BACKGROUND: There is significant attention to the growing elderly African American population and estimating who and how many within this population will be affected by cognitive impairment. OBJECTIVE: The etiology of cognitive impairment has not been well studied in African Americans and the contribution of genetic and environmental influences to cognitive impairment is not clear. METHODS: We calculated concordance rates and heritability for cognitive impairment in 95 same-sexed pairs of African American twins from the Carolina African American Twin Study on Aging (CAATSA). The sample had an average age of 59.6 years (SD = 8.6 years, range 50-88 years) and 60% were female. The Telephone Interview for Cognitive Status (TICS) was used to assess cognitive impairment with a lower cutoff based on our previous research with African Americans. RESULTS: Thirteen of the monozygotic (MZ) twins (30.2%) and 9 of the dizygotic (DZ) twins (17.3%) were cognitively impaired. The concordance rate was 72% for MZ and 45% for DZ. We found the heritability for cognitive impairment to be 54%. CONCLUSIONS: The study findings indicate that cognitive impairment is highly heritable, suggesting that genetics may play a relatively large role in the development of cognitive impairment in African American twins.
BACKGROUND: There is significant attention to the growing elderly African American population and estimating who and how many within this population will be affected by cognitive impairment. OBJECTIVE: The etiology of cognitive impairment has not been well studied in African Americans and the contribution of genetic and environmental influences to cognitive impairment is not clear. METHODS: We calculated concordance rates and heritability for cognitive impairment in 95 same-sexed pairs of African American twins from the Carolina African American Twin Study on Aging (CAATSA). The sample had an average age of 59.6 years (SD = 8.6 years, range 50-88 years) and 60% were female. The Telephone Interview for Cognitive Status (TICS) was used to assess cognitive impairment with a lower cutoff based on our previous research with African Americans. RESULTS: Thirteen of the monozygotic (MZ) twins (30.2%) and 9 of the dizygotic (DZ) twins (17.3%) were cognitively impaired. The concordance rate was 72% for MZ and 45% for DZ. We found the heritability for cognitive impairment to be 54%. CONCLUSIONS: The study findings indicate that cognitive impairment is highly heritable, suggesting that genetics may play a relatively large role in the development of cognitive impairment in African American twins.
Authors: Jennifer J Manly; Diane M Jacobs; Pegah Touradji; Scott A Small; Yaakov Stern Journal: J Int Neuropsychol Soc Date: 2002-03 Impact factor: 2.892
Authors: L H Kuller; O L Lopez; W J Jagust; J T Becker; S T DeKosky; C Lyketsos; C Kawas; J C S Breitner; A Fitzpatrick; C Dulberg Journal: Neurology Date: 2005-05-10 Impact factor: 9.910
Authors: Regina C Sims; Roland J Thorpe; Alyssa A Gamaldo; Adrienne T Aiken-Morgan; LaBarron K Hill; Jason C Allaire; Keith E Whitfield Journal: J Aging Health Date: 2014-07-21