Obesity may exacerbate a heart disorder in African-American females.(Brief Article)

2002 JUN 27 - (NewsRx.com & NewsRx.net) -- Sedentary lifestyle habits, poor dietary habits, and childhood obesity are becoming epidemic in America. These behaviors are more prevalent in children than ever before. Low levels of physical activity and poor dietary habits are causes of childhood obesity, a condition associated with risk factors for adult chronic diseases.

Previous studies reveal that African American girls are more likely to be overweight than Caucasian girls. The trend continues into their adulthood, as 30% of younger (18-30 years) and 77% of older (45-65 years) black women are obese compared with 14% and 46% respectively, for their white counterparts. Overall, black women are 60% more likely to become obese than are white women. Women in minority groups are less physically active than the general American population, and the overall health status of people of color, including African American women, is lower than that of the general America population.

Obesity can lead to cardiovascular problems. Another disorder of the heart is long QT syndrome (LQTS), an inherited or acquired condition of the heart's electrical system. People with LQTS are at risk for syncope (loss of consciousness) and sudden death, often at a young age. Although it is known that African Americans have a higher incidence of obesity compared with Caucasians, race-specific information is not available for the prevalence of LQTS. Furthermore, while it is well-known that chronic physical activity reduces the incidence of obesity, little is known about the effects of chronic physical activity on QT (time from electrocardiogram Q wave to the end of the T wave corresponding to electrical systole, or contraction and relaxation of the ventricles) duration.

A new research study, "QTc is related to obesity and physical activity level for African American females," has been conducted by C. Jayne Brahler, PhD, et al., who presented their findings during the American Physiological Society annual meeting in New Orleans, Louisiana.

The subjects were 44 low-income African American women (ages 21-53 years) and 66 biological daughters (ages 5-17 years). Eligibility criteria included premenopausal, not on estrogen therapy, not pregnant, and apparently healthy and medically stable, with no known acute heart disease complications, endocrine problems, complications from diabetes mellitus, HIV/AIDS, or other major diseases as determined by completing a health history questionnaire.

Subjects were 12-14 hours fasted upon arrival. Trained faculty and university student technicians measured body weight, height, and waist and hip (at the greatest girth of the gluteus) circumferences. BMI was calculated as weight in kilograms divided by height in meters squared. Waist-to-hip ratio (WHR) was calculated as waist circumference (cm) divided by hip circumference (cm). QT interval was measured from the earliest onset of the QRS complex to the end of the T wave in lead II. Measurements from five ...