] A stratified random sampling technique was adopted to recruit the study participants into these two groups.^[10] The following selection criteria were adopted:

Inclusion criteria:

1. Non-pregnant and non-lactating women aged 25-45 years
2. Asymptomatic and undiagnosed cases of CVD

Exclusion criteria:

1. Women suffering from acute illness and chronic debilitating diseases.
2. Physically challenged

Data collection tool and technique:

(A) Pretested and validated modified survey questionnaire based on WHO Cardiovascular Survey Method to gather information on (1) Demographic variables (age, location), (2) Socioeconomic variables (employment, nature of work), (3) Health related behaviour (smoking, tobacco exposure, alcohol consumption, daily dietary recall as interpreted in WHO Food Record Form), (4) Family history of stroke, high blood cholesterol, hypertension, heart attack, cancer and diabetes mellitus by WHO Family History Questionnaire and history of antihypertensive, antidiabetic, or lipid lowering medications^[10,11,12]

(B) Rose Questionnaire for angina and intermittent claudication ^[13]

(C) Sphygmomanometer for blood pressure screening (an average of four readings five minutes apart in resting position with the same instrument which had been pre-calibrated against the reference standard) ^[10]

(D) 10-12 hours fasting samples for estimation of fasting plasma glucose (FPG; glucose oxidase-peroxidase method), serum total cholesterol (STC; cholesterol oxidase-peroxidase method), serum triglyceride (STG; Fossati and Prencipe method with Trinder reaction), High Density Lipoprotein Cholesterol (HDL-C; Enzymatic Quantitative Assay), Low Density Lipoprotein Cholesterol (LDL-C) and Very Low-Density Lipoprotein Cholesterol (VLDL-C), both calculated by Friedewald Equation  and 2 hours postprandial plasma glucose (PPPG; glucose oxidase-peroxidase method); using uniform reagent kits of identical batch number from a standard specific manufacturer in a semi autoanalyzer (Erba Chem7, TransAsia^®, Dubai, UAE) following stringent quality control criteria as recommended for samples, reagents and equipment^[14] All the assay methods were FDA (Food and Drug Administration, USA) approved. The reagents used for respective tests were stored at the proper storage temperature and of identical batch and lot number. Validation studies in terms of precision, accuracy, linearity, reportable range and reference interval verification were conducted. To minimise random and systematic error, two-level control was run daily, and all the instruments were calibrated at designated intervals as per NABL (National Accreditation Board for Testing and Calibration Laboratories, India) standards.

(E) ECG status of the participants was obtained by using a standard 12-lead electrocardiograph and interpreted according to Minnesota codes such as 1-1, 4-1, 5-9, 5-2 or 9-2.^[10]

Ethical consideration:

The study was conducted following approval of the Institutional Ethics Committee. Written informed consent was obtained from each participant. The process flow was clearly explained in a detailed Participant Information Sheet provided to them. They were also given the choice of opting out anytime during the study.

Statistical analysis method:

Data was entered into a Microsoft Excel spreadsheet (Microsoft, Redwoods, WA, USA) and was checked for accuracy. Categorical data were expressed in numbers and proportions. Pearson’s chi-square tests were used to find out any association between two categorical variables. Continuous data were checked for normal distribution by the Kolmogorov-Smirnov Test. A significant P value indicated a skewed distribution. Continuous data were expressed in median and interquartile range (IQR). The Mann-Whitney U Test was computed to find out the difference between two independent groups. Kruskal-Wallis H Test was calculated to analyse the differences between more than two independent groups.^[15] Statistical analysis was conducted by using SPSS software, version 20.0 (Statistical Package for the Social Sciences Inc., Chicago, IL, USA). A P value equal to or less than 0.05 was considered statistically significant.^[15].

Out of two hundred working women, 100 (50%) belonged to Kolkata, and the remaining 50% were from other districts like North 24 Parganas, South 24 Parganas, Hooghly, Howrah and Nadia. Out of two hundred homemakers, 150 (75%) were from Kolkata, and rest 25% were from other districts. Overall, professionals constituted 100 (50%), associate professionals 60 (30%), service workers 20 (10%), and domestic helpers 20 (10%). Family history of stroke (cerebrovascular accident), heart attack (myocardial infarction), hypertension, hyperlipidemias, type 2 diabetes and cancer revealed significant differences in proportion between working groups and homemakers (P=0.003). Daily consumption of processed/snacks/fast/outside food/sweets was comparatively more among homemakers, whereas occasional consumption (once or twice a month) was higher among working women (χ² = 22.62, df=1, P=0.00001). Based on the estimated average daily individual calorie requirement of 1660 kcal for a sedentary woman and 2130 kcal for a moderately active woman, the intake of calories among homemakers (63%) was comparatively higher than that of working women (31%), statistically significant at a 5% level (χ² = 42.62, df=2, P=0.00001).^[12] A similar statistically significant proportional difference was found between working women from different professions (χ² =12.944, df=6, P = 0.04). Based on normal average carbohydrate consumption of 130 g/day for both sedentary and moderate workers, median consumption was higher among homemakers. Among clubbed professions, median carbohydrate consumption was highest among domestic helpers, followed by service workers.^[12] Based on the daily allowance of protein as 45.7 g for both sedentary and moderate workers, high protein consumption was observed among both the working women and homemakers, but no statistically significant difference in proportion was obtained. However, a significant proportion was found among individual professions at 5% level.^[12] Dietary fibre consumption was significantly higher among homemakers (75%) than among working women (25%). 60% of working women consumed low fibre compared to 25% of homemakers, which was statistically significant at the 5% level (proportional z-score=7.0801, P=0.00001), considering the recommended fiber intake as 40g/2000 kcal daily per individual.^[12] The study revealed that visible fats and/or oil consumption was above recommended levels suggested by ICMR-NIN, 2020, in both working women and homemakers. ^[12] Comparison between working women and homemakers on the basis of daily consumption of foodstuff using the Mann-Whitney U test revealed statistically significant differences in consumption of refined cereals, pulses, fish/chicken, visible fats, oil and sugar. Kruskal Wallis H test revealed statistically significant differences in refined cereals, unrefined cereals, mixed vegetables, roots and tubers, fruits, milk, fish/chicken, visible fats/oil and sugar consumption per day between different clubbed professions at 1% level of significance, except pulses which remained constant for all the groups [Table 1, S1].

Table 1: Comparison between working women and home-makers on the basis of consumption of foodstuff per day.

*Significance p<0.05, **Significance p<0.01           Abbreviations-See text.

Mann Whitney U test suggests statistically significant differences in consumption of refined cereals, pulses and fish/chicken at 1% level and in consumption of visible fats and oil and sugar at 5% level between working women and homemakers

Table S1: Comparison between clubbed professions on the basis of consumption of foodstuff per day.

**Significance p<0.01                                                              Abbreviations-See text.

Kruskal Wallis H test reveals statistically significant differences in consumption of refined cereals, unrefined cereals, mixed vegetables, roots and tubers, fruits, milk, fish/chicken, visible fats/oil and sugar consumption per day between different clubbed professions at 1% level of significance except pulses which remained constant for all the groups.

Statistically significant differences between working women and homemakers were observed by the Mann-Whitney U test in PPPG at the 1% level and in STG and VLDL-C at the 5% level. Kruskal-Wallis H test detected significant differences in STC, STG, HDL-C, LDL-C and VLDL-C among clubbed professions [Table 2, S2].

Table 2: Difference between working women and home-makers according to biochemical components.

**Significance p < 0.01, *Significance p < 0.05                  Abbreviations-See text.

Mann Whitney U test suggests that statistically significant differences exist in post-prandial plasma glucose at 1% level and in serum triglyceride and VLDL at 5% level between working women and homemakers.

Table S2: Difference between clubbed professions according to biochemical components.

**Significance p < 0.01.                                                          Abbreviations-See text.

Kruskal Wallis H test reveals that clubbed professions have statistically significant differences in serum total cholesterol (STC), serum triglyceride (STG), HDLC, LDL-C and VLDL-C at 1% level of significance.

Mann-Whitney U test revealed statistically significant differences in systolic blood pressure (SBP) and diastolic blood pressure (DBP) values between working women and homemakers (P=0.0001). Pearson’s Chi-square test showed statistically significant proportional difference in SBP and DBP among different professions (χ² = 75.66, df=6, P=0.00001).^[16] The distribution of smoking habits among working women and homemakers was statistically significant at the 5% level, however, no significant proportional difference existed in alcohol consumption among them. The study revealed that 79.5% of homemakers were exposed to tobacco smoke, compared to 55% of working women, which was statistically significant at 5% level [Table 3].

Table 3: Comparison on the basis of smoking habit, alcohol consumption and passive smoke exposure.

Chi square statistic shows no statistically significant proportional difference in the distribution of alcohol consumption among working women and homemakers at 5% significance level

Homemakers (28%) suffering from angina pectoris were much more than the proportion of working women (16%) (χ² = 8.38, df=1, P=0.004), however, no significant difference in proportion was observed among clubbed professions (χ² = 2.87, df=3, P = 0.41). Intermittent claudication was well distributed between the two groups (χ² = 10.95, df=1, P=0.001) and also among clubbed professions (χ² = 24.72, df=3, P=0.00001). Three levels of ECG status, as ECG normal, ECG probable and ECG ischemic, were well distributed between the two groups and among clubbed professionals, statistically significant at the 5% level [Table 4].

Table 4: Comparison on the basis of ECG status.

Chi-square statistic reveals statistically significant proportional difference in the distribution of ECG status between working women and homemakers, as well as among clubbed professions at 5% significance level.

Note: Electrocardiographic (ECG) findings are interpreted according to Minnesota codes. ECG Normal coded as 4, ECG Probable coded as 2, ECG Ischemic coded as 3. ECG normal means participants without any cardiac ailments; ECG Probable means participants having a probability of ischemic heart disease (IHD) in the near future, as evidenced by nonspecific ST-T changes; ECG ischemic means participants diagnosed with IHD. ^[10,17]

The present study involved population from a wide socio-economic background. It evaluated socio-economic status as an important component of CVD. Education increases awareness among people, thereby lowering the burden of CVD and its predictors. On the other hand, it raises the income level and purchasing capacity of people. Enhanced purchasing capacity acts as a double-edged sword if they lack awareness, thereby making them vulnerable to CVD. These findings align with previous and more contemporary studies. ^[17,18] The present study also confirmed that a positive family history of CVD raises the risk potential among the participants in near future on longitudinal follow up. This observation is in keeping with another study specifically undertaken to examine the impact of positive family history on CVD and advocates non-pharmacological behavioural modifications as a mode of primordial prevention.^[19] The current study revealed that daily consumption of processed foods, snacks, fast foods, restaurant foods, sweets, ice-creams and soft drinks was higher among homemakers. Among working women engaged in different professions, service workers ranked first in daily consumption of these foods. These two groups were reported to have increased episodes of angina pectoris on follow up. Therefore, a healthy dietary pattern rich in fruits, vegetables, whole grains, legumes, fish, poultry, eggs and dairy is inversely proportional to the risk of development of CVD, a fact well substantiated in the CORDIOPREV randomized controlled trial.^[20] According to the present study, significantly higher calorie intake was observed among homemakers; while among clubbed professions, professionals were the highest consumers of high calories and domestic helpers, the lowest. Carbohydrate consumption was higher among homemakers. Among clubbed professions, median carbohydrate consumption was highest among domestic helpers, followed by service workers. Curtailment of carbohydrate consumption reduces body fat, thereby reducing body weight as well as STG, STC, systolic blood pressure (SBP) and diastolic blood pressure (DBP) with the elevation of HDL-C level.^[21] This explains increased episodes of cardiovascular events among homemakers in the present study. Further literature survey revealed that high carbohydrate diet poses a potential health risk by increasing LDL-C and VLDL-C. It recommends a portfolio dietary pattern comprising nuts, viscous fiber, phytosterols and plant monounsaturated fatty acids (MUFA) which is significantly associated with a lower risk of total CVD, CAD and stroke.^[22] The current study revealed a high protein consumption between both the working women and homemakers. Median daily protein consumption was significantly different between professionals and associate professionals. Excessive protein intake in addition to the recommended daily allowance (RDA) stimulates neoglucogenesis, resulting in weight gain.^[23] Median dietary fibre consumption was significantly higher among homemakers. Dietary fibre reduces the risk of CVD by lowering blood sugar, STC, LDL-C, VLDL-C and BP. ^[11,12] Median daily fat intake was uniformly high in both the working group and homemakers. However, median daily fat consumption was highest among professionals and associate professionals, with more uniformity in the former. Hypercholesterolemia gradually paves the way to atherosclerosis.^[11,12] Median daily consumption of refined cereals was higher in homemakers, but unrefined cereal consumption was similar for both groups, with more uniformity among homemakers. Median daily consumption of unrefined cereals was similar among associate professionals and service workers. Refined cereals popularly include white bread, pasta, biscuits, refined grain breakfast cereals, white rice, white flour; on the contrary, unrefined or whole grain cereals comprise oats, barley, maize, millets, whole wheat products (broken wheat or Dalia) and flour, brown bread, brown rice.^[24] Literature study indicated that a high intake of unrefined cereal reduces PPPG and STG.^[25] Therefore, a diet rich in refined cereals makes homemakers more vulnerable to cardiovascular episodes as evidenced in the present study. Self-reported data indicated similarity in legume or pulse intake between working women and homemakers. No statistically significant difference was found in mixed vegetable consumption between the two groups. Regular consumption of mixed vegetables and salads has an inverse relationship with CVD.^[24] Similarity in daily intake of roots and tubers was observed from the median values between the study groups. However, more consistency was found among homemakers. Roots and tubers intake should be moderate, as they are starch-based polysaccharides without any satisfactory fibre content. This readily raises blood glucose levels.^[24] The study revealed regular consumption of fruits from the median values in both groups, but without any statistically significant difference. Literature study supports that regular fruit consumption is inversely related to hypertension, obesity and CVD due to its cardioprotective nature.^[26] The study revealed a comparatively less consumption of milk and dairy products along with fish and/or chicken by homemakers. CVD is inversely associated with healthy eating pattern, which includes increased consumption of fruits, vegetables, double-toned milk, fish and complex carbohydrates.^[24] Unhealthy eating habit, therefore, remains a major reason for susceptibility of the homemakers to CVD. Statistically significant differences were found between working women and homemakers with respect to PPPG, STG and VLDL-C levels. Kruskal-Wallis H test detected significant differences in STC, STG, HDL-C, LDL-C and VLDL-C among clubbed professions. Therefore, the study shows significant dyslipidemias among the working group, a fact that might be related to occupational stress. Biochemical variables were found to be significantly deranged among patients having CVD risk factors. One of the most contemporary studies conducted in South India recommends dietary modifications and moderate intensity exercise as effective modalities to curb metabolic syndrome.^[27] The present study reported 60% of domestic helpers as prehypertensive, followed by professionals (45%), service workers and associate professionals (40% each approximately). Statistically significant proportional differences existed in smoking habits between working women and homemakers, but not in the case of alcohol consumption. The majority of working women and homemakers were exposed to tobacco smoke. In this study, homemakers were more passive smokers than working women. The existence of a direct relationship between smoking, tobacco smoke exposure (passive smoking) and CVD risk as evidenced in the current study is well supported by previous and more recent literatures. ^[28,29] The current study has also observed that homemakers suffered more from angina pectoris (chest pain) and intermittent claudication based on history and emerging symptoms on longitudinal follow up. Therefore, homemakers had a higher probability of developing overt disease later in life. However, working women had more diagnosed cases of ischemic heart disease by ECG. Angina pectoris, hypertension, intermittent claudication and ECG status are specific outcome measures which are directly linked to CVD. This is well established in the present study and is duly supported by previous studies. ^[13,30]

A large proportion of asymptomatic women aged 25–45 in West Bengal, India, are exposed to various cardiovascular disease (CVD) risk factors that, if left unaddressed, could develop into overt illness later. To prevent this progression, early intervention backed by effective health policies is vital. Increasing political support and improving socioeconomic conditions among the target group can work together to lower CVD risk. Policies should ensure equitable access to health resources, including affordable nutritious food, which is increasingly affected by advances in food production and distribution. Additionally, workplace health policies need to tackle occupational stress by creating supportive environment. Social norms and personal attitudes influence behavioural risks like smoking and alcohol consumption, highlighting the need for culturally specific health promotion strategies. Tackling these complex factors requires strong leadership, coordinated efforts across sectors, and active community participation. Using evidence-based policies based on local epidemiological data is essential to reduce the long-term CVD burden in this group.

Novelty of the study: The present study, analyzing the role of food consumption pattern and occupational exposure as determinants of cardiovascular risk in women of childbearing age, is the first of its kind being undertaken in the southern part of the Indian state of West Bengal. The present study used a pretested, validated, and standardized questionnaire for data collection. The statistical data, therefore, enhances the depth of understanding and corroboration. There is a dearth of studies purely involving reproductive-aged women, both working professionals in various fields and homemakers, in the literature. Thus, the study will be helpful for the policy makers to implement intervention measures to curb the cardiovascular risk among the studied population.

Strength of the study: A huge sample size based on statistical assumptions on either arm of the study is certainly a matter of strength. Women of reproductive age, both working and non-working, were recruited in the community setting; and the association of CVD with certain risk factors was established.  

Weakness/limitation of the study: The study was conducted in a limited area of West Bengal state, India. Therefore, the data generated cannot have sufficient external generalizability. Moreover, the inadvertent possibility of bias (subjective, observer and bias of evaluation) and temporal association due to cross-sectional study design cannot be entirely ruled out.

Suggestions for further research: Larger multicentre longitudinal studies are recommended to generate stronger evidence-based data to help formulate newer public health guidelines for the prevention of the emergence of coronary artery disease among women in the reproductive age group, when the protective estrogenic effect disappears.           

Acknowledgement: We are thankful to the study participants for voluntarily participating in the study and to the institution authority for allowing us to carry out the research work, providing necessary logistics and infrastructure.

AI Policy: No AI tools were used in the writing of the manuscript or the collection and analysis of data.

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