Does parity matter in women’s risk of dementia? A COSMIC collaboration cohort study
Jong Bin Bae, Darren M. Lipnicki, Ji Won Han, Perminder S. Sachdev, Tae Hui Kim, Kyung Phil Kwak, Bong‐Jo Kim, Shin Gyeom Kim, Jeong Lan Kim, Seok Woo Moon, Joon Hyuk Park, Seung‐Ho Ryu, Jong Chul Youn, Dong Young Lee, Dong Woo Lee, Seok Bum Lee, Jung Jae Lee, Jin Hyeong Jhoo, Juan J. Llibre Rodríguez, Jorge J. Llibre‐Guerra, Adolfo J. Valhuerdi-Cepero, Karen Ritchie, Marie‐Laure Ancelin, Isabelle Carrière, Ingmar Skoog, Jenna Najar, Therese Rydberg Sterner, Nikolaos Scarmeas, Mary Yannakoulia, Efthimios Dardiotis, Kenichi Meguro, Mari Kasai, Kei Nakamura, Steffi G. Riedel‐Heller, Susanne Roehr, Alexander Pabst, Martin P.J. van Boxtel, Sebastian Köhler, Ding Ding, Qianhua Zhao, Xiaoniu Liang, Márcia Scazufca, António Lobo, Concepción De‐la‐Cámara, Elena Lobo, Ki Woong Kim, Perminder S. Sachdev, Darren M. Lipnicki, Steve R. Makkar, John D. Crawford, Anbupalam Thalamuthu, Nicole A. Kochan, Yvonne Leung, Jessica Lo, Yuda Turana, E. Costa, Bagher Larijani, Iraj Nabipour, Kenneth Rockwood, Xiao Shifu, Richard Lipton, Mindy J. Katz, Pierre‐Marie Preux, Maëlenn Guerchet, Linda Lam, Ingmar Skoog, Toshiharu Ninimiya, Richard Walker, Hugh C. Hendrie, Antonio Guaita, Liang‐Kung Chen, Suzana Shahar, Jacqueline C. Dominguez, Murali Krishna, Mary Ganguli, Kaarin J. Anstey, Michael Crowe, Mary N. Haan, Shuzo Kumagai, Tze Pin Ng, Henry Brodaty, Kenichi Meguro, Richard Mayeux, Nicole Schupf, Perminder S. Sachdev, Mary Ganguli, Ronald C. Petersen, Richard Lipton, Edwin S. Lowe, Karen Ritchie, Ki-Woong Kim, Louisa Jorm, Henry Brodaty
Abstract
BACKGROUND: Dementia shows sex difference in its epidemiology. Childbirth, a distinctive experience of women, is associated with the risk for various diseases. However, its association with the risk of dementia in women has rarely been studied. METHODS: We harmonized and pooled baseline data from 11 population-based cohorts from 11 countries over 3 continents, including 14,792 women aged 60 years or older. We investigated the association between parity and the risk of dementia using logistic regression models that adjusted for age, educational level, hypertension, diabetes mellitus, and cohort, with additional analyses by region and dementia subtype. RESULTS: Across all cohorts, grand multiparous (5 or more childbirths) women had a 47% greater risk of dementia than primiparous (1 childbirth) women (odds ratio [OR] = 1.47, 95% confidence interval [CI] = 1.10-1.94), while nulliparous (no childbirth) women and women with 2 to 4 childbirths showed a comparable dementia risk to primiparous women. However, there were differences associated with region and dementia subtype. Compared to women with 1 to 4 childbirths, grand multiparous women showed a higher risk of dementia in Europe (OR = 2.99, 95% CI = 1.38-6.47) and Latin America (OR = 1.49, 95% CI = 1.04-2.12), while nulliparous women showed a higher dementia risk in Asia (OR = 2.15, 95% CI = 1.33-3.47). Grand multiparity was associated with 6.9-fold higher risk of vascular dementia in Europe (OR = 6.86, 95% CI = 1.81-26.08), whereas nulliparity was associated with a higher risk of Alzheimer disease (OR = 1.91, 95% CI 1.07-3.39) and non-Alzheimer non-vascular dementia (OR = 3.47, 95% CI = 1.44-8.35) in Asia. CONCLUSION: Parity is associated with women's risk of dementia, though this is not uniform across regions and dementia subtypes.