Growth hormone (GH) is widely recognized for its classical function in stimulating growth and development, primarily through the induction of insulin-like growth factor-1 (IGF-1) produced by the liver. However, emerging research reveals a far more intricate role for GH, particularly in regulating metabolism beyond merely fostering physical growth. It exerts profound regulatory influence over glucose and lipid metabolism across multiple peripheral organs, including the liver, skeletal muscle, and critically, adipose tissue. This renewed interest stems from a groundbreaking shift in our understanding of adipose tissue—not simply a passive fat reservoir but a dynamically active organ playing pivotal roles in endocrine and metabolic regulation.
Since the mid-20th century, the relationship between GH and adipose tissue has intrigued scientists, yet only recently has intensive research begun unraveling the multifaceted mechanisms involved. Modern perspectives illuminate that GH affects adipose tissue on many levels: it drives lipolysis and influences lipogenesis, modulates adipocyte proliferation and differentiation, and even regulates the secretion of adipocyte-derived cytokines. These hormonal effects extend into more nuanced pathways such as promoting the browning of white adipose tissue and influencing the fibrosis of adipose compartments, processes previously underestimated for their metabolic significance.
As the field has advanced, novel discoveries highlight even more complex interactions; GH not only influences basic metabolic processes in adipose tissue but also plays a key role in the tissue’s aging and immune landscape. It shapes the adipose tissue immune microenvironment, modulating inflammatory responses and immune cell infiltration that are crucial in obesity- and age-related metabolic dysfunction. Furthermore, GH governs the heterogeneity of adipocyte subpopulations, demonstrating a sophisticated layering of regulatory control at the cellular level that affects whole-body energy homeostasis.
In parallel with these mechanistic insights, clinical observations have noted a persistent pattern: patients with obesity consistently exhibit diminished circulating GH levels. This association intimates a biological link that may underlie some metabolic pathologies seen in obesity, particularly insulin resistance and lipid abnormalities. Given GH’s broad regulatory potential, alterations in its secretion or signaling could critically disrupt adipose function, compounding metabolic derangements and complicating therapeutic outcomes.
Physiologically, GH’s lipolytic effect mobilizes fatty acids from adipose tissue, thereby influencing substrate availability and utilization in peripheral tissues. This action is not a simple on/off switch but involves complex feedback loops and cross-talk with other hormones such as insulin, leptin, and adiponectin. The balance between lipolysis and lipogenesis ensures energy storage during excess nutrient availability and energy release during fasting or increased demand. GH’s modulation of these processes is thus critical for metabolic flexibility, a feature often impaired in metabolic diseases.
At the cellular level, GH encourages the proliferation of preadipocytes while modulating their differentiation trajectory. This influence shapes adipose tissue expansion and remodeling, especially critical when considering obesity’s pathophysiology characterized by adipocyte hypertrophy and hyperplasia. By controlling these processes, GH indirectly affects adipose tissue function and systemic metabolism, highlighting its potential role as a therapeutic target in obesity and metabolic syndrome.
Moreover, adipose tissue is a secretory organ producing numerous bioactive substances called adipokines that regulate appetite, inflammation, and insulin sensitivity. GH affects the profile and quantity of adipokines released, thus mediating systemic metabolic responses. This regulatory role could explain observed changes in metabolic homeostasis among individuals with altered GH secretion patterns and serves as a nexus linking endocrine and immune functions within adipose tissue.
An intriguing dimension of GH’s influence involves the browning of white fat—an adaptive process where energy-storing white adipocytes acquire characteristics of energy-dissipating brown adipocytes, including enhanced thermogenesis. GH has been found to facilitate this conversion, suggesting avenues for increasing energy expenditure and combating obesity. This finding expands the potential of GH-related therapies aiming not just at weight reduction but at improving metabolic health through adipose tissue plasticity.
Adipose tissue fibrosis, long thought to be a pathological hallmark in metabolic disorders, is also modulated by GH signaling. Fibrotic remodeling impairs adipose tissue expandability and function, exacerbating insulin resistance and inflammation. The regulatory effect of GH on this process underscores its role beyond simple metabolic modulation, painting a picture of GH as a guardian of adipose tissue health and homeostasis over time.
Compounding this complexity, GH’s role in adipose tissue aging reveals that diminished GH activity may accelerate senescence-like changes in adipocytes, leading to functional decline and metabolic impairment. Such insights align with clinical evidence of GH decline in aging populations and link these phenomena to increased obesity risk and metabolic abnormalities observed with advancing age.
This detailed mechanistic picture is reinforced by extensive research using animal models genetically engineered to exhibit altered GH signaling—both excess and deficiency. These models faithfully recapitulate the metabolic phenotypes observed in humans, validating GH’s pivotal role in adipose tissue regulation. Through these studies, it has become evident that the precise tuning of GH action is critical: both excess and deficiency can result in pathological states, emphasizing the importance of homeostatic balance.
Furthermore, the immune microenvironment of adipose tissue, a critical determinant of metabolic health, is intricately regulated by GH. GH modulates immune cell composition and cytokine milieu, which affects inflammation—a central driver of insulin resistance in obesity. Understanding how GH controls these immune-metabolic axes opens exciting avenues for novel interventions targeting inflammatory pathways within adipose tissue.
Integrating knowledge from both clinical and experimental studies, a complex interplay emerges, where GH influences adipose tissue function, which in turn can feedback to affect GH secretion and signaling. This bidirectional regulation highlights a homeostatic circuit that, when disrupted, may precipitate metabolic disorders such as obesity, type 2 diabetes, and associated comorbidities. Targeting this axis therapeutically offers a promising strategy to restore metabolic balance.
The recognition of decreased GH levels in obesity and its contribution to metabolic dysfunction challenges conventional treatment paradigms. Therapeutic strategies aiming to restore or mimic GH action might offer benefits beyond weight loss, including normalization of lipid profiles, improvement of insulin sensitivity, and reduction of adipose tissue inflammation and fibrosis. However, such interventions must carefully consider the multifaceted roles of GH to avoid adverse effects.
This comprehensive review punctuates the evolving landscape of adipose biology and endocrine regulation, revealing growth hormone as a central figure in regulating adipose tissue metabolism, structure, and immune environment. The implications for obesity and metabolic disease are profound, nudging the scientific and medical communities to rethink GH’s potential beyond growth promotion towards a metabolic regulator and therapeutic target.
Future research is poised to delve deeper into the cellular and molecular mechanisms by which GH orchestrates adipose tissue functions, as well as exploring how genetic and environmental factors modulate this axis. Advances in technology such as single-cell sequencing, adipose tissue imaging, and novel biomarker identification will propel these endeavors, hopefully translating into innovative treatments for obesity-related metabolic diseases.
In summary, growth hormone’s role in adipose tissue extends far beyond traditional views, integrating metabolic, endocrine, and immune functions within this dynamic organ. The adverse metabolic consequences seen in GH deficiencies and excesses underscore its critical homeostatic role, making it a promising target to counteract obesity and metabolic syndrome. The future landscape of obesity intervention will likely embrace the modulation of growth hormone and its adipose tissue interplay, fostering a nuanced approach to metabolic health.
Subject of Research: The regulatory effects of growth hormone on adipose tissue at physiological and pathological levels and its relationship with obesity.
Article Title: The regulatory effects of growth hormone on adipose tissue at physiological and pathological levels and its relationship with obesity.
Article References:
Liu, Y., Zhu, H., Yang, H. et al. The regulatory effects of growth hormone on adipose tissue at physiological and pathological levels and its relationship with obesity. Int J Obes (2026). https://doi.org/10.1038/s41366-026-02132-0
Image Credits: AI Generated
DOI: 01 July 2026
