Nutritional factors, including diet, exercise, and smoking, are known risk factors for atherosclerosis, the primary cause of cardiovascular disease ([@B1]). An atherogenic diet is characterized by a high content of saturated fatty acids, total calories, and fat, a low content of polyunsaturated fatty acids, total carbohydrates, and fiber, and poor fruit, vegetable, and fish consumption ([@B2]). Diet and exercise are cornerstones of cardiovascular prevention, although there are substantial variations in dietary intake among patients with coronary heart disease (CHD) ([@B3]). Therefore, the current study used a diet and exercise questionnaire to evaluate the relationship between diet and exercise and atherosclerosis among diabetic patients in Hamadan, Iran. RESEARCH DESIGN AND METHODS {#s5} =========================== The cross-sectional study was performed on 385 outpatients with diabetes aged 15--85 years from November 2006 to December 2008 in the Diabetes Research Center (Hamadan University of Medical Sciences, Hamadan, Iran). The diabetic patients had no cardiovascular disease, no history of taking any cholesterol-lowering drug, and no history of taking any drugs affecting the heart or blood vessels. The study protocol was approved by the local ethics committee. The study protocol was in accordance with the Helsinki Declaration of 1975. All of the participants read and signed a consent form before entering the study. Participants filled out a 2-day food record, including a weekend day and a working day. The participants were instructed on how to record foods in a 7-day food record (including 2 weekdays and 1 weekend day) ([@B4]). These forms were provided to the patients to be filled out at home, and all data were analyzed using Nutritionist IV software (first version; N-Squared Computing, Salem, OR). In this study, we used the AHA classification ([@B5]) to classify diets into 5 types, A, B, C, D, and E. The five categories are as follows: A, the diet of patients with CHD; B, the diet of diabetic patients; C, the diet of patients with CHD or diabetes; D, the diet of diabetic patients with CHD; and E, the diet of diabetic patients with no CHD. The questionnaire for calculating physical activity levels consisted of six questions about physical activities in a typical week, including swimming, climbing stairs, running, walking, housework, and heavy work. The participants were requested to quantify their activity level based on the metabolic equivalent (MET) index, which is a multiple of the person\'s body weight divided by the product of the resting metabolic rate and 3.5 (moderate activity). The total physical activity level was calculated by the formula METs\*min/week. This physical activity scale is used to estimate the energy requirements of individuals. The total MET minutes/week for moderate physical activity was calculated by multiplying the MET value of each activity by the minutes spent on that activity ([@B6]). The levels of physical activity of the subjects were recorded. Physical inactivity was defined as METs\*min/week ≤400. The subjects were categorized as physically active or inactive. In this study, physically inactive patients, those who had not exercised for at least 30 min three times a week, were placed in the inactive group. The physically active subjects exercised more than 40 min at least 3 times per week. Arterial stiffness was measured using a vascular screening device (Mobil-O-Graph; IEM, Stolberg, Germany). The stiffness index (SI) was used to evaluate arterial stiffness. The calculation of SI was based on the pulse wave at the central arterial level. For this purpose, five measurements were performed in patients with sinus rhythm, and 20 measurements were performed in patients with atrial fibrillation. For the purposes of this study, we evaluated the association of dietary intake with SI as a marker of atherosclerosis in patients with diabetes mellitus. The SI was considered to be a continuous variable. Logistic regression analyses were used to evaluate dietary intake as risk factors for atherosclerosis. In the univariate analysis, the *t* test and χ^2^ test were used to determine associations between SI with all possible predictors (age, sex, cigarette smoking, BMI, hypertension, physical activity, and the type of diet). The multivariate analysis was conducted using logistic regression analysis after adjusting for age and sex and considering all potential confounders. Analyses were performed using SPSS version 17 (SPSS, Chicago, IL), and the level of statistical significance was set at *P* ≤ 0.05. RESULTS {#s6} ======= A total of 385 patients (154 males and 231 females) were enrolled in this study. The mean age of the participants was 58.3 years. In this study, 53 patients (13.9%) had type 1 diabetes, 33 patients (8.6%) had type 2 diabetes, and 309 patients (80.6%) had both types of diabetes. The results showed that 73 patients (18.9%) had hypertension, 18 patients (4.6%) had hyperlipidemia, and 18 patients (4.6%) had CVD ([Table 1](#T1){ref-type="table"}). ###### Descriptive characteristics of the study participants  There were significant differences between the atherosclerosis and atherosclerosis-free groups in terms of age, sex, hyperlipidemia, and hypertension. The mean age was significantly higher among patients with atherosclerosis than those without atherosclerosis (59.2 ± 9.3 vs. 55.3 ± 10.8 years, *P* \< 0.001). The proportion of male participants was significantly higher among patients with atherosclerosis than those without atherosclerosis (50.6% vs. 39.6%, *P* = 0.015). Patients with atherosclerosis were more likely to have hyperlipidemia (27.8 vs. 15.9%, *P* = 0.003) and hypertension (57.5 vs. 43.4%, *P* = 0.001). More patients with atherosclerosis than without atherosclerosis had type 2 diabetes (87.3 vs. 60.4%, *P* \< 0.001). The mean SI was significantly higher among patients with atherosclerosis than those without atherosclerosis (1.13 ± 0.1 vs. 1.0 ± 0.1, *P* \< 0.001). There was no significant difference in the SI among smokers and nonsmokers in patients with or without atherosclerosis (1.1 ± 0.1 vs. 1.1 ± 0.1, *P* = 0.93). The most prevalent type of diet among the subjects was type A, and the least prevalent type of diet was type E ([Fig. 1](#F1){ref-type="fig"}). [Table 2](#T2){ref-type="table"} shows the association between SI and type of diet and total physical activity level as a continuous variable. There was a significant association between diet type and SI (type A, 1.2 ± 0.1; type B, 1.1 ± 0.1; type C, 1.1 ± 0.1; type D, 1.1 ± 0.1; type E, 1.1 ± 0.1, *P* = 0.005). A significant positive association was found between SI and total physical activity as a continuous variable in all patients (Spearman correlation coefficient, *P* \< 0.001). {#F1} ###### Association between SI and type of diet as a continuous variable  There were significant associations between SI and age, sex, total physical activity, and cigarette smoking among patients with diabetes. SI was significantly higher in older participants than younger participants (*P* = 0.005), in males than in females (*P* \< 0.001), in nonsmokers than in smokers (*P* \< 0.001), and in patients with a low physical activity level compared with those with a moderate or high physical activity level (*P* = 0.004). SI was significantly higher in patients with hypertension than without hypertension (*P* = 0.005) ([Table 3](#T3){ref-type="table"}). SI was significantly higher in patients with atherosclerosis than those without atherosclerosis (*P* \< 0.001). ###### Association between SI and risk factors for atherosclerosis among patients with diabetes  [Table 4](#T4){ref-type="table"} shows the relationship between SI and variables as a categorical variable in all participants. SI was significantly higher in men than in women (1.2 ± 0.1 vs. 1.1 ± 0.1, *P* = 0.006). SI was significantly higher in nonsmokers than in smokers (1.2 ± 0.1 vs. 1.1 ± 0.1, *P* = 0.049). SI was significantly higher in patients with hyperlipidemia than in patients without hyperlipidemia (1.2 ± 0.1 vs. 1.1 ± 0.1, *P* = 0.048). There was a significant association between SI and diet type in all participants (type A, 1.2 ± 0.1; type B, 1.1 ± 0.1; type C, 1.2 ± 0.2; type D, 1.1 ± 0.1; type E, 1.0 ± 0.1, *P* = 0.003). ###### Association between SI and variables as a categorical variable ![](