Patients with diabetes were the target population in several studies on their knowledge, attitudes, and practice about diabetes. However, in this study, analyses were conducted on general individuals. The results showed that general awareness about DM among the subjects was at a moderate level of 12.13 ± 3.84, which was 13.33 ± 3.63 and 11.71 ± 3.64 amid diabetic and non-diabetic ones, respectively. In other words, people with diabetes inevitably receive more information from this disease, especially are informed by their doctors. Therefore, they are more likely to obtain more knowledge about their illness. According to Fatima et al. studies, the average level of knowledge among subjects without DM and respondents with T2DM are 70 and 68%, respectively. Our research is consistent with two other studies in Bangladesh (
4). However, in most investigations in developing countries, poor knowledge of diabetes has been reported among the general population (
20). In this study, people's knowledge of diabetes is significantly associated with age, BMI, gender, educational level, family history, smoking, cardiovascular diseases, and information source. Women were more knowledgeable than those with academic education, people with positive family history, non-smokers and cardiovascular diseases, and those who were the source of their information. In subjects without DM, knowledge is associated with age, level of education, occupation, high blood pressure, blood lipid, and family history. In this study, the most common source of information was in both groups of physicians. Having a chronic disease in a close relative may be a good source of health information, but such a resource is only helpful and cannot be a reliable source (
21,
22). The knowledge levels among all partakers are directly associated with the level of ability to read and write, the activity level of imparting and acquiring skills received and ease to use of information on diabetes (
23). According to the study of Fatema et al., the people's knowledge on diabetic/non-diabetic status is related to age, gender, place of residence, education, income, but contrary to our study that women's knowledge was greater. Researches showed higher knowledge levels belong to men and higher levels of attitude and performance belong to women (
4). The findings of our study show that the gender gap is identical to studies in different countries, including Bangladesh, about KAP about DM (
24). According to Salehi et al. in 2016, there was a significant relationship between the level of education and the family history of diabetes with knowledge gained, and younger ones were more likely to seek and increase knowledge about diabetes than their elderly counterparts (
25). Against our study, the level of knowledge was related directly to age. In the study of Rezaee Esfahrood et al., an increase in the health literacy score was associated with increasing age and decreasing the incidence of diabetes. Furthermore, the mean health literacy score was significantly higher in males than in females and in retired people, residents of the city, people with a high school diploma and a high and medium economic status (
26). In a study conducted in South Sri Lanka, men and educated people had more knowledge than women and those with lower education (
19), which is consistent with the study of Fatema et al. (
4). In another study, a significant relationship was found between gender and marital status with knowledge. So that men and married women had more information than single women (
27). In a study done in China in 2016, diabetes health literacy was significantly different from age, family history of DM and chronic diseases, BMI, high blood pressure or type of diabetes, and others. Men and women without a hyperglycemia history and low education had lower health literacy levels about DM than others (
1). Bukhsh et al. researched health literacy levels, which correlated significantly with age, education, and marital status, and married people with higher education and age had higher health literacy and a better understanding of health information and instructions taken (
12). In the study of Demaio et al., the rural dwellers were unemployed, with a lower level of education than men with lesser knowledge (
14). This knowledge gap indicates huge differences in the pattern of public health policy and interventions in countries (
28). According to the regression test in this study, BMI, education, and information source was a common fact affecting the knowledge of and people with and without DM. Since obesity is one of the major risk factors for T2DM (
4), the mean BMI in patients with DM was higher than in patients without DM. Therefore, regarding the development of practice programs for diabetics, especially in prevention clinics, more attention should be devoted to exercise and diet. Besides, individuals should gain more knowledge in the field of information supply than before. Participants in this research suffered from a lack of perception, and the mean of patients with DM was higher than participants without DM. Time-efficient diagnosis and proper treatment play a significant role to prevent renal failure and blindness. Fatema et al.
4 study indicated that attitude scores did not have a significant effect on different groups (P < 0.05). Many factors contribute to diabetes effectiveness, such as age, education level, marital status, occupation, high blood pressure, blood lipids, family history, smoking, cardiovascular diseases, and information source. The attitude of people related to educational academic level, martial, and occupation status. In people without DM, attitudes had a significant relationship with age, gender, educational level, family history, smoking, cardiovascular diseases, and information source. As a result, women have a better attitude than those with academic education, a positive family history of diabetes, non-smokers, people with cardiovascular diseases, and those who obtained information from the doctor. According to the regression test, the factors affecting the attitudes of diabetics and non-diabetics are different and people have a greater impact on gender and duration of diabetes, but in the case of non-diabetic people and their knowledge about diabetes. The performance of diabetics was related only to age and place of residence. The performance of people without DM significantly correlated with age, marital status, education, blood pressure, blood lipids, family history of DM, and cardiovascular diseases. Therefore, the performance of married, educated people, with a lack of blood pressure and lipids, with no positive family history, and with no history of cardiovascular diseases was better. According to Fatema et al., people with higher BMI had better performance (
4). In Herath et al., individuals who were required to exercise and had a job had better control of their blood glucose than those with better physical activity and no occupation (
19). According to the regression test, the knowledge of individuals is one of the most important factors affecting the performance of both diabetic and non-diabetic groups and indicates that increasing their knowledge about DM will improve their performance. The results of Fatema et al. study showed that good quality of performance rose with better educational levels and better income in both respondents with/without DM (
4). Many studies have been done on the level of knowledge of patients' attitudes and practices in Iran (
29). In the study of Niroomand et al., the patients in this study had a high level of general knowledge and attitude, and the practice score was good in comparison with previous evaluations in Iran (
18). Not many studies are available, which indicate the relationship between knowledge and practice among NDM and DM groups. It has been described that patients with DM have a higher KAP score than patients without DM (
30,
31). The present study shows a significant positive relationship between attitude and knowledge and practice. A high level of knowledge is connected with a high level of attitude and practice, and a high level of attitude is associated with a high level of practice. This means better knowledge, better attitude, and ultimately better performance toward diabetes. These results harmonize in opinion with the results of other studies (
4,
32,
33).