Prevalence of type 2 diabetes complications and its association with diet knowledge and skills and self‐care barriers in Tabriz, Iran: A cross‐sectional study

Abstract Background and Aims Diabetes can lead to multiple complications that can reduce the quality of life, impose additional costs on the healthcare systems and ultimately lead to premature death. Proper self‐care in diabetic patients can impede or delay the onset of diabetes complications. This study aimed to investigate diabetes complications and their association with diet knowledge, skills, and self‐care barriers. Methods This was a cross‐sectional study. A total of 1139 patients with Type 2 Diabetes Mellitus (T2DM) referring to health centers in Tabriz, Iran, were included from January to July 2019. Data were collected using two questionnaires: (1) a sociodemographic questionnaire and (2) a Personal Diabetes Questionnaire (PDQ). Data were analyzed using SPSS software version 22. χ 2 test was used to examine the association between the socioeconomic and disease‐related variables and the prevalence of diabetes complications. T‐test was used to examine the association between diet knowledge and skills, self‐care barriers, and the incidence of diabetes complications. Results In this study, 76.1% of patients had at least one complication, and 30.2% had a history of hospitalization due to diabetes complications during the past year. Approximately 49% and 43% were diagnosed with high blood pressure and hyperlipidemia, respectively. Cardiovascular disease was the most common diabetes complication (15.9%) and the cause of hospitalization (11.01%) in patients with diabetes. Barriers to diet adherence, blood glucose monitoring, and exercise were significantly associated with self‐reported diabetes complications (p < 0.001). Our results showed no significant association between the number of complications and diet knowledge and skills (p = 0.44). Conclusion This study indicated that the prevalence of diabetes complications was higher among patients with more barriers to self‐care. In light of these findings, taking appropriate measures to reduce barriers to self‐care can prevent or delay the onset of diabetes complications.


| INTRODUCTION
The prevalence of diabetes is rising at an alarming rate, particularly in developing nations. 1 In 2021, 537 million adults (20-79 years) were living with diabetes.
This number is projected to rise to 643 million by 2030 and 783 million by 2045. Over 3 in 4 adults with diabetes live in low-and middleincome countries. 2 According to World Health Organization (WHO), 1.5 million deaths are directly attributed to diabetes yearly. 3 According to the latest figures from the International Diabetes Federation (IDF) in 2022, the prevalence of diabetes and total cases of diabetes in adults in Iran is estimated to be 9.5% and 5,450,300, respectively. 4 It is projected that in Iran, 9.2 million will have diabetes by 2030. 5 Patients with diabetes are at higher risk of morbidity, mortality, 6 and other chronic noncommunicable or infectious diseases. 7 Diabetes can lead to life-threatening complications, including cardiovascular disease, retinopathy, nephropathy, neuropathy, and diabetic foot ulcer. [8][9][10] However, diabetes can be controlled and managed with proper self-care behaviors. 11 Self-care is an influential factor in controlling diabetes 12 and preventing complications, 13 and it has been shown that it can be even more effective than drug interventions. 12 The diabetes self-care behaviors include adherence to a dietary regime, medication adherence, regular physical activity, proper medication follow-up, blood glucose self-monitoring, monitoring disease progression, and foot care practices. [14][15][16][17] Commitment to these behaviors can reduce the risk of complications and improve quality of life. [18][19][20] The ability to self-manage depends on some factors, such as sociodemographic and clinical factors (e.g., the complexity of treatment regime and comorbidities), as well as systemic factors (e.g., social support and communication) with healthcare providers. 21 Research also shows adequate knowledge is a significant component of diabetes management. 22,23 Diabetes knowledge is an essential precondition for effective self-care activities and favorable health outcomes. 24 Assessing the associations between diabetes complications and self-care barriers and diet knowledge can help to identify barriers to self-care that affect the incidence of diabetes complications.
Assessing the associations between diabetes complications and self-care barriers and diet knowledge can assist health policymakers and health managers in identifying the most important barriers to self-care in diabetes complications and adopting effective measures/interventions to address the barriers in patients with T2DM.
This study aimed to examine the prevalence of diabetes complications and their associations with diabetes self-care barriers in patients with T2DM.

| Study design and setting
This cross-sectional study examined the association between the prevalence of T2DM complications, diet knowledge and skills, and self-care barriers. A cross-sectional study helps establish preliminary evidence for a causal relationship. A total of 1139 patients with T2DM were recruited in this study. The statistical population included all patients with T2DM in Tabriz, Iran. The inclusion criteria for this study were as follows: age of ≥18 years and a confirmed diagnosis of T2DM. Those with a physical or mental disability were excluded from the study.

| Sample size and sampling method
Using the consecutive sampling method, we included all patients referring to educational hospitals, diabetes clinics, and primary healthcare centers affiliated with Tabriz University of Medical Sciences and private endocrinologist offices from January to July 2019.
This study was a part of a PhD thesis (Grant Number; IR.TBZMED.REC.61521), and a part of this was related to the design of a questionnaire to assess reasons for forgone care in diabetic patients. Therefore, the researcher needed to perform exploratory and confirmatory factor analysis. Comrey and Lee 25 provided the following guidance in determining the adequacy of sample size for conducting factors analysis: 100 = poor, 200 = fair, 300 = good, 500 = very good, and 1000 or more = excellent. The researchers, therefore, needed more than 1000 samples to improve sampling adequacy. However, considering the impact of sample size on factor analysis results (a larger sample will lead to more reliable results), 1200 questionnaires were distributed among subjects, and 61 questionnaires were discarded due to incomplete and/or incorrect information. Finally, 1139 patients were included in our analysis.

| Data collection tools and data collecting process
Data were collected through two questionnaires. The first questionnaire consisted of three parts. The first part was related to sociodemographic characteristics such as age, gender, educational status, income level, and insurance coverage status. The second part was related to variables such as disease duration, Body Mass Index (BMI), current treatment type, and the history of hospital admission during the last year due to diabetes complications. The third part was questions related to comorbidities and diabetes complications such as high blood pressure status, hyperlipidemia, heart diseases, neuropathy, nephropathy, retinopathy, and foot ulcer.
The second questionnaire was the Personal Diabetes Questionnaire (PDQ). This questionnaire is a brief yet comprehensive measure of diabetes self-care behaviors, perceptions, and barriers and is used to collect data related to the status of diet knowledge and skills, diet decision-making, eating problems, diet adherence barriers, blood glucose monitoring barriers, medication barriers, and exercise barriers.
The development and initial evaluation of the psychometric properties of the PDQ questionnaire were assessed by Stetson et al. 26 Subscales demonstrated good internal consistency (Cronbach α = 0.650-0.834) and demonstrated significant associations with BMI (p ≤ 0.001) and HbA1c (p ≤ 0.001). In this study, the questionnaire was first translated from English to Persian and then back-translated into English by a professional translator to ensure the first translation was accurate.
Also, face validity was conducted by asking the endocrinologists, general practitioners, nutritionists, and public health specialists to comment on the clarity and flow of the questions in the proposed questionnaire. In our study, Cronbach's α was 0.81 for the total score, with subscales ranging from 0.68 to 0.84.
In our study, literate participants completed the questionnaire in 10 min, and for those who were illiterate, the questions were read to them, and they responded accordingly. Each interview lasted 20 min.
Trained interviewers did all interviews.

| Subscale description and scoring
The PDQ consists of eight subscales: diet knowledge and skills, diet decision-making, eating problems, diet adherence barriers, blood

| Statistical analysis
Statistical analyses were performed using SPSS software version 22.
Descriptive statistics such as frequency, mean, and standard deviation (SD) were used to examine sociodemographic and disease characteristics, the prevalence of comorbidities and diabetes complications, diet knowledge and skills, and self-care barriers. χ 2 test was used to examine the association between the socioeconomic and disease-related variables and the prevalence of diabetes complications. T-test was used to examine the association between diet knowledge and skills, self-care barriers, and the incidence of diabetes complications. A generalized linear model regression was used to assess the factors influencing the number of diabetes complications.
Multivariate linear regression was applied to assess the effect of self-care barriers on the number of diabetes complications. The tests were carried out at a 5% significance level, and a p ≤ 0.05 was considered significant.

Ethics approval and consent to participate
This study was a part of a comprehensive PhD thesis work, ethically approved by the Ethics Committee of Tabriz University of Medical Sciences (Reference Number; IR.TBZMED.REC.1397.166). All participants were assured that the data would be confidential and anonymous. Verbal informed consent was obtained from all participants involved in this study. Informed consent from all participants has been obtained. All methods were performed in accordance with relevant guidelines and regulations that must be considered in research where humans are involved.

| RESULTS
The sociodemographic and disease characteristics of the 1139 participants are shown in Table 1. The mean age of participants was 56.93 ± 13.34. Two-thirds of the participants were women, and most (41.5%) were illiterate. The yearly household income of 74.8% was >2287.26 (PPP, Current International $). More than two-thirds of participants were not covered by supplemental insurance. Most of the patients (88.1%) resided in urban areas. Most participants were on oral medicine, and just 6.2% changed their lifestyle as the main treatment strategy. The mean duration of diabetes and the mean BMI of the participant were estimated at 9.06 ± 7.12 years and 28.37 ± 5.27, respectively. Table 1, the variables of gender, age, education, BMI, disease duration, type of treatment, and history of forgoing treatment were significantly associated with the presence of diabetes complications (p < 0.05). Women, older people, those with lower education, higher BMI groups and those with longer disease durations, those with a history of forgoing treatment, and those whose main treatment was based on insulin injection were Results showed that 76.1% of patients had at least one complication. In our study, 48.6% and 42.7% were diagnosed with high blood pressure and hyperlipidemia, respectively. The mean score of reported barriers to diabetes self-care in individuals with and without complications is presented in Table 2.

As shown in
T A B L E 1 The prevalence rate of diabetes complications is based on demographic and socioeconomic, and disease characteristics.  59 Ong et al. 60 showed that the factors that influenced the self-monitoring of blood glucose were mainly related to cost, participants' emotions, and the self-monitoring of the blood glucose process.
In the United States, reimbursement criteria have been announced for therapeutic continuous glucose monitoring devices for patients with T1DM and T2DM on intensive insulin treatment. 61

ACKNOWLEDGMENTS
The authors thank the staff of educational hospitals, clinics, and primary health centers in Tabriz for assistance during the data collection process. We also thank all patients that participated in this study. This study was supported by Tabriz

CONFLICT OF INTEREST STATEMENT
The authors declare no conflict of interest.

DATA AVAILABILITY STATEMENT
The data sets used and/or analyzed during this study are available from the corresponding author upon reasonable request.

TRANSPARENCY STATEMENT
The lead author Habib Jalilian affirms that this manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.