Diabetes mellitus (DM) and its chronic complications are the major world health problem having an upward trend in the whole world. It is believed that currently 366 millions of people suffer from DM worldwide, and by the year 2030 the number of diabetics will increase to 552 million. The number of patients with DM rises in all countries, and 80% percent of the world’s population suffering from diabetes live in developing countries or newly industrialized countries. (1) The Republic of Croatia (HR) and Bjelovar-Bilogora County (BBZ) are not exempt from this trend and the prevalence of DM in Croatia is 6.1%, while the incidence of glucose metabolism disorder (fasting hyperglycemia) is 11.3%, which data exceeds our expectation. (2) According to the 2011 population census, 119,000 of citizens live in BBZ. Compared to the population census conducted 10 years ago, when 133,000 persons lived in the County, this is a decrease in the number of population by 14,000! Natural growth in the same year amounted to -656 persons, and the average age is 42, which indicates a significant proportion of older population.

It is known that besides genetic factors for occurrence of DM, particularly of type 2, the environmental factors and especially lifestyle factors greatly influence the incidence of the disease. Physical inactivity, alcohol and eating habits (obesity), except for being well-known risk factors for the occurrence of DM type 2, also contribute to poorer control of the disease that is present. (3) The BBZ region belongs to the regions in the HR where more animal fat is used in diet, more salt is added to food, people eat more refined sugar and less fruit and vegetables. (4) This County is classified in the regions in the HR with the greatest prevalence of alcohol consumption. (5) Therefore, each year there is an increasing number of patients suffering from DM type 2 at the Center for Diabetes in BBZ.

Cardiovascular complications are the leading cause of morbidity and mortality among patients with DM, and the risk of coronary artery disease (CAD) is 2-4 times higher than in the general population. (6) Compared to the healthy population, the total mortality from myocardial infarction (MI) is four times higher among men and 7 times higher among women. Heart disease (68%) and stroke (16%) are the most common causes of death in diabetics. (7) Dyslipidemia characterized by high cholesterol levels, especially LDL fraction and high triglycerides and reduced HDL values are a frequent finding seen in diabetics. (8) Many intervention studies have clearly demonstrated the reduction in mortality from CHD after the regulation of hypercholesterolemia and hypertriglyceridemia. (8) Arterial hypertension is the most common cause of heart failure. (9)

Good control of DM or HbA1c reduction by only 1% reduces the overall risk of developing diabetic complications by 21%, reduces the risk of microvascular complications by 37% and reduces the risk of MI by 14%. (7)

The aim of this article is to present the trends of modifiable cardiovascular risk factors in the database of diabetic outpatients in the region of BBZ.

Data were collected by using the database of the computer program CroDiab NET that was introduced by the Center for Diabetes BBZ in 2001 as part of the national registry for diabetes.

This study included 4,408 anamneses processed during the period from 2001 to 2012 considering the type of DM, body mass index (BMI), type of therapy, Hba1c level, frequency of dyslipidemia, arterial hypertension, history of MI and stroke. The frequency of observed characteristics has been presented in all patients, as well as the trend of the observed characteristics over the years.

The value of BMI was calculated by using the formula BMI = body weight (kg)/ body height (m)2. The value up to 25 was considered normal, the patients whose BMI value was 25-30 were considered overweight, and the patients whose BMI value was BMI >30kg/m2 were considered obese patients.

The values of glycated hemoglobin (Hba1c) <6.5% were considered to be a sign of good control, the marginal values were considered to be the values between 6.6% -7.5% and Hba1c value greater than 7.5% was considered a sign of poor disease control. (7)

Considering the fact that this is the population suffering from DM, the elevated blood pressure is considered to be the value over 130/80 mmHg. (10)

Dyslipidemia refers to the value of LDL cholesterol >2.6 mmol/L, HDL cholesterol <1.02 mmol/L, triglycerides >1.7 mmol/L. (11)

According to the data of CroDiab NET for the year 2006 only 21.6% of patients have the value of Hba1c <6.5% at the level of the HR, or the good regulation of DM, while in the year 2012 this percentage was 26.9%. (12) The data for the observed subjects from BBZ are worse. Only 18% of the observed population has good glycemic control, but there is an encouraging fact that there is an upward trend of well regulated and marginally regulated patients with a decline in the proportion of patients with very high Hba1c (over 7.5%) in the last two years. There is also encouraging data concerning ever smaller percentage of patients with unknown Hba1c that at the beginning of the observed period was not determined in the Bjelovar General Hospital at all (still is not determined in the laboratory of the Health Centres in BBZ), which means that by being persistent, both patients and their physicians got accustomed to the need of monitoring this result.

Over 50% of patients have been recorded and treated for arterial hypertension. The data have not been known for 37% and it is possible that there are hypertensive patients among them. This data corresponds to the data on nondiagnosed hypertension in Mongolia where 35% of inhabitants have not been diagnosed. (13) On the other hand, there are estimates that 13% of the population have hypertension and 4.2% have diabetes in Canada. (14) The 2003 Canadian study CCHC also confirms the prevalence of hypertension by 12.7%. (15) The 2005 Iranian study finds 20.8% of hypertensive patients in the surveyed population of diabetics type 2. (16)

Dyslipidemia is commonly present in patients with DM. An excessive amount of free fatty acids increases hepatic gluconeogenesis, whereas beta cell lipotoxicity is increased. Balanced cholesterol metabolism is important for the ability of insulin secretion from the beta cell. (17) The proportion of patients with dyslipidemia of 25% corresponds to the proportion of 24.4% mentioned in the 2006 German study. (18) The 2011 South Carolina study suggests that 62% of African Americans are overweight, 64% of them have hypertension, 23% of them have DM and 40% of them have dyslipidemia. Three risk factors (hypertension, obesity, dyslipidemia) were present in 13% of them, and four risk factors were present in 10% (hypertension, obesity, dyslipidemia and DM). (19) Decline in the proportion of patients with dyslipidemia corresponded with reductions of Hba1c value in the last three years.

The incidence of CHD is significantly linked with DM. Thus, the 2006 Iran study suggests that the prevalence of coronary heart disease among the diabetics is 28%. (20) On the other hand, the prevalence of CHD among the diabetics in Korea is 8.7%. (21)

The results of the 2001 retrospective study based on the data on 297 patients treated for acute MI in the Bjelovar General Hospital show that among the patients 24% of men and 37% of women had DM. DM was recorded in 32% of men and 37% of women with fatal outcome of acute MI. Diabetic patients with fatal outcome of MI were younger than patients without DM. (22)

The proportion of patients with history of MI was 10% and the entire observed period remained almost unchanged, with the lowest proportion in 2010. At the same time, during that year the rate of patients who controlled DM well or marginally well started to rise.

The proportion of patients with other observed macrovascular complication of diabetes (stroke) is 9%. The tendency of decline of patients with a history of stroke to 7% is also inversely correlated with well or marginally well regulated diabetes which has been seen in the last 3 years. Most studies that examined stroke in the hospital population suggest that 10-25% of patients suffering from stroke have DM. (23)

Very high and ever higher rates of incidence of DM in the world and in RH raise the concern. We are facing ever greater number of patients in the Centre for Diabetes in BBZ. The level of regulation of diabetes, body mass index, as well as other observed modifiable cardiovascular disease risk factors (arterial hypertension, dyslipidemia) is not satisfactory. The downward trend of the level of Hba1c value is encouraging, which is probably the consequence of introduction of new drugs for the treatment of DM (DPP 4 inhibitors and GLP 1 analogues), and pronounced introduction of insulin in the last three years. It would probably result in the reduced proportion of patients with myocardial infarction and stroke.