Sex hormones, lipids, lipoprotein cholesterols, and apolipoproteins in normal and obese subjects: atherogenic relationships

Abstract

Our aim in the current study of 20 normal controls, 28 overweight, and 26 severely overweight (obese) subjects was to assess interrelationships of obesity, endogenous estradiol (E2) and testosterone (T), and the E2/T ratio with major independent explanatory variables for coronary heart disease (CHD), including lipids, lipoproteins, and apolipoproteins. Most of the lipid and lipoprotein variables (total, high-, low-, and very-low-density lipoprotein cholesterols) as well as apolipoproteins A1, A2, and B did not vary significantly with the presence of obesity. With increasing relative ponderosity, there were, however, increasing levels of total triglycerides and VLDL triglyceride. Levels of FSH, LH, prolactin, and testosterone did not differ significantly with obesity. The obese subjects had the highest E2 and E2/T levels; overweight subjects had intermediate levels which were also significantly higher than in the controls. Using multiple regression analyses, in obese subjects increasing T was associated with increasing apo B, and increasing E2 was correlated with decreasing apo A1. Opposite relationships were found in the normal controls where increasing T and increasing Quetelet indices were associated with diminished apo B and increasing E2 was associated with increasing A1. Obesity's association with increased CHD risk may be mediated through increasing E2 and apo B and reducing apo A1. Since obese subjects have higher E2 levels and often have lower T, they are likely to have a pattern of endogenous sex hormones (higher E2, lower T, higher E2/T ratios) similar to those observed in young men with premature myocardial infarction.