Interleukin-6 Modulates Plasma Cholesterol and C-Reactive Protein Concentrations in Nonagenarians

TLDR: To establish whether the relationship between interleukin‐6 and plasma lipid and C‐reactive protein (CRP) concentrations is different in Finnish nonagenarians than in middle‐aged subjects with lower inflammatory status.

Abstract: OBJECTIVES: To establish whether the relationship between interleukin-6 (IL-6) and plasma lipid and C-reactive protein (CRP) concentrations is different in Finnish nonagenarians than in middle-aged subjects with lower inflammatory status. DESIGN: Cross-sectional. SETTING: Observational cohort study concentrating on the oldest old. PARTICIPANTS: Nonagenarians (n = 291, mean age ± standard deviation 90 ± 1; 68 men, 223 women) who lived in the Tampere municipality in southern Finland and a middle-aged control population from the same area (n = 227, aged 44 ± 8). MEASUREMENTS: Plasma high sensitive CRP and lipid concentrations were analyzed using an automatic analyzer and IL-6 levels using enzyme-linked immunosorbent assay. RESULTS: Plasma concentrations of IL-6 (4.39 ± 5.25 vs 1.88 ± 1.98 pg/mL) and CRP (3.54 ± 4.98 vs 1.53 ± 1.91 mg/L) were significantly higher in nonagenarians than in middle-aged subjects (P<.001). In nonagenarians, plasma CRP levels increased (P<.001) and plasma total cholesterol (P=.006), low-density lipoprotein cholesterol (P=.02), and high-density lipoprotein cholesterol (P=.002) levels decreased according to IL-6 quartiles. In middle-aged subjects, similar associations were not found. CONCLUSION: The relationship between IL-6 and plasma CRP and cholesterol levels in nonagenarians with enhanced systemic inflammation differs from that of middle-aged subjects.