Abstract
The clinical relevance of testosterone in women over 65 y is unknown. Pre- and perimenopausal women with polycystic ovarian syndrome have a high prevalence of cardiovascular risk factors. Early postmenopausal women with high testosterone concentrations are more likely to have insulin resistance and cardiovascular disease.
Women (n = 368) were randomly sampled from the Cardiovascular Health Study (CHS). Blood was drawn in the morning after a 12-h fast. Total testosterone was measured by radioimmunoassay and free testosterone concentration by equilibrium dialysis. Age ranged from 65 to 98 y (median 74 y).
There was a stepwise increase in homeostasis model assessment of insulin resistance (HOMA-IR) with increasing total and free testosterone concentrations with a corresponding decrease in insulin sensitivity. Higher testosterone and free testosterone concentrations were strongly associated with abdominal obesity and high fasting glucose. After adjustment, women in the top quartile of total testosterone had three-fold greater odds of metabolic syndrome and cardiovascular disease than those in the bottom quartile.
Higher testosterone concentrations are associated with insulin resistance, metabolic syndrome and cardiovascular disease in older women. There is a need to establish whether testosterone is a marker or mediator of cardiovascular disease. Further studies are required to determine the relationship between testosterone and insulin resistance.