['To investigate whether low-grade inflammation-related factors such as serum low-density (LDL-C) and high-density lipoprotein cholesterol (HDL-C) modify the association between periodontal infection and C-reactive protein.', 'This study was based on a subpopulation of the Health 2000 Survey, which consisted of dentate, non-diabetic, non-rheumatic subjects who were 30-49\xa0years old (n\xa0=\xa02710). The extent of periodontal infection was measured by means of the number of teeth with periodontal pocket ≥4\xa0mm and teeth with periodontal pocket ≥6\xa0mm and systemic inflammation using high sensitive C-reactive protein.', 'The extent of periodontal infection was associated with elevated levels of C-reactive protein among those subjects whose HDL-C value was below the median value of 1.3\xa0mmol/l or LDL-C above the median value of 3.4\xa0mmol/l. Among those with HDL-C\xa0≥\xa01.3\xa0mmol/l or LDL-C\xa0≤\xa03.4\xa0mmol/l, the association between periodontal infection and serum concentrations of C-reactive protein was practically non-existent.'] Do serum lipids modify periodontal infection - C-reactive protein association?