Variation of lipid profile in patients with acute myocardial infarction of different age groups

Objective To investigate the variation of lipid profile in patients with acute myocardial infarction (AMI) of different age groups. Methods Total 1214 patients of AMI were admitted to our hospital from May 2007 to July 2011. The age of patients ranged 40-89 years, and patients were divided into 5 age groups with 10-years step. Differences in lipid levels were observed by using pair-wise comparison among different age groups. Results Pair-wise comparisons among different age groups indicated that TC levels were higher in 40-69 years age groups [(4.71±1.08), (4.80±1.30), (4.69±1.03) mmol/L, respectively] than those in the 70-89 age groups [(4.41±0.96), (4.38±1.03) mmol/L], all P<0.05 (t values were 2.381, 2.323, 4.382, 3.965, 3.317, 3.096). TG levels among three age groups < 59 years had no significant difference, which were higher than those in groups over 60 years. Among 50-89 years age groups, TG gradually reduced with increase of age. HDL levels were lower in 40-59 years age groups [(1.03±0.23), (1.05±0.26) mmol/L, respectively] than those in 60-89 years age groups [(1.11±0.28), (1.11±0.28), (1.16±0.34) mmol/L, respectively], all P<0.05 (t values were -2.777, -2.789, -3.731, -2.543, -2.566, -3.644). Total cholesterol (TC) (r=-0.123, P<0.01), low-density lipoprotein cholesterol (LDL) (r=-0.139, P<0.01) and triglyceride (TG) (r=-0.287, P<0.01) were negatively but high-density lipoprotein cholesterol (HDL) (r=0.125, P<0.01) was positively correlated with age of patients. TC levels in female patients were higher than those in male patients in 50-89 years age groups; LDL levels in female patients were higher than those in male patients in 50-69 years age groups and HDL levels in female patients were higher than those in male patients in 40-79 years age groups (all P<0.05, t values were -2.878, -3.007, -3.352, -3.333). Conclusions show that the non-elderly AMI patients (<60 years) have higher levels of TC, LDL and TG, and lower level of HDL than the elderly patients; the TC, LDL and HDL levels are higher in female AMI patients than those in male patients at the same age groups. Key words: Dyslipidemia; Myocardial infarction; Age distribution