Leukocyte telomere length (LTL) is reduced in stable mild cognitive impairment but low LTL is not associated with conversion to Alzheimer's disease: a pilot study.
Leukocyte telomere length (LTL) is associated with the aging process and may be related to cognitive aging. Previous studies have shown conflicting results whether LTL is affected in patients with Alzheimer's disease (AD). In this pilot study, we investigated LTL in a well-defined homogeneous mono-center population. Sixty consecutive patients admitted for cognitive impairment to a memory clinic were recruited. The participants included patients with AD or mild cognitive impairment (MCI) diagnosed with AD upon follow-up (n=32), patients with stable MCI (n=13), patients with other dementias diagnosed at primary evaluation or upon follow-up (n=15), and healthy controls (n=20). LTL was determined using a quantitative PCR assay. Patients with AD had similar LTL as healthy controls. Patients with stable MCI had reduced LTL both compared to AD patients (p=0.02) and controls (p=0.008). Subanalyses within the AD group showed that patients with MCI that later converted to AD had similar LTL as patients with clinical diagnosis of AD at primary evaluation and healthy controls whereas the LTL was longer compared to the stable MCI group (p=0.02). There were no correlations between LTL and the core AD biomarkers Aβ(1-42), T-tau and P-tau. In conclusion, in this pilot study, patients with AD or MCI that later converted to AD had similar LTL as healthy controls. Patients with stable MCI that did not progress to dementia had reduced LTL compared to controls, which might suggest a more marked biological aging as a cause of the cognitive symptoms in this group.
Institute of Medicine, Department of Internal Medicine, the Sahlgrenska Academy, University of Gothenburg, S-41345 Gothenburg, Sweden. Sofia.Skrtic@gu.se
Sofia
S
Movérare-Skrtic
Per
P
Johansson
Niklas
N
Mattsson
Oskar
O
Hansson
Anders
A
Wallin
Jan-Ove
JO
Johansson
Henrik
H
Zetterberg
Kaj
K
Blennow
Johan
J
Svensson
D000368:Aged; D000375:Aging / Q000235:genetics*; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid / Q000175:diagnosis* / Q000209:etiology; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid; D015415:Biomarkers / Q000134:cerebrospinal fluid; D016022:Case-Control Studies; D060825:Cognitive Dysfunction / Q000134:cerebrospinal fluid / Q000150:complications / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007962:Leukocytes; D008297:Male; D009483:Neuropsychological Tests; D010446:Peptide Fragments / Q000134:cerebrospinal fluid; D010865:Pilot Projects; D016615:Telomere / Q000235:genetics; D059506:Telomere Shortening / Q000235:genetics; D016875:tau Proteins / Q000134:cerebrospinal fluid
D016229:Amyloid beta-Peptides; D015415:Biomarkers; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D016875:tau Proteins