Sex modulates effect of cognitive reserve on subjective cognitive decline

In an Italian study, premorbid intelligence was associated with age at onset and severity of cognitive complaints in men. However, premorbid intelligence and years of education had opposite effect on age at onset of subjective cognitive decline (SCD) in women.

Demographic factors, genetic factors, and cognitive reserve influence SCD, which in turn increases the risk of Alzheimer’s disease (AD). The study presented by Dr Giulia Giacomucci (University of Florence, Italy) aimed to analyse how sex might modulate the influence of cognitive reserve on SCD [1]. The study included 381 patients with SCD aged >40, who had self-reported symptoms of cognitive decline during ≥6 months. Patients underwent clinical evaluation, neuropsychological assessment, the Test di Intelligenza Breve (TIB) to evaluate premorbid intelligence, the Memory Assessment Clinics-Questionnaire (MAC-Q) to evaluate cognitive complaints, Hamilton Depression Rating Scale (HDRS) to evaluate depressive symptoms, and ApoE genotyping.

The cohort contained about twice as many women as men: 68.7% versus 31.3%. Women were younger at SCD onset and at study baseline (P=0.02), had less years of education (P=0.007), lower TIB scores (P<0.001), and higher HDRS (6.3 vs 5.12; P=0.007) and MAC-Q scores (26.3 vs 25.0; P=0.012). The number of years of education was inversely associated with age at onset only in women (ρ=0.259; P<0.001). The only factor influencing MAC-Q was sex. TIB was directly associated with MAC-Q only in men (ρ=-0.292; P<0.005). Sex and cognitive reserve influenced severity of cognitive complaints, which was higher in women. In men, higher cognitive reserve was associated with worse cognitive complaints in a linear fashion.

This result contradicts previous studies reporting that less educated individuals showed a higher degree of cognitive complaints. Dr Giacomucci said this discrepancy may be explained by the different cognitive reserve proxy, and/or the different recruitment method. “Sex and cognitive reserve interact in influencing age at onset and severity,” Dr Giacomucci concluded. She added it is not possible to describe the relationship between sex and cognitive reserve in SCD in a complete and uniform model.

1. Giacomucci G, et al. Sex influences the effect of cognitive reserve on subjective cognitive decline. OPR-043, EAN 2021 Virtual Congress, 19–22 June.

 

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Posted on 18 August 202125 March 2024