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Gerald B Phillips

Publications and source records attributed to Gerald B Phillips.

7 recordsLinked to original sources
PubMed2005

Is atherosclerotic cardiovascular disease an endocrinological disorder? The estrogen-androgen paradox.

The strikingly lower incidence of myocardial infarction (MI) in premenopausal women than in men of the same age suggests an important role for sex hormones in the etiology of MI. Supporting such a role are studies, carried out mostly in men, that report abnormalities of sex hormone levels in patients with MI, correlations of sex hormone levels with degree of atherosclerosis and with levels of risk factors for MI, and changes in the levels of risk factors with administration of sex hormones. Studies have also reported a prospective relationship in men of testosterone level with progression of atherosclerosis, accumulation of visceral adipose tissue, and other risk factors for MI. Puzzling, however, is that neither the level of testosterone nor of estrogen was found to be predictive of coronary events in any of the eight prospective studies that have been carried out. Also puzzling is that whereas the gender difference in incidence of MI would suggest that testosterone promotes and/or estrogen prevents MI, the cross- sectional, hormone administration, and prospective studies have suggested that in men testosterone may prevent and estrogen promote MI. These studies have thus revealed an estrogen-androgen paradox: that endogenous sex hormones may relate both to atherosclerotic cardiovascular disease and its risk factors oppositely in women and men. Recently recognized experiments of nature and their knockout mouse models may present another manifestation of this estrogen-androgen paradox and could help resolve these apparent contradictions.

Androgens↗
PubMed2004

Are major risk factors for myocardial infarction the major predictors of degree of coronary artery disease in men?

Although numerous cross-sectional studies have reported associations of hypertension, hypercholesterolemia, diabetes, smoking, and/or obesity with the presence of coronary artery disease (CAD), correlations of these risk factors for myocardial infarction (MI) with the degree or progression of CAD have been less consistent. Nevertheless, these risk factors are generally assumed to be major determinants not only of MI, but of the degree of CAD as well. The present study is an attempt to evaluate the relationship of major risk factors for MI to degree of CAD. From 182 men who underwent diagnostic coronary arteriography, the 154 with CAD were selected for study. These 154 patients were divided into 2 groups, those with hypertension, hypercholesterolemia, diabetes, smoking, and/or obesity (n = 121) and those with none of these risk factors (n = 33). The mean degree of CAD in the group with risk factors for MI (44.4%) and in the group without (50.6%) was not significantly different (P =.15); nor was the increase in CAD with age augmented by the presence of these risk factors. On multiple regression analysis, none of these risk factors was associated with degree of CAD. Three other variables that were considered in this study, age, high-density lipoprotein-cholesterol (HDL-C), and free testosterone (FT), did show an independent association with degree of CAD. These findings, together with the findings of previous studies from other laboratories, raise the possibility that in men selected for coronary arteriography, age, HDL-C, and FT may be stronger predictors of degree of CAD than are blood pressure, cholesterol, diabetes, smoking, and body mass index (BMI).

Age Factors↗
PubMed2004

The GILHT-E Syndrome?

Explore the source record for details and available documents.

Diabetes Mellitus, Type 2↗
PubMed2003

Relationships in men of sex hormones, insulin, adiposity, and risk factors for myocardial infarction.

That sex hormones, insulin, and obesity all correlate with the constellation of risk factors for myocardial infarction (MI) that has come to be known as "syndrome X," the "insulin-resistance syndrome," or the "metabolic syndrome" suggests that any one or more of them could underlie and link the risk factors to form the constellation. That sex hormones, insulin, and obesity also correlate with each other complicates their identification as an underlying link. To compare the likelihood of each being a link, we measured and determined the interrelationships of sex hormones, insulin, adiposity variables, and risk factors for MI in 80 apparently healthy men. Of the adiposity variables, visceral adipose tissue (VAT) correlated more strongly with the risk factors for MI than did body mass index (BMI), total adipose tissue (TAT), subcutaneous adipose tissue (SCAT), waist-to-hip ratio (WHR), and waist circumference (W). Controlling for VAT eliminated all of the other adiposity correlations that had been significant. VAT, therefore, was used as the measure of adiposity for further data analysis. VAT correlated more strongly with risk factors for MI than did sex hormones and insulin, and most of the correlations of sex hormones and insulin with risk factors for MI lost statistical significance after controlling for VAT. Testosterone and the ratio of estradiol-to-testosterone (E/T) correlated with insulin; on controlling for VAT, only the E/T-insulin correlation remained significant (r =.38, P <.001) and on multiple linear regression analysis, insulin was associated with estradiol (P =.01) and testosterone (P =.04) independently of VAT and age. In conclusion, (1) VAT in men may largely explain the correlations of sex hormones, insulin, and obesity with the risk factors for MI measured, (2) VAT may be the principal factor in men, independently of other measures of adiposity, that links risk factors for MI to form the constellation, and (3) estradiol may play a more important role in the sex hormone-insulin relationship in men than has generally been considered.

Adipose Tissue↗