Type 2 diabetes mellitus (T2DM) is among the most common forms of chronic metabolic disorders, accounting for about 90% of all people with diabetes [1]. Type 2 diabetes mellitus is associated with a greater risk of cardiovascular diseases (CVD), including coronary artery disease (CAD) with chest pain (angina), heart attack, stroke, atherosclerosis, and hypertension [2]. Carotid intima-media thickness (CIMT) is related to cardiovascular risk factors and diseases, and its measurement by means of ultrasound makes it possible to detect thickening in the initial phases of atherosclerosis [3]. For every 0.1-mm increase in carotid IMT, the relative risk of ischemic heart disease increases by 15% and that of cerebrovascular disease by 18% [4].

CIMT is significantly higher in diabetic patients than in nondiabetic subjects, and an increased CIMT is associated with angiography-evaluated coronary artery disease and predicts future events of silent brain infarction and coronary heart disease in type 2 diabetic subjects [5].

It was an observational cross-sectional study. It included 120 patients according to inclusion criteria. The study was approved by institutional ethical committee and all participants signed informed consent forms before enrolment.

We included those • Patients attending J.A.H. group of hospitals diagnosed as Diabetics in last 5 years. • Patients of Age >18 years • Normotensives and we excluded those: • Known case of Diabetes mellitus for more than 5 years. • Pregnant women • Patient with chronic disease like chronic kidney disease, chronic obstructive pulmonary disease, chronic liver disease, asthma, congenital heart disease. • Patients with diabetic ketoacidosis. • Patients with hyperosmolar hyperglycaemic state. • Patients on chronic steroid therapy.

We collected information including demographic data, weight, height, history of smoking, and hypertension etc. (BMI) was defined as the person’s body weight divided by the square of the person’s height. Laboratory tests were performed using standard methods.

Ultrasound investigation of carotid arteries with estimation of CIMT and identification of plaques was performed. The CIMT was measured as an average of the segmental maximum along the distal 1 cm region of each common carotid artery, within a region free of plaques with a clearly identified double-line pattern. CIMT values above 0.9 mm were considered as increased. A plaque was identified as a focal wall thickening at least 50% greater than that of the surrounding vessel wall, or as a focal region with CIMT > 1.5 mm that protrudes into the lumen and is distinct from the adjacent boundary, according to the recommendations of the American Society of Echocardiography. Left ventricular ejection fraction was also measured.

Statistical analysis: All analyses were performed using the Statistical Package for Social Sciences, version 26.0 (SPSS, PC version, Chicago, IL, USA). Categorical variables were expressed as numbers and percentages, while continuous variables were expressed as mean ± standard deviation (SD). The chi-square (χ2) test was used to compare categorical variables; hence, continuous variables were compared with a Student t-test. Correlation analysis was performed using Pearson or Spearman tests. Levels of statistical significance were set at a P value < 0.05.

Demographic variable:  A total of 120 patient were included in the study. Majority patients were within the 51-60 years age group (34.2%), followed by the 61-70 years (28.3%) and 41-50 years (15.8%) age groups. A smaller proportion of patients were either younger than or equal to 40 years (13.3%) or older than or equal to 71 years (8.3%). Out of the 120 patients, 76 (63.3%) were male, while 44 (36.7%) were female. Most patients (75.0%) fall into the obese category (BMI of 25.0-29.9 kg/m²), highlighting a significant prevalence of excess weight in this population. A smaller percentage of patients are categorized as normal weight (15.0%), with very few patients classified as severely obese (≥30.0 kg/m²) as seen in table 1.

Table 1:  Demographic distribution

Diabetes history: A relatively even distribution of diabetic patients between those newly diagnosed (61 patients, 50.8%) and those with known cases of diabetes (59 patients, 49.2%) was observed in the study. Many patients (71.2%) have been diagnosed diabetes for 2-4 years, followed by a smaller proportion (22.0%) diagnosed within the past 2 years. A very small percentage (6.8%) had history of diabetes for more than 4 years. A significant portion (55.8%) reported not being on any treatment while the majority were newly diagnosed. Among those receiving treatment, the most common regimen was oral hypoglycaemic agents (OHA) alone (34.2%), followed by a combination of insulin and OHA (6.7%), and lastly, insulin alone (3.3%).A substantial proportion (31.7%) of the patients reported having a current smoking habit, while the majority (68.3%) were non-smokers

Table 2: History of diabetes distribution

Addiction history:  A substantial proportion (31.7%) of the patients reported having a current smoking habit, while the majority (68.3%) were non-smokers. Notably, a considerable proportion (32.5%) of patients reported a current habit of chewing tobacco, while 67.5% were non-users.

Table 2:  Addiction distribution

Blood investigation:

Fasting blood sugar: Many patients (67.5%) had FBS levels within the 126-200 mg/dL range, indicating suboptimal glycaemic control. A smaller proportion (25.0%) had higher FBS levels (≥201 mg/dL), suggesting poor glycaemic control and a heightened risk of complications. Only a small percentage (7.5%) achieved optimal FBS levels (≤125 mg/dL).

Post prandial blood sugar: Many patients (57.5%) had PPBS levels in the 201-300 mg/dL range, indicating suboptimal glycaemic control after meals. A substantial proportion (23.3%) had even higher PPBS levels (≥301 mg/dL), suggesting poor postprandial glycaemic control.

HbA1C Levels: The largest proportion of patients (38.3%) fell within the 7.1-9.0% range, indicating fair glycaemic control. However, a combined 46.7% of patients had HbA1c levels above 9.0%, with 22.5% in the 9.1-11.0% range (poor control) and 24.2% with levels exceeding 11.1% (very poor control).

Total cholesterol: A substantial proportion of patients (41.7%) had optimal total cholesterol levels (<200 mg/dL). However, a significant number (58.3%) presented with borderline high or high total cholesterol levels (200-239 mg/dL and ≥240 mg/dL, respectively).

LDL levels: While 21.7% of patients had optimal LDL levels (<100 mg/dL), a considerable portion (78.3%) presented with elevated levels. This includes 23.3% in the near optimal/above optimal range (100-129 mg/dL), 20.0% in the borderline high range (130-159 mg/dL), 19.2% in the high range (160-189 mg/dL), and 15.8% in the very high range (≥190 mg/dL).

Total serum TG levels in mg/dL: A small proportion (14.2%) had optimal triglyceride levels (<150 mg/dL). The majority (46.7%) had borderline high levels (150-199 mg/dL), while a significant 39.2% had high levels (200-499 mg/dL). Notably, no patients had very high triglyceride levels (≥500 mg/dL).

Table 3: blood parameter distribution

Echocardiography:

Right CIMT values in mm: A significant proportion of patients (37.5%) had normal or near-normal right CIMT values (≤0.80 mm). However, a combined 55% of patients exhibited increased CIMT values, with 25% in the 0.81-1.00 mm range and 30% in the 1.01-1.20 mm range, suggesting subclinical atherosclerosis. A smaller percentage (7.5%) had right CIMT values exceeding 1.21 mm, indicating a higher risk of cardiovascular events.

Left CIMT values in mm: left carotid intima-media thickness (CIMT) values within the study population. A substantial proportion of patients (35.8%) exhibited normal or near- normal left CIMT values (≤0.80 mm). However, more than half of the patients (64.2%) showed increased CIMT values, with 25.8% in the 0.81-1.00 mm range, 30.0% in the 1.01-1.20 mm range, and 8.3% with values exceeding 1.21 mm.

LV systolic dysfunction: A notable 35.0% of patients were diagnosed with LV systolic dysfunction, indicating impaired contractile function of the heart's left ventricle. The remaining 65.0% of patients did not exhibit this dysfunction

LV ejection fraction: The majority of patients (39.2%) had LVEF values in the 41-50% range, indicating normal cardiac function. A substantial proportion (35.8%) had LVEF values in the 51-60% range, suggesting slightly above-normal function. However, a combined 23.4% of patients had LVEF values below 40%, indicating varying degrees of impaired cardiac function, with 16.7% in the 31-40% range (mild to moderate dysfunction) and 6.7% below 30% (severe dysfunction).

ECG: A significant portion of the patients (40.8%) presented with ECG abnormalities, while the remaining 59.2% had normal ECG findings

Table 4: Echocardiography Distribution

Comparison of cardiac media thickness with blood sugar levels:

Fasting blood sugar: A one-way ANOVA test reveals a statistically significant difference in mean CIMT between the groups (F = 6.663, p = 0.002). Specifically, the mean CIMT progressively increases with higher FBS levels (0.806 mm for ≤125 mg/dL, 0.896 mm for 126-200 mg/dL, and 1.021 mm for ≥201 mg/dL), suggesting that poorer glycemic control, as reflected by higher FBS, is associated with increased carotid artery wall thickness, a marker of cardiovascular risk

Post prandial sugar: Statistically significant difference in mean CIMT between the groups (F = 7.464, p < 0.001) was found. Specifically, the mean CIMT progressively increases with higher PPBS levels (0.832 mm for ≤140 mg/dL, 0.798 mm for 141-200 mg/dL, 0.909 mm for 201-300 mg/dL, and 1.044 mm for ≥301 mg/dL). This suggests that poorer postprandial glycemic control, reflected by higher PPBS levels, is associated with increased carotid artery wall thickness, a well-established marker of cardiovascular risk in diabetic patients.

HbA1C:  Similarly a statistically significant difference in mean CIMT between these groups (F = 4.768, p = 0.004). The mean CIMT demonstrates a trend of increasing with higher HbA1c levels (0.8806 mm for ≤7.0%, 0.8622 mm for 7.1-9.0%, 0.9367 mm for 9.1-11.0%, and 1.0245 mm for ≥11.1%). This suggests a positive association between long-term glycemic control, as reflected by HbA1c, and carotid artery wall thickness, a well-established marker of cardiovascular risk in diabetic patients.

Table 5: Comparison of cardiac media thickness with blood sugar levels

Corelation between carotid intima-media thickness (CIMT) and glycemic parameter:

The Spearman rank correlation coefficients between carotid intima-media thickness (CIMT), glycemic control measures (FBS, PPBS, HbA1c), and diabetes duration:  As expected, all three CIMT measurements (mean, right, and left) demonstrate very strong positive correlations with each other (r > 0.98, p < 0.01). This indicates that the thickness of the carotid artery wall is consistent across different locations. significant positive correlations are observed between CIMT and all glycemic parameters. CIMT shows moderate correlations with FBS (r = 0.285, 0.308, 0.282), stronger correlations with PPBS (r = 0.366, 0.383, 0.359), and the strongest correlations with HbA1c (r = 0.365, 0.380, 0.357), all with p < 0.01. These findings suggest that poorer glycemic control, reflected by higher levels of FBS, PPBS, and HbA1c, is associated with increased carotid artery wall thickness, a known marker of cardiovascular risk in diabetic patients. Additionally, there's a moderate positive correlation between diabetes duration and CIMT (r = 0.322, 0.332, 0.311, p < 0.05), suggesting that longer duration of diabetes may contribute to the progression of atherosclerosis in the carotid arteries. The strong positive correlations observed between FBS, PPBS, and HbA1c (r > 0.75, p < 0.01) underscore the interconnectedness of these glycemic control measures. Similarly, the moderate positive correlation between diabetes duration and each of the glycemic parameters (p < 0.01) suggests that longer duration of diabetes is associated with poorer glycemic control.

Table 6: Corelation between carotid intima-media thickness (CIMT) and glycemic parameter

Corelation between carotid intima-media thickness (CIMT) and lipid profile parameter:

The Spearman rank correlation coefficients between carotid intima-media thickness (CIMT) and lipid profile parameters in diabetic patients.Crucially, CIMT exhibits strong positive correlations with total cholesterol (r = 0.676, 0.671, 0.678) and LDL cholesterol (r = 0.632, 0.627, 0.630), and a moderate positive correlation with triglycerides (r = 0.575, 0.581, 0.571), all with p < 0.01. These findings strongly suggest that elevated levels of these lipids contribute to the development and progression of atherosclerosis in the carotid arteries of diabetic individuals.Conversely, CIMT shows strong negative correlations with HDL cholesterol (r = -0.611, -0.606, -0.602, p < 0.01). This indicates that higher levels of HDL cholesterol, may exert a protective effect against arterial wall thickening in diabetic patients.

Table 5: Corelation between carotid intima-media thickness (CIMT) and lipid profile parameter

cIMT is widely recognized as a marker of early stage atherosclerosis and the severity of CAD, which can be used to indirectly assess coronary artery conditions. In the study conducted by Dehdasht et al., a highly significant association was found between blood sugar levels and CIMT. Similarly, Mita et al. noted that glycemic control levels were linked with CIMT, with HbA1c levels showing a significant inverse correlation with CIMT. Haring et al. examined the relationship between HbA1c and mean CIMT among 1,798 individuals without diabetes, finding a positive correlation that helps explain the link between elevated HbA1c levels and increased cardiovascular disease and mortality risks.[8]

Contrarily, a combined analysis of five longitudinal studies involving 1,881 Japanese patients with diabetes demonstrated that an increase in the common carotid artery mean intima-media thickness (CCA-mean-IMT) over time was a significant prognostic factor for cardiovascular disease (CVD) (HR 2.37 for every 0.1-mm/year increase, 95% CI 1.63–3.47, P < 0.001). Notably, this association remained significant even after adjusting for traditional risk factors (HR 1.77 for every 0.1-mm/year increase, 95% CI 1.18–2.66, P = 0.006).[9]

Previously, studies have suggested that T2DM is a coronary heart disease (CHD) risk equivalent, prompting recommendations for aggressive cardiovascular risk management and pharmacotherapy. However, recent insights reveal that not all T2DM patients face the same level of cardiovascular risk, highlighting the need for a more personalized approach based on individual cardiovascular risk profiles. Specifically, while T2DM may be a CHD equivalent in patients with longer disease duration, this may not apply to those in earlier stages. Beyond glycemic control, cardiovascular risk in T2DM patients is also influenced by factors such as obesity, hypertension, pro-atherogenic lipids, insulin resistance, and chronic low-grade inflammation. Current international guidelines stress the importance of tailoring treatment for T2DM patients, considering factors like atherosclerotic cardiovascular disease (ASCVD) presence and disease duration to guide decisions on antihyperglycemic therapy and glycemic treatment targets.[10]

We find that patients with poorly controlled type 2 diabetes (DM2) who have macrovascular disease show more severe vascular dysfunction, as indicated by non-invasive markers of subclinical atherosclerosis. Additionally, patients who have been diagnosed with diabetes for less than 5 years tend to have a significantly better vascular profile. Future prospective studies should investigate the potential of using vascular indices to assess cardiovascular risk in patients with DM2, both with and without existing cardiovascular disease

1. Dehdashti Sharokh H, Zakerkish M, Sina A H, Saki A, Forouzan F Diagnostic Value of Carotid Artery Intima-media Thickness in Patients with Type 2 Diabetes and Its Correlation with HbA1c Levels. Jundishapur J Chronic Dis Care. 2021 ; 10(2): e111308 
2. Morrish NJ, Wang SL, Stevens LK, Fuller JH, Keen H. Mortality and causes of death in the WHO Multinational Study of Vascular Disease in Diabetes. Diabetologia. 2001;44 Suppl 2:S14-21.
3. O’Leary DH, Polak JF, Kronmal RA, Manolio TA, Burke GL, Wolfson SK.Carotid-artery intima and media thickness as a risk factor for myocardial infarction and stroke in older adults. Cardiovascular Health Study Collaborative Research Group.N Engl J Med., 340 (1999), pp. 14-22
4. Lorenz MW, Markus HS, Bots ML, Rosvall M, Sitzer M.Prediction of clinical cardiovascular events with carotid intima-media thickness: a systematic review and meta-analysis.Circulation., 115 (2007), pp. 459-467
5. Yokoyama H, Katakami N, Yamasaki Y. Recent advances of intervention to inhibit progression of carotid intima-media thickness in patients with type 2 diabetes mellitus. Stroke. 2006 Sep;37(9):2420-7. doi: 10.1161/01.STR.0000236632.58323.cd. Epub 2006 Aug 3. PMID: 16888250.15.
6. Mita T, Watada H, Shimizu T, Tamura Y, Sato F, Watanabe T, Nateglinide reduces carotid intima-media thickening in type 2 diabetic patients under good glycemic control. Arterioscler Thromb Vasc Biol. 2007;27(11):2456-62.
7. Haring R, Baumeister SE, Lieb W, von Sarnowski B, Volzke H, Felix SB,. Glycated hemoglobin as a marker of subclinical atherosclerosis and cardiac remodeling among non-diabetic adults from the general population. Diabetes Res Clin Pract. 2014;105(3):416-23.
8. Dehdashti Sharokh H, Zakerkish M, Sina A H, Saki A, Forouzan F, . Diagnostic Value of Carotid Artery Intima-media Thickness in Patients with Type 2 Diabetes and Its Correlation with HbA1c Levels. Jundishapur J Chronic Dis Care. 2021;10(2):e111308. https://doi.org/10.5812/jjcdc.111308.
9. Katakami N, Mita T, Gosho M, Clinical utility of carotid ultrasonography in the prediction of cardiovascular events in patients with diabetes - a combined analysis of data obtained in five longitudinal studies. J Atheroscler Thromb 2018; 25: 1053–1066.
10. Antoniou, S.; Naka, K.K.; Papadakis, M.; Bechlioulis, A.; Makriyiannis, D.; Tsatsoulis, A.; Michalis, L.K.; Tigas, S. Relationship between Indices of Vascular Function and Presence of Overt Cardiovascular Disease among Persons with Poorly Controlled Type 2 Diabetes. J. Cardiovasc. Dev. Dis. 2021, 8, 185. https://doi.org/10.3390/jcdd8120185