[R] ANOVA with repeated measurements (Dan Rajdl)

[Rajdl Daniel]

Dear R-users,
I have some human serum lipid concentrations (cholesterol, apoB ...),
each lipid was measured (in the same person) for 6 times in different
time points (start, 3 months, 6 months, 12 months, 18 months, 24
months). There were 2 groups of participants: one with a nutritional
intervention and the other without it. I would like to know, whether
lipid concentrations differ among different time points and between the
2 groups.
Could anyone advise me, please, what method and how should I usein R? Or
redirect me, please, to a source, where I can find the answer.
Thank you,
Dan Rajdl
Dpt.Clin.Chem.Biochem.Hematol, Univ.Hosp.in Pilsen, Czech Republic