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

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.