Estrogen, Age, and Visceral Fat's Combined Impact on Women's Growth Hormone

Growth hormone (GH) is crucial for maintaining healthy metabolism, body composition, and bone density, but its secretion naturally declines with age. While estrogen and visceral fat (fat stored around abdominal organs) are known to influence GH dynamics, the interplay of these factors on pulsatile GH secretion in healthy women has not been fully elucidated.

The study revealed that age emerged as the strongest independent predictor of reduced GH secretion, demonstrating a significant 30% decrease in GH pulse amplitude for every decade after age 30 (p<0.001). Furthermore, visceral fat area was independently and inversely correlated with lower GH levels, showing a robust 15% reduction in overall GH secretion for every 1 kg increase in visceral fat (p<0.005). The role of estrogen was more intricate; premenopausal women with higher circulating estradiol levels exhibited a 1.8-fold higher GH pulse frequency compared to their postmenopausal counterparts, suggesting a modulatory effect on pulsatility rather than amplitude. The most significant finding was that the combined and synergistic effects of increasing age and higher visceral fat accounted for over 60% of the observed variability in the decline of growth hormone secretion in healthy women (R² = 0.62, p<0.001). This highlights a powerful, cumulative negative impact, where both factors substantially contribute to the age-related reduction in this vital hormone.