Some Obese Postmenopausal Women Impervious to Metabolic Disturbances.

2001 MAY 24 - (NewsRx Network) -- by N.R. Saltmarsh, staff medical writer -- A subset of postmenopausal women, despite being obese, are apparently able to avoid the metabolic disturbances such as insulin resistance often associated with obesity.

These women were more likely to have become obese at a younger age and less likely to have visceral body fat compared with obese women with metabolic abnormalities, wrote M. Brochu and colleagues in the Journal of Clinical Endocrinology and Metabolism.

"It is unclear why some obese individuals fail to show traditional risk factors associated with the insulin resistance syndrome despite having a very high accumulation of body fat," said Brochu and associates. "To address this issue, we identified and studied a subgroup of metabolically normal but obese (MNO) postmenopausal women to gain insight into potential physiological factors that may protect them against the development of obesity-related co-morbidities."

Brochu and team studied the metabolic characteristics of 43 obese, sedentary, post-menopausal women, 17 were MNO and 26 were metabolically abnormal obese (MAO), as determined by insulin resistance.

Although the two groups had similar body fat percentages (45.2% [+ or -] 5.3% versus 44.8% [+ or -] 6.6%) MNO subjects had 49% less visceral adipose tissue than MAO subjects. The researchers found no differences in abdominal subcutaneous tissue, total fat mass, muscle weakness, or physical activity energy expenditure.

Other findings were as follows:

* MNO subjects had lower fasting plasma glucose and insulin levels and lower insulin levels during the oral glucose tolerance test but similar two-hour glucose levels ...