Background Early menopause is linked to an increased risk of cardiovascular disease mortality; however, the association between early menopause and incidence and timing of cardiovascular disease is unclear. We aimed to assess the associations between age at natural menopause and incidence and timing of cardiovascular disease. MethodsWe harmonised and pooled individual-level data from 15 observational studies done across five countries and regions (Australia, Scandinavia, the USA, Japan, and the UK) between 1946 and 2013. Women who had reported their menopause status, age at natural menopause (if postmenopausal), and cardiovascular disease status (including coronary heart disease and stroke) were included. We excluded women who had hysterectomy or oophorectomy and women who did not report their age at menopause. The primary endpoint of this study was the occurrence of first non-fatal cardiovascular disease, defined as a composite outcome of incident coronary heart disease (including heart attack and angina) or stroke (including ischaemic stroke or haemorrhagic stroke). We used Cox proportional hazards models to estimate multivariate hazard ratios (HRs) and 95% CIs for the associations between age at menopause and incident cardiovascular disease event. We also adjusted the model to account for smoking status, menopausal hormone therapy status, body-mass index, and education levels. Age at natural menopause was categorised as premenopausal or perimenopausal, younger than 40 years (premature menopause), 40-44 years (early menopause), 45-49 years (relatively early), 50-51 years (reference category), 52-54 years (relatively late), and 55 years or older (late menopause). FindingsOverall, 301 438 women were included in our analysis. Of these 301 438 women, 12 962 (4•3%) had a first nonfatal cardiovascular disease event after menopause, of whom 9369 (3•1%) had coronary heart disease and 4338 (1•4%) had strokes. Compared with women who had menopause at age 50-51 years, the risk of cardiovascular disease was higher in women who had premature menopause (age <40 years; HR 1•55, 95% CI 1•38-1•73; p<0•0001), early menopause (age 40-44 years; 1•30, 1•22-1•39; p<0•0001), and relatively early menopause (age 45-49 years; 1•12, 1•07-1•18; p<0•0001), with a significantly reduced risk of cardiovascular disease following menopause after age 51 years (p<0•0001 for trend). The associations persisted in never smokers, and were strongest before age 60 years for women with premature menopause (HR 1•88, 1•62-2•20; p<0•0001) and early menopause (1•40, 1•27-1•54; p<0•0001), but were attenuated at age 60-69 years, with no significant association observed at age 70 years and older.Interpretation Compared with women who had menopause at age 50-51 years, women with premature and early menopause had a substantially increased risk of a non-fatal cardiovascular disease event before the age of 60 years, but not after age 70 years. Women with earlier menopause need close monitoring in clinical practice, and age at menopause might also be considered as ...

In this study, we compared the response rates of blood, saliva, and buccal cell samples in a pilot study on the Danish nurse cohort and examined the quantity and quality of the purified genomic DNA. Our data show that only 31% of the requested participants delivered a blood sample, whereas 72%, 80%, and 76% delivered a saliva sample, buccal cell sample via mouth swabs, or buccal cell sample on FTA card, respectively. Analysis of purified genomic DNA by NanoDrop and agarose gel electrophoresis revealed that blood and saliva samples resulted in DNA with the best quality, whereas the DNA quality from buccal cells was low. Genotype and PCR analysis showed that DNA from 100% of the blood samples and 72% to 84% of the saliva samples could be genotyped or amplified, whereas none of the DNA from FTA cards and only 23% of the DNA from mouth swabs could be amplified and none of the DNA from swabs and 94% of the DNA from FTA cards could be genotyped. Our study shows that the response rate of self-collection saliva samples and buccal cell samples were much higher than the response rate of blood samples in our group of Danish nurses. However, only the quality of genomic DNA from saliva samples was comparable with blood samples as accessed by purity, genotyping, and PCR amplification. We conclude that the use of saliva samples is a good alternative to blood samples to obtain genomic DNA of high quality and it will increase the response rate considerably in epidemiologic studies. (Cancer Epidemiol Biomarkers Prev 2007;16(10):2072 -6)

STUDY QUESTIONAre parity and the timing of menarche associated with premature and early natural menopause?SUMMARY ANSWEREarly menarche (≤11 years) is a risk factor for both premature menopause (final menstrual period, FMP <40 years) and early menopause (FMP 40–44 years), a risk that is amplified for nulliparous women.WHAT IS KNOWN ALREADYWomen with either premature or early menopause face an increased risk of chronic conditions in later life and of early death. Findings from some studies suggest that early menarche and nulliparity are associated with early menopause, however overall the evidence is mixed. Much of the evidence for a direct relationship is hampered by a lack of comparability across studies, failure to adjust for confounding factors and inadequate statistical power.STUDY DESIGN, SIZE, DURATIONThis pooled study comprises 51 450 postmenopausal women from nine observational studies in the UK, Scandinavia, Australia and Japan that contribute to the International collaboration for a Life course Approach to reproductive health and Chronic disease Events (InterLACE).PARTICIPANTS/MATERIALS, SETTING, METHODSAge at menarche (categorized as ≤11, 12, 13, 14 and 15 or more years) and parity (categorized as no children, one child and two or more children) were exposures of interest. Age at FMP was confirmed by at least 12 months of cessation of menses where this was not the result of an intervention (such as surgical menopause due to bilateral oophorectomy or hysterectomy) and categorized as premature menopause (FMP before age 40), early menopause (FMP 40–44 years), 45–49 years, 50–51 years, 52–53 years and 54 or more years. We used multivariate multinomial logistic regression models to estimate relative risk ratio (RRR) and 95% CI for associations between menarche, parity and age at FMP adjusting for within-study correlation.MAIN RESULTS AND THE ROLE OF CHANCEThe median age at FMP was 50 years (interquartile range 48–53 years), with 2% of the women experiencing premature menopause and 7.6% early menopause. Women with early menarche (≤11 years, compared with 12–13 years) were at higher risk of premature menopause (RRR 1.80, 95% CI 1.53–2.12) and early menopause (1.31, 1.19–1.44). Nulliparity was associated with increased risk of premature menopause (2.26, 1.84–2.77) and early menopause (1.32, 1.09–1.59). Women having early menarche and nulliparity were at over 5-fold increased risk of premature menopause (5.64, 4.04–7.87) and 2-fold increased risk of early menopause (2.16, 1.48–3.15) compared with women who had menarche at ≥12 years and two or more children.LIMITATIONS, REASONS FOR CAUTIONMost of the studies (except the birth cohorts) relied on retrospectively reported age at menarche, which may have led to some degree of recall bias.WIDER IMPLICATIONS OF THE FINDINGSOur findings support early monitoring of women with early menarche, especially those who have no children, for preventive health interventions aimed at mitigating the risk of adverse health outcomes associated with early menopause.STUDY FUNDI...