In women, diabetes triples risk for CVD death
In a large, international cohort of adults with no previous vascular disease, diabetes tripled the risk for death from ischemic heart disease or stroke in women and doubled the risk for men, according to findings from a meta-analysis published in The Lancet Diabetes & Endocrinology.
“While diabetes is an important cause of premature death from heart attack or stroke in both men and women, it seems to pose a particularly high risk for middle-aged women,” Sarah Lewington, DPhil, associate professor of statistical epidemiology and program leader at the MRC Population Health Research Unit at the University of Oxford, told Endocrine Today. “But these vascular risks can be greatly reduced by inexpensive drugs that control blood sugar, blood pressure and cholesterol.”
Lewington and colleagues analyzed individual, participant-level baseline data from 980,793 adults from 68 observational studies included in the Prospective Studies Collaboration and the Asia Pacific Cohort Studies Collaboration (412,268 women). Studies were conducted in 19 countries, with participants from western and central Europe, Southeast Asia, North America and Australia, with a mean age at recruitment of 46 years. Baseline data were collected between 1949 and 1997 and included age, sex, diabetes status, total cholesterol, BP, tobacco use, height and weight. Last follow-up took place between 1985 and 2002. Participants had mortality follow-up data in the age range of 35 to 89 years. Causes of death were determined from death certificates. Researchers estimated the sex-specific prevalence of diabetes by age and levels of vascular risk factors (BMI, cholesterol, BP) and used Cox regression models stratified by study to estimate the relevance of diabetes to cause-specific mortality, yielding death risk ratios over the average study period.
During 9.8 million person-years of follow-up, 76,765 participants died, including 19,686 participants who died from CVD causes at a mean age of 66 years (91% from ischemic heart disease). At recruitment, 4.3% of participants had diabetes, with prevalence increasing from a baseline prevalence of 2.1% in men and 1.4% in women to 8.9% in men and 6% in women by age 70 years. Prevalence of diabetes rose with increasing BMI, systolic BP and total cholesterol (both adjusted for BMI), according to researchers, and decreased with increasing HDL cholesterol level.
Overall, diabetes more than doubled vascular mortality risk (RR = 2.3; 95% CI, 2.18-2.44); however, the risk for death was higher in women (RR = 3; 95% CI, 2.71-3.33) vs. men (RR = 2.1; 95% CI, 1.97-2.24). The RRs for death were higher at younger vs. older ages (P for trend = .001), according to researchers, with the findings especially marked among women aged 35 to 59 years (RR = 5.55; 95% CI, 4.15-7.44). The higher RRs for death among women persisted within levels of other vascular risk factors, the researchers noted.
“Future analyses considering sex-hormone concentrations and subclasses of lipids would be of interest,” Lewington said. “Sex differences in inflammation might also exist, and since targeting interleukin-1-beta can reduce occlusive vascular risk, inflammation should be a focus of future research aimed at devising novel therapeutic approaches.” – by Regina Schaffer
For more information:
Sarah Lewington, DPhil, can be reached at the MRC Population Health Research Unit, University of Oxford, Richard Doll Building, Old Road Campus, Oxford OX3 7LF, U.K.; email: email@example.com.
Disclosures: One author reports he has received grant support from Boehringer Ingelheim. Another author reports he has received grant support from Abbott, AstraZeneca, Bayer, British United Provident Association, GlaxoSmithKline, Liposcience, Merck, Novartis, Pfizer and Solvay.