Early age at natural menopause and risk of cardiovascular and all-cause mortality: A meta-analysis of prospective observational studies

Abstract

Menopause is defined as the permanent cessation of menstruation because of loss of ovarian follicular function. Menopause is a marker of the end of a woman's reproductive life. The age at menopause varies in different ethnic populations [ [1] Baber R.J. East is east and West is west: perspectives on the menopause in Asia and the West. Climacteric. 2014; 17: 23-28 Crossref PubMed Scopus (19) Google Scholar ]. Menopause between the ages of 40 and 45 years is usually described as early menopause [ [2] Miro F. Parker S.W. Aspinall L.J. Coley J. Perry P.W. Ellis J.E. Sequential classification of endocrine stages during reproductive aging in women: the FREEDOM study. Menopause. 2005; 12: 281-290 Crossref PubMed Scopus (34) Google Scholar ], while occurring before the age of 40 years is defined as premature menopause [ [3] Luborsky J.L. Meyer P. Sowers M.F. Gold E.B. Santoro N. Premature menopause in a multi-ethnic population study of the menopause transition. Hum. Reprod. 2003; 18: 199-206 Crossref PubMed Scopus (302) Google Scholar ]. Early or premature menopause can be naturally spontaneous or induced by medical interventions including chemotherapy or bilateral oophorectomy. Some epidemiologic studies [ 4 Snowdon D.A. Kane R.L. Beeson W.L. Burke G.L. Sprafka J.M. Potter J. et al. Is early natural menopause a biologic marker of health and aging?. Am. J. Public Health. 1989; 79: 709-714 Crossref PubMed Scopus (279) Google Scholar , 5 Cooper G.S. Sandler D.P. Age at natural menopause and mortality. Ann. Epidemiol. 1998; 8: 229-235 Abstract Full Text Full Text PDF PubMed Scopus (219) Google Scholar , 6 Jacobsen B.K. Knutsen S.F. Fraser G.E. Age at natural menopause and total mortality and mortality from ischemic heart disease: the Adventist Health Study. J. Clin. Epidemiol. 1999; 52: 303-307 Abstract Full Text Full Text PDF PubMed Scopus (195) Google Scholar , 7 Mondul A.M. Rodriguez C. Jacobs E.J. Calle E.E. Age at natural menopause and cause-specific mortality. Am. J. Epidemiol. 2005; 162: 1089-1097 Crossref PubMed Scopus (184) Google Scholar , 8 Cooper G.S. Baird D.D. Weinberg C.R. Ephross S.A. Sandler D.P. Age at menopause and childbearing patterns in relation to mortality. Am. J. Epidemiol. 2000; 151: 620-623 Crossref PubMed Scopus (49) Google Scholar , 9 Jacobsen B.K. Heuch I. Kvale G. Age at natural menopause and all-cause mortality: a 37-year follow-up of 19,731 Norwegian women. Am. J. Epidemiol. 2003; 157: 923-929 Crossref PubMed Scopus (208) Google Scholar , 10 Amagai Y. Ishikawa S. Gotoh T. Kayaba K. Nakamura Y. Kajii E. Age at menopause and mortality in Japan: the Jichi Medical School Cohort Study. J. Epidemiol. 2006; 16: 161-166 Crossref PubMed Scopus (44) Google Scholar , 11 Hong J.S. Yi S.W. Kang H.C. Jee S.H. Kang H.G. Bayasgalan G. et al. Age at menopause and cause-specific mortality in South Korean women: Kangwha Cohort Study. Maturitas. 2007; 56: 411-419 Abstract Full Text Full Text PDF PubMed Scopus (72) Google Scholar , 12 Tom S.E. Cooper R. Wallace R.B. Guralnik J.M. Type and timing of menopause and later life mortality among women in the Iowa Established Populations for the Epidemiological Study of the Elderly (EPESE) cohort. J. Womens Health (Larchmt). 2012; 21: 10-16 Crossref PubMed Scopus (21) Google Scholar , 13 Li S. Rosenberg L. Wise L.A. Boggs D.A. LaValley M. Palmer J.R. Age at natural menopause in relation to all-cause and cause-specific mortality in a follow-up study of US black women. Maturitas. 2013; 75: 246-252 Abstract Full Text Full Text PDF PubMed Scopus (37) Google Scholar , 14 Wu X. Cai H. Kallianpur A. Gao Y.T. Yang G. Chow W.H. et al. Age at menarche and natural menopause and number of reproductive years in association with mortality: results from a median follow-up of 11.2 years among 31,955 naturally menopausal Chinese women. PLoS One. 2014; 9: e103673 Crossref PubMed Scopus (57) Google Scholar , 15 Jacobsen B.K. Heuch I. Kvale G. Age at natural menopause and stroke mortality: cohort study with 3561 stroke deaths during 37-year follow-up. Stroke. 2004; 35: 1548-1551 Crossref PubMed Scopus (46) Google Scholar ] suggested that women who experienced early natural menopause or premature menopause were at increased risk of all-cause mortality. However, findings from these studies are conflicting. Therefore, we conducted this meta-analysis on all available prospective studies to quantitatively evaluate the early age at natural menopause and risk of cardiovascular or all-cause mortality.