The Invstigation of Lipid Profile in Saudi Healthy Population and the Effects of Lifestyle

In this study differences in the response of plasma total cholesterol, triglycerides, Low Density Lipoprotein Cholesterol and High Density Lipoprotein Cholesterol were investigated in normal healthy Saudi population according to sex, age and lifestyle (rural and urban). This study was carried out for a total of (873) subjects (475 males and 398 females). Each of these two sex groups is classified into six subgroups according to ages ([0-14],[15-24],[25-40],[41-55],[56-69],[70+]).

For the all tested people the blood was drawn after overnight fasting period (12-14hrs) using heparinized tubes. For all the required parameters (total cholesterol, triglycerides, LDL-C, HDL-C) enzymatic colorimetric method is used and the mean values were obtained accordingly.

For plasma total cholesterol, triglycerides, HDL-C and LDL-C, the results showed lower Total Cholesterol, Triglycerides and Low Density Lipoprotein Cholesterol levels through childhood group (0-14) in both males and females. However HDL-C remains high in children with similar values as in adults in both males and females between city and village population. Neonatal and children plasma contains proportionately higher HDL-C than that of adult, decreases during adolescence to a constant value and remains constant up to the age of 55 years in both sexes, then it starts to rise to a constant level and remain constant throughout life. For both males and females at birth and through early years of life (infants and children) there were no considerable differences in all parameters (T.C, HDL-C, LDL-C, TG) tested and that is may be due to absolute and close similarity of dietary habits and lifestyle between villagers and city populations for infants and children respectively. These levels increase with increasing of age for both sexes depending deeply upon the diet, and the increase of total cholesterol is significant or close to significant up to the age of 69 years in males, then it starts to fall, but it continued to rise in women. Similarly LDL-C level increases up to the age of 69 in males and then it remains constant through all the rest of the life, but for females it continues on increasing throughout life. Triglyceride levels increase up to the age of 55 in males where it started to fall throughout life, whereas in females it follow the same manner as T.C and LDL-C since it increases throughout life. The increasing of LDL-C is quite obvious throughout life in females, whereas it remains constant after the age of 69 in males.

On the other hand it seems that differences of dietary habits and lifestyle are much more effective in the adult groups of age (15-24), (25-40), (41-55), (56-69), (70+), since there are significant or nearly significant differences between villagers and city populations in plasma total cholesterol, LDL-C, HDL-C and triglycerides.

It is quite obvious that the variability in plasma lipids and lipoproteins (T.C, TG, HDL-C and LDL-C) among populations precludes the establishment of universally acceptable limits. What may be considered "normal" for one populations group may not necessarily be applicable to another. Even within a country, these reference intervals may vary from a city to a village due to differences in dietary habits and lifestyle and also markedly age and sex.