Interleukin-6 modulates plasma cholesterol and C-reactive protein concentrations in nonagenarians.

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.