Women With Diabetes at High Risk for Cardiovascular Disease

June 9, 2014

Women tend to be diagnosed with cardiovascular disease later in life than men. But a diagnosis of type 2 diabetes in a woman appears to nullify a gender-protective effect.

Studies performed over the past decade have suggested that women with type 2 diabetes (T2DM) are at higher risk for-and for dying of-heart disease than men with T2DM.1 Researchers estimate that compared with the general population, women with T2DM have a 3 to 4 times greater risk for cardiovascular disease (CVD), and men with T2DM have a 2 to 3 times greater risk.2

While men in the general population are thought to develop heart disease at a younger age than women, the gender advantage on CVD risk may not apply for women with T2DM. Though deaths from CVD among women without T2DM have decreased by 23% over the past 30 years (likely as a result of increased awareness and better management of CVD risk factors among women), deaths from CVD among women who do have T2DM have actually increased by about 30% during approximately the same period of time.3 Two recently published studies add to existing evidence that suggests having T2DM erodes the relative positive effect of gender on the development of CVD.

In the first study,4 researchers in the Netherlands, United Kingdom, Australia, and the United States performed a meta-analysis and systematic review of research on sex differences and the effect of diabetes on risk for coronary heart disease (CHD). Sixty-four population-based cohort studies published between January 1966 and February 2013 were included in the analysis.

Key findings4:

  • Study sample: 858,507 individuals (42% women) and 28,203 CHD events

  • Women with diabetes had 44% greater risk of developing CHD, compared with men with diabetes (relative risk ratio [RRR] = 1.44; 95% CI, 1.27 to 1.63)

  • The risk of dying of a cardiac event was more than 40% greater in women with diabetes, compared with men with diabetes (women to men RRR = 1.44; 95% CI, 1.20 to 1.73)

“Greater awareness of early symptoms of CHD in women and sex-specific therapeutic risk factor management, irrespective of the presence of diabetes, is optimal for improving clinical outcomes in both women and men,” the authors emphasized.

The second study5 looked at gender difference and control of cardiovascular risk factors among 680 patients with T2DM attending 3 primary clinics in South Carolina. The study relied on patient self-report with the aid of trained research assistants, and medical records data.

Key points5:

  • Study sample: 56% men, 67% non-Hispanic black, and 78% with an annual income less than $35,000.

  • Systolic blood pressure: Significantly higher in women than in men  (134 mm Hg vs 130 mm Hg, respectively; P=.005)

  • LDL-C: Significantly higher in women than in men (99.7 mg/dL vs 87.6 mg/dL, respectively; P<.001)

  • Control of combined CVD risk factors (HbA1c, BP, LDL-C): Significantly worse in women than in men (5.9% vs 17.3%, respectively), a relationship that remained after adjusting for confounders

“These findings” the authors note in their conclusion “suggest that, despite the existence of specified treatment goals and guidelines for better control, disparities between men and women still persist.”5 They call for educating women on the modifiable risk factors for CVD and on their own personal risk profiles for heart disease. “They must be empowered to adopt healthier lifestyles and behaviors such as adhering to prescribed medication regimens to achieve improved outcomes,” the authors emphasized. “It is imperative that clinicians provide consistent care, so the differences between men and women are not perpetuated.”5

References:

  • Huxley R, Barzi F, Woodward. Excess risk of fatal coronary heart disease associated with diabetes in men and women: meta-analysis of 37 prospective cohort studies. BMJ. 2006;332:73-78.
  • Norhammar A, Schenck-Gustafsson K. Type 2 diabetes and cardiovascular disease in women. Diabetologia. 2013;56:1–9. doi:10.1007/s00125-012-2694-y
  • Cleveland Clinic. Women, Diabetes and Cardiovascular Disease. http://my.clevelandclinic.org/heart/disorders/cad/diabetes-women-cardiovascular-disease.aspx. Accessed June 4, 2014.
  • Peters SAE, Huxley RR, Woodward M. Diabetes as risk factor for incident coronary heart disease in women compared with men: a systematic review and meta-analysis of 64 cohorts including 858,507 individuals and 28,203 coronary events. Diabetologia.  2014;16:1-7. doi:10.1007/s00125-014-3260-6.
  • Strom Williams JL, Lycnh CP, Winchester R, et al. Gender differences in composite control of cardiovascular risk factors among patients with type 2 diabetes. Diabetes Technol Ther. 2014;1-7. doi:10.1089/dia.2013.0329