Study: Waist Circumference a Strong Predictor of Heart Disease
Among patients with diabetes but without known heart disease, abdominal obesity, such as when one’s shape is more like an apple than a pear, compared to other forms of obesity, is associated with a greater reduction in heart function, according to a new study.
“Obesity, especially the abdominal form, which can be identified simply by measuring waist circumference (WC), continues to be bad for patients on even more fronts than previously thought,” said study author Brent Muhlestein, MD, co-director of research at the Intermountain Medical Center Heart Institute, Salt Lake City.
__________________________________________________________________________________________________________________________________________________________________________
RELATED CONTENT
Could Waist Circumference Influence Colorectal Cancer Risk?
Study Links High Body Mass and Large Waist to Hearing Loss
__________________________________________________________________________________________________________________________________________________________________________
Researchers evaluated the effect of an active diagnostic approach in asymptomatic diabetes patients on total and event-free survival. They randomized participants to screening coronary CT angiography or standard of care. Overall, 200 consecutive patients randomized to screening also underwent 2D echo with speckle tracking. Using offline software global systolic longitudinal strain (Ell) and early diastolic strain (E`) were determined from apical 2 and 4 chamber views. The investigators studied the relationship between WC and regional left ventricular (LV) function.
Among the entire group (mean age=60 years, hypertension=79%), BMI was 32 kg/m2 and WC was 108 cm. Median coronary calcium score (CCS) was 27 Agatston units, ejection fraction 67%, global Ell: -12.9%, and peak E` was 0.81 sec-1. Greater WC was associated with progressively worse global strain (Ell in the lowest WC quartile was -14.6% vs. highest quintile: -11.4%, p<0.0001 for trend).
The researchers saw this association in both genders (in women p=0.001 and men p=0.0003, for trend). The relation between Ell and WC remained significant after multivariable adjustment for age, gender, coronary artery disease severity, CCS, diabetes type, hypertension, and systolic blood pressure (beta=0.1 %/cm, p<0.001). After including either weight or BMI in the regression model, only WC remained an independent predictor of global Ell (p=0.001 and 0.003 after including weight and BMI, respectively), while weight and BMI became non-significant (p=0.81 and 0.65, respectively).
“Although we have known that abdominal obesity is more linked to coronary atherosclerosis than other forms of obesity, our previous understanding of the mechanism behind this finding would not necessarily link itself also to heart function,” Muhlestein said. “The fact that this form of obesity also adversely affects heart function was surprising to me. This study just provides another reason for all of us to continue our fight against obesity.”
He hopes to perform more studies in order to determine the mechanism by which abdominal obesity is especially harmful. Specifically, he plans to compare genetic and plasma biomarkers between obese people with a pear vs. apple shape.
-Mike Bederka
Reference:
Rosen BD, Sharma RK, Horton KD, et al. Waist circumference is a strong predictor of regional left ventricular dysfunction in asymptomatic diabetic patients. The Factor-64 study. Paper presented at the American College of Cardiology Scientific Session, Chicago. April 2, 2016.