| |
In
older obese women, midthigh fat deposits are associated
with risk factors for cardiovascular disease (CVD), type
2 diabetes and lipid disorders. Ryan et al., in a study
published in The American Journal of Clinical Nutrition,
demonstrated that a regime of low-intensity walking combined
with weight loss could specifically reduce midthigh fat
while improving glucose metabolism as well as lipid metabolic
risk factors for CVD. Women with the most midthigh fat
at baseline lost the most fat and gained the most muscle
in this region and realized the greatest improvements
in glucose metabolism.
The
24 subjects were all overweight nonsmokers averaging
58 years old, were not receiving hormone replacement
therapy, and had no overt evidence of any disease. During
the 6 month weight loss intervention, the women attended
weekly classes led by a registered dietitian who provided
them with instruction in the principles of a reducing
diet conforming to American Heart Association guidelines.
Additionally they were encouraged to perform low-intensity
walking 3 days per week, with one of the weekly walking
sessions performed on a treadmill at an exercise facility
associated with the research site. At baseline, a CT
scan of the midthigh region was done to quantify muscle
area and fat tissue, and assessments were made of glucose
metabolism and blood lipids including total cholesterol,
triglycerides, HDL and LDL cholesterol.
At
the conclusion of treatment, the women's body weight
and body mass index had decreased by an average of 8%;
waist and hip circumferences had decreased by 4%; and
the walking intervention produced an overall 8% increase
in aerobic capacity. There was a significant 4% decrease
in the circumference of the midthigh which, when assessed
using a CT scan, showed a 16% decrease in fat and a
7% increase in muscle. The increase in midthigh muscle
area as a result of walking was similar to that previously
reported in men, consistent with the prevention of sarcopenia
(loss of skeletal muscle mass) in these postmenopausal
obese women. Sarcopenia is a major age-related cause
of loss of mobility and subsequent injury from falls
in elderly persons. At baseline 42% of the women had
impaired glucose tolerance; however, this metabolic
abnormality was reduced to 17% at the conclusion of
the program, consistent with positive body composition
changes. Although overall cholesterol levels did not
change significantly, plasma triglycerides were reduced
by an average of 19%.
The
combination of moderate weight loss and increased physical
fitness in the midthigh area was associated with an
array of extended health benefits for the women in this
study.
|
|
