The oldest old: red blood cell and plasma folate in African American and white octogenarians and centenarians in Georgia.

OBJECTIVE

To determine the overall folate status of a population-based multi-ethnic sample of octogenarians and centenarians and the specific dietary, demographic and physiological factors associated with observed abnormalities.

DESIGN

Population-based multiethnic sample of adults aged 80 to 89 and 98 and above.

SETTING

Northern Georgia, USA.

PARTICIPANTS

Men and women aged 80 to 89 (octogenarians, n = 77) and 98 and older (centenarians, n = 199).

ANALYSES: Wilcoxon rank sum tests, and Chi square and logistic regression analyses were used to examine associations of low and high folate status with hematological indicators and other variables of interest.

RESULTS

The prevalence of low red blood cell (RBC) folate was low overall, but tended to be higher in centenarians than in octogenarians (6.5% vs. 1.3%, p = 0.058; defined as RBC folate < 317 nmol/L). The risk of having lower RBC folate (< 25th vs. > 25th percentile for RBC folate for 60yr+ in NHANES 1999-2000) was greater in association with vitamin B12 deficiency (OR = 5.36; 95%CI: 2.87-10.01), African American race (OR = 4.29; 95%CI: 2.08-8.83), and residence in a skilled nursing facility (OR = 3.25; 95%CI: 1.56-6.78) but was not influenced by age, gender, B-vitamin supplement use, high/low food score or presence of atrophic gastritis. Combined high plasma folate and low vitamin B12 status was present in some individuals (n=11), but was not associated with increased prevalence of anemia or cognitive impairment in this study.

CONCLUSIONS

Low RBC folate status (< 317 nmol/L) was rare in this post folic acid fortification sample of octogenarians and centenarians. RBC folate status (< 25th percentile) was strongly associated with 1) vitamin B12 deficiency, which has strong implications for vitamin treatment, and 2) with being African American, suggesting racial disparities exist even in the oldest old.