1. Associations of the −174 G/C Interleukin-6 Gene Promoter Polymorphism with Serum Interleukin 6 and Mortality in the Elderly
- Author
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Mabel Martelli, Paola Forti, Luigi Bolondi, Giovanni Ravaglia, Fabiola Maioli, Erminia Mariani, Paolo Dolzani, Martina Chiappelli, Federico Licastro, Marisa Bianchin, Ravaglia G., Forti P., Maioli F., Chiappelli M., Dolzani P., Martelli M., Bianchin M., Mariani E., Bolondi L., and Licastro F
- Subjects
Male ,Senescence ,Heterozygote ,Aging ,medicine.medical_specialty ,Statistics as Topic ,Population ,Gastroenterology ,Cohort Studies ,Polymorphism (computer science) ,Internal medicine ,Humans ,Medicine ,Genetic Predisposition to Disease ,Mortality ,Promoter Regions, Genetic ,education ,Aged ,Aged, 80 and over ,Genetics ,education.field_of_study ,Polymorphism, Genetic ,Interleukin-6 ,business.industry ,Incidence ,Hazard ratio ,Odds ratio ,Middle Aged ,Confidence interval ,Italy ,Quartile ,Cohort ,Female ,Geriatrics and Gerontology ,business ,Gerontology - Abstract
Serum interleukin-6 (sIL6) is an acknowledged predictor of all-cause mortality in older age. A common G/C polymorphism has been identified at position −174 of the IL6 gene promoter (IL6−174G>C), but its associations with sIL6 and mortality are still unclear. Data from a population-based elderly cohort (n = 824) were used to study the associations of baseline sIL6 with the IL6−174 C-allele (C+) carrier status and all-cause mortality at 4 years, in the presence and absence of preexisting major diseases (PMD). Analyses were adjusted for socio-demographic factors and body-mass-index. Three-hundred-eighty-eight participants (47.1%) had PMD. Compared to the bottom sIL6 quartile, mortality increased both in presence [Hazard Ratio (HR) = 3.04; 95% confidence interval (CI): 1.48–6.25] and absence of PMD [HR = 3.91; 95%CI: 1.42–10.72] for the third higher sIL6 quartile, but only in presence of PMD for the top sIL6 quartile [HR = 2.30; 95%CI: 1.09–4.83]. In absence of PMD, C+ carrier status did not affect both sIL6 and mortality. In presence of PMD, C+ carrier status was associated with increased baseline sIL6 [odds ratio 2.01; 95%CI: 1.25–3.22, for all sIL6 quartiles above the bottom] but not with increased mortality risk. A survival advantage was even found for C+ carriers with PMD and sIL6 in the top quartile [HR = 0.31, 95%CI: 0.13–0.76]. In conclusion, although associated with increased sIL6 levels in presence of major diseases, the IL6−174 C-allele does not seem to have direct detrimental effects on survival in older age.
- Published
- 2005