The question addressed by this analysis is, “Is there relationship between Cholesterol and age?” There are many variables that can affect this relationship. It was hypothesized that as people get older in age, they may have higher risk of developing cholesterol. Variables like blood pressure, age at start, cholesterol, death cause, cholesterol status, sex will be analyzed to understand the relationship. The study was conducted to understand if there are more males or females who developed cholesterol, how blood pressure is affected with developing of cholesterol, if patients with cholesterol have mean average of high blood pressure or low blood pressure based on gender and if there were any deaths related to heart issues based on gender.
Categorical variables in the study used are cholesterol status, blood pressure status, death cause, sex, weight status. Using SAS studio, PROC FREQ procedure was conducted at first. Frequency distribution was created to see if participants with high cholesterol developed any other symptoms such as high blood pressure. We also created frequency distribution to understand if being overweight played any role in cholesterol development.
Then using the SAS PROC UNIVARIATE procedure, univariate statistics were conducted for Cholesterol, Age at start, and age at death. To understand the clear picture of the data, histograms were used and compared. For final descriptive analysis, the data was sorted by cholesterol status, blood pressure status, age at start and sex of the participants.
Descriptive statistics for the sample in the study shows that there are more females in the study than males. Frequency distribution for cholesterol status shows there are more borderline participants and high cholesterol status than desirable. Distribution of blood pressure shows that there were more high blood pressure patients than normal and optimal. Frequency distribution for cause of death shows that the most deaths were caused by Coronary Heart Disease as compared to any other death causes which can be related to high cholesterol levels and high blood pressures. The univariate procedure for cholesterol shows there were 5057 participants with mean of 227.4 and standard deviation of 44.93. High standard deviation indicated there are some outliers in the data. The distribution of cholesterol is positively skewed. Univariate procedure for age at start with 5209 participants, mean of 44.068 with standard deviation of 8.574 indicating slight positive skewness in the data. In Univariate procedure for age at death had 1991 participants with mean age of 70.536 with standard deviation of 10.559. The data shows negative skewness. The univariate procedure for age at death with 1991 participants with mean age of 70.53 and standard deviation of 10.56. The data was negatively skewed.
T-test were conducted to understand the relationship between sex and age at start of the study, cholesterol and sex, systolic and sex, diastolic and sex. For t-test for cholesterol and sex, there were 2774 females with mean of 228.5 and 46.92 standard deviation and 2283 males with mean of 226.1 and standard deviation of 42.36 indicating there is skewness in the data. By looking at histogram there is slight positive skewness indicating there were some outliers for the data as well. It was expected for females to have higher cholesterol levels than males. Cholesterol increases with age, males being significantly higher than in females at age range 25–49 years and significantly lower than in females at age range 50–64 years. (Analysis of relationship between cholesterol).
For T-test for sex and age at start to understand average age of participants when the study was conducted. There were 2873 females with mean age of 44.05 with 8.5 standard deviation and 2336 males with mean age of 44.08 with standard deviation of 8.6. The distribution of data on histogram was no so normal and there were some outliers in the data. T-test for sex and systolic blood pressure were conducted and there were 2873 females and 2336 males with mean of 136.9, but females had 25.98 standard deviation and males with 20.64 standard deviation indicating females had more outliers than males. Later t-test for diastolic and sex we conducted. There were 2873 females with mean of 84.65 with 13.34 standard deviation and 2336 males with 86.23 mean and 12.45 standard deviation. Distribution on graph was not normal. There was positive skewness in males and females. It was expected for males to have higher blood pressure as compared to females. There are gender-associated differences in blood pressure in humans, with men having higher blood pressure than women and being at greater risk for cardiovascular and renal diseases. (American Journal of Hypertension).