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Clinical Question:
Does a low cholesterol level predict mortality in the elderly?
Bottom Line:
Low cholesterol level is a robust predictor of mortality in the nondemented
elderly and may be a surrogate of frailty or subclinical disease. More
research is needed to understand these associations.
Reference:
Relationship between plasma lipids and all-cause mortality in nondemented
elderly.Schupf N, Costa R, Luchsinger J, Tang MX, Lee JH, Mayeux R.J Am
Geriatr Soc. 2005 Feb;53(2):219-26.
Study Design:
cohort (prospective) study
Setting:
Population-based
Synopsis:
The author investigated the relationship between plasma lipids and risk of
death from all causes in nondemented elderly. Prospective cohort study was
done in a Community-based sample of Medicare recipients, aged 65 years and
older, residing in northern Manhattan. Two thousand two hundred
seventy-seven nondemented elderly, aged 65 to 98; 672 (29.5%)
white/non-Hispanic, 699 (30.7%) black/non-Hispanic, 876 (38.5%) Hispanic,
and 30 (1.3%) other. Anthropometric measures: fasting plasma total
cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C),
low-density lipoprotein cholesterol (LDL-C), and non-HDL-C, body mass index,
and apolipoprotein E (APOE) genotype. clinical measures: neuropsychological,
neurological, medical, and functional assessments; medical history of
diabetes mellitus, heart disease, hypertension, stroke, and treatment with
lipid-lowering drugs. Vital status measure: National Death Index date of
death. Survival methods were used to examine the relationship between plasma
lipids and subsequent mortality in younger and older nondemented elderly,
adjusting for potential confounders. Nondemented elderly with levels of
total cholesterol, non-HDL-C, and LDL-C in the lowest quartile were
approximately twice as likely to die as those in the highest quartile (rate
ratio (RR)=1.8, 95% confidence interval (CI)=1.3-2.4). These results did not
vary when analyses were adjusted for body mass index, APOE genotype,
diabetes mellitus, heart disease, hypertension, stroke, diagnosis of cancer,
current smoking status, or demographic variables. The association between
lipid levels and risk of death was attenuated when subjects with less than 1
year of follow-up were excluded (RR=1.4, 95% CI=1.0-2.1). The relationship
between total cholesterol, non-HDL-C, HDL-C, and triglycerides and risk of
death did not differ for older (>or=75) and younger participants (>75),
whereas the relationship between LDL-C and risk of death was stronger in
younger than older participants (RR=2.4, 95% CI=1.2-4.9 vs RR=1.6, 95%
CI=1.02-2.6, respectively). Overall, women had higher mean lipid levels than
men and lower mortality risk, but the risk of death was comparable for men
and women with comparable low lipid levels. |