CONTEXT: Alzheimer disease (AD) represents a major and increasing public health problem. If populations were identified with significantly lower or higher incidence rates of AD, the search for risk factors in the genesis of AD could be greatly enhanced. OBJECTIVE: To compare incidence rates of dementia and AD in 2 diverse, elderly community-dwelling populations. DESIGN: The Indianapolis-Ibadan Dementia Project, a longitudinal, prospective population-based study consisting of a baseline survey (1992-1993) and 2 subsequent follow-up waves after 2 years (1994-1995) and 5 years (1997-1998). Each wave followed a 2-stage design, with an in-home screening interview followed by a full diagnostic workup of a subsample of participants based on screening performance. SETTING AND PARTICIPANTS: A total of 2459 community-dwelling Yoruba residents of Ibadan, Nigeria, without dementia, and 2147 community-dwelling African American residents of Indianapolis, Ind, without dementia (all aged 65 years or older). The cohorts were followed up for a mean of 5.1 years and 4.7 years, respectively. MAIN OUTCOME MEASURES: Incident cases of dementia and AD in each of the 2 populations. RESULTS: The age-standardized annual incidence rates were significantly lower among Yoruba than among African Americans for dementia (Yoruba, 1.35% [95% confidence interval [CI], 1.13%-1.56%]; African Americans, 3.24% [95% CI, 2.11%-4.38%]) and for AD (Yoruba, 1.15% [95% CI, 0.96%-1.35%]; African Americans, 2.52% [95% CI, 1.40%-3.64%]). CONCLUSION: This is the first report of incidence rate differences for dementia and AD in studies of 2 populations from nonindustrialized and industrialized countries using identical methods and the same group of investigators in both sites. Further explorations of these population differences may identify potentially modifiable environmental or genetic factors to account for site differences in dementia and AD.
CONTEXT: Alzheimer disease (AD) represents a major and increasing public health problem. If populations were identified with significantly lower or higher incidence rates of AD, the search for risk factors in the genesis of AD could be greatly enhanced. OBJECTIVE: To compare incidence rates of dementia and AD in 2 diverse, elderly community-dwelling populations. DESIGN: The Indianapolis-Ibadan Dementia Project, a longitudinal, prospective population-based study consisting of a baseline survey (1992-1993) and 2 subsequent follow-up waves after 2 years (1994-1995) and 5 years (1997-1998). Each wave followed a 2-stage design, with an in-home screening interview followed by a full diagnostic workup of a subsample of participants based on screening performance. SETTING AND PARTICIPANTS: A total of 2459 community-dwelling Yoruba residents of Ibadan, Nigeria, without dementia, and 2147 community-dwelling African American residents of Indianapolis, Ind, without dementia (all aged 65 years or older). The cohorts were followed up for a mean of 5.1 years and 4.7 years, respectively. MAIN OUTCOME MEASURES: Incident cases of dementia and AD in each of the 2 populations. RESULTS: The age-standardized annual incidence rates were significantly lower among Yoruba than among African Americans for dementia (Yoruba, 1.35% [95% confidence interval [CI], 1.13%-1.56%]; African Americans, 3.24% [95% CI, 2.11%-4.38%]) and for AD (Yoruba, 1.15% [95% CI, 0.96%-1.35%]; African Americans, 2.52% [95% CI, 1.40%-3.64%]). CONCLUSION: This is the first report of incidence rate differences for dementia and AD in studies of 2 populations from nonindustrialized and industrialized countries using identical methods and the same group of investigators in both sites. Further explorations of these population differences may identify potentially modifiable environmental or genetic factors to account for site differences in dementia and AD.
Authors: Frederick W Unverzagt; Lin T Guey; Richard N Jones; Michael Marsiske; Jonathan W King; Virginia G Wadley; Michael Crowe; George W Rebok; Sharon L Tennstedt Journal: J Int Neuropsychol Soc Date: 2012-03-09 Impact factor: 2.892
Authors: Adesola Ogunniyi; Su Gao; Frederick W Unverzagt; Olusegun Baiyewu; Oyewusi Gureje; James Tat Nguyen; Valerie Smith-Gamble; Jill R Murrell; Ann M Hake; Kathleen S Hall; Hugh C Hendrie Journal: Int Psychogeriatr Date: 2010-08-25 Impact factor: 3.878
Authors: Brenda L Plassman; Kenneth M Langa; Ryan J McCammon; Gwenith G Fisher; Guy G Potter; James R Burke; David C Steffens; Norman L Foster; Bruno Giordani; Frederick W Unverzagt; Kathleen A Welsh-Bohmer; Steven G Heeringa; David R Weir; Robert B Wallace Journal: Ann Neurol Date: 2011-03-18 Impact factor: 10.422
Authors: Kala M Mehta; Eleanor M Simonsick; Ronica Rooks; Anne B Newman; Sandra K Pope; Susan M Rubin; Kristine Yaffe Journal: J Am Geriatr Soc Date: 2004-12 Impact factor: 5.562
Authors: S J Szwast; H C Hendrie; K A Lane; S Gao; S E Taylor; F Unverzagt; J Murrell; M Deeg; A Ogunniyi; M R Farlow; K S Hall Journal: Neurology Date: 2007-11-06 Impact factor: 9.910
Authors: Paul K Crane; Kaavya Narasimhalu; Laura E Gibbons; Dan M Mungas; Sebastien Haneuse; Eric B Larson; Lewis Kuller; Kathleen Hall; Gerald van Belle Journal: J Clin Epidemiol Date: 2008-05-05 Impact factor: 6.437