Onset of Heart Disease is Delayed in Women

Recent research suggests that young women are better able to handle the clinical complications associated with insulin resistance, which may explain why women usually develop heart disease a decade later than men.

Insulin resistance is known to raise the risk of metabolic abnormalities—such as diabetes, dyslipidemia, and hypertension—that can increase the risk of heart disease. Investigators at Stanford University examined insulin resistance and cardiovascular disease risk in a cross-sectional study of 468 women and 354 men, ages 19 to 79.

They divided the study participants by age, sex, and body mass index. They looked at the relationship between insulin resistance and five cardiovascular disease risk factors: • Systolic blood pressure

• Diastolic blood pressure

• Fasting glucose levels

• Triglyceride levels

• HDL-C concentrations

They found that female participants ages 50 or younger who were highly insulin resistant had lower blood pressure, lower fasting blood sugar levels, and lower triglyceride concentrations than their male counterparts.

Highly insulin-resistant younger women also had considerably lower fasting glucose and triglyceride levels than women over 50 with the same degree of insulin resistance.

The researchers also found that insulin resistance increased with body mass index, and that older women and men were generally more insulin resistant than their younger counterparts. “If we can better understand how young women compensate for insulin resistance, it can help us treat many of the metabolic abnormalities associated with insulin resistance and heart disease,” said lead author Sun H. Kim, MD, MS, Assistant Professor of Medicine at the Stanford University Medical Center.

“Until then, we should all strive to be insulin sensitive—sex (and age) differences were minimized in insulin-sensitive individuals.” Dr Kim wants to better understand the mechanisms that protect young women against the complications associated with insulin resistance.

“Our next step may be to evaluate how insulin resistance affects fat handling and fat distribution,” she said. The full study is scheduled to appear in the November issue of the Journal of Clinical Endocrinology & Metabolism.

—Colleen Mullarkey

Reference

Kim SH, Reaven G. Sex differences in insulin resistance and cardiovascular disease risk. J Clin Endocrinol Metab. 2013 Sept 24. [Epub ahead of print].