Growth Hormone in the Aging Process

Aging involves a decline of Growth Hormone. amount of HGH after the age of 21 to 31 falls about 14% per decade, so that the total 24 hour HGH production rate is reduced in half by age 60.

The fall in GH secretion seen with aging coincides with changes in body composition and fat metabolism that are similar to those seen in adults with GH deficiency including impaired psychological well-being and quality of life with depressed mood, increased anxiety reduced vitality, reduced lean body mass, reduced bone mineral density, increased body mass, increased waist: hip ratio, reduced exercise performance, etc.

Can Human Growth Hormone Reverse the Effects of Aging?

The impact of GH treatment on body composition in adult GHD is unequivocal: fat mass and volume are decreased (by 7-15%), with the greatest reductions seen in abdominal visceral depots; lean body mass and skeletal muscle volume are increased (by 5-10%). Most studies showed little change in overall body weight, but rather a shift from fat to lean mass. GH also promotes genuine muscle growth.

Another universal finding is that GH replacement improves cardiac performance.

Improvements in exercise performance are probably due to a combination of increased skeletal muscle strength, fat-to-lean alterations in body composition, expanded red blood cell volume (resulting from IGF-I stimulation of erythropoiesis), and enhanced sweating capacity.

GH replacement stimulates bone turnover and remodeling, as judged by increases in markers of both bone formation and resorption. modestly lowers total cholesterol, LDL, and apolipoprotein B and tends to lower triglycerides in patients with elevated baseline levels. There is also an equivocal elevation of HDL. These changes are all desirable with regard to cardiovascular risk, and they are maintained for at least 4 years with therapy.

On the skin GH treatment increased skin thickness among normal elderly men selected for low IGF-I levels.

Studies of the effect of GH replacement on psychological and social end points in adults with GHD have universally reported a therapeutic benefit. Improvements were found in subjective well-being, mood, energy, sleep, emotional reaction, behavior, pain perception, and overall quality of life.

In summary, GH replacement reverses most signs of GHD in young adults but this is something that needs to be closely monitored by a specialist physician, because there are potential adverse side effects with any hormone replacement therapy.

Side Effects of GH Therapy

The side effects of GH therapy arise from the hormonal impact of overreplacement because rhGH is identical to the endogenous hormone and thus should not elicit hypersensitivity reactions, except in the very rare patients with congenital GH gene deletions. Fluid retention due to the antinatriuretic actions of GH is by far the most common untoward effect among adults with GHD receiving replacement therapy. In experimental trials, ~40% of subjects report clinically apparent edema, ~20% develop joint swelling (especially in the hands) and/or noninflammatory arthralgias, and ~15% suffer from myalgias. Arthralgias probably result from fluid accumulation in joint spaces, as inflammatory changes and radiographic anomalies are not found. These side effects are generally mild and resolve within a few weeks with therapy. However, ~10% of subjects develop carpal tunnel syndrome.

GH administration is currently contraindicated for patients with active malignancy, benign intracranial hypertension, and proliferative or preproliferative diabetic retinopathy.

Reducing Potential Adverse Side Effects

Because all adverse effects of GH administration are dose dependent, they may be minimized by titrating GH injections to the lowest effective dose and replacing growth hormone in a natural way, this means using physiologic, not pharmacologic doses on a daily basis.