Growth Hormone in Elderly: Bad Insulin Effects, Good Lipid Effects

Growth hormone increases insulin resistance and modestly improves lipid profiles in healthy older men and women, according to a new report.

Growth hormone is widely and inappropriately used as anti-aging therapy, the authors explain, but few studies have assessed the combined effects of growth hormone plus sex steroids on glucose tolerance and insulin sensitivity in healthy older individuals.

Dr. Thomas Munzer from the National Institutes of Health, Baltimore, and colleagues examined the effects of growth hormone, without or with concomitant sex steroid administration, on circulating glucose, insulin, lipid concentrations and insulin sensitivity in 131 healthy individuals age 65 to 88 years.

• Increased 2-hour insulin and insulin AUC after growth hormone
• Decreased insulin sensitivity after growth hormone
• Decreased total cholesterol after hormone replacement therapy
• Decreased LDL cholesterol after hormone replacement therapy and after growth hormone
• No significant effect when growth hormone was given along with hormone replacement therapy.

• Increased 2-hour glucose levels, glucose AUC, and insulin AUC after growth hormone alone and growth hormone plus testosterone
• Decreased insulin sensitivity after growth hormone and after growth hormone plus testosterone
• Decreased total cholesterol after testosterone and after growth hormone plus testosterone
• Decreased LDL cholesterol levels after growth hormone and growth hormone plus testosterone
• Increased triglycerides after growth hormone

“In summary, growth hormone administration to healthy older women and men for 6 months increased insulin resistance and exerted moderately beneficial effects on serum lipids,” the authors conclude.

They add, “In women, hormone replacement therapy appeared to preserve insulin sensitivity when coadministered with growth hormone, whereas testosterone given to men exerted no obvious effects on insulin sensitivity.”