In addition, potential interactions between the G/R241 polymorphism and age, sex and smoking status were tested.The sample population included 182 families with various patterns including one or two parents and at least one child.The next laboratory tests had the highest cut-off values that follow: aspartate aminotransferase (AST) or alanine aminotransferase (ALT) activities higher than 200 U/l; apo E concentration, 200 mg/l; orosomucoid or haptoglobulin, 3 g/l; cholesterol or triglyceride, 10 mmol/l; C-reactive protein (CRP), 30 mg/l; or glucose, 8 mmol/l.
there is still no study of the association between this mutation and the protein level in serum.
The aim of the present study is to estimate the association between the G/R241 polymorphism and serum s ICAM-1 levels in a healthy population, taking into account the other biological determinants.
ANOVA and pairwise comparison procedure with Bonferroni correction were performed to test differences in the s ICAM-1 level between age and sex groups.
Stepwise multiple regression analysis was used to test relations between s ICAM-1 level and ICAM-1 gene polymorphism accounting for age, sex and the other potential covariates listed in Table 1.
This population came back for a second visit in 1999–2000.
For this specific study, the subjects were selected with the following criteria: to be present at the first (1994–1995) and the second (1999–2000) health screening, free from serious and/or chronic diseases, especially cardiovascular, hepatic or renal failure; without treatment with lipid-lowering drugs.
In addition, interaction terms between ICAM-1 polymorphism (as dominant score: GG vs GR RR) and age (as continuous variable), male sex and current smoking (as categorical variable) were tested in the model. For both children and adult groups, the best model for age- and sex-adjusted s ICAM-1 level was summarized by multiple linear regression with ICAM-1 polymorphism and the covariates significantly associated at least in one group.
As individuals within a family were not independent, ANOVA and final multiple linear regression analysis were conducted by using the SAS GENMOD procedure with a family factor as repeated statement.
Circulating levels of s ICAM-1, interleukin-6 (Il-6) and tumor necrosis factor- (TNF-) were measured with the commercially available enzyme-linked immunosorbent assays (R&D System, Abingdon, UK).
Genomic DNA was extracted by the salting-out method. One of the biotinylated primer pairs in the Multiplex was designed to amplify the gene of ICAM-1.
Moreover, significant independent associations were found between s ICAM-1 and smoking, insulin resistance index (HOMA IR), interleukin-6 level, and alkaline phosphatase and aspartate aminotransferase activities.