Adequate nutrition for people suffering from HF disease is of high importance because of the imbalance of electrolytes and vitamins and lack of micronutrients due to the use of diuretics [10, 11]. According to dietary guidelines, dietary diversity is one of the components of a healthy diet. Eating a variety of diets provides the most protection against chronic diseases [35, 36]. There is very limited information about cardiac patients’ nutritional status in north of Iran . To the best of our knowledge this study is one of the first studies evaluating DDS and food security in HF patients.
This study conducted among patients with HF showed high prevalence of low dietary diversity in subjects (Mean DDS = 2.10 ± 0.92). Regarding the assessment of DDS in relation to CVDs risk factors, mean dietary diversity score (mean DDS = 4.71) obtained in Farhangi et al. study was higher than this study . In the study of Dere KAL et al. who investigated DDS in diabetic and hypertensive patients, average individual DDS was reported to be poor, although mean of obtained DDSs in both groups of patients were higher than present study . Also, mean DDS in Azadbakht et al. research evaluating the association of DDS and CVDs risk factors was found higher than this study . Iran is a multi-ethnic country with a rapid nutrition and health transition which results in significant alterations in nutrition status of the population [38, 39]; Therefore, dietary insufficiency and specific nutrients deficiencies characterize the diet of the people, and overeating and obesity are evident in over a third of the population [40, 41].
In present study the most consumed food groups belonged to fruits and grains, however, Azadbakht et al. study which investigated the association of DDS with metabolic syndrome in tehranian adults reported that dairy products, vegetables and fruits, were most used by the study subjects, respectively . In Dere K et al. research the most consumed food groups belonged to vegetables (onion, tomato and peppers), cereals, fish, oils and fats in both diabetic and hypertensive groups while fruits, other vegetables, nuts and seeds were the least consumed . The differences between studies can be considered as a result of differences in characteristics of study population, various sample size and different questionnaire use. Furthermore, geographical and cultural aspects can highly affect diet and nutrition habits which should not be ignored.
Present survey reported a significant relationship between duration of suffering from HF, hypertension, smoking status and dietary diversity. Subjects with hypertension, longer duration of suffering from HF and patients who were not taking any supplement had less varied diet while those who quit smoking (former smokers) showed greater dietary diversity in comparison to non-smokers. In addition, our results showed that individuals with high cholesterol level and low ejection fraction were more likely to experience low diversity in their diet.
On the basis of Azadbakht et al. study, carried out on tehranian adults, dietary diversity had an inverse association with metabolic syndrome, high blood pressure, high triglyceride level and abnormal glucose levels. In their study, participants with greater DDS reported consuming healthier food groups. Hence, they concluded that greater dietary diversity might be in association with lower possibility of having some metabolic disorders . Another research in Iran showed that people with higher dietary diversity score had lower risk of hypertension . Also, Farhangi et al. found that patients with lower DDS had significantly higher serum triglycerides and systolic blood pressure value . This can possibly be attributed to a healthier lifestyle related to higher DDS such as using more fiber, fruits, vegetables and lower intake of meat and cholesterol .
All these findings demonstrate that dietary diversity can be associated with some CVDs risks. Higher dietary diversity may have significant correlation with lower CVDs risks and better health condition. Also it can show that DDS may be useful for investigating correlations between diet quality and some chronic diseases including cardiovascular risks [3, 4, 6].
There have been several definitions for food security. All of them state that food security includes two main parts; physical access (availability of food) and economical access [22, 23]. Regarding the obtained results on the status of food security among HF patients, in current research more than half of the patients (57%) were experiencing degrees of food insecurity. The prevalence of food insecurity in this study is in consistency with prior studies conducted in this region. A systematic review on 31 studies in 2016 indicated that prevalence of food insecurity among Iranian households was about 49% . Moreover, approximately 294.7 million people in south Asia have experienced food insecurity to some extents . Bashir et al. also reported that 23% of the households in Pakistan were found to be food insecure . The situation is getting worse in developing countries as a result of high prices of products and economic crises.
Since food insecurity is associated with several cardio-metabolic problems, including diabetes and obesity [24, 25], interventions aiming to reduce the prevalence of food insecurity can be effective in developing nutritional status of patients with chronic diseases.
Based on findings of this study, subjects with lower educational level and higher waist circumference were more likely to have food insecurity. Additionally, food insecurity was independently associated with gender and household economic condition. Patients with low economic status were more likely to have food insecurity. Prevalence of food insecurity based upon household income/expenditure surveys was 10% according to a meta-analyze experiential/perception-based study in Iran, this systematic review and meta-analysis survey reported rates of mild, moderate and severe food insecurity of 9.3, 5.6 and 3.7%, respectively in 2004 . In the current study, we found that women tended to be more food secure and mild insecure than men; meanwhile, men were more likely to experience severe food insecurity in comparison to women. This finding may be due to the probability that men, as heads of households in this region, pay more attention to other family members’ diet than their own, especially in low-income families struggling with difficult financial access to food.
Chronic diseases are nutrition related and establishing a therapy to prevent and manage chronic diseases is a modification [45,46,47]. Seligman et al. in their study found a relationship between food insecurity and clinical evidence of hypertension and diabetes . In the study of Vaccaro et al. adults with chronic diseases had greater food insecurity and men had better dietary security state , but in present study there was not found any significant correlation between chronic diseases and food insecurity which can be because of the possibility that in our study the overall amount of severe food insecurity was low.
Although the mean of dietary diversity at different levels of food security was higher in patients with complete food security and mild insecurity than patients with moderate to severe insecurity, the difference was not statistically significant. This might be due to the fact that food security questionnaire mostly emphasizes on economic access and the availability of healthy and nutritious food than the diversity of diet.
There are some limitations in this study, such as the cross-sectional design of the study which limits causal relationship between dietary diversity, food security and related factors. Furthermore, although the sample size calculated based on the previous study had a power of 80 and 95% confidence interval, it seems that designing larger prospective cohort studies might be of value in better investigating the determinant factors of dietary diversity and food security.