Estrone (E1), a key estrogen hormone, is a crucial marker in the Comprehensive 24-Hour Urine Steroid Hormone Profile Test, emphasizing its importance in assessing male hormonal balance and health. In men, while estrogen is typically associated with female physiology, estrone plays a significant yet often underestimated role. It is involved in bone metabolism, brain function, and cardiovascular health. Estrone is produced primarily from the conversion of androstenedione, a steroid hormone. The measurement of estrone levels in a 24-hour urine sample provides a comprehensive overview of its daily production and metabolism, offering valuable insights into the endocrine system's functioning. Elevated levels of estrone in men can be indicative of various conditions, including obesity, liver disease, or excessive conversion of androgens to estrogens, which might lead to symptoms like increased body fat, reduced muscle mass, and emotional changes. Conversely, low levels of estrone could be linked to issues such as osteoporosis or diminished overall well-being.

A component of the estrone level may be due to aromatization of androstenedione and testosterone by CYP19 (aromatase) enzyme in adipose tissue, and/or conversion from estradiol due to HSD17B activity. Aromatase up-regulation and increased intracellular estrogens in men may contribute to increased adiposity, metabolic syndrome, and prostate pathology. CYP19 enzyme is induced during times of stress, exposure to xeno-estrogens, high glycemic diet, excessive adipose tissue, and alcohol consumption.