Statin Use but Not Metabolic Syndrome Is Associated with Cognitive Decline in the Elderly: The Sydney Memory and Ageing Study
Program: Abstracts - Orals, Poster Preview Presentations, and Posters
Session: PP15-Lipids, Lipoproteins, Dyslipidemia & Fatty Liver Disease
Sunday, June 22, 2014: 11:15 AM-11:30 AM
W178 (McCormick Place West Building)
Poster Board SUN-0841
Katherine Samaras, MBBS, PhD, FRACP1, John D Crawford, PhD2, Elizabeth Blanchard, BMSc3, Nicole Kochan, PhD4, Julian N Trollor5, Henry Brodaty4 and Perminder Sachdev2
1Garvan Institute of Medical Research, Sydney NSW, Australia, 2University of New South Wales, Randwick, Australia, 3Garvan Institute of Medical Research, Darlinghurst, NSW, Australia, 4University of New South Wales, Kensington, Australia, 5University of New South Wales, Randwick
The cardiovascular (CV) risk factors of diabetes, hyperlipidemia and hypertension are associated with cognitive decline and are dementia risk factors. Metabolic syndrome (MS) describes clustering of these risks factors; it is unclear whether MS adversely affects cognition. Further, there is controversy whether statin use may impair cognition. We examined if Metabolic Syndrome (MS) and statin use were associated with greater cognitive decline in the elderly over 4 years.
Methods: Participants were drawn from the Sydney Memory and Aging Study, a longitudinal population-derived cohort recruited from the electoral roll (70-90 years at baseline), assessed at baseline, 2 and 4 years, as described.1 Global cognition was measured by neuropsychological testing in five domains (memory, processing speed, language, visuospatial and executive function), to form a composite normalized Z-score, as described.2 MS was defined using IDF criteria.1 Medical history and use of statin therapy and type were documented. Data on 677 participants were analyzed by repeated measure ANCOVA, with covariates (age, sex, years education, smoking, English/non-English speaking background and apolipoprotein E e4 genotype [APOEe4]).
Mean ± SD age at baseline was 78.3 ± 4.6 years, 47% males, BMI 27.1 ± 4.9 kg/m2, fasting glucose 5.6 ± 1.1 mmol/L. Baseline prevalences of MS, statin-use and diabetes were 54%, 52% and 11%, respectively.
Baseline global cognition was similar between participants with and without MS (-0.65 ± 1.3 v -0.52 ± 1.3, p=0.13). Metabolic syndrome was not associated with any greater decline in global cognition (p=0.97), nor with any domain decline score for memory, language, processing speed, visuospatial or executive function. Results were similar when subjects with diabetes were excluded.
Baseline global cognition was similar between statin-users or not (-0.58 ± 1.3 v -0.59 ± 1.3, p=0.92). Statin-use was not associated with any greater decline in global cognition over 4 years (p=0.25), however significantly greater decline in memory was observed (-0.27±0.04 v. -0.07±0.05, p=0.001). Statin-use was not associated with any greater 4-year decline in language (p=0.51), processing speed (p=0.85), visuospatial (p=0.75) or executive (p=0.96) functions. To examine whether CV risks may interact with statin-use to heighten the decline in memory, interactions were sought in models of statin use and CV or dementia risk factors (including covariates). None was found with diabetes, heart disease, stroke, smoking or APOEe4 carriage.
Conclusion: In this large cohort of community-dwelling well-elderly, statin-use was associated with greater decline in memory at 4 years, but no other cognitive domain. Metabolic syndrome was not associated with accelerated cognitive decline. The impact of metabolic risk and its treatment on cognition in the elderly requires greater interrogation.
COMMENT: One must always be careful about drawing conclusions from an abstract. However, this presentation at the International Congress of Endocrinology/Endocrine Society meeting has received considerable press response so I felt that it was worthwhile to post the abstract in its entirety. It does contain considerable good news. There was no association between cognitive decline and the metabolic syndrome. Also the title is a bit misleading in that statin use was not associated with global cognitive decline only with an increased loss of memory function. This, of course, is not a trivial finding, but one wonders if this is a fixed decline or just the effect of the statin, per se, that would be reversed by stopping the statins. An important question that I hope the investigators address.