Background. An increase in total adiposity and in particular an abdominal distribution of adiposity may contribute to the decline in metabolic insulin sensitivity observed in older men and women. The objective of this cross-sectional study was to determine which measure of abdominal adiposity would provide the best sex-independent predictor of metabolic insulin sensitivity in older men and women. Methods. Insulin sensitivity and abdominal adiposity were measured in healthy, nondiabetic older (64 ± 6 years; mean ± standard deviation) men (n = 23) and women (n = 31). Metabolic Insulin Sensitivity Index (S1) was determined from a frequently sampled insulin-assisted intravenous glucose tolerance test. Body fat mass and abdominal fat mass were determined from dual energy X-ray absorptiometry (DXA) scans. Anthropometric measures included waist and hip circumferences, height, and body weight. Results. Although waist circumference, waist index (waist circumference divided by height), and waist-hip ratio (WHR) were all lower in women than in men, there was no sex difference in DXA L1-L4 fat mass. In univariate analyses. Si was significantly inversely related with body weight, body mass index, waist circumference, waist index, percentage of total body and abdominal fat, and DXA L1-L4 fat mass but not with WHR. The DXA L1-L4 fat mass was identified as the best independent predictor of Si, accounting for 41.2% of the variance (p < .0001) in a stepwise multiple regression model that controlled for sex. Conclusions. WHR is not associated with S, in either men or women. Abdominal adiposity measured by DXA L1-L4 fat mass provides a sex-independent predictor of Si in older men and women.
|Original language||English (US)|
|Number of pages||6|
|Journal||Journals of Gerontology - Series A Biological Sciences and Medical Sciences|
|State||Published - Jul 2005|
Bibliographical noteFunding Information:
ACKNOWLEDGMENTS Dr. Maxwell is funded by a New Investigator Award from the Canadian Institutes of Health Research (CIHR)–Institute on Aging and a Health Scholar Award from the Alberta Heritage Foundation for Medical Research (AHFMR). Shelly Vik is currently a PhD candidate (Epidemiology) and is funded by the Alberta Provincial CIHR Training Program in Bone and Joint Health. Dr. Hogan holds the Brenda Strafford Foundation Chair in Geriatric Medicine and the chair provides financial support to both Drs. Hogan and Maxwell. Micaela Jantzi, Jeff Poss, and Dr. Hirdes acknowledge the Primary Health Care Transition Fund, in part, for financial support. Dr. Hirdes’s participation was supported by a CIHR Investigator Award. We also thank Dr. Michael Eliasziw for consulting on the statistical analyses.