CHAPTER I INTRODUCTION

1.1 Background

High cholesterol levels in the blood have an important role in the process of atherosclerosis which will then cause cardiovascular abnormalities. Many cohort studies show that the higher the blood cholesterol level, the higher the incidence of cardiovascular disorders. Likewise, the lower the cholesterol level, the lower the incidence of cardiovascular disease both for primary prevention and secondary prevention. Each 1% decrease in total cholesterol results in a 1.5% reduction in cardiovascular mortality risk. Likewise with the large levels of LDL and HDL cholesterol. Reduction in Low Density Lipoprotein (LDL) cholesterol by 1 mg / dl reduces the risk of cardiovascular events by 1% and an increase in High Density Lipoprotein (HDL) cholesterol levels decreases the risk of cardiovascular events by 2-3%.

Hypertension is one of the main risk factors for CHD Research in various places in Indonesia (1978) found the prevalence of hypertension for Indonesia ranged from 6-15%, whereas in developed countries such as the United States National Health Survey found a higher frequency of reaching 15-20%. Approximately 60% of people with hypertension are not detected, 20% can be known but not treated or not well controlled, while only 20% can be treated properly. The cause of death due to hypertension in America is 45% heart failure, 35% myocardial infarction, 15% cerebrovascular accident and 5% kidney failure. Complications that occur in essential hypertension are usually due to changes in systemic arterial and arterial structures, especially in untreated cases. Initially there will be hypertrophy of the tunica media followed by local hyalinization and thickening of fibrosis of the intima tunica and eventually narrowing of the blood vessels will occur. The most dangerous place is when it comes to myocardium, arterial and systemic arterial coronary and cerebral arteries and kidney blood vessels (Anwar, 2004).

In Indonesia, the incidence of hypercholesterolemia in the MONICA I study (1988) was 13.4% for women and 11.4% for men. In MONICA II (1994) it was found to increase to 16.2% for
women and 14% for men. The prevalence of hypercholesterolemia in rural communities, reaching 200-248 mg / dL or reaching 10.9 percent of the total population in 2004 ,. Patients in the younger generation, namely the age of 25-34 years, reached 9.3 percent. Women are the group that suffers the most from this problem, which is 14.5 percent, or almost double the group of men.

Hypercholesterolemia is one of the disorders of blood fat (dislipidemia) in which the blood cholesterol level is over 240 mg / dl. Hypercholesterolemia is closely related to LDL cholesterol levels in the blood. Dislipidemia is a disorder of lipid metabolism marked by increased total cholesterol, LDL cholesterol, triglycerides above normal values and decreased HDL cholesterol.

Logistic regression model is a form of regression analysis to determine a causal relationship (causality) if the response variable Y has only 2 possible values or dichotomous data. The method often used to solve logistic regression problems is the Maximum Likelihood Estimation (MLE) method in which the parameter estimation process is preceded by the establishment of the likelihood function. Therefore, we want to estimate the parameters of the logistic regression model to be applied in determining how much influence the hypercholesterolemia factors have on randomly selected Yogyakarta Health Laboratory patients.

1.2 Problem Formulation

 The formulation of the problem in this study are:

1. Are the basic factors of cholesterol, LDL, HDL, and triglyceride levels having a significant effect on hypercholesterolemia indications?

2. How big is the effect of cholesterol, LDL, HDL, and triglyceride levels on the indication of hypercholesterolemia?

3. What is the logistic regression model from the case study of cholesterol test patient data at the Yogyakarta Health Laboratory Center (January - March 2009)?

1.3 Purpose
This research aims to:

1. Knowing whether the basic factors, namely cholesterol, LDL, HDL, and triglyceride levels have a significant influence on the indication of hypercholesterolemia

2. Knowing how much influence the levels of cholesterol, LDL, HDL, and triglycerides on the indication of hypercholesterolemia

3. Knowing the logistic regression model from the case study Cholesterol Test Patients Data Yogyakarta Health Laboratory Center (January - March 2009)