Apolipoprotein E genotypes and cognitive functions in healthy elderly persons

Objectives- We investigated whether apoE genotypes correlate with cognitive functions in clinically healthy persons. Methods - In 1993 and 1995, we measured information processing speed, delayed free recall and semantic aspects of long-term memory in 227 men and 105 women aged 65 and over, a randomly selected subsample of the prospective Basel Study. Cardiovascular risk factors and education were assessed. Results -E2 were more prevalent in old-old (>75 years, 23.5% vs 15%) compared to E4 than in young-old (<75 years, 19.3% vs 23.5%). Taking into account age and education, subjects with ɛ3/ɛ4 or ɛ4/ɛ4 alleles (E4) performed lowest in all 3 tests compared to those homozygous for ɛ3 (E3) or carriers of one or two ɛ2 alleles (E2) (reaction time P=0.009, free recall P=0.05, WAIS-R vocabulary P<0.05). In old-old there was a significant difference between E2 and E4 for reaction time (P=0.02) and free recall (P<0.02) but not for vocabulary (P=0.086). In all 3 groups there were no significant changes after 2 years. The subgroup with the genotype ɛ2/ɛ4 performed consistently best in the cognitive tests. Cholesterol was significantly increased in the E4 and E3 group compared to the E2 group. Conclusion - ApoE genotype correlates with cognitive performance. The increased prevalence of E2 in the old-old and the significantly lower plasma cholesterol levels suggest differential morbidity and mortality as important factors influencing the prevalence of cognitive disorders in late life.

Subclinical Thyroid Dysfunction and Depressive Symptoms among Elderly: A Prospective Cohort Study

BACKGROUND Subclinical hypothyroidism has been associated with depressive symptoms in cross-sectional studies, but prospective data and data on subclinical hyperthyroidism are scarce. METHODS In the Leiden sub-study of the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER) among adults aged 70-82 years with pre-existing cardiovascular disease or known cardiovascular risk factors, TSH and free T4 levels were measured at baseline and repeated after 6 months to define persistent thyroid function status. Main outcome measures were depressive symptoms, assessed with the Geriatric Depression Scale 15 (GDS) at baseline and after 3 years. All analyses were adjusted for age, gender and education. RESULTS Among 606 participants (41% women, mean age 75 years) without anti-depressant medication, GDS scores at baseline did not differ for participants with subclinical hypothyroidism (n = 47; GDS 1.75, 95% CI 1.29-2.20, p = 0.50) or subclinical hyperthyroidism (n = 13; GDS 1.64 [0.78-2.51], p = 1.00) compared to euthyroid participants (n = 546, mean GDS 1.60 [1.46-1.73]). After 3 years, compared to euthyroid participants, change in GDS scores did not differ for participants with subclinical hypothyroidism (ΔGDS -0.03 [-0.50-0.44], p = 0.80), while subclinical hyperthyroidism was associated with an increase in GDS scores (ΔGDS 1.13 [0.32-1.93] p = 0.04). All results were similar for persistent subclinical thyroid dysfunction. CONCLUSIONS In this largest prospective study on the association of persistent subclinical thyroid dysfunction and depression, subclinical hypothyroidism was not associated with increased depressive symptoms among older adults at high cardiovascular risk. Persistent subclinical hyperthyroidism might be associated with increased depressive symptoms, which requires confirmation in a larger prospective study. © 2015 S. Karger AG, Basel.